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2001-7095 G Y_ City O fENGINEERING SERVICES DEPARTMENT Encinitas Capital Improvement Projects District Support Services Field Operations Sand Replenishment/Stormwater Compliance Subdivision Engineering Traffic Engineering October 11, 2006 Attn: Temecula Valley Bank 27710 Jefferson Avenue Suite A -100 P.O. Box 690 Temecula, CA 92593 -0690 RE: Bruce Wiegand, Inc. 1060 & 1064 Wiegand Street APN 264 - 240 -08 Grading Permit 7095 -GI ' Final release of security Permit 7095 -GI authorized earthwork, storm drainage, site retaining wall, and erosion control, all as necessary to build the described project. The Field Inspector has approved the grading and finaled the project. Therefore, a release in the remaining security deposit is merited. Letter of Credit 00067, in the original amount of $22,132.00, (reduced by 75% to $5,533.00) is hereby released in entirety. The document original is enclosed. Should you have any questions or concerns, please contact Debra Geishart at (760) 633- 2779 or in writing, attention this Department. Sinc ely, Debra Geish y Lembach Engineering Technician Finance Manager Subdivision Engineering Financial Services Cc: Jay Lembach, Finance Manager Bruce Wiegand Debra Geishart File Enc. TEL 760 - 633 -2600 1 FAX 760 - 633 -2627 505 S. Vulcan Avenue, Encinitas, California 92024 -3633 TDD 760 - 633 -2700 � recycled paper i -- City o NGINEERING SER VICES DEPAR TMENT Ca pital ital Irn Projects Improvement Pro Encinitas P p J District Support Services Field Operations Sand Replenishment/Stormwater Compliance Subdivision Engineering Traffic Engineering March 13, 2006 Attn: Temecula Valley Bank 27710 Jefferson Avenue Suite A -100 P.O. Box 690 Temecula, CA 92593 -0690 RE: Bruce Wiegand, Inc. 1060 & 1064 Wiegand Street APN 264 - 240 -08 Grading Permit 7095 -GI Partial release of security Permit 7095 -GI authorized earthwork, storm drainage, site retaining wall, and erosion control, all as necessary to build the described project. The Field Inspector has approved rough grade. Therefore, a reduction of the security deposited is merited. Letter of Credit 00067, in the amount of $22,132.00, may be reduced by 75% to $5,533.00. The document original is enclosed. The retention and a separate assignment guarantee completion of finish grading. Should you have any questions or concerns, please contact Debra Geishart at (760) 633- 2779 or in writing, attention this Department. Sincerely, , Q iinance Debra Geis em ach Engineering Technician Manager Subdivision Engineering Financial Services Cc: Jay Lembach, Finance Manager Bruce Wiegand Debra Geishart File TEL 760- 633 -2600 / FAX 760 -633 -2627 505 S. Vulcan Avenue, Encinitas, California 92024 -3633 TDD 760- 633 -2700 � recycled paper '* City fi SERVICES DEPARTMENT Enci Capital Improvement Projects District Support Services Field Operations Sand Replenishment/Stormwater Compliance Subdivision Engineering Traffic Engineering October 11, 2006 Attn: American Contractors Indemnity Company C/o HCC Surety Group 1081 Camino Del Rio Suite 107 San Diego, California 92108 RE: Bruce Wiegand, Inc. 1060 & 1064 Wiegand Street APN 264 - 240 -08 Grading Permit 7095 -G Final release of security Permit 7095 -G authorized earthwork, storm drainage, single driveway, and erosion control, all needed to build the described project. The Field Operations Division has approved the rough grading. Therefore, a reduction in the security deposit is merited. Performance Bond 246539, in the original amount of $88,528.00, (reduced by 75% to $22,132.00) is hereby released in entirety. The document original is enclosed. Should you have any questions or concerns, please contact Debra Geishart at (760) 633- 2779 or in writing, attention this Department. Sincerely, G� Debra Geishart J y L bach Engineering Technician inance Manager Subdivision Engineering Financial Services CC Jay Lembach, Finance Manager Wiegand, Bruce Debra Geishart File Enc. TEL 760 - 633 -2600 / FAX 760 - 633 -2627 505 S. Vulcan Avenue, Encinitas, California 92024 -3633 TDD 760 - 633 -2700 recycled paper city o E NGINEERING SERVICES DEPARTMENT � Encinitas Capital Improvement Projects District Support Services Field Operations Sand Replenishment/Stormwater Compliance Subdivision Engineering Traffic Engineering March 9, 2006 Attn: American Contractors Indemnity Company C/o HCC Surety Group 1081 Camino Del Rio Suite 107 San Diego, California 92108 RE: Bruce Wiegand, Inc. 1060 & 1064 Wiegand Street APN 264 - 240 -08 Grading Permit 7095 -G Partial release of security Permit 7095 -G authorized earthwork, storm drainage, single driveway, and erosion control, all needed to build the described project. The Field Operations Division has approved the rough grading. Therefore, a reduction in the security deposit is merited. Performance Bond 246539, in the amount of $88,528.00, may be reduced by 75% to $22,132.00. The document original will be kept until such time it is fully exonerated. The retention and a separate assignment guarantee completion of finish grading. Should you have any questions or concerns, please contact Debra Geishart at (760) 633- 2779 or in writing, attention this Department. Sincerely, Debra Geish y L bach Engineering Technician finance Manager Subdivision Engineering Financial Services CC Jay Lembach, Finance Manager Wiegand, Bruce Debra Geishart File TEL 760- 633 -2600 / FAX 760- 633 -2627 505 S. Vulcan Avenue, Encinitas, California 92024 -3633 TDD 760- 633 -2700 � recycled paper Geotechnics Incorporated ' Principals: Anthony F. Belfast Michael P. Imbriglio W. Lee Vanderhurst GEOTECHNICAL INVESTIGATION FOR GRADING COPPER CREEK ESTATES, LOTS 4 AND 6 ENCINITAS, CALIFORNIA 1 prepared for Bruce D. Wiegand, Inc. ' 1060 Wiegand Street Olivenhain, California 92024 ' by ' GEOTECHNICS INCORPORATED Project No. 0007 - 003 -09 Document No. 0 -0059 May 19, 2000 9245 Activity Rd., Ste. 103 • San Diego, California 92126 Phone (858) 536 -1000 • Fax (858) 536 -8311 Geotechnlcs Incorporated ' Principals: Anthony F. Belfast Michael P. Imbriglio W. Lee Vanderhurst ' May 19, 2000 Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 1060 Wiegand Street Document No. 0 -0059 Olivenhain, California 92024 ' Attention: Mr. Bruce D. Wiegand ' SUBJECT: GEOTECHNICAL INVESTIGATION FOR GRADING Copper Creek Estates, Lots 4 and 6 Carlsbad, California Gentlemen: The following report presents the findings and conclusions of our supplemental geotechnical investigation of the site, as well as remedial grading recommendations for preparing the site to ' receive structures. Although geotechnical constraints exist which need to be addressed, there were no conditions apparent in our investigation which would preclude development, provided that the ' recommended site preparation is conducted. We appreciate this opportunity to provide professional services. If you have any questions or ' comments regarding this report or the services provided, please do not hesitate to contact us. ' GEOTECHNICS INCORPORATED (� �/7 ; � � Anthony F. Belfast, P.E. 40333 ' Principal Engineer Distribution: (4) Addressee 9245 Activity Rd., Ste. 103 • San Diego, California 92126 Phone (858) 536 -1000 • Fax (858) 536 -8311 GEOTECHNICAL INVESTIGATION FOR GRADING ' COPPER CREEK ESTATES, LOTS 4 AND 6 ENCINITAS, CALIFORNIA TABLE OF CONTENTS ' 1.0 PURPOSE AND SCOPE OF WORK ........... ............................... 1 ' 2.0 SITE DESCRIPTION ........................ ............................... 2 ' 3.0 PROPOSED DEVELOPMENT ................ ............................... 2 4.0 GEOLOGY AND SUBSURFACE CONDITIONS . ............................... 2 ' 4.1 Delmar Formation ( Td) .................. ............................... 3 4.2 Landslide Debris (Qls) . 4 4.3 Colluvium (Qcol) ...................... ............................... 4 ' 4.4 Alluvium (Qal) ........................ ............................... 4 4.5 Groundwater .......................... ..............................5 5.0 GEOLOGIC HAZARDS ..................... ............................... 5 5.1 Seismicity ............................ ..............................5 5.2 Ground Rupture ....................... ..............................6 ' 5.3 Liquefaction .......................... ..............................7 5.4 Landslides and Lateral Spreads ........... ............................... 7 ' 5.5 Tsunamis, Seiches, Earthquake Induced Flooding ........................... 7 6.0 CONCLUSIONS ............................. ..............................8 7.0 RECOMMENDATIONS ..................... ............................... 9 7.1 Plan Review .......................... ..............................9 ' 7.2 Excavation and Grading Observation ...... ............................... 9 7.3 Slopes ........................9 7.4 Site Preparation ...................... ............................... 11 ' 7.4.1 General ....................... .............................11 7.4.2 Removal of Compressible Soils .. ............................... 11 7.4.3 Removal of Landslide Debris ... ............................... 11 ' 7.4.4 Selective Grading for Lower Buttress ............................ 12 7.4.5 Lime Treatment of Upper Buttress .............................. 13 7.4.6 Subsurface Drains ............. ........................ 14 7.4.7 Building Areas ....... 15 7.4.8 Temporary Excavations ........................................ 15 ' 7.4.9 Fill Compaction .............. ............................... 16 ' Geotechnics Incorporated 1 t GEOTECHNICAL INVESTIGATION FOR GRADING COPPER CREEK ESTATES, LOTS 4 AND 6 ' ENCINITAS, CALIFORNIA ' TABLE OF CONTENTS (Continued) 7.5 Surface Drainage ....................... .............................16 ' 7.6 Preliminary Foundation Considerations ... ............................... 17 7.7 Expansive Soils ........................ .............................17 ' 7.8 Reactive Soils ...................................................... ............... ............................17 . 7.9 Earth- Retaining Structures 18 ' 8.0 LIMITATIONS OF INVESTIGATION ......... ............................... 18 ' ILLUSTRATIONS Site Location Map ....................... ............................... Figure ' Fault Location Map ...................... ............................... Figure 2 Lower Buttress Plan ...................... ............................... Figure 3 Upper Buttress Plan ...................... ............................... Figure 4 ' Subdrain Headwall Details ................ ............................... Figure 5 Retaining Wall Drains .................... ............................... Figure 6 ' Regional Seismicity ....................... ............................... Table 1 ' Geologic Map ............................................................ ......................... .................. Platel ............. Geotechnical Plan Plate 2 ' APPENDICES REFERENCES .......................................... Appendix A ........ ... SUBSURFACE EXPLORATION ............................ Appendix B LABORATORY TESTING ............. ............................... Appendix C ' SLOPE STABILITY ANALYSIS ........ ............................... Appendix D SEISMIC ANALYSIS ................. ............................... Appendix E Geotechnias Incorporated 1 ' GEOTECHNICAL INVESTIGATION FOR GRADING COPPER CREEK ESTATES, LOTS 4 AND 6 ENCINITAS, CALIFORNIA 1 ' 1.0 PURPOSE AND SCOPE OF WORK ' The purpose of our investigation was to evaluate the existing geotechnical conditions at the site as they relate to the proposed improvements, and to make recommendations regarding site preparation ' and remedial grading. Our work included an evaluation of the existing undeveloped slope with regard to landslide hazards that may affect residential structures bordering the site. The ' recommendations contained herein are based on a surface reconnaissance, subsurface exploration, laboratory testing, and professional experience in the general site area. Design values may include presumptive parameters based on professional judgement. Our scope of work was limited to: ' literature related general geologic conditions 1.1 Review of available 1 a o g g og co d bons at the site, including ' the referenced slope stability evaluation (San Diego Soils, 1989). 1.2 A visual reconnaissance and subsurface exploration of the site including the drilling of ' two borings with a truck mounted, 30 -inch diameter bucket auger drill rig. The borings were down -hole logged by our geologist, and were used to supplement the previous investigation ' and provide information regarding the proposed cut slope along the western edge of the site. Bulk and relatively undisturbed soil samples were collected for laboratory testing. 1.3 Laboratory testing of selected samples collected during the subsurface exploration. Testing was primarily used to provide shear strength parameters for slope stability analysis. 1.4 Assessment of general seismic conditions and geologic hazards affecting the area, and ' their likely impact on the project. ' 1.5 Engineering analysis for the development of site preparation, slope stabilization, and remedial earthwork recommendations. ' 1.6 Preparationof this report summarizing our findings, conclusions and recommendations. ' Geotechnics Incorporated Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 2 ' 2.0 SITE DESCRIPTION ' The subject site, consisting of Lots 4 and 6 of the Copper Creek Estates, is located at the western terminus of Wiegand Street in the City of Encinitas, California. The approximate location of the site is shown in the Site Location Map, Figure 1. The eastern edge of the site is bordered by the previously developed Lots 3 and 7 of Copper Creek Estates, and the western edge is bordered by an ' adjacent residential development. The northern property boundary is bordered by undeveloped sloping parcel. The southern edge of the site is adjacent to a private driveway. The site is situated on a moderately sloping natural hillside, with slope gradients generally ranging between 2.5:1 and ' 6:1(horizontal:vertical). Elevations on site range from approximately 195 feet near Wiegand Street, to approximately 302 feet along the western property line. A minor gully exists near the middle of Lot 4. Vegetation on site consists of weeds and grasses, with pockets of chaparral. The approximate layout of the site is shown on the Geologic Map, Plate 1. 3.0 PROPOSED DEVELOPMENT The grading plans for the site were prepared by Pasco Engineering, and have been used as the base ' plans for the Geologic Map and Geotechnical Plan, Plates 1 and 2. Grading of the site will produce two relatively flat building pad areas as well as associated driveways. An approximately 20 to 40 ' foot high fill slope will be constructed along the eastern edge of the property, and an approximately 20 to 40 foot high cut slope is proposed along the western edge of the lots. Although not specifically addressed in this investigation, it is our understanding that two single family residence will be ' constructed on the pads, along with associated exterior flatwork and utilities. Recommendations for the design of these improvements should be provided in the as- graded geotechnical report. ' 4.0 GEOLOGY AND SUBSURFACE CONDITIONS The subject site is located within the coastal plain section of the Peninsular Range Geomorphic ' Province of California. Our subsurface investigation and literature review indicates that the site is underlain at depth by the Delmar Formation, covered with a variable depth of colluvium. Alluvium ' may exist within the eastern portion of the gully in Lot 4. Two relatively recent landslides were also observed. The approximate locations of the exploratory borings and test pits conducted at the site are shown on the Geologic Map, Plate 1. Logs of the explorations are given in Appendix B. The ' specific units encountered in our investigation and literature review are discussed below. ' Geotechnics Incorporated CD o � 0 0 0 � 9 o W O E i i I _ L _ 3a037y O O e, W _ o O / O C \/� o Q ° 01 `v� °� car Q o-` 4 3arsaootia er ; Z �. r' Z E J J 4 U ul J .70 �n lA V V � m OrWJ °�bJ `�� i � d i s � ° J•�g ~ w Q Gp��E MARGARI ON3a3S n Elf o 133d 7V ` �Q \� LL < 3I�JNP Oa CD F-- ,oa w < Jvr �— Q i r� ; 3N07 CO ILLS Cora )� ° � sr4 Q CL O c : Yl rIA'01(JIIVtl s 1 70N U a fONV 3„Y3 031 � �g WINDMIL Q bN1S JJ i 3 7 h 1 37J' �N W Y SSI M RANCH RD ' UM 3SOa �4sd ".Oa 7303 1a3S3a °� HJ 7 A3p7 N y0 ! "G Doot m o rNrnir� 7y 370J +1 `s,'�Exvo•• s" � 1S "S u114 a b1Nb$ OH�Nyy ysr A "� I4 m bO J V�p �1 �' OD%Vl A O F� ~ • N �' ° o >� ^� arc ° s3a AI ff 3� c O n � NbS d 3 i a ro a un yb a ,! rrx 01 z 403 ^ o °� m: a� O N N ' 1 OOB 7d 3A7,0 N�,y. 30 S al �,� ? �' •, �+ _� y •: 8 N sNI o NaN Dot RD SPRIN D Y ,dd g @ O V W G'NOO "DSIDV ni'AILVIEWs AN .4 O v 1.0 } J ! 3rJ La t3 Ca L N6REEN WY $p DR 8 ° ` A �y J WI LOWSPRIhD N 9 r' d 9 I W v as s ° a aD aoabr RSpKG DR Oyu >J, S suv w '� 1q Y a {o tv G CL VAka a . G N3 ` c} +o �� z,y� LL a0 a N3 i✓Y' Q G� BELLE, 10 l : 3 s &4RDENDP� AVO, El �aQ �= `o � ''d, k K N U leave v IEU a 133 au ;"!e N rD 6 I CERRO g 3 e L LOD ��as n 8 M BPip aAawo m Nl) 08 :EVO ,/ ate J ly p e < Ie PE LOBES O A° p PL W l �bh r 8 i y ECU = CCj aY' e`•�jy h .� Y'S k .. �`v�'o° XIN� "�. "yaosE J W TURNER A pup COS P ig R i a 9 H Y z 0 L, ��j tIn foci S.' 5 E CI S C ,� r ?y 6 'J 3a0W$NNO' N� p O O W 'i ZARI g �D - 1 m ' �.. E<ISE ■ m " REAL ! O �. Locus eLOS sI A - -D U 64RDENIEW CT ' ^EL W`` rii N BEECNTREE OR 5L i A tAVtM vu F WITHAM O TA E / Y t LO cram nW RID VGA rLA � A z 1 e cl �. ` rs vAUC v " vsw LW z RD `r l fi:� ry l � rrnl 4V� VO a i VIA YILLENA� rt w i Irae n 3 M p"L'1Bt I CANTEBRIA vIA 3 N VIA c r `i IAI �� rr � o SEEMAN I DR +❑A" DE ; ' Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 3 ' Boring 1 from this investigation was drilled at a ground surface elevation of approximately 316 feet, and Boring 2 was drilled at a ground surface elevation of approximately 274'/2 feet. These two ' borings were drilled down to elevations of approximately 216 and 214'/2 feet, respectively. Borings and test pits conducted for the referenced landslide investigation encountered similar soil conditions ' to those described herein, and extended down the slope to a minimum elevation of approximately 191 feet (San Diego Soils, 1989). We combined the subsurface information from both investigations ' to model the stratigraphy between elevation 191 to 316 feet. 4.1 Delmar Formation ffib The Eocene age Delmar Formation was encountered in both borings near the western edge ' of the site. Based on our review, the Delmar Formation is believed to underlie the entire site at depth (San Diego Soils, 1989). As observed in the exploratory borings, the Delmar ' Formation ranges from a silty sandstone to a sandy siltstone to a fat claystone. The silty sandstone is typically gray, light brown, or yellow brown in color, dry to moist, fine grained, dense to very dense, and friable. The sandy siltstone is similar in color, contains very fine ' sands, is hard, moist, and moderately weathered with some groundwater stains. The fat claystone is generally dark olive or blue gray, moist, highly plastic, massive, and moderately ' indurated with random fractures. In general, we anticipate that fat claystone will be the primary material encountered in ' excavations below 234 feet. Between elevations of 234 and 254 feet, we anticipate that relatively low plasticity silty sandstone will primarily be encountered, with some interbedded ' sandy siltstone. From elevation 254 to 280 feet, we anticipate that another massive bed of fat claystone will be encountered. Excavations above 280 feet will likely encounter ' interbedded sandy siltstone and silty sandstone. The stratigraphy of the Delmar Formation at the site is presented in Cross Section A -A' on the Geologic Map, Plate 1. ' 4.2 Landslide Debris (Qls) ' Landslide debris was not encountered in the exploratory borings conducted for this investigation. However, the referenced investigation indicates that two distinct landslides ' exist at the site (San Diego Soils, 1989). The approximate locations of these slides have been reproduced on the Geologic Map, Plate 1. ' Geotechnics Incorporated ' Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 4 ' The referenced report indicates that the landslide in Lot 4 has an approximate basal elevation 226 feet, and that the landslide on Lot 6 has a basal elevation of approximately 218 feet. It ' should be noted that these elevations apply only to the rupture surface as observed in the exploratory borings for that investigation. The actual basal elevations of these landslides ' may vary across the site. The debris from both landslides appears to have been generated from a failure within the lower fat claystone bed of the Delmar Formation, and is therefore similar at both locations. As described in the referenced investigation, the landslide debris generally consists of a dark green gray claystone that is highly fractured. The rupture surface consists of a' /4 to 1 inch thick seam of remolded dark green clay that is very soft and moist. ' It should be noted that the referenced report indicates that the upper portions of the landslide (approximately above elevation 234) consist of fractured sandstone, similar to the massive ' sandstone in the Delmar Formation described in Section 4.1. ' 4.3 Colluvium (Ocol) Colluvium is an accumulation of topsoil and weathered formational materials formed on ' slopes as a result of slow downhill creep due to gravity. Colluvium was encountered in both exploratory borings conducted for this investigation, as well as in all of the test pits ' conducted for the previous investigation. As observed on site, this material varies from a fine grained silty sand (SM) to a sandy clay (CL), depending upon the parent material. The colluvium was generally 2 to 4 feet thick. 4.4 Alluvium (Qal) ' Alluvial soils were shown on the Geologic Ma in the referenced investigation g p g (San Diego ' Soils, 1989). However, these materials were not discussed in the text of that report, and were not observed in the exploratory borings conducted for this investigation. Based on the previously prepared map, alluvium may be encountered in the eastern portion of the gully ' in Lot 4. Our previous experience with similar soil conditions suggests that the alluvium depths will typically be greater than that of the colluvium, possibly on the order of 10 feet ' near the property line between Lots 3 and 4. We anticipate that the alluvium will appear similar in composition to the colluvium described above. 1 Geotechnics Incorporated Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 ' May 19, 2000 Document No. 0 -0059 Page 5 4.5 Groundwater ' Minor seepage was observed at several elevations during our investigation. The seepage typically consisted of groundwater perched on the fat claystone beds at the interface between sandstone and claystone. Perched groundwater of this nature was observed at elevations of 236 and 279 feet. In addition, seepage was observed at elevations of 218 and 224 feet. In ' our opinion, these seepage zones may be associated with the existing rupture surfaces in the landslides east of the boring locations, and may indicate that seepage will be encountered near the rupture surface during remedial excavation of the slide masses. It should be noted that changes in rainfall, site drainage, or irrigation practices may produce ' seepage or locally perched groundwater conditions at any elevation within the soil or formational materials under the subject site. As observed in the subsurface investigation, this typically occurs at underlying contacts with less permeable materials, such as the interfaces that exist between the fill and the underlying formational material, or between the sandstone and claystone. Drainage recommendations are provided in this report to aid in the mitigation ' of perched groundwater conditions. ' 5.0 GEOLOGIC HAZARDS ' The subject site is not located within an area previously known for significant geologic hazards, although landsliding is common within the Delmar Formation. Seismic hazards at the site are anticipated to be caused by ground shaking from distant active faults. The nearest active fault is within the Rose Canyon fault zone, which is located approximately 7'/z miles west of the site. 5.1 Seismicity ' Several commercially available computer programs were used to evaluate potential seismicity at the subject site. The results of our analysis are presented in Appendix E. These programs determine the distance between the site and known faults based on the approximate latitude and longitude. The program TOPO! was used to estimate site coordinates of latitude ' 33.0622° north, and longitude 117.2183° west. Geotechnics Incorporated Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 6 Table 1 summarizes the properties of known active faults within 100 kilometers of the site. The approximate location of these faults are shown on the Fault Location Map, Figure 2. i The values presented in Table 1 were developed using the program EQFAULT (Blake, 1998). The deterministic values of peak ground acceleration for each fault are shown in Table 1 for comparison to the Maximum Probable Earthquake discussed below. The EQFAULT results are also presented in Appendix E, along with a listing of historical earthquakes from nearby faults from the program EQSEARCH (Blake, 1998). The program FRISKSP was used perform a probabilistic analysis of seismicity at the site using the characteristic earthquake distribution of Youngs and Coopersmith (1985). The results are ' also presented in Appendix E. Based on the results of the probabilistic analysis, the "Maximum Probable" peak ground acceleration for the site is 0.28g. The Maximum Probable Earthquake is defined as the motion with a 10 percent probability of being exceeded in 50 years (475 -year return period). i The nearest known active fault is within the Rose Canyon Fault zone. The Rose Canyon Fault is a Type B Seismic Source based on the 1997 UBC criteria. The subject site is ' situated in 1997 UBC Seismic Zone 4 (Z = 0.40). Since the distance between the site and the nearest active fault is greater than 10 km, the 1997 UBC near source acceleration and ' velocity factors both equal 1.0. The site is underlain by very hard formational materials to depths greater than 100 feet. Based on our previous experience with these materials, a 1997 UBC seismic Soil Profile S would apply to the site (soft rock). Design of structures should comply with the requirements of the governing jurisdictions, building codes and standard practices of the Association of Structural Engineers of California. 5.2 Ground Rupture ' Evidence of active faulting at the site was not found. Accordingly, ground rupture is not considered to be a significant hazard at the site. 5.3 Liquefaction Liquefiable soil typically consists of cohesionless sands and silts that are loose to medium q YP Y ' dense, and saturated. To liquefy, these soils must be subjected to a ground shaking of sufficient magnitude and duration. Given the relatively dense and clayey nature of the subsurface materials, and the absence of a true groundwater table, the potential for ' liquefaction is considered to be negligible at the site. ' Geotechnics Incorporated ' o � � Lu W Q D o J LLJ Q W UO N r 0 0 0 0 0 0 01 0 0 O m ' CL O M LIB N r `Ct M r �- � ` 0 N Q � C 0 -0 C7 J O O E W U) U) L O ' a) Z a _ _ ¢ E c W � " ° z E ' H U O O O O O O O O O O J O fQ j U Q r r r r r r r r �- �- - �-. 00 a) O W — — Cfl m N W} M CO M M M M M M M M M O W = a CO CO CO CO CO CO CO CO M co M M � O m 2 W r O W C H �--� O O O O O O O O O O O O ` ' Q a N r r r r r r r r r r r r Y L v c) 0 co 00 0 0 LO O O LO r o c- U) cn co O CC) r r O O In O M CY) r 0 C N c6 C W LL r r U co M N (0 r t1) r CO a) °J cu ' L C ul O V O tV ca c (A J C 2 O= j r O� ti LO N 0 Un 0 m m 0 00 t) ALL W a a O U M N r r r r 0 0 0 0 r r r c 4 - O Q N Y U 0 0 0 0 0 0 0 0 0 0 0 6 o W ca J W Q O Q Y c U) L W w L L O O Z Y o d :3 V O '� C a) a) O � �C � to a) U m m a U ` W a)� 70 W a) m ' W L 5 a � Z LO o ca c a -: m 4- ns o V W f O r LO u - ) LO LO O O N O N 0 �� • � U z � co ti r I-- ti r- ti r` r-- 00 M rn- m ' >C O O r p rn ca > a Q EL (1) � L Q>, W VO-a.c U W �OOE�c H Z N CO to CO O N O r r r r r 00 (A C N Y r' N N M� LO O r M M 0 00 m O 4 L - - O O D O u r C cn O a o C a) L N m O O O �' 00ENE U ' >+ U L O O N O Sr c 0 -'� o f a) E c c c -� O o LO c O o= c E o ca o U V o o m m ca c o 0 o a) 0 L v� T 0 L) U M U 3 C o cv -o .0 O w nJ ° c aa) c m Z o N a) u� c> U o U >, 0 cu o O LL O C CM J O W - V cu .L Z I, ' o U � w = U (a a cY E c� —1 acv:: a) Z ri dW F— N co 1 8 / 20 30 40 60 60 R KILOMETERS M,gORF- WCAMONGA FAULT LOS A*,,LES s, SCALE y 34' \ � gti�R b `� ♦ hyV1% ` J�ti INDIO� o A /� � /,y /fir ° 1 SAN JUAN 0 9p ' °a lF40 CAPISTRANO �•�, t F O C p C +O I,, %` J ` ' \ Co' y �ci• OCEANSIDE ��` �`. `% \ Oy yI - ,G` °y • ES CO rho 7 ti� 33• 1 I t / °y .` \ ` SAN "( 1��k EL CENTRO ".% 'L DIEG i y 'y �� USA _ • _ MEXICALI G MEXICO F • TIJUANA �♦♦ R PO p Th %4 0 G 32' `� • ENSENADA ?o yF RC V, eCAkc \ ' A FAUL °HE eo � io r Modified from Anderson, Rockwell, Agnew, 1989 ' =G e o t e c h n i c s FAULT LOCATION MAP Project No. 0007- 003 -09 I n c o r p o r a t e d Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 Bruce D. Wiegand, Inc. FIGURE 2 ' Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 7 1 5.4 Landslides and Lateral Spreads Two relatively recent landslides have been identified at the subject site. The pertinent geotechnical characteristics of landslide debris were described in Section 4.2 of this report. ' Additional details regarding these landslides may be found in the referenced investigation (San Diego Soils, 1989). Details regarding the slope stability analyses conducted in order to evaluate the existing stability of the site slopes and provide recommendations for mitigation are presented in Section 7.3 and Appendix D. 5.5 Tsunamis, Seiches, Earthquake Induced Flooding The distance between the subject site and the coast, and the sites elevation above sea level, preclude damage due to seismically induced waves (tsunamis). Nearby bodies of water of significant size were not noted during this investigation, and accordingly, seiches and earthquake induced flooding is not anticipated to be a potential hazard. r ' Geotechnics Incorporated ' Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 8 6.0 CONCLUSIONS ' No geotechnical conditions were apparent during the investigation which would preclude the proposed development. However, some factors exist which require special consideration. ' • There are no known active faults underlying the project site. The most likely seismic hazards 1 at the site would be associated with significant ground shaking from an event centered within the nearby Rose Canyon Fault Zone. ' • Two existing landslides are present at the site. Our analysis indicates that because of these slides, the existing slope does not have a safety factor suitable to safeguard the developed areas below the site against a future slope failure. We recommend that mitigation measures be taken to increase the slope stability in accordance with the standards of the "City of ' Encinitas Grading, Erosion, and Sediment Control Ordinances ". • The alluvium, colluvium, and landslide debris throughout the site is considered compressible t and unsuitable for the support of fill or structural loads. All compressible soil and landslide debris should be excavated throughout the site and replaced as a uniformly compacted fill. • Our analysis indicates that the proposed cut and fill slopes do not have an adequate safety factor against deep seated failure (F.S. >1.5). Consequently, we have recommended that these slopes be buttressed. The lower fill slope buttress has been designed assuming that select sandy fill from excavations within the Delmar Formation will be used. The upper cut slope buttress has been designed assuming that the existing clays will be excavated, lime stabilized, and replaced within the buttress area, and that the pad will be constructed in ' general accordance with the configuration shown on the Geotechnical M<ip. 1 • The proposed buttresses are intended to stabilize the slopes with regard to deep seated failures. However, the potential for surficial slope failures may still exist, particularly if the slope faces are allowed to become deeply saturated. Therefore, measures should be ' implemented in order to improve and maintain the surficial stability of the site slopes. These measures focus on landscape planting, and controlling surface water runoff. • The fat clay within the Delmar Formation is considered highly expansive. Expansive materials within building and slab subgrade may cause differential movement and cracking. Mitigation alternatives for expansive soils should be provided in the as- graded report. Geotechnics Incorporated ' Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 9 1 7.0 RECOMMENDATIONS ' The remainder of this report presents recommendations regarding earthwork construction. These recommendations are based on empirical and analytical methods typical of the standard of practice ' in southern California. If these recommendations appear not to cover any specific feature of the project, please contact our office for additions or revisions to the recommendations. 7.1 Plan Review ' We recommend that grading plans be reviewed by Geotechnics Incorporated prior to plan finalization to evaluate conformance with the intent of the recommendations of this report. 7.2 Excavation and Grading Observation Site grading excavations should be observed by Geotechnics Incorporated. Geotechnics Incorporated should provide observation and testing services continuously during grading. Such observations are considered essential to identify field conditions that differ from those anticipated by the preliminary investigation, to adjust designs to actual field conditions, and to determine that the grading is accomplished in general accordance with the recommendations of this report. Recommendations presented in this report are contingent upon Geotechnics Incorporated performing such services. Our personnel should perform sufficient testing of fill during grading to support our professional opinion as to compliance with compaction recommendations. 7.3 Slopes ' In order to characterize the behavior of the site soils, representative samples of the various materials observed on site were sampled and transported to the laboratory for direct shear testing. The results of the laboratory tests are presented in Figures C -2.1 through C -2.8. Based on the results of the shear tests, shear strength parameters were determined for use in 1 the various slope stability analyses. The shear strength test results and design values are summarized in Table C -1. Geotechnics Incorporated Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 10 The pertinent slope stability analyses are summarized in Appendix D. Surficial slope stability was analyzed using an idealized infinite slope composed of a cohesive, frictional ' material, with steady state down slope seepage forces applied parallel to the slope surface (Abrahamson et al, 1996). As shown in Figures D -1 through D -4, these analyses suggests ' that fill slopes constructed from the fat clay may be susceptible to Surficial slope failure, given substantial wetting of the slope face. PCSTABL6 software was used to analyze the gross stability of the site and design the buttresses discussed in Sections 7.4.4 and 7.4.5. Pertinent results from these analyses are included in the remaining figures of Appendix D. t In general, all slopes are subject to some creep, whether the slopes are natural or man-made. Slope creep is the very slow, down -slope movement of the near surface soil along the slope ' face. The degree and depth of the movement is influenced by soil type and the moisture conditions. This movement is typical in slopes and is not considered a hazard. However, it may affect structures built on or near the slope face. If fat clay is used in the upper portions of the lower buttress, we recommend that settlement sensitive improvements not be constructed within 10 feet of the top of the slope without specific evaluation of the slope ' conditions by the geotechnical consultant ' All slopes constructed at the site may be susceptible to Surficial slope failure and erosion given substantial wetting of the slope face. The surficial slope stability may be enhanced by ' providing proper site drainage. The site should be graded so that water from the surrounding areas is not able to flow over the top of the slope. Diversion structures should be provided where necessary. Surface runoff should be confined to gunite -lined swales or other appropriate devices to reduce the potential for erosion. ' It is recommended that slopes be planted with vegetation that will increase their stability. This would be particularly important in the lower fill slope if fat clay is used in the upper 15 feet ofthe buttress. Ice plant is generally not recommended. We recommend that vegetation include woody plants, along with ground cover. All plants should be adapted for growth in semi -arid climates with little or no irrigation. A landscape architect should be consulted in order to develop a specific planting palate suitable for slope stabilization. Geotechnics Incorporated Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 11 ' 7.4 Site Preparation ' Grading and earthwork should be conducted in accordance with the Grading Ordinance of the City of Encinitas and Appendix Chapter 33 of the Uniform Building Code. The ' following recommendations are provided regarding aspects of the proposed earthwork construction. These recommendations should be considered subject to revision based on field conditions observed by the geotechnical consultant. 7.4.1 General General site preparation should include the removal of deleterious materials, existing structures or other improvements from areas to be subjected to fill or structural loads. Deleterious materials include vegetation, trash, construction debris, and rock fragments with greatest dimensions in excess of 6 inches. Existing subsurface utilities that are to be abandoned should be removed and the trenches 1 backfilled and compacted as described in Section 7.4.9. 7.4.2 Removal of Compressible Soils The topsoil, colluvium, and alluvium ' materials throughout the site are considered to be potentially compressible. These materials should be removed from areas that will be subject to development. Excavations should expose competent formational material as determined by our personnel during grading. In general, excavations are anticipated to be on the order of 2 to 4 feet, although deeper alluvium removals may be required in the gully on Lot 4. The removed soil that is free of deleterious material should be replaced in accordance with Section 7.4.9 as a uniformly compacted fill. It should be noted that I some of the excavated soil may have high moisture contents, and may require drying prior to inclusion in compacted fills. 7.4.3 Removal of Landslide Debris The landslide debris is considered to be potentially unstable, compressible, and unsuitable for the support of fill or structural loads in the present configuration. Landslide debris should be excavated from areas that will be subject to development. Excavations should completely remove the rupture surface, and should expose competent formational material as determined by our personnel during grading. The excavated soil that is free of deleterious material should be replaced in accordance with Section 7.4.9 as a uniformly compacted fill. 1 Geotechnics Incorporated ' Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 12 ' The approximate extent of the two landslides on site is shown on the Geologic Map, Plate 1. Based on the referenced landslide investigation, we anticipate that the ' rupture surfaces are located at an elevation of approximately 220 feet near the daylight with the natural slope (San Diego Soils, 1989). The investigation also ' indicates that the back -scarp of these landslides should not extend west of the 260 foot elevation contour on the natural slope. Note that a 1:1 backcut from the 260 foot ' elevation contour down to the rupture surface elevation should remove most of the landslide mass throughout the site. The rupture surface may be located approximately between elevations 220 and 230 at the western edge of the slide mass. 7.4.4 Selective Grading for Lower Buttress As discussed in Section 4.1 of this ' report, the Delmar Formation at the subject site consists primarily of a fat claystone below an elevation of approximately 234 feet. This material possesses a low shear strength, and is susceptible to failure in slopes, as evidenced by the two landslides which occurred within this material on the natural slope. Consequently, we recommend that a select fill buttress be constructed on the fill slope proposed below the pads. The proposed buttress is shown on the Geotechnical Plan, Plate 2. The general buttress configuration is depicted on the Lower Buttress Plan, Figure 3. ' The select fill should primarily be obtained from excavation within the silty sandstone which exists within the Delmar Formation approximately between elevations of 234 and 254 feet. However, any granular, freely draining fill material which possesses an internal angle of friction greater than 32 degrees (when plotted ' with zero cohesion) may be used in this buttress. Excavations for removal of the landslide debris will encounter much of the select fill on site. Consequently, the ' lower buttress keyway and false slope face (see below) should be ewtablished as soon as possible, in order to provide an area for placement of the select fill generated from the landslide excavations. Select fill may also be generated from excavations in the interbedded siltstone and sandstone above elevation 280 feet. ' The proposed location, width and elevation of the lower buttress key is shown on the Geotechnical Plan along with a false slope which extends back and up from the keyway elevation to the pad grade. In general, only select fill should be placed in the area between the false slope and the ultimate proposed fill slope face. However, in the event that insufficient quantities of select fill are generated from cuts within the Delmar Formation to complete the buttress, the upper 15 feet of the buttress fill ' Geotechnics Incorporated 9 C 'O w ) co C') C5 at C) CS 4) CN 9 M -0-0 W I- CIO a) z C) LL 0) Co C) Z U) :3 0 0 N (o CL Cc w c; o a E (D Z E O LO > N (1) 0 0 c w W (1):2 m U) CL 6. 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Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 13 (between elevations 244 and 229) may be constructed using any of the materials excavated from the site, including the fat clays. Although this slope will be stable ' with regard to deep seated failure, the upper 15 feet of the slope may be susceptible to surficial failure. Recommendations were provided in Section 7.3 to reduce the potential for surficial slope failures throughout the site. 7.4.5 Lime Treatment of Upper Buttress The second fat claystone bed that exists in the Delmar Formation on site will daylight in the proposed cut slope, creating a potentially unstable condition. Consequently, we recommend that a second buttress i be constructed for the cut slope between elevation 244 and 280 feet. The approximate location of this buttress is also shown on the Geotechnical Plan, Plate 2. The approximate configuration of the buttress is shown in the Upper Buttress Plan, Figure 4. Note that the upper buttress should have a minimum width of at least ' 20 feet, in order to provide complete coverage with the compaction equipment. The upper buttress should be constructed using lime stabilized fat claystone ' materials. At least 30 days prior to commencing lime stabilization operations, two samples of the upper claystone bed should be gathered and tested for the percent ' hydrated lime required for stabilization in general accordance with ASTM C977. Specifications for the application of the hydrated lime in the field should be provided at that time. After the lime application rate is determined, the two lime stabilized soil samples should be remolded to approximately 90 percent of the maximum dry density determined in general accordance with ASTM D1557. The remolded lime stabilized samples should then be tested for unconfined compressive strength in general accordance with ASTM D2166. Note that our analysis assumed a minimum 28 -day unconfined compressive strength for the lime stabilized buttress material of 70 psi. Previous tests conducted on similar fat clay materials with sufficient lime for stabilization indicate that the 28 -day unconfined compressive strength will often be on the order of 100 to 200 psi. We suggest that the proposed pad grade be attained prior to commencing the upper lime treated buttress. The 20 foot wide upper buttress key may then be cut from the ' top down, and the fat clay generated from the excavation may be spread across the building pad area. The hydrated lime slurry should be uniformly spread after each lift of clay is placed on the building pad. A mixer capable of pulverizing, blending, ' and mixing the lime treated materials should be used to produce a homogeneous ' Geotechnics Incorporated 1 0) 0') qe C) LO w C ; C) W C) O C) W z 06 ♦ 1 -_ �_ Lu E < 6 Q LU < C) CL Co m < _ C) z CK < < LLI L 0 fn CO z L W LLI UJ 0 j LLI CL 0 z E -j Z ? z < -j WW< =3 Z Q LU z < 0 0 Co LU 0 LIJ < Z 2 F LU 0 LL LL , 0 W A N CL < Z VE LL J) 2 LU N W U) W �- 0 U) o 0 W LU LL Cwr- C A mom I � U) > < 0 W C-) a- V) �Y - 2 L 0 LLJ 0 z A Kom 0 CL:!t co W Lu w U) A 00 L < L W M w U) CL U- > LU f= CL 0 2 2<= 0 m < m z cn (D 0 CIO co —j cu cu 04 CL 00 1; F- C14 -ac) LU 0 0 CD CU _j - 0 D LU D 0 N vi m a o c). E U) CM - a Ca a) W W (D 0'a 0) -a — a) LU W a) > U- w C) r z O C) "D a) cu ID L- 'a CN I- a) (D 0 > L) cc :3 21- .0 C) CID u) W o > :3 (D z IL M CL C%4 (D - r- CL =3 < CL CL co cam ) E — co s -C CL E 0) 0 C) 0-- o) a (D (1) -- -r- -- cm— E , - 0 F- W.- a to >is 0 -a CL 1 v . o 0o L) ov (Dc > 'S z ao r a) 0 . - —j - , C n 0 E Z 0 r- a ca -j is E LU LL Z a m o (6 ( D Q, w U ) u 0) - �- a <� .-,, 1 - 0 0 LL ,.cu a) �c W a- LL -j � L) Z U) C W C) cu 7 N 55 - i LLJ c co co 0 ML a) co 0 (n .0 ,2 co m a. Coil - (L) UJI :3 -- CIL O r a CL F- 0 F 0 E cc =3 LU o 0 UJ uj 0 -J " M 0) W M CO 0 CL — M - D z r r-L oo 0 C) cc = < Co w CN 10 w co C: > 0 Cc co U) Z C) w (J) 0 B O 0 0 m C) CD -C corn Oil U) M U) 0 1 Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 14 ' mixture of soil, lime, and water. Adequate mixing of the lime - treated material should be confirmed by the geotechnical consultant in the field using gradation ' analysis prior to placing the next lift of fat clay. This process should be repeated until the entire buttress fill is placed on the pad (approximately 7 feet high). After ' a pre- determined "mellowing" period, the lime stabilized clay should be excavated and placed as a uniformly compacted fill in the upper buttress. ' 7.4.6 Subsurface Drains Several seepage zones were observed in the subsurface investigation, as described in Section 4.5. Seepage was observed at the interfaces between the sandstone and claystone at elevations of 279 and 236 feet. Seepage was also observed between elevations of 218 and 224 feet. We recommend that several ' subsurface drains be constructed at the site in order to draw down seepage and reduce the potential for future slope failures. The approximate drain configurations, with ' suggested outlet locations, are shown on the Geotechnical Map, Plate 2. A backdrain should be constructed at the toe of the temporary slope during remedial excavation of the landslide debris, as described in Section 7.4.3. Continuous panels should extend up the backcut approximately from elevation 220 to 236 feet. The ' backdrain should connect to a main collector subdrain between the two lots. The collector subdrain should consist of a 6 inch diameter perforated PVC pipe, surrounded by 6 ft'/ft of crushed rock, wrapped in a needle punched filter fabric. ' Note that the landslide removal bottom should be sloped at a minimum 2 percent gradient to direct drainage to the main collector subdrain. The upper buttress should ' contain a drain to collect seepage at the 279 foot elevation. The lower buttress may also need a drain to collect seepage below 220 feet. The approximate configuration ' of the subdrains in the upper and lower buttresses was shown in Figures 3 and 4. The actual extent of panel drain coverage should be determined in the field, based on the conditions observed by the geotechnical consultant during grading. All subdrains should be connected into permanent outlets such as a storm drain, brow ' ditch or a natural drainage course. If drains are outlet onto natural ground, a permanent headwall should be constructed around the outlet to reduce the potential ' for burying, damaging or clogging the subdrain pipe. Typical subdrain headwall details are shown in Figure 5. ' Geotechnics Incorporated ' N0. 3 REBAR WITH ` : ": �°. • ', 90 DEGREE BEND . • 18 INCHES 4 TO 8 INCH DIAMETER •. �;y SUBDRAIN OUTLET PIPE` (WITH % -INCH STAINLESS n STEEL MESH COVER) 4 INCHES " 18 INCHES A 4 INCHES i SOIL BACKFILL SECTION A -A' � ' 4 TO 8 INCH DIAMETER SUBDRAIN OUTLET PIPE ' r t ' 24 INCHES ' Admh--_G e o t e c h n i c s SUBDRAIN HEADWALL DETAILS Project No. 0007 - 003 -09 I n c o r p o r a t e d Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 Bruce D. Wiegand, Inc. FIGURE 5 1 ' Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 15 7.4.7 Building Areas Based on the remedial grading recommendations presented herein, the proposed building pads will be underlain by a relatively uniform depth of ' compacted fill. Adverse differential settlement or slope instability is not anticipated to be a geotechnical hazard for future structures. The primary geotechnical consideration for buildings will therefore be the highly expansive nature of the fat clay within the Delmar Formation. ' Ideally, the upper five feet of the building pad could be capped with non - expansive, select fill. However, we have recommended that the select fill materials be placed ' in the lower buttress zone. Preliminary quantity analysis suggests that there will not be sufficient select fill available to place in the building pad area. If the highly ' expansive fat clay is placed in the upper five feet of the building pad without treatment, post- tension slab foundations could be designed to reduce distress from ' differential heave. However, exterior flatwork and other improvements would still be susceptible to distress from the highly expansive nature of these clays. Recommendations for foundations and improvements should be provided after the site is graded, based on the actual as- graded soil conditions. To facilitate laboratory analysis for geotechnical design, we recommend that representative bulk samples be ' collected from the upper five feet of the building pad areas during grading. ' 7.4.8 Temporary Excavations An approximately 30 to 40 foot high temporary excavation will be required at the toe of the proposed 2:1 cut slope in order to remove the landslide debris, as discussed in Section 7.3.3. The temporary excavation should generally be conducted from the top down, in order to reduce the potential for reactivating the landslide mass. Excavating the slide mass starting with the toe of the slide is not recommended. ' Temporary excavations should conform with Cal -OSHA guidelines. The temporary excavation in the Delmar Formation should be inclined no steeper than 1:1 for heights up to 40 feet. If the temporary excavations encounter heavy seepage or other ' potentially adverse conditions, these should be evaluated by the geotechnical consultant on a case -by -case basis during grading. Remedial measures may include ' shoring, or reducing slope inclinations. ' Geotechnics Incorporated ' Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 16 7.4.9 Fill Compaction All fill and backfill to be placed in association with site development should be accomplished at slightly over optimum moisture conditions ' and using equipment that is capable of producing a uniformly compacted product. The minimum relative compaction recommended for fill is 90 percent of maximum ' density based on ASTM D1557 -91. Sufficient observation and testing should be performed by Geotechnics Incorporated so that an opinion can be rendered as to the ' compaction achieved. Imported fill sources, if needed, should be observed prior to hauling onto the site to ' determine the suitability for use. Representative samples of imported materials and on site soils should be tested by Geotechnics in order to evaluate their appropriate ' engineering properties for the planned use. During grading operations, soil types other than those analyzed in the geotechnical reports may be encountered by the contractor. Geotechnics should be notified to evaluate the suitability of these soils for use as fill and as finish grade soils. 7.5 Surface Drainawe ' Foundation and slab performance depends greatly on how well the runoff waters drain from the site. This is true both during construction and over the entire life of the structure. The ' ground surface around structures should be graded so that water flows rapidly away from the structures without ponding. The surface gradient needed to achieve this depends on the prevailing landscape. In general, we recommend that pavement and lawn areas within five ' feet of buildings slope away at gradients of at least two percent. Densely vegetated areas should have minimum gradients of at least five percent away from buildings in the first five 1 feet. Densely vegetated areas are considered those in which the planting type and spacing is such that the flow of water is impeded. ' Planters should be built so that water from them will not seep into the foundation, slab, or pavement areas. Roof drainage should be channeled by pipe to storm drains, or discharge at least 10 feet from building lines. Site irrigation should be limited to the minimum necessary to sustain landscaping plants. Should excessive irrigation, surface water intrusion, ' water line breaks, or unusually high rainfall occur, saturated zones or "perched" groundwater may develop in the underlying soils. ' Geotechnics Incorporated ' Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 17 7.6 Preliminary Foundation Considerations ' The design of the foundation system should be performed by the project structural engineer, incorporating the geotechnical parameters developed in the as- graded geotechnical report ' prepared after site grading is completed. Expansive soil conditions are anticipated to be the primary geotechnical consideration for foundation design. 7.7 Expansive Soils ' The soils observed during our investigation included high plasticity silts and clays, as well as silty sands (SM). No expansion testing was conducted as a part of this investigation. ' However, based on our previous experience with the site materials, the fat clays are considered to be highly expansive, whereas the sands and silts may have a low to medium ' expansion potential. Expansion index testing may be conducted during grading on selected samples of the soils placed within the foundation influence zone in order to determine the expansion behavior for foundation design. 7.8 Reactive Soils ' The presence of significant quantities of sulfate in a lime treated soil may lead to the ' formation of ettringite and other minerals, which can result in substantial soil heave (Hunter, 1988). Consequently, the soluble sulfate content of a selected sample of the high plasticity clay from the site was determined in general accordance with ASTM D516. The test results ' indicated a sulfate content of 0.9 percent by weight of water soluble sulfate in the soil, which is considered to be a "severe" sulfate exposure based on UBC Table 19 -A -4. Lime treatment ' of the soil beneath the building pad area is therefore not recommended. In order to reduce the potential for distress to the proposed buttress fill, we have recommended an extended ' "mellowing" period for the lime treated clays prior to placement and compaction, as discussed in Section 7.4.5. The mellowing period should reduce the ultimate heave potential. Geotechnics Incorporated ' Bruce D. Wiegand, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 18 7.9 Earth- Retaining Structures ' Backfilling retaining walls with highly expansive soil can increase lateral pressures well beyond normal active or at -rest pressures. We recommend that retaining walls be backfilled ' with a select soil having and expansive index of 20 or less. The select fill materials from the Delmar Formation may meet this requirement. The backfill area should include the zone ' defined by a 1:1 sloping plane, back from the base of the wall. Retaining wall backfill should be compacted to at least 90 percent relative compaction. Backfill should not be placed until walls have achieved adequate structural strength. Heavy compaction equipment which could cause distress to walls should not be used. ' Cantilever retaining walls backfilled with select granular soil may be designed for an active earth pressure approximated by an equivalent fluid pressure of 3 5 lbs /ft The active pressure should be used for walls free to yield at the top at least 1 percent of the wall height. For walls with a 2:1(horizontal:vertical) backfill, an equivalent fluid pressure of 551bs /ft should be used. The above pressures do not consider surcharge loads or hydrostatic pressures. If ' these are applicable, they will increase the lateral pressures on the wall, and we should be contacted for additional recommendations. Walls should contain an adequate subdrain to ' eliminate any hydrostatic forces. Recommended wall drain details are presented in Figure 6. Wall drains may be outlet to the collector drain for the proposed buttresses. 8.0 LIMITATIONS OF INVESTIGATION This investigation was performed using the degree of care and skill ordinarily exercised, under ' similar circumstances, by reputable geotechnical consultants practicing in this or similar localities. No other warranty, expressed or implied, is made as to the conclusions and professional opinions included in this report. The samples taken and used for testing and the observations made are believed representative of the ' project site; however, soil and geologic conditions can vary significantly between borings. findings. If this occurs, the changed conditions must be evaluated by the geotechnical consultant and ' additional recommendations made, if warranted. ' Geotechnics Incorporated ' DAMP - PROOFING OR WATER - PROOFI G AS REQUIRED ROCK AND FABRIC ALTERNATIVE 'O MPACTED ' BACKFILL. •': ' . .12 . 12 -INCH MINIMUM 0 o MINUS 3/4 -INCH CRUSHED ROCK ' yIv ENVELOPED IN FILTER FABRIC (MIFAFI 140NL, SUPAC 4NP, OR �- > APPROVED SIMILAR) 1 DAMP - PROOFING OR WATER- L PROOFING AS REQUIRED 4 -INCH DIAM. ADS OR PVC ', fj PERFORATED PIPE ' GEOCOMPOSITE PANEL DRAIN =111 • • .' . •• •• IIII =' COMPAGTED. u m' BACKFILI: 1 CU. FT. PER LINEAL FOOT OF PANEL DRAIN ' MINUS 3/4 -INCH CRUSHED ALTERNATIVE ROCK ENVELOPED IN FILTER FABRIC. ' 4 -INCH DIAM. ADS OR PVC PERFORATED PIPE - - - - -__ NOTES ' 1) Perforated pipe should outlet through a solid pipe to a free gravity outfall. Perforated pipe and outlet pipe should have a fall of at least 1 %. 2) As an alternative to the perforated pipe and outlet, weep holes may be included in the bottom of the ' wall. Weepholes should be at least 2 inches in diameter, and be spaced no greater than 8 feet. 3) Filter fabric should consist of Mirafi 140N, Supac 5NP, Amoco 4599, or similar approved fabric. Filter fabric should be overlapped at least 6- inches. ' 4) Geocomposite panel drain should consist of Miradrain 6000, J -DRain 400, Supac DS -15, or approved similar product. 5) Drain installation should be observed by the geotechnical consultant prior to backfilling. G e o t e c h n i c s RETAINING WALL DRAINS Project No. 0007 - 003 -09 I n c o r p o r a t e d Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 Bruce D. Wiegand, Inc. FIGURE 6 ' Bruce D. Wiepril, Inc. Project No. 0007 - 003 -09 May 19, 2000 Document No. 0 -0059 Page 19 ' This report is issued with the understanding that it is the responsibility of the owner, or of his representative, to ensure that the information and recommendations contained herein are brought to ' the attention of the necessary design consultants for the project and incorporated into the plans, and the necessary steps are taken to see that the contractors carry out such recommendations in the field. ' The findings of this report are valid as of the resent date. However, changes in the condition of a g p p g ' property can occur with the passage of time, whether due to natural processes or the work of man on this or adjacent properties. In addition, changes in applicable or appropriate standards of practice may occur from legislation or the broadening of knowledge. Accordingly, the findings of this report ' may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. GEOTECHNICS INCORPORATED V VFESS /p y , A. ,cYel 5�� ®C ol o a� A% M W. LEE 0: � � � VANDERHURST � ' No. 1 Matthew A. Fagan, P. .57248 Ev, i2 ' � / 'K • CERTI ! N ENGINEERING Project Engineer J, � CIVIC. �� >► GEOLOGIST 9TE OF CAUFOQ` � Op C AL� ' Anthony . Belfast P.E. 40333 W. Lee Vanderhurst Y , C.E.G. 1125 Principal Engineer Principal Geologist Geotechnics Incorporated ' APPENDIX A REFERENCES Abrahamson, Lee, Sharma, and Boyce (1996). Slope Stability and Stabilization Methods, 1st ed., ' New York, John Wiley and Sons, 627 p. American Society for Testing and Materials (1999). Annual Book of ASTM Standards, Section 4, ' Construction, Volume 04.08 Soil and Rock, ASTM, West Conshohocken, PA, 976 p. Anderson, J. G. , Rockwell, T. K., Agnew, D. C. (1989). Past and Possible Future Earthquakes of Significance to the San Diego Region, Earthquake Spectra, Vol. 5, No. 2. pp 299 -335. Bowles, J. E. (1996). Foundation Analysis and Design, 5th ed.: New York, McGraw Hill, 1175 p. California Division of Mines and Geology (1975). Recommended Guidelinesfor Determining the Maximum Credible and the Maximum Probable Earthquakes, California Division of Mines and Geology Notes, Number 43. California Division of Mines and Geology (1992). Fault Rupture Hazard Zones in California, P Alquist- Priolo Special Studies Zone Act of 1972: CDMG Special Publication 42 Hunter, D. (1988). Lime Induced Heave in Sulfate Bearing Clay Soils, Journal of Geotechnical Engineering, ASCE, Vol. 114, No. 2, pp. 150 through 187. International Conference of Building Officials (1997). Uniform Building Code (with California ' Amendments) Title 23. Jennings, C. W. (1994). Fault Activity Map of California and adjacent areas with Locations and Ages of Recent Eruptions, CDMG, Geologic Data Map Series, Map No. 6. ' Kennedy, M. P., and Peterson, G. L. (1975). Geology of San Diego Metropolitan Area, California: California Division of Mines and Geology Bulletin 200, 56 p. San Diego Soils Engineering (1989). Slope Stability Evaluation, 8 Lot Subdivision, Lone Jack Road, Encinitas, California, Job No. 04- 3864 - 002- 01 -00, Log No. 9 -1721, dated June 8. ' Wesnousky, S. G. (1986). Earthquakes, Quaternary Faults, and Seismic Hazard in California: Journal of Geophysical Research, v. 91, no. B12, p. 12587 - 12631. Geotechnics Incorporated APPENDIX B FIELD EXPLORATION Field exploration consisted of a visual reconnaissance of the site, and the drilling of two exploratory borings with a truck- mounted, hollow stem, continuous flight drill rig on January 5, 2000. The borings were 30 inches in diameter, and were drilled to a maximum depth of 100 feet. Borings were logged by the project geologist, and then backfilled. The approximate locations of the borings are shown on the Geologic Map, Plate 1. Logs describing the subsurface conditions encountered are presented on the following Figures B -1 through B -6. Relatively undisturbed samples were collected from the borings using a 3 -inch outside diameter, ring lined sampler (modified California sampler). Ring samples were sealed in plastic bags, placed in rigid plastic containers, labeled, and returned to the laboratory for testing. The telescoping Kelly bar ' was dropped for approximately 30 inches to drive the sampler. For each sample, we recorded the number of blows needed to drive the sampler 12 inches. This value is shown on the attached logs ' under "blows per ft." Bulk samples are indicated on the boring logs with shading, whereas California samples are indicated by the abbreviation "CAL ". Boring locations were surveyed by the project civil engineer. The lines designating the interface g g g between soil units on the boring logs are determined by interpolation and are therefore approximations. The transition between the materials may be abrupt or gradual. Further, soil conditions at locations between the borings may be substantially different from those at the specific ' locations explored. It should be noted that the passage of time can result in changes in the soil conditions reported in our logs. ' Geotechnics Incorporated I LOG OF EXPLORATION BORING NO. 1 Logged by: MAS Date Drilled: 115/00 Method of Drilling: 30 -inch diameter bucket auger Elevation: 316' MSL F " a ��o a . N v N DESCRIPTION LAB TESTS CL lL 0 J Z N O m G m G 1 COLLUVIUM: Silty sand, (SM), brown to reddish brown, fine to very fine grained, dry, trace medium to coarse sand, rootlets. 2 DEL MAR FORMATION Silty sandstone, tan to yellow brown, very fine grained, dry, 3 highly weathered, friable, calcite lenses 4 6 4 ?# .... .... .................................................................................................................................... .......................... ..... 7 Sandy siltstone, gray to yellow to brown, very fine grained sand, damp to moist, moderately weathered to highly weathered, moderately indurated, some iron staining. 8 calcite lens to approximately one eighth -inch wide. 9 11 ..6. ....................... : " " " "" ........................................................................ ............................... Coiil' acf` "g "rai3a�foiial;'1Ta�= lyiri'g " " ' 12 Silty sandstone, tan to yellow brown, damp, very fine grained, moderately to highly weathered, some iron staining. 13 I 14 15 16 At 15.5 feet: Fossiliferous sandstone concretion layer, one foot thick, tan, dry, fine to medium grained, very well cemented. 17 ..... ............................... irorit"acf`.'sliarp fifaf = lying " ............................................................................................ ...................... ......... 18 Sandy siltstone, gray to orange brown, moist, very fine grained sand, trace clay, moderate to highly weathered, moderately indurated. I ,9 20 110 17 Becomes damp Gradation 21 5 Direct Shear 22 I 23 24 25 ..... Oclationafconl act;' tl af= lyiri' g"; .............................. ............................. . ' 26 6 ice': silty sandstone, brown to orange brown to tan, damp g to moist, fine rained, moderate) y weathered, moderately to poorly cemented. 27 3 inch thick black, sandy coal deposit, fine to medium grained. 28 29 t 30 PROJECT NO. 0007 -003 -09 GEOTECHNICS INCORPORATED FIGURE B -1 1 ' LOG OF EXPLORATION BORING NO. 1 (continued) Logged by: MAS Date Drilled: 1/5/00 Method of Drilling: 30 -inch diameter bucket auger Elevation: 316' MSL ' LL — t= W a y y y DESCRIPTION LAB TESTS CL U, 1 w 3 >_ J z y O rn Weig 9 ; DEL MAR FORMATION Silty sandstone, brown to orange brown to tan, damp to moist, Moisture Content ' 31 fine grained, moderately weathered, moderately cemented. 32 33 Bedding N45W /4E ' At 32.9 to 34.0 feet, fine to medium grained, moist clasts of gray claystone 34 ............................................................................................................................................................................. ..................... .......... 35 Sandstone, white to pinkish tan, damp, fine grained, strongly cemented. 36 4 >r 37 Seepage cimtacfnw irp ffaf ......................................................................................................... ............................... 38 Claystone, gray to green brown, moist, highly weathered poorly indurated, intensly fractured, Gradation 39 iron staining along undulating fractures, some fractures pollished, highly plastic, massive. Hydrometer Atterberg ' Remolded Shear 40 109 20 Unit Weight 41 7 Moisture Content ' 42 Less fractures, moderately indurated, becomes blue gray in color. 43 45 112 17 Direct Shear 7 1 ' 47 Gray brown in color. 48 ' 49 50 51 6kE ' 52 ' 53 54 55 ............................................................. ............................... ' Coritacf` "g "rail'a�ioiial; fi'af= 'g " " " " "' .. ' .. ' . ' . ' . ' .. ' 20 Sandy siltstone, brown to gray, damp, very fine grained sand,some clay, moderately indurated, some iron staining 57 ' 58 59 Cbfitacf`g mationafnT - 'in ": ........... ......................................................................... ............................... 9 Y 9 ' 60 Silty sandstone, tan to gray, damp, very fine grained sand, moderately to well cemented. PROJECT NO. 0007 -003 -09 GEOTECHNICS INCORPORATED FIGURE B -2 1 LOG OF EXPLORATION BORING NO. 1 (continued) Logged by: MAS Date Drilled: 1/5/00 Method of Drilling: 30 -inch diameter bucket auger Elevation: 316' MSL U . F W 0. v e ti y N DESCRIPTION LAB TESTS ' w 3 > Uj J z D m G m C 61 DEL MAR FORMATION Silty sandstone, tan to gray, damp, very fine grained sand, moderately to well cemented. 62 Color changes to orange brown to gray, random iron staining. ' 63 64 65 115 21 Gradation 20 £ Direct Shear 66 67 ' 68 Becomes fine to medium grained. 69 70 15 Vii: Doiit'a'cf'.'sharp; 'ftaf= lyiri'g: "'" 71 Siltstone, tan brown to green brown to gray, damp, some very fine sand, trace clay, moderately to well indurated, random iron staining. 72 73 ..... ............................... ............................................................................................ ............................... irorit'acf`'sliarp " "; 'ffaf= l'y'ing. 74 Interbedded siltstone and sandstones: siltstone is tan brown to green brown to gray, damp, moderately to well indurated. Sandstone is yellow to orange brown to gray, damp, very fine 75 grained, moderately cemented. Remolded Shear 76 20 rL ' 77 Bedding: E -W /5N 78 ' 79 80 30 ';> 116 16 Minor seepage 1 81 g.. 82 83 •:,.: 84 ............ r;rr;r .................. on .................... ............................... ....................................... ............................... 85 <' Claystone, dark blue gray, damp, moderately to strongly indurated, massive, random ' 30 ; infrequent fractures, highly plastic. 86 8" 87 88 89 ' 90 PROJECT NO. 0007 - 003 -09 GEOTECHNICS INCORPORATED FIGURE B -3 1 LOG OF EXPLORATION BORING NO. 1 (continued) Logged by: MAS Date Drilled: 1 /5 /00 Method of Drilling: 30 -inch diameter bucket auger Elevation: 316' MSL F a s .Wi v e 2 IL N y y DESCRIPTION LAB TESTS ' CL LU w 3> J z y m G Co G 91 8" DEL MAR FORMATION Claystone, dark blue gray, damp, moderately to strongly ' indurated, massive, random infrequent fractures, highly plastic. 92 ' 93 94 Seepage, moderate. 95 35 112 17 Gradation 96 7" R Hydrometer Atterberg Direct Shear 97 ' 98 99 ' 100 101 Total depth 102 Seepage 37% RrC 0 f 93%: fee ' No groundw wng 103 Backfilled 01/05/00 104 3 ' 105 106 107 108 ' 109 110 ' 111 112 ' 113 114 ' 115 116 117 ' 118 119 ' 120 PROJECT NO. 0007 -03 -09 GEOTECHNICS INCORPORATED FIGURE B-4 ' LOG OF EXPLORATION BORING NO.2 Logged by: MAS Date Drilled: 1 /6 /00 Method of Drilling: 30 -inch diameter bucket auger Elevation: 274 1 /2' MSL F , LL a W v y y ti D DESCRIPTION LAB TESTS ' G o> J Z N ' 1 COLLUVIUM: Silty sand, (SM), brown to reddish brown, fine to very fine grained, dry, trace medium to coarse sand, rootlets. 2 DEL MAR FORMATION: Silty claystone,dark grayish green to brown, damp to moist, some 3 fine sand, highly plastic, well indurated, massive, highly fractured, (one quarter -inch to ' one -inch spacing), polished surfaces, orange to red brown iron staining. 4 5 6 7 8 9 Less fractures. 11 2 3 Hard clasts of siltstone, gray, angular fragments, in crushed clay matrix. ' 12 13 14 15 16 17 Grades to sandstone 18 19 20 - ............................................................................... ............................... tip "'t'4" Cbhlaot °g'rad'aiiorial; iiaf'lyih'g'. "' Unit Weight 21 2 tii Silty sandstone, olive gray to light brown to orange brown, damp to moist, fine grained, trace Moisture Content moderate to highly weathered, weakly cemented to friable, some iron staining. 22 ' 23 24 ' 25 Becomes yellow brown to gray in color. 26 26' to 28': Indistinct 6" to 1' angular fragments of gray siltstone in fine sandstone matrix. 27 ' 28 29 ' 30 3" concretionary layer, white to gray, fine grained, strongly cemented. PROJECT NO. 0007 -03 -09 GEOTECHNICS INCORPORATED FIGURE B7-5 1 ' LOG OF EXPLORATION BORING NO. 2 (continued) Logged by: MAS Date Drilled: Method of Drilling: 30 -inch diameter bucket auger Elevation 274'/z MSL 1 U` a v o U. CL N N DESCRIPTION LAB TESTS ' IL W 3 > LU J z y D m G m G emo a ear 31 5 DEL MAR FORMATION Silty sandstone, olive gray to light brown to orange brown, ' damp to moist, fine grained, trace of clay, moderate to highly weathered, weakly cemented 32 to friable, some iron staining. Less silt. ' 33 34 35 Small clasts of greenish siltstone. ' Bedding: flat 36 37 38 39 ' 5 concretionary layer white to gray fine grained strongly cemented . ......•••• Gradation 41 4A# Claystone,greenish gray to blue gray, moist to damp, highly fractured, polished surfaces, Direct Shear moderately to poorly indurated, massive, some iron stain, few calcite veins. ' 42 becomes moderately indurated, few fractures, minimal iron staining. 43 45 46 ' 47 50 n 51 8 / ' 52 ' 53 54 ' 55 56 Seepage, becomes moist. 57 ' S8 Total de feet Seepag t 56 fee 59 No groundwa er or caving Backfilled 01/06/00 60 lo, PROJECT NO. 0007 -03 -09 GEOTECHNICS INCORPORATED FIGURE 13-6 ' APPENDIX C LABORATORY TESTING Laboratory testing was conducted in a manner consistent with that level of care and skill ordinarily ' exercised by members of the profession currently practicing under similar conditions and in the same locality. No other warranty, expressed or implied, is made as to the correctness or serviceability of ' the test results, or the conclusions derived from these tests. Where a specific laboratory test method has been referenced, such as ASTM, Caltrans, or AASHTO, the reference applies only to the specified laboratory test method and not to associated referenced test method(s) or practices, and the ' test method referenced has been used only as a guidance document for the general performance of the test and not as a "Test Standard ". A brief description of the tests performed follows. Classification Soils were classified visually according to the Unified Soil Classification System. ' Visual classification was supplemented by laboratory testing of selected samples and classification in accordance with ASTM D2487. The classifications are shown on the Boring Logs. ' Particle Size Analysis Particle size analyses were performed in general accordance with ASTM D422. The grain size distribution was used to determine presumptive strength parameters and foun- dation design criteria. The results are given in Figures C -1.1 through C -1.5. Atterberg Limits ASTM D4318 -84 was used to determine the liquid limit, plastic limit, and plasticity index of selected samples. The results are shown in Figures C -1.2 and C -1.4. ' In -Situ Moisture/Density The in -place moisture content and dry unit weight of selected samples were determined using relatively undisturbed samples from the liner rings of a 2.375 -inch ID ' Modified California Sampler. The results are shown on the Boring Logs. Sulfate Content To assess the potential for reactivity with below grade concrete, selected soil ' samples were tested for water soluble sulfate content. The water soluble sulfate was extracted under vacuum from the soil using a 10:1 (water to dry soil) dilution ratio. The extracted solution was then ' tested for water soluble sulfate in general accordance with ASTM D516. ' Direct Shear Test The shear strength of the bearing soils was assessed using shear tests performed in general accordance with ASTM D3080. The results are shown in Figures C -2.1 through C -2.8. The shear strength parameters used for slope stability analysis are summarized in Table C -1. Geotechnics Incorporated ' o 0 o LO w �;� o , �_ V _ o ' o o W M �- ~ w o Ix :3 � Z oo Z D CD W 0 U O u- co S P W d_ 0 U Z E Q J 0 U U (D Q O ' a a O O D ' ZQ } � � U o U) v` co Z C m _ ~ - _ V J C N U) N w N W J y > LL U CD m N N a z c O �j ' C N S Z Q O to < V Q LL U) o 5 w U o � �' a 4) ' W U N LL N O W O � G O N W U LL m N U O ' J W O O H U W Z O N O w Ix LU a a a a CL °O w O O O O O O O O O O O O a) 00 n 0 to d' M N 44618M Aq jaui ;ua3.19d ' o 0 O 0 0 CD N H 0 CD M W co f0 N M o ' O O LU o J I_ F ' X O o Z m o ? 00 = 0 Es o IL ¢ cn 0 0 0 U o U v` O Z "10 C O � � C = c O y U LL cm cu a in w y W J Y m N z U) = U > U- U > U L N c J L m m O a N Z O ' C � f6 Z ¢ U U V � LL U1 U ca Q Q 0 J U- 00 c a O ' W w v i-► z Cd LU � N �V Q j cq W U m � U _ O W m° O < U W 0 Z O V ' O W ¢ a ¢ a U O p W O O O O O O O O O O O O O co n (fl d' M N ' 44Blem Aq jauid 4ua:).18d ' o 0 O LO M 0 T V ' H x o ° W ❑ Z W U Z O C N V- g a a O O ❑ ' Z } E J U o cn v 1 (O Z � C O fc ' U 0 C 03 V J O y a� CD � CD N � aYo w CD a) in LL U ) U � � J U � ai 0 m` ^' c a cn z o ' z Q ❑ U Q U Q N LL U) ' ❑ 5 w U J Z � N � c a � ' w W V (n LL a0 W 0 O co O w u ' J w O O a M z ' w z o o w p a a m U N Q O r p a O X r- w O O O O O O O O O O O O 0) 00 n c0 LO It M N 44618M Aq Jauid;ua3-1ad O 0 � rn rn d; o LO CD LO co CD o W J H W Ti --- N cl {Qj J O U Z O � 0_ _) ~ Z E LL U 0 Q J d � U U O) 0 O a IL 1 0 O I Z ,. w � U E to v` 1 O Z : c O fU 1 v a o iT) V J -10 c > O N U LL fC m 1 cts m Q LU m = w J a) a) Lo LL V " 0 1 N J� N O (1`) m CL fn Z N p c o a V cc z U) " 5 LL � y U g 1 U- W U co J o o uJ a W W cn lL u�1 Z W �V O � O C) O w U V LL m m ' J W O O H D U cr Z ' O O Z O w LU o a a 2 U a o Zo ' O N a_ O X w O O O O O O O O O O O O a) 00 n co to -Ft M N 146iaM Aq Bawd }usawd ' o 0 p m rn LO o LO o V ' o o W Z oo Z W O U O C U. Z E U Q J d V U O O i O ' a � O O Z } � � U o U) v` O Z c C O cm CL) U w CD O H U N 1 "� O US w to m E w J -x D z U a) U- S J U m d O a� N_ '^ n O Z v/ O ' O S o U W Q V } N L g r N U g Q s < LL w U 00 J LLI G a � N LL N Cd it— Q 2 a � O Z m LL W o O D w O Z O 03 O w CL W -j O (L < m N _j p a O X w OO 00 O co L O o O O O 146iaM Aq jauid ;u ad y 3500 �— a, 3000 - -� f■7� * ■ ■ ■ ■�■ ■■■■■■� ■� cn 2500 - 2000 ■ l ►- 1500 '�- -- � ® ■ ■ ® ® ® ® ® ■® ®® ® ® ® ® ®�� ' a 1 000 500 � ®- ■■ ■ ■■ ■■ ■ ■■■ ■ ■� ■■ ■ ■� ■■■■� = 0 E -- y 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 STRAIN [ %] ' 5000 r • ULTIMATE SHEAR: ' ! M PEAK SHEAR_ 4000 1 - C I " 3000 Cn Cn ! LLJ y l i j w 2000 - - — - N � 1000 1 0 ' 0 1000 2000 3000 4000 5000 NORMAL STRESS [PSF] ' SAMPLE: B1 @ 20'- 21' PEAK ULTIMATE ' DELMAR FORMATION (Td) Gray to 0' 35 28 orange brown fine grained silty sand (SM) L C. 0 PSF 0 PSF ' IN -SITU AS- TESTED STRAIN RATE: 1 0.0050 IN /MIN Yd 109.8 PCF 109.8 PCF (Sample was consolidated and drained) w 17.1 % 26.3 % A gMG e o t e c h n i c s DIRECT SHEAR TEST RESULTS Project No. 0007 - 003 -09 I n c o r p o r a t e d Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 ' Bruce D. Wiegand, Inc. FIGURE C -2.1 �- 1000 l IN 500 Q j = o w ■ ■■■■■■■ ■ ■■■�■■■■■■ ■;■ ■�■ ■ ■�■� ■ ■■ ■ I ' 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 STRAIN 5000 — I ' ORE SIDUAL SHEAR 4000 I I I I � I i n-. 3000 — - - - -- — ---j W Cn w� I k a 2000 W 1 II N � I I 1000 j 1 ' 0 1000 2000 3000 4000 5000 i NORMAL STRESS [PSF] SAMPLE: B1 @ 38' RESIDUAL DELMAR FORMATION (Td) Remolded, 80 fat claystone (CH). Soil was pre- sheared. C' 0 PSF ' IN -SITU AS- TESTED STRAIN RATE: 1 0.0005 IN /MIN y 109.0 PCF 109.0 PCF (Sample was consolidated and drained) w� 20.2 % 37.8 ' iM6,G e o t e c h n i c s DIRECT SHEAR TEST RESULTS Project No. 0007 - 003 -09 I n c o r p o r a t e d Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 ' Bruce D. Wiegand, Inc. FIGURE C -2.2 ' � 53 L a 3000 �— ■ ■ ��■ ' cn 2500 ■■ w 2000 -�- U, 1000 ■ a-M M Q 500 ■■�� ■ ■ ■ ■ ■ ■ ■ ■_ ■ ■ ■■ = 0■ ■ ■ N 0. 0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 STRAIN [ %] ' I 1 4500- - I ,� I 4000 • ULTIMATE SHEAR: ®PEAK SHEAR: 3500 F - -- - 3000 - ------ - - -- - -- y N 2500 -- - - --� -- - • l 2000 - -� - -- - - - w ' 1500 -- - -- -- r -T ' 1000 500 - — i 0� 0 500 1000 1500 2000 2500 3000 3500 4000 4500 NORMAL STRESS [PSF] SAMPLE: B1 @ 45' - 46' PEAK ULTIMATE ' DELMAR FORMATION (Td) Olive 34 27 gray fat claystone (CH) C. 0 PSF 0 PSF ' IN -SITU AS- TESTED STRAIN RATE: 1 0.0050 IN /MIN y 112.1 PCF 112.1 PCF (Sample was consolidated and drained) w. 17.0 % 28.7 % M6,G e o t e c hn i c s DIRECT SHEAR TEST RESULTS Project No. 0007 - 003 -09 I n c o rp orate d Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 Bruce D. Wiegand, Inc. FIGURE C -2.3 ' LL 10000 N 8000 ■ w 6000 ■ ■ ■ ■ ! � ■ ■ ■i■ E■ H EEE■ ��■ N 4000 ■ EtMB Ina of ® ® ® ■ME ® ® Q 2000 ■ ■1■ f■ w y 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 STRAIN [ %] ' 9000 — I ULTIMATE MATE S ' 8000 -- E m PEAK SHEAR: I 7000 �-- r -- 6000 '- — -- -- LL y 5000 ' - -- -- —— - LU 1 4000 j -- - Lu k 3000 � }- ® 2000 1000 � ' I p I 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 NORMAL STRESS [PSF] SAMPLE: B1 @ 65'- 66' PEAK ULTIMATE ' DELMAR FORMATION (Td) Light 43 37 ° yellow gray silty sandstone (SM) C. 600 PSF 0 PSF IN -SITU AS- TESTED STRAIN RATE: 1 0.0500 IN /MIN yd 114.9 PCF 114.9 PCF (Sample was consolidated and drained) w, 9.3 % 21.0 % ' G e o t e c h n i c s DIRECT SHEAR TEST RESULTS Project No. 0007 - 003 -09 I n c o r p o r a t e d Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 ' Bruce D. Wiegand, Inc. FIGURE C -2.4 � 52 00 I � 2000 I ■ ■ ■ ■ , w 1500 T- y 1000 ■ i ' w 500 : fir■ f i f■ ■ ■ ■-■ t.t -a■ u ■ M EEI y ' 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 STRAIN [ %] ' 5000 •ULTIMATE SHEAR: ' ■ PEAK SHEAR: i 4000 - -- — r � a ' I 3000 N i N w H � N r W 2000 �- 2 W I 1000 i � ' 1 0 ' 0 1000 2000 3000 4000 5000 NORMAL STRESS [PSF] SAMPLE: B1 @ 75' - 76' PEAK ULTIMATE ' DEL MAR FORMATION (Td) Remolded 28 0 25 siltstone and claystone. C. 0 PSF 0 PSF ' IN - SITU AS- TESTED STRAIN RATE: 1 0.0200 IN /MIN rd 99.5 PCF 99.5 PCF (Sample was consolidated and drained) w, 15.4% 21.4% ' G e o t e c h n i c S DIRECT SHEAR TEST RESULTS Project No. 0007 - 003 -09 I n c o r p orate d Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 ' Bruce D. Wiegand, Inc. FIGURE C -2.5 1 ' LL 5000 � r E ■t ■ ■ ■ ■ ■ ■■ a. 4000 �� W 3000 ■ 2000 ® ® ® OEM ®I ® ® i a 1000 f■■■}■ ■ ■ ■r ■ ■ ■ ■ ■ ■ ■ ■■ ■ ■ ■ ■ ■ ■ ■ ■� ■ ■ ■■ ■ ■ ■ ■. = 0 ■■ i N 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 L STRAIN [ %] i 8000 I I ULTIMATE SHEAR: j 1 7000 ® PEAK SHEA -- 6000 cn 5000 -- - - - -- -- 1 r V � I U) (n W 4000 - -— i i W 3000 -- i L ' 2000 I C I 1000 _ _ i � I r I I o i 0 1000 2000 3000 4000 5000 6000 7000 8000 i NORMAL STRESS [PSF] SAMPLE: 131 @ 95'- 96' PEAK ULTIMATE DELMAR FORMATION (Td) Dark 29 ° 24 blue gray fat claystone (CH) C. 0 PSF 0 PSF i IN -SITU AS- TESTED STRAIN RATE: 1 0.0090 IN /MIN yd 112.0 PCF 112.0 PCF (Sample was consolidated and drained) w, 16.9% 28.3 % ' G e o t e c h n i c s DIRECT SHEAR TEST RESULTS Project No. 0007 - 003 -09 ff� n c o rp orate d Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 Bruce D. Wiegand, Inc. FIGURE C -2.6 1 N 3500 � - - -- T �- ■ ��■ cn 2500 EM�it ■ ■ ■ ■ I ■ ■ ■■ ' W 2000 ■ ■ ■ ■ ■ 1500 Cn 1000 ■® ® ® ® ® ® w 500 ■ ■ ■ � 0 ' 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 STRAIN [ %] 4000 -- ' ♦ ULTIMATE SHEAR: 3500 PEAK SHEAR: 3000 U. - - -- - - cn 2500 ! - — 1 a N U) r ' W 2000 - -- - U) i = 1500 i 1000 r _ I I I 500 0 0 500 1000 1500 2000 2500 3000 3500 4000 NORMAL STRESS [PSF] SAMPLE: B2 @ 30' - 31' PEAK ULTIMATE ' DELMAR FORMATION (Td) Remolded, 39 32 ° yellow gray silty sandstone (SM). L C' 0 PSF 0 PSF ' IN -SITU AS- TESTED STRAIN RATE: 1 0.0200 IN /MIN yd 100.0 PCF 100.0 PCF (Sample was consolidated and drained) w, 12.1 % 20.4% e o t e c h n i c s DIRECT SHEAR TEST RESULTS Project No. 0007 - 003 -09 I n c o r p o r a t e d Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 ' Bruce D. Wegand, Inc. FIGURE C -2.7 I , . 2500 — � ■ — - -- 2000 ■ -I �f■ ■ 1500 I- 1000 r ■— - --�— 500 0 _ _�— i N 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 ' STRAIN [ %] ' 4000 — �— — • ULTIMATE SHEAR: ' 3500 PEAK SHEAR: I -- ' 3000 LL I 2500 a r Cl) ®, it 2000 — — Q I j w 1500 - 1 y 1000 — 500 I, 0 500 1000 1500 2000 2500 3000 3500 4000 NORMAL STRESS [PSF] SAMPLE: B2 @ 40'- 41 PEAK ULTIMATE ' DELMAR FORMATION (Td1 Olive 28 22 ° gray fat claystone (CH) C. 300 PSF 200 PSF ' IN -SITU AS- TESTED STRAIN RATE: 1 0.0020 IN /MIN r 100.8 PCF 100.8 PCF (Sample was consolidated and drained) w, 23.1 % 3 3. 3 ' G e o t e c h n i c s DIRECT SHEAR TEST RESULTS Project No. 0007 - 003 -09 Inc o r p orate d Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 ' Bruce D. Wegand, Inc. FIGURE C -2.8 1 Z 0) rnV- o O o U W fp O ' O i 0 ' C) O 00 M O J 2 N O O J > O U i I I II I � O m 1 O C F- O J N co N III M N N M N Z c i E LL¢ j 0 �n E 0 0 0 W 2 M 0 O 0 1 C 0 O O Cl) O 0 0 O O M 0 ! i J a o j 1 00 � 't C-) O M MN,N M N' MNN M LL Q 1 . I =, (D a a y I U) N I= N, (� c u Z cf) ca c .., oil 2! 2 JiU o' = �IU <p; U in U! U p, N Uj UI U) N opl U) = C y, o c o f o' o w �I ,^ O cc r - I O - _ C ' c H y N T c0 > M N 1 c6 = fA L9 IL Ni c0 _ c0', .T,j , ~,^^ r O _ U U'. c N c6 U j y o_ N, N1 Z N U o w Co f CU Cc o . o = W W T W 0) y i'', m e tm oI �I >, o �I �, of °) �; y ccI. L m �'Ol� Y'�lo! = o l � x o rni D �i of L! m! (D! E ; a Q- T �, U) " 0, w U) I o 0 t7' E I' to U co E, co i ! I L) 0 cn � I U in i U I c) L) 0: cn i I W I a� W W W D I- ZIW Z J N! M 0� 0 rn cM V 0 I0 0 ', 0 d UIUi@� �U) I �- cl) 1(n a m mom m mlm,m m 04 Q�Ig!g, a, vs I cn v v • r•, z z z z z z z z z z z 0 0 0 0 0 1 0 O 0 I O O j O l 0 Z H: H! F f- H H H HI H u-' O V Q Q Q QjQ,Q Q Q ;Q Q'Q Ql = gy m m m l LLJ 0 I1 w X w l w F' 0 0 0 1 0 0 010 O 0 0 1 0 01 w J LL LL LL LL LL LL LL i LL J LL LL LL LL D W W Q Q Q Q Q Q Q Q Q Q Q Q 00 W W W W W W W' � W � W W W W N O 0 O! 0 LU W H i � APPENDIX D SLOPE STABILITY ANALYSIS surficial and gross sloe stability an performed for this project he sur g p ty are summarized in the y p p � ' following appendix. The shear strength parameters used for the analysis are summarized in Table C -1. The lower bound of the ultimate shear strengths were chosen for the analysis in order to approximate the worse -case long term strength conditions. The seepage that was observed in the ' borings was included in the analysis as perched groundwater at the interfaces between the sandstone and claystone beds. ' SURFICIAL STABILITY Surficial stability was analyzed using an idealized infinite slope ' composed of a cohesive, frictional material. Steady state seepage forces were applied parallel w the slope surface using an idealized flow net. The analysis procedure is based on that presented by Abrahamson et al., 1996. Note that the factor of safety against surficial failure is plotted versus the ' depth of the wetted zone in Figures B -1 through B -4. A factor of safety of 1.5 is typically deemed acceptable against surficial failure. A factor of safety of 1.0 would indicate imminent failure given ' a particular depth of wetted zone. GROSS STABILITY The gross stability of the proposed slopes was analyzed using PCSTABL6 ' software. Pertinent results are presented in the remaining figures of this appendix. Gross stability of the proposed slopes with evaluated with steady state seepage of groundwater perched on claystone ' beds. Analyses were conducted using Bishop's circular surface search routines and Rankine's sliding block analysis. Spencer's method of slices was used to refine the stability of the critical failure ' surfaces. Buttresses were designed where necessary in order to attain a safety factor of 1.5 against deep seated failure, which is the generally accepted safety factor for stability analysis. Pseudo - static seismic analysis was used after the buttress designs were completed to determine if the slopes had ' a safety factor greater than 1.0 given the maximum probable repeatable acceleration. 1 ' Geotechnics Incorporated INPUT PARAMETERS - DEL MAR FORMATION SANDSTONE Friction Angle (CD) 35 [DEGREES] Cohesion (CD) 100 [PSF] Dry Unit Weight 115 [PCF] Water Content 10 [ %] Slope Surface ' Specific Gravity 2.70 Slope Angle X 2.00 X � � H ' CALCULATED PARAMETERS Void Ratio 0.47 F.S. = c + H (Ysat y) cos' (p) tano' ' Moist Unit Weight 127 [PCF] y H sing cosp Saturated Unit Weight 135 [PCF] Sa ' Friction Angle 0.61 [RADIANS] Slope Angle 0.46 [RADIANS] SURFICIAL STABILITY (After Abrahamson et. al, 1996) ' 6.00 (H) [FT] F.S. 0.50 4.87 0.75 3.52 1.00 2.85 5.00 1.25 2.44 1.50 2.17 ' 1.75 1.98 2.00 1.83 2.25 1.72 LL 4.00 2.50 1.63 2.75 1.56 y 3.00 1.50 ' 3.25 1.44 X3.00 3.50 1.40 3.75 1.36 4.00 1.33 ' 4.25 1.30 `0 2.00 4.50 1.27 R LL ' 4.75 1.25 5.00 1.23 5.25 1.21 .00 5.50 1.19 5.75 1.17 6.00 1.16 6.25 1.15 0.00 ' 6.50 1.13 0.00 1.00 2.00 3.00 4.00 5.00 6.00 Depth of Wetted Zone (H) [Feet] ' G e o t e c h n i c s SURFICIAL SLOPE STABILITY Project No. 0007 - 003 -09 ANNEEMbbZ `Incorporat Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 Bruce D. Wiegand, Inc. FIGURE D -1 ' INPUT PARAMETERS - SELECT FILL IN LOWER BUTTRESS Friction Angle (CD) 32 [DEGREES] Cohesion (CD) 100 [PSF] Dry Unit Weight 100 [PCF] Water Content 15 [ %] Slope Surface ' Specific Gravity 2.70 Slope Angle X 2.00 X� 1 H ' CALCULATED PARAMETERS Void Ratio 0.68 c' + H (Ysar Yw) Co S 2 (p) tan0' F.S. _ Moist Unit Weight 115 [PCF] y t H sing cusp Saturated Unit Weight 125 [PCF] 1 Friction Angle 0.56 [RADIANS] Slope Angle 0.46 [RADIANS] SURFICIAL STABILITY (After Abrahamson et. al, 1996) ' 6.00 (H) [FT] F.S. 0.50 4.87 ' 0.75 3.47 1.00 2.77 5.00 1.25 2.34 1.50 2.06 1.75 1.86 2.00 1.71 2.25 1.60 LL 4.00 R 2.50 1.50 U 2.75 1.43 y 3.00 1.36 3.25 1.31 X3.00 3.50 1.26 w 3.75 1.22 4.00 1.19 0 4.25 1.16 0 2.00 4.50 1.13 LL 4.75 1.10 5.00 1.08 5.25 1.06 1.00 ' 5.50 1.04 5.75 1.03 6.00 1.01 ' 6.25 1.00 0.00 6.50 0.99 0.00 1.00 2.00 3.00 4.00 5.00 6.00 Depth of Wetted Zone (H) [Feet] i G e o t e c hn i c s SURFICIAL SLOPE STABILITY Project No. 0007 - 003 -09 Incorporat Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 Bruce D. Wiegand, Inc. FIGURE D -2 t INPUT PARAMETERS - LIME TREATED FILL IN UPPER BUTTRESS Friction Angle (CD) 0 [DEGREES] ' Cohesion (CD) 1000 [PSF] Dry Unit Weight 100 [PCF] Water Content 20 [ %] Slope Surface ' Specific Gravity 2.70 Slope Angle X 2.00 X � � H ' CALCULATED PARAMETERS Void Ratio 0.68 F S = c' + H(YSat y) COS (R) tan gy ' ' Moist Unit Weight 120 [PCF] y sin co Saturated Unit Weight 125 [PCF] ' Friction Angle 0.00 [RADIANS] Slope Angle 0.46 [RADIANS] SURFICIAL STABILITY (After Abrahamson et. al, 1996) ' (H) [FT] F.S. 6.00 0.50 35.67 ' 0.75 23.78 1.00 17.84 5.00 1.25 14.27 1.50 11.89 ' 1.75 10.19 2.00 8.92 2.25 7.93 U. 4.00 A ' 2.50 7.13 •" 2.75 6.49 y 3.00 5.95 H ' 3.00 3.25 5.49 0, 3.50 5.10 >. 3.75 4.76 R ' 4.00 4.46 N 4.25 4.20 0 2.00 4.50 3.96 U 4.75 3.76 5.00 3.57 5.25 3.40 .00 ' 5.50 3.24 5.75 3.10 6.00 2.97 ' 6.25 2.85 0.00 6.50 2.74 0.00 1.00 2.00 3.00 4.00 5.00 6.00 Depth of Wetted Zone (H) [Feet] ' G e o t e c h n i c s SURFICIAL SLOPE STABILITY Project No. 0007 - 003 -09 Incorporated Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 Bruce D. Wiegand, Inc. FIGURE D -3 INPUT PARAMETERS - FAT CLAY FILL SLOPE Friction Angle (CD) 24 [DEGREES] ' Cohesion (CD) 100 [PSF] Dry Unit Weight 100 [PCF] Water Content 23 [ %] Slope Surface ' Specific Gravity 2.80 \� Slope Angle X 2.00 X� 1 H ' CALCULATED PARAMETERS Void Ratio 0.75 F = c' + H(Y Y) COS 2 (p) tan ' Moist Unit Weight 123 [PCF] 7so rH sing cusp Saturated Unit Weight 127 [PCF] ' Friction Angle 0.42 [RADIANS] Slope Angle 0.46 [RADIANS] ' SURFICIAL STABILITY (After Abrahamson et. al, 1996) ' 6.00 (H) [FT] F.S. 0.50 4.31 ' 0.75 3.02 1.00 2.37 5.00 1.25 1.99 1.50 1.73 ' 1.75 1.55 0 2.00 1.41 2.25 1.30 LL 4'00 2.50 1.22 2.75 1.14 0' 3.00 1.09 3.25 1.04 ii 3.00 3.50 0.99 a 3.75 0.96 4.00 0.93 w ' 4.25 0.90 0 2.00 4.50 0.87 A ' 4.75 0.85 LL 5.00 0.83 5.25 0.81 ' 5.50 0.79 5.75 0.78 6.00 0.76 6.25 0.75 0.00 ' 6.50 0.74 0.00 1.00 2.00 3.00 4.00 5.00 6.00 Depth of Wetted Zone (H) [Feet] ' G e o t e c h n i c s SURFICIAL SLOPE STABILITY Project No. 0007 - 003 -09 Incorpora Copper Creek Estates, Lots 4 and 6 Document No. 0 -0059 Bruce D. Wiegand, Inc. FIGURE D-4 1 o 0 M Ln E °- o O � � N ' N r O ' m O M fCl� C u O ' CL IM a Nz 3333 N 0 LL (A N L m x .. . a = � o a "o. o000o X � � U ' m�E co G CL r' a` a O II O = m V C m M N N M N o a N Lo ' V Cc e ro a ,o ° O LLI CL -= F C (L d O C• O V C. U MMMMM O 0 0. o V WD � r3 c w j 11�N�Nr' L C U N cr) of u1 }Z} ^ � � J Q Q a J y V y V ' J m J LL H F— F — F— to O O N N t0 t0 P% P% P% ' y 00 0D Q1 W 0) 0) 0) Oa W 0) tL��r- ��r- •r N tf � V1 b P 00 T H ' O Lo O La O O N � � N Q o 0 M Lo Q ' O N N ' N r N � O ' m O M •p O Ln W C ' 0 0 Viz 3333 N `P O � U. y .► N a m= a 1 Q ' U) v yCa 00000 � r 3 ar0 X � O U r 4 m ' C `o -W 00000 p 2 a s Ln 0 I I V >� c •C �� m o7 O1 m N W tr LC'! E V ' / t7 C� MNNMN co ► li Q ` LL �C J G1 c m w O N J V 220 W ,on0000 Q ' o� v c p d m «: N M O o o isLnLnLn C d fl. V � � G MMMMM '� O r v iifN�N� ' C v � U O yFZ —Nm e n � J J LLHH 0= I NIJ Ln N N N N O O O O O O ' p Ln O 1n N � W Q o 0 M LO E LO M N W � O 3 O M 'p O D. 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O C U rma LL L) C. U m CL �3 0LnLn�nLn o CO I c �� a o _ U) -p CV) 0 C tnN -N•' 1 a ' C Ir p " i O W ~� a 1 IL j U U �z r } °} U) Gaza di JQJ U W J mc)ufc) j 1 � J F-1- L Cl) 1 N N r N Q 0 La M 1 co O r � .. r N N � O � M � m � � M N O m O C iti i0 p N N O .•. Cc G t Q, =z 3333 N (n N L U. L C N m a o000o ep M a`v X M m M 1 C a~°2mmm 00000 � CL II ++ a O m F Oly NOOd't°� LL . MNNMN � LO Y CL oa CD wmw o 1 V � m�q �0000 J L W 05 Q IL F- �, a m - cn CL 9 `•�.. v MMMMM V O V ? fZ V V y M V Ow+O. � U .m M Lo ' 0 ql F . z ypy O �QZ Ln 01 JJQJ ' Q7 ,JU1V 0 6U �' J - �0'O r��n�nu�coconnaoao ' y Lq UnU�LnLoUnU�LnUnUn O O O O O O r co co N N d � ' W ' o 0 M m O o M Ln O N N � � O O MM M 1 W O ' a r a 3z 3333 o N N U. ♦2 m C Qtr. •X = C; Q yyw o000o Q C t ` X 3 a0 m co C aa`om� 00000 a II t+ a O V Ln m C_ C •C N m V C f L o U- CL C G O ro-- LO V � • m � N 0 000 0 o —� W v5 Q CL CL d a- N O. �3: ou��n�nin p +. tl MMMMM C.� C (� �g ��. O 4. 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O d oo i U) ' d o m a ° I 00 43 W v 5 a a H d- N a 3 o In Ln lc) In ° o a O w 3 - U CL 2 ~ Cl U ' O U H �YZY Lfl C 0 2 666 - 6 6UNU J nnnnaoaoaoo)mCn U- r— r ' O CV) N N � C N a 1 ' o I I CV) ' I I 0 I i ' m C ca N z 3333 I � LL. a '..w ' L y W N 00000 I � V 0 0 ' � ca a °9 10 0 00000 � r Lo C co ' M m omNat N E I ; • O d o CL Ln 00 �M ' IL y u0 $ 00 000 J V d 020 a oc0�0 t m cn Cl) ' d w3 ofninfnfn i Q U Q ., NMMMM Q 0. � U U �3w 0N N� r f) MMfhM Q •V U r� y >.Z N M a tff 0 Q � Gaza C WfA Lo ~ J ~ F- N.- NNN 0 0 rl� ' O NMMMMP cicicl q LL. r- v- v- r- r- r- e- r- r- r- rl N PI h V l� 00 O1 N 1 O M N N Lo A . } ' o I I i CO) � 1 I I N I I • N , , , CL I I W 0 1 Ln N IM I N CL ' y � ♦ � a I � W N , V ' a 3Z 3333 ti 3 LL •N (L c ' X 1 a U 1 M y C c 000000 1 Q 3 ' v M i 00 ' CL d E I et d o ma 000000 , , r ' II a i i In -- I c C m _ bo ' V C.�p co -e I 1 cn 1 L LLQ- LL 00 J a I 1 a C 1 ayi v y 0 00000 I 1 m ' W M i U J m n- L3 0LoLninLna O U • =a a d >r 1 1 ' f 1 r3•� ON-N-In V AS 0. 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O a r I Lo }r O d O 1 U LL m l e 000000 I m CD a Cl) Y ;3w oln�lnino 0 U ' CD O r C G NMMMMM a N t- a y ' �3� ON�Nr'tn Q a O U U -m y y ~ >Z �NMatnGO � t. ro �aQJ2 m Wv)UtAUU in 0 m q* Ln In r- cococo0 Iq Iq Un Iq U Un In co 0 O N L O O N ' W r r 0 I I M I I r N I 1 i 1 � E I CL I I LO r � O O I I ri W r• r• N N N � O i"/ a �Z 3333 I ,t, N cc OD U. 3 y C1 y u, y 000000 I X � CL t n U I M � r G ` I 8-2 d � a°mW 000000 s I I I ONNd'NN I Cl) J W Q d C i a ° d am o o I m W s as a , c o� Q c US C' �3w o 0 LninLaLn 0 O d U V « C O. NMMMMM L V cn :) U 4 L �3w ONr'Nr'�n --- fl. D O y Nd„Z r- NM��nlO M 0 ~ O G CC JazQ LO p� c m JQJx QD .0 tL N U y V V in �j JI- F-HHu. 5 ��cocOnt�aoCO� ' y �000G��00 00 LL r - r - r - r r- N N N e e .n v r oo a .. O O r O N Lo M O N r e- r W "" t 1 ' APPENDIX E SEISMIC ANALYSIS Seismic analysis was conducted for the subject site in order to develop parameters for structural ' design. This appendix presents the raw data from our analysis from three commercially available computer programs, EQFAULT, EQSEARCH and FRISKSP (Blake, 1998). All three analyses used the same published attenuation relationship for rock sites (Idriss, 1994). EQFAULT The program EQFAULT was used to develop the deterministic peak ground ' acceleration parameters summarized in Table 1 of this report. EQSEARCH The program EQSEARCH was used to generate a table of estimated characteristics of nearby seismic events which were recorded between 1800 and 1999. This table is presented within Appendix E, and shows the epicenters, magnitudes, and dates of these nearby earthquakes, ' along with the estimated peak ground acceleration for the site. ' FRISKSP The program FRISKSP was used perform a probabilistic analysis of seismicity at the subject site based on the characteristic earthquake distribution of Youngs and Coopersmith (1985). ' The results are also presented within Appendix E. The probabilistic analysis was used to define the Maximum Probable Earthquakes for the site for use in structural design. 1 ' Geotechnics Incorporated DATE: Monday, April 10, 2000 ****** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** * * E Q F A U L T * * Ver. 2.20 * * ****** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** ' (Estimation of Peak Horizontal Acceleration From Digitized California Faults) SEARCH PERFORMED FOR: Bruce D. Wiegand, Inc. JOB NUMBER: 0007 - 003 -09 JOB NAME: Copper Creek Estates, Lots 4 and 6 SITE COORDINATES: LATITUDE: 33.0622 N LONGITUDE: 117.2183 W SEARCH RADIUS: 62 mi ATTENUATION RELATION: 17) Idriss (1994) Horiz. - Rock /Stiff Soil ' UNCERTAINTY (M =Mean, S= Mean +1 - Sigma): M SCOND: 0 COMPUTE PEAK HORIZONTAL ACCELERATION FAULT -DATA FILE USED: CALIFLT.DAT ' SOURCE OF DEPTH VALUES (A= Attenuation File, F =Fault Data File): A 1 1 ----------------------------- ' DETERMINISTIC - SITE - PARAMETERS ' Page 1 ------------------------------------------- MAX. CREDIBLE EVENT MAX. PROBABLE EVENT APPROX. ------------- - - - - -- --------------- - - -- ABBREVIATED DISTANCE MAX. PEAK SITE MAX. PEAK SITE 1 FAULT NAME mi (km) CRED. SITE INTENS PROB. SITE INTENS MAG. ACC. g MM MAG. ACC. g MM -------------------- - - - - -- --- - - - - -- - - --- - - - - -- - - - - -- - - - -- - - - - -- - - - - -- BORREGO MTN. (San Jacinto) 61 ( 98) 6.50 0.023 IV 6.20 0.016 IV 1 ____ -- - - - - -- --- - -- - -- - - - -- - - - - -- - - -- -- _ - - -- - - - - -- ____ -- CASA LOMA -CLARK (S.Jacin.) 48 ( 77) 7.00 0.052 VI 7.00 0.052 VI -------------------- - - - - -- --- - - - - -- - - - -- - - - - -- - - - - -- - - - -- - - - - -- - - - - -- CATALINA ESCARPMENT 43 ( 69) 7.00 0.060 VI 6.10 0.026 V 1 -- --------- ----- ---- - - - - -- --- - - - - -- - - - -- - - - - -- - - - - -- - -- -- - - - - -- - - - - -- CHINO 54 ( 87) 7.00 0.054 VI 5.40 0.010 III --------- ----------- - - - - -- --- - - - - -- - - - -- - - - - -- - - - - -- - - - -- - - - - -- - - - - -- COMPTON-LOS ALAMITOS 54 ( 87) 7.20 0.147 VIII 5.80 0.040 V r -------------------- - - - - -- --- - - - - -- - - - -- - - - - -- - - - - -- - - - -- - - - - -- - - - - -- CORONADO BANK -AGUA BLANCA 22 ( 36) 7.50 0.165 VIII 6.70 0.104 VII --------------- ----- - - - - -- --- - - - - -- - - - -- - - - - -- - - - - -- - - - -- - - - - -- - - - - -- COYOTE CREEK (San Jacinto) 49 ( 78) 7.00 0.051 VI 6.10 0.021 IV ELSINORE ------------ - - - - -- - 25 - ( - 40) - 7_50 0.151 VIII 6.60 0.088 VII - - - - -- - - - - -- - - - -- - - - - -- - - - - -- GLN.HELEN-LYTLE CR- CLREMNT 53 ( 86) 7.00 0.045 VI 6.70 0.034 V i _-- -_ - -_- ---- -- --- ---- -- --- -- - - - - -- - - - - -- - - - -- - - - - -- -- - - -- HOT S -BUCK RDG.(S.Jacinto) 50 { 80) 7.00 0.049 - VI -- 6.10 0.020 - IV -- -------------------------- --- - - - - -- - - - -- - - - - -- - - - - -- - - - - -- - LA NACION 16 ( 25) 6.50 0.165 VIII 4.20 0.024 V NEWPORT_INGLEWOOD- OFFSHORE - 15 - ( - 23) - 7_10 - 0_198 - VIII - - 5_90 - 0_085 -- VII - PALOS VERDES HILLS 50 ( 81) 7.20 0.058 VI 6.20 0.023 IV ROSE CANYON -- 8 - ( - 12) - 700 0.305 - - IX -- 5.90 0.142 VIII ------------- ------- - - - - -- - - - - -- - - - -- - - - --- - - - - -- SAN CLEMENTE - SAN ISIDRO 54 ( 87) 8.00 0.096 VII 6.50 0.028 V ' SAN - DIEGO TRGH__BAHIA - SOL. - 33 - ( - 52) - 7_50 - 0_115 - - VII - - 620 - 0_044 - - VI -- WHITTIER - NORTH ELSINORE 59 ( 95) 7.10 0.043 VI 6.00 0.013 III -END OF SEARCH- 17 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE ROSE CANYON FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 7.6 MILES AWAY. ' LARGEST MAXIMUM- CREDIBLE SITE ACCELERATION: 0.305 g LARGEST MAXIMUM- PROBABLE SITE ACCELERATION: 0.142 g 1 1 1 DATE: Monday, April 10, 2000 * * * E Q S E A R C H * * * Ver. 2.20 * * * ******** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** (Estimation of Peak Horizontal Acceleration From California Earthquake Catalogs) SEARCH PERFORMED FOR: Bruce D. Wiegand, Inc. JOB NUMBER: 0007- 003 -09 JOB NAME: Copper Creek Estates, Lots 4 and 6 SITE COORDINATES: LATITUDE: 33.0622 N LONGITUDE: 117.2183 W TYPE OF SEARCH: RADIUS 1 SEARCH RADIUS: 62 mi SEARCH MAGNITUDES: 5.0 TO 9.0 ' SEARCH DATES: 1800 TO 2000 ATTENUATION RELATION: 17) Idriss (1994) Horiz. - Rock /Stiff Soil UNCERTAINTY (M =Mean, S= Mean +1 - Sigma): M SCOND: 0 FAULT TYPE ASSUMED (DS= Reverse, SS= Strike - Slip): DS COMPUTE PEAK HORIZONTAL ACCELERATION EARTHQUAKE -DATA FILE USED: ALLQUAKE.DAT TIME PERIOD OF EXPOSURE FOR STATISTICAL COMPARISON: 25 years SOURCE OF DEPTH VALUES (A= Attenuation File, E= Earthquake Catalog): A Page 1 SITE ITE SITE APPROX. FILE LAT. LONG. DATE (GMT) DEPTH QUAKE ACC. IMM DISTANC C ODE NORTH WEST H M Sec (km) MAG. g DMG 33.000 117.300 11/22/1800 2130 0.0 10.0 6.50 0.348 IX 6 [ 101 MGI 32.800 117.100 5/25/1803 0 0 0.0 10.0 5.00 0.037 V 19 [ 31] 1 MGI 33.000 117.000 9/21/1856 730 0.0 10.0 5.00 0.059 VI 13 [ 211 T -A 32.670 117.170 12/ 0/1856 0 0 0.0 10.0 5.00 0.022 IV 27 [ 441 DMG 32.700 117.200 5/27/1862 20 0 0.0 10.0 5.90 0.054 VI 25 [ 401 T -A 32.670 117.170 10/21/1862 0 0 0.0 10.0 5.00 0.022 IV 27 [ 441 ' T -A 32.670 117.170 5/24/1865 0 0 0.0 10.0 5.00 0.022 IV 27 [ 44J T -A 32.250 117.500 1/13/1877 20 0 0.0 10.0 5.00 0.006 II 58 [ 94] DMG 33.900 117.200 12/19/1880 0 0 0.0 10.0 6.00 0.016 IV 58 [ 931 DMG 33.400 116.300 2/ 9/1890 12 6 0.0 10.0 6.30 0.024 V 58 [ 931 1 DMG 32.700 116.300 2/24/1892 720 0.0 10.0 6.70 0.036 V 59 [ 951 DMG 33.200 116.200 5/28/1892 1115 0.0 10.0 6.30 0.023 IV 60 [ 961 DMG 32.800 116.800 10/23/1894 23 3 0.0 10.0 5.70 0.035 V 30 [ 491 DMG 33.800 117.000 12/25/1899 1225 0.0 10.0 6.40 0.032 V 52 [ 841 DMG 33.700 117.400 4/11/1910 757 0.0 10.0 5.00 0.009 III 45 [ 731 DMG 33.700 117.400 5/13/1910 620 0.0 10.0 5.00 0.009 III 45 [ 731 DMG 33.700 117.400 5/15/1910 1547 0.0 10.0 6.00 0.024 V 45 [ 731 DMG 33.500 116.500 9/30/1916 211 0.0 10.0 5.00 0.007 II 51 [ 831 DMG 33.750 117.000 4/21/1918 223225.0 10.0 6.80 0.051 VI 49 [ 79] MGI 33.800 117.600 4/22/1918 2115 0.0 10.0 5.00 0.006 II 55 [ 89J DMG 33.750 117.000 6/ 6/1918 2232 0.0 10.0 5.00 0.008 II 49 [ 791 DMG 33.200 116.700 1/ 1/1920 235 0.0 10.0 5.00 0.018 IV 31 [ 511 1748 0.0 10.0 5.30 0.018 IV 37 [ 601 MGI 33.200 116.600 10/12/1920 DMG 33.617 117.967 3/11/1933 154 7.8 10.0 5 .30 0.025 V 58 [ 93] DMG 33.575 117.983 3/11/1933 518 4.0 10.0 5.20 0.007 II 57 [ 91J 10.0 5.10 0.006 II 60 [ 961 DMG 33.617 118.017 3/14/1933 19 150.0 .00 0.015 IV 60 [ 971 DMG 33.408 116.261 3/25/1937 1649 1.8 10.0 5.50 0.014 IV 47 [ 761 t DMG 33.699 117.511 5/31/1938 83455.4 10.0 5 DMG 33.000 116.433 6/ 4/1940 1035 8.3 10.0 5.10 0.010 III 46 [ 73J DMG 33.283 116.183 3/19/1954 95429.0 10.0 6.20 0.020 IV 62 [ 991 DMG 33.283 116.183 3/19/1954 95556.0 10.0 5.00 0.005 II 62 [ 991 DMG 33.283 116.183 3/19/1954 102117.0 10.0 5.50 0.009 III 62 [ 991 DMG 33.283 116.183 3/23/1954 41450.0 10.0 5.10 0.006 II 62 [ 991 DMG 33.710 116.925 9/23/1963 144152.6 10.0 5.00 0.008 III 48 [ 771 DMG 33.343 116.346 4/28/1969 232042.9 10.0 5.80 0.015 IV 54 [ 871 PAS 33.501 116.513 2/25/1980 104738.5 10.0 5.50 0.012 III 51 [ 821 PAS 32.971 117.870 7/13/1986 1347 8.2 10.0 5.30 0.017 IV 38 [ 621 -END OF SEARCH- 37 RECORDS FOUND COMPUTER TIME REQUIRED FOR EARTHQUAKE SEARCH: 0.4 minutes MAXIMUM SITE ACCELERATION DURING TIME PERIOD 1800 TO 2000: 0.3488 MAXIMUM SITE INTENSITY (MM) DURING TIME PERIOD 1800 TO 2000: IX I MAXIMUM MAGNITUDE ENCOUNTERED IN SEARCH: 6.80 NEAREST HISTORICAL EARTHQUAKE WAS ABOUT 6 MILES AWAY FROM SITE. NUMBER OF YEARS REPRESENTED BY SEARCH: 201 years 1 RESULTS OF PROBABILITY ANALYSES ------------------------------- ' TIME PERIOD OF SEARCH: 1800 TO 2000 LENGTH OF SEARCH TIME: 201 years ATTENUATION RELATION: 17) Idriss (1994) Horiz. - Rock /Stiff Soil I * ** TIME PERIOD OF EXPOSURE FOR PROBABILITY: 25 years PROBABILITY OF EXCEEDANCE FOR ACCELERATION ------------------------------------------ ' NO.OF AVE. RECURR. COMPUTED PROBABILITY OF EXCEEDANCE ACC. TIMES OCCUR. INTERV. in in in in in in in g EXCED # /yr years 0.5 yr 1 yr 10 yr 50 yr 75 yr 100 yr * ** yr ' 0.01 25 0.124 8.040 0.0603 0.1170 0.7117 0.9980 0.9999 1.0000 0.9554 0.02 15 0.075 13.400 0.0366 0.0719 0.5259 0.9760 0.9963 0.9994 0.8452 0.03 8 0.040 25.125 0.0197 0.0390 0.3283 0.8633 0.9495 0.9813 0.6303 0.04 4 0.020 50.250 0.0099 0.0197 0.1805 0.6303 0.7752 0.8633 0.3920 0.05 4 0.020 50.250 0.0099 0.0197 0.1805 0.6303 0.7752 0.8633 0.3920 0.06 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.07 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.08 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.09 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.10 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.11 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 ' 0.12 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.13 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.14 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.15 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.16 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.17 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.18 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.19 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.20 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.21 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.22 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.23 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 I 0.24 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.25 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.26 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.27 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.28 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.29 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.30 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.31 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.32 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 0.33 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920i0.1170 0.34 1 0.005 201.000 0.0025 0.0050 0.0485 0.2202 0.3114 0.3920 0.1170 -------------------------------------------------------------------------- 1 1 PROBABILITY OF EXCEEDANCE FOR MAGNITUDE --------------------------------------- NO.OF AVE. RECURR. COMPUTED PROBABILITY OF EXCEEDANCE MAG. TIMES OCCUR. INTERV. in in in in in in in ' EXCED # /yr years 0.5 yr - - 1 - yr 10 yr 50 yr - 75 - yr 100 yr * ** yr - - -- - - - -- - - - - -- - - - - -- - - - - -- - - - - -- - - - - -- - - - - -- 5.00 37 0.184 5.432 0.0879 0.1681 0.8413 0.9999 1.0000 1.0000 0.9900 5.50 17 0.085 11.824 0.0414 0.0811 0.5708 0.9854 0.9982 0.9998 0.8793 11 0.055 8 8 6.50 3 0.015 67.000 0.0074 0.0148 0.1386 0.5259 0.6735 0.7752 0.3114 --------------------------------------------------------------------------- GUTENBERG & RICHTER RECURRENCE RELATIONSHIP: a- value= 1.874 b- value= 0.527 beta - value= 1.213 ' 0 50 100 ' SCALE (Miles) SAN FRANCISCO 4d� � L ANGELES o � SITE LOCATION ( +): Latitude — 33.0622 N Longitude — 117.2183 W Copper Creek Estates, Lots 4 and 6 FRISKSP FAULT M JOB No.: 0007- 003 -09 1 1 Ln o r� ' � o 0 0 O N z ' Q O W 1 � o W U � � U � ' Q ° z 00 O � o Q LLJ ° J O w 1 W �� 1 z 0 O 1 w � o IH IH 0� w o � _ 0 U) > I Q O � m b f N m f N m b r N m Ip f N m �o f N w 10 ♦° Q O O O O O O LLJ = O O O O O �\ CD 0 O O O O y O O O O O L o') O O .. N Q� O i v 1 1 F � V) O LL- ' O �? � 0 z 0 N O o Q = Z O W W 0 U U) U Q o z 0 � �O 0 Q W U o W z J Q �u O U W Q W ,n U 0 W d 0 1 ' O CD 0 � N 0 L i 0 0 O T ' L- 0 O U-) O O O O O O O O O O O 00 0 0 — 0 m 00 O Ln d- M N O x (�) ui :]3N`da ]I]3x] -�o , ui Ln ' CLN X W ��. Geotechnlc s ' Incorporated Principals: Anthony E Belfast \` Michael P. Imbriglio W. Lee Vanderhurst August 23, 2004 Wiegand Neglia Corporation �rcject No. 0007 - 003 -09 760 Garden View Court, Suite 200 Document No. 04 -0741R ' Encinitas, California 92024 - Attention: Mr. Bruce Wiegand SUBJECT: UPDATED SLOPE MITIGATION RECOMMENDATIONS (REVISED) Copper Creek Estates, Lots 4 and 6 Olivenhain, California Gentlemen: In accordance with your request, we are providing herein updated slope mitigation recommendations for Lots 4 and 6 of the Copper Creek Estates project in Olivenhain, California. Remedial grading recommendations for the site were initially provided in the referenced investigation report ( Geotechnics, 2000a). Three geotechnical constraints related to slope stability were identified. These conditions are reiterated below. Alternatives for mitigation of two of these conditions are presented in the remainder of this report. All other recommendations presented in the referenced report remain applicable to site development. To begin with, the site contains two existing landslides. In Section 7.4.3 of the referenced report, we recommended that the landslide debris and basal failure planes be completely removed and replaced with compacted fill. In Section 7.4.6 of the report, we recommended that an extensive system of subsurface drains be constructed to intercept existing seepage zones and further improve long -term slope stability. These recommendations remain applicable to site development. However, it should be noted that the actual location and extent of the subsurface drainage system should be determined in the field by Geotechnics Incorporated. 9245 Activity Rd., Ste. 103 • San Diego, California 92126 Phone (858) 536 -1000 • Fax (858) 536 -8311 Wiegand Neglia Corporation Project No. 0007 - 003 -09 August 23, 2004 Document No. 04 -0741 R I Page 2 I Secondly, the proposed 45 foot high fill slope beneath the building pad (referred to in the report as the "lower fill slope ") was deemed to have an insufficient safety factor against deep seated slope failure. In Section 7.4.4 of the referenced report, we recommended that selective grading ' be used to generate granular soil from on -site sources in order to buttress the lower fill slope. Although these recommendations remain generally valid, we have modified the proposed buttress configuration as described in the following sections of this report. Finally, the proposed 40 -foot high cut slope above the building pad (the "upper cut slope ") was deemed to have an insufficient safety factor against deep seated slope failure. In Section 7.4.5 of the referenced report, we recommended that lime stabilized clay be used to construct a buttress ' for the upper cut slope. Based on our conversations with you, it is our understanding that a lime stabilized buttress is not feasible for use at the subject site. In the following sections of this document, we provide a mechanical mitigation alternative for the upper cut slope. This alternative uses two grade beams that are anchored into the underlying sandstone. SLOPE STABILITY ANALYSES ' In order to characterize the behavior of the site soils, samples of the various materials observed on site were tested for shear strength in general accordance with ASTM D3080. Based on the shear test results, lower bound strength parameters were estimated for use in the slope stability analyses. The test results and shear strengths used for analysis were summarized in the referenced report ( Geotechnics, 2000a). The design values are given in Figure 1 of Appendix B. Subsequent to the initial investigation of the subject site, we conducted several additional shear strength tests on the Del Mar Formation in the site vicinity. The laboratory test results were presented in the referenced reports ( Geotechnics, 2000c, 2001). The amalgamated test results for the Del Mar Formation are shown in Figure 2. For the analyses presented herein, we used the supplementary testing to improve our estimate of the lower bound cohesion of the Del Mar Formation (the cohesion estimate was increased from 0 to 50 lb /ft Nine cross sections were analyzed using Slope /W software in order to develop the updated slope mitigation recommendations presented herein. The approximate cross section locations are shown on the Remedial Grading Plan, Plate 1. The cross sections are presented in the figures of Appendix B. Slope buttress and mechanical mitigation alternatives were developed in order to provide a minimum safety factor of 1.5 against deep seated slope failure for each section. The results of the stability analyses are also presented in Appendix B. Geotechnics Incorporated Wiegand Neglia Corporation Project No. 0007 -003 -09 August 23, 2004 Document No. 04 -0741R Page 3 Surficial slope stability was analyzed using an idealized infinite slope composed of a cohesive, frictional material, with steady state down slope seepage forces applied parallel to the slope surface (Abrahamson et al, 1996). The results are presented in Figures 3 to 5 of Appendix B. Our analyses indicate that all of the slopes proposed at the site are susceptible to surficial slope failure and erosion given substantial wetting of the slope face. - As recommended in Section 7.3 of the referenced report, surficial slope stability should be enhanced by providing proper drainage (Geotechnics, 2000a). The site should be graded so that i water is prevented from flowing over the slope tops. Diversion structures should be provided where necessary. Surface runoff should be confined to g_unite -lined swales or other appropriate devices to reduce the potential for erosion. It is recommended that slopes be planted with vegetation that will increase their surficial stability. Ice plant is not recommended. We recommend that vegetation include woody plants and ground cover. All plants should be adapted for growth in semi -arid climates with little or no irrigation. Irrigation should be limited to the minimum necessary to maintain landscaping vegetation. A landscape architect should be consulted in order to develop a planting palate suitable for slope stabilization. ' LOWER FILL SLOPE In Section 7.4.4 of the referenced report, we recommended that select granular soil be used to buttress the lower fill slope (Geotechnics, 2000a). The recommended buttress configuration is shown on the Remedial Grading Plan, Plate 1. The select granular soil may be mined from on- site sandstone sources. Laboratory testing should be conducted during grading to confirm that the select fill has a friction angle of at least 32 degrees and 50 lb /ft cohesion when compacted to at least 90 percent relative compaction based on ASTM D1557. After our stability analysis was presented in Section 7.4.4 of the referenced report, the lower fill slope was flattened, and a brow ditch was added, as required by the City of Encinitas. In general, the slope inclination was reduced from a maximum of 2:1 (horizontal to vertical) to an inclination which varies from about 2.9:1 to 3.4:1. At your direction, we previously conducted a brief review of the revised slope configuration to illustrate that the buttress recommended for the 2:1 fill slope would remain applicable for the revised slope configuration. The results of our analysis were presented in the referenced supplement (Geotechnics, 2000b). Geotechnics Incorporated Wiegand Neglia Corporation Project No. 0007 - 003 -09 August 23, 2004 Document No. 04 -0741 R Page 4 ' As part of this current study, additional cross sections were analyzed for the lower fill slope in order to determine if the volume of select fill needed for the buttress could be reduced as a result of the flattened slope gradient. Our updated analyses are presented in Cross Sections A -A' and ' C -C' of Appendix B. In Section 7.4.4 of the referenced investigation, we indicated that the select fill buttress could be terminated at an elevation of 229 feet (the -upper 15 feet of the proposed 2:1 fill slope could be composed of on -site fat clay without adversely impacting gross slope stability). Our updated analysis of the revised (flattened) fill slope configuration indicates that the select granular soil for the lower buttress may be terminated at an elevation 216 feet. In other words, the upper 28 feet of the fill slope may be constructed out of the on -site fat clay. UPPER CUT SLOPE The main focus of the analyses presented herein was to develop a mechanical stabilization alternative for the upper cut slope. Seven cross sections of the upper cut slope were analyzed using SLOPE /W both with and without slope anchors. The results of our analyses are presented in Appendix B. The cross section locations are shown on the Remedial Grading Plan, Plate 1. Our analyses indicate that the proposed cut slope has a safety factor of between 1.1 and 1.8 without any stabilization measures. The addition of various idealized uniform loads was used to increase the factor of safety of the entire proposed cut slope to at least 1.5. The magnitude, location and inclination of the loads were varied to develop an efficient configuration that would be relatively simple to implement in the field. The results of our analyses are presented in the figures of Appendix B. ' In summary, our analysis indicates that the upper cut slope may be stabilized using two grade beams, each applying a uniform load of 8 kips per foot to the underlying formational materials. The grade beams should be dimensioned so that the bearing pressure on the formation does not exceed 2,000 lb /ft The bottom of the grade beams should be located at elevations of 264 and 274 feet, and should be situated at least 4 feet (measured vertically) below the face of the finished slope. The lateral extent of the recommended grade beams is shown on the Remedial Grading Plan, Plate 1. Geotechnics Incorporated Wiegand Neglia Corporation Project No. 0007- 003-09 August 23, 2004 Document No. 04 -0741 R Page 5 Grouted anchors should be used to develop the proposed 8 kip per foot stabilizing load. The anchors should be inclined down from horizontal at a 30 degree angle, as shown in the figures of Appendix B. The anchors may be grouted through the claystone and into the underlying sandstone bed to develop the required resistance. For anchor design, the sandstone may be assumed to have a friction angle of 35 degrees with 100 lb /ft cohesion. -Our borings indicate that the sandstone bed exists between elevations of approximately 234 and 254 feet. We recommend that a structural engineer and specialty contractor be consulted to develop specific details for development and distribution of the stabilization load. This should include anchor spacing as well as allowable anchor capacity, and details for construction of the anchors, connections, and grade beam. All anchors should be load tested to at least 133 percent of their design load. At least 5 percent of the anchors should be creep tested at 150 percent of their design load. An anchor load testing program should be developed by the structural engineer and specialty contractor in general accordance with the current standards of care. Anchor design, details, and load testing specifications should be reviewed by Geotechnics prior to finalization. LIMITATIONS Our services were performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable soils engineers and geologists practicing in this or similar localities. No warranty, express or implied, is made as to the conclusions and professional i advice included in this report. We appreciate this opportunity to be of continued service. Please feel free to call the office if you should have any questions, comments, or need anything further. ED GE GEOTECHNICS INCORPORATED W 0: V �Np 1126 �pFESStp 0 CERTIf A EL E GEq.OGIST � w X2-31'0 C57218 � '° 0 Ex p. Matthew A. Fagan, PEE. 57248 s� CIVIL W. Lee Vanderhurst, C.E.G. 1125 Project Engineer ��OFCAL�F Principal Geologist Distribution: (2) Addressee, Mr. Bruce Wiegand (Messenger) Geotechnics Incorporated i i APPENDIX A REFERENCES Abrahamson, Lee, Sharma, and Boyce (1996). Slope Stability and Stabilization Methods, Ist ed., New York, John Wiley and Sons, 627 p. Testing and Materials 2000. Annual Book o American Society for g ( ) ASTMStandards, Section 4, .� Construction, Volume 04.08 Soil and Rock (1); Volume 04.09 Soil and Rock (II); Geosynthetics, ASTM, West Conshohocken, PA, 1624 p., 1228 p. Geotechnics Incorporated (2000a). Geotechnical Investigation for Grading, Copper Creek Estates, Lots 4 and 6, Encinitas, CA, Project 0007 - 003 -09, Document 0 -0059, May 19. Geotechnics Incorporated (2000b). Supplementary Slope Analysis, Copper Creek Estates, Lots 4 and 6, Encinitas, CA, Project No. 0007 - 003 -09, Document No. 0 -0719, July 13. ' Geotechnics Incorporated (2000c). Geotechnical Investigation, Dove Hollow Farm, Encinitas, CA, Project No. 0407 - 001 -00, Document No. 0 -0706, August 14. Incorporated 2001. Geotechnical Investigation, Geotechnics rp ( ) Double LL Ranch Development, g Olivenhain, California, Project No. 0007 - 010 -00, Document No. 1 -1332, December 14. Geotechnics Incorporated APPENDIX B i SLOPE STABILITY ANALYSIS The slope stability analyses performed for this project are presented in the following appendix. The shear strength parameters used for the gross stability analyses are summarized in Figures 1 and 2. In general, shear strengths were chosen to approximate the lower bound envelop for each ' geologic unit. The analyses are intended to approximate worst -case long term strength conditions. Surficial Stability Surficial stability was analyzed using an idealized infinite slope composed of a cohesive, frictional material. Steady state seepage forces were applied parallel to the slope surface using an idealized flow net. The analysis procedure is based on that presented in the referenced text (Abrahamson et al., 1996). The factor of safety against surficial failure is plotted versus the depth of the wetted zone in Figures 3 through 5. A factor of safety of 1.5 is typically deemed acceptable against surficial failure. A factor of safety of 1.0 would indicate failure given a particular depth of wetted zone. The analysis indicates that all of the slopes proposed at the site are susceptible to surficial slope failure given substantial wetting of the slope faces. Biological reinforcement and limited irrigation is recommended to improve surficial stability. Gross Stability The gross stability of the proposed slopes was analyzed using SLOPE /W software. Cross sections of the slopes are presented in Figures A -1 through I -1 (for Cross Sections A -A' through I -I', respectively). The approximate cross section locations are shown on the Remedial Grading Plan, Plate 1. Analyses were conducted using Spencer's method of slices to identify the critical failure surfaces. The analyses indicate that the proposed cut and fill slopes possess an adequate factor of safety against deep seated slope failure (F.S. >1.5) for the configurations shown on the Remedial Grading Plan, provided that the recommended remedial grading is conducted, and that the proposed buttresses, subdrains, and grade beams are constructed throughout the site in general accordance with our recommendations. For the worst -case fill and cut slope conditions (Cross Sections A -A' and B -B', respectively), a pseudo- static lateral load of 0.1g was applied to estimate the lower bound safety factors given seismic loading. The seismic safety factor generally exceeds 1.2, which is typically deemed acceptable for this manner of seismic analysis. Geotechnics Incorporated rn M ~ � O Z Oi q O 1� O (7 W W (1) O to tt O t O p LL = d - O Z > OV u N Z Z F-- U 7 O w U -j Cl) in co N O ch N O 0 R LL Q a J t U ' L c d C � a J cn U m J Co ° `� - Q Z �a cn O c O L c m o a ° a w � N w N N I N ) a V O p _p ' W .D C j. O O V N N f0 x x C O f6 ' E O t0 N N N L p O N Q W cn � U U N U D 1 p w w w w Z Z Z Z p p } CL LU o � o O Z fjr a Z (A � U U 0 � O a 0 0 0 0 U) U O LL Z Q Q Q Q W U w O O LL LL LL LL O O O m w O U' J w Z `J w U 5000 T � i � 4500 • Ultimate Values 0 Peak Values 4000 — Ultimate Strength Peak Strength 3500 1 U-3000 1 a. W2500 r r -T2000 Cf) 1500 1000 500 0 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 NORMAL STRESS [PSF] DELMAR FORMATIONIIEL PEAK ULTIMATE A summary of direct shear tests conducted for the Double LL Ranch, Dove Hollow Farm, 24 - 7 0 1 and Copper Creek Estates projects. L C. 50 PSF PSF G e o t e c h n i c s Project No. 0007-003-09 N I n c o r o r at e d DIRECT SHEAR TEST SUMMARY Document No. 04-0741 FIGURE 2 INPUT PARAMETERS - 2.9:1 FILL SLOPE Friction Angle (CD) 24 [DEGREES] Cohesion (CD) 50 [PSF] Dry Unit Weight 100 [PCF] Water Content 25 [ %] Slope Surface R Specific Gravity 2.75 Slope Angle X 2.90 � H CALCULATED PARAMETERS Void Ratio 0.72 Z(P) o, Moist Unit Weight 125 [PCF] F.S. = c + H( YSat y) cos tan Saturated Unit Weight 126 [PCF] YSatH sino cosp Friction Angle 0.42 [RADIANS] ' Slope Angle 0.33 [RADIANS] SURFICIAL STABILITY (After Abrahamson et. al, 1996) 6.00 H F F.S. 0.50 3.34 I 0.75 2.45 1.00 2.01 j 5.00 1.25 1.74 j 1.50 1.56 1.75 1.44 ' I 2.00 1.34 2.25 1.27 •,4.00 -- - - + -- U- 2.50 1.21 2.75 1.16 N 3.00 1.12 1i 3.00 -- i - - -- - -- � -- - - 3.25 1.08 a 3.50 1.06 3.75 1.03 U) 4.00 1.01 o 4.25 0.99 0 2.00 - - - --� - 4.50 0.97 4.75 0.96 5.00 0.94 j 5.25 0.93 1.00 - - -- -T - - 5.50 0.92 I 5.75 0.91 6.00 0.90 6.25 0.89 0.00 6.50 0. 88 0.00 1.00 2.00 3.00 4.00 5.00 6.00 Depth of Wetted Zone (H) [Feet] G e o t e c h n i c s Project No. 0007 - 003 -09 Inco rporated SURFICIAL SLOPE STABILITY Document No. 04 -0741 FIGURE 3 INPUT PARAMETERS - 3.4:1 FILL SLOPE Friction Angle (CD) 24 [DEGREES] Cohesion (CD) 50 [PSF] Dry Unit Weight 100 [PCF] ' Water Content 25 [ %] Slope Surface Q Specific Gravity 2.75 Slope Angle X 3.40 1 H CALCULATED PARAMETERS Void Ratio 0.72 c' + H(y sat yd co s 2 (0) tano' ' Moist Unit Weight 125 [PCF] F.S. = Saturated Unit Weight 126 [PCF] y� sing cosh Friction Angle 0.42 [RADIANS] Slope Angle 0.29 [RADIANS] SURFICIAL STABILITY ' (After Abrahamson et. al, 1996) 6.00 H F F.S. 1 0.50 3.88 0.75 2.85 1.00 2.34 5.00 - - 1.25 2.03 1.50 1.83 ! I I 1.75 1.68 j i 2.00 1.57 =4.00 - -- 2.25 1.49 M 2.50 1.42 2.75 1.36 N ! 3.00 1.32 E _ 1 3.25 1.28 Q 3.00 - 3.50 1.24 1 3.75 1.21 n w 4.00 1.19 ° i 4.25 1.16 � 2.00 4.50 1.14 LL 4.75 1.13 5.00 1.11 I 5.25 1.10 1.00 -- - -- 5.50 1.08 j 5.75 1.07 6.00 1.06 6.25 1.05 0.00 6.50 1.04 0.00 1.00 2.00 3.00 4.00 5.00 6.00 Depth of Wetted Zone (H) [Feet] G e o t e c h n i c s Project No. 0007 - 003 -09 _ Incorporated SURFICIAL SLOPE STABILITY Document No. 04 -0741 FIGURE 4 INPUT PARAMETERS - 2:1 CUT SLOPE ' Friction Angle (CD) 24 [DEGREES] Cohesion (CD) 100 [PSF] Dry Unit Weight 100 [PCF] 1 Water Content 25 [ %] Slope Surface Specific Gravity 2.75 Slope Angle X 2.00 1 Fi CALCULATED PARAMETERS Void Ratio 0.72 (� cos tangy' Moist Unit Weight 125 [PCF] F.S. = c' + H s,, yd Saturated Unit Weight 126 [PCF] H sink cosR Friction Angle 0.42 [RADIANS] Slope Angle 0.46 [RADIANS] SURFICIAL STABILITY (After Abrahamson et. al, 1996) 6.00 H F F.S. j 1 0.50 4.32 0.75 3.03 1.00 2.38 5.00 - - 1.25 1.99 1.50 1.73 i 1.75 1.55 2.00 1.41 �' I =4.00 -- - T - -- - - -- 2.25 1.30 U- 2.50 1.22 a 2.75 1.15 3.00 1.09 H 1 M3.00 -- - - - 3.25 1.04 rn j 3.50 1.00 I ' I 3.75 0.96 Cn 4.00 0.93 ° 4.25 0.90 t 2.00 LL i 4.50 0.87 4.75 0.85 5.00 0.83 5.25 0.81 1.00 -- 5.50 0.79 ' 5.75 0.78 6.00 0.76 6.25 0.75 0.00 1 6.50 0.74 0.00 1.00 2.00 3.00 4.00 5.00 6.00 Depth of Wetted Zone (H) [Feet] G e o t e c h n i c s Project No. 0007 - 003 -09 Incorporated SURFICIAL SLOPE STABILITY Document No. 04 -0741 FIGURE 5 0 CD co s, a' N O O N Q O O a N -p m O W a ' O CL ~ O O O O C) z t� 1 co p N LL Z E U 7 ' o . N U N Q O N N O O N � a o 0 co 1 to U IRT w U) I' Cl) C6 co ° v LL o N O O O U co CDO � � O 1 `o co O M N C) N ' O O O O O O O O Co O O O m cn N co co N N N cfl [IaaJ] uOIJenaJ�] C) C) C � M T N G ? N � O U) U ' Q 0 N "C fl O I W C O O O O v °o Z U' co N O Z c U O N L-0 a o N ' O O N 1_ O p N (� co W ° co " V) C6 p O N r O O � O O •� CD O 1 4 - O o N ' O O O O O O O O O O O O N O a0 (� M M M co N N N N �- [le9 j] uOIJeA91A O r C) N CI) C) C CD C:) N Q 0 1 C ) ' N o a LL Z C U =3 �_ U N a- (L O N N ' O N O 0 co � U ' O a? W co II to co C, o N r ' O O � as c O 1 co CD co O U O ' o U v U r ' o N O O O O O O O O O Cl O Cl M c M N N N N N ' [199j] U01lena13 0 O CO O N Q 0 0 N CL o W o a m p O = CD C) Z_ C7 N C LL Z U O _O O N op CL ' O N O O N � Q O .N Z Go L _O C) C'? W o r C (1) II I) o L 3 U O N r O J O � U 4 O 4� r--i O o N o N ' O O O O O O Cl O O O Co O M M M N N N N N - r' [}aaJ] u01}enal3 Y \' / N M I1 O m �� co CL Q LL '. ±✓ O O t CL �^- U Z °: .• LL N V O _ .^ N � N t S S - ids O r., O N co c � .1 i� O QO h- r ' ' COO vJ r '^ V0 N r f 1 O O N r � o (n N O +-j LL: Cd (30 O U O N IT O N O 0 co N Cl a C N O co M c'o ch M N N N N N ' [}aaj] u01jena13 ' O C) ' M N N O o� rn Lu N �° 0 O CL r O U O� O CD ♦� N _ q Z A` h i V/ ' O U C3 O sr d N -r w>x. N M 1 W O O O L ' W C) VJ VJ O U ' o O M r ' 0 7:$ C) cli O LL 4-A N cd CL O C) YO .� Q ' II Q C) a� N O O O O O O O O O O O Cl co C m M co N N N N N UOIJen913 C) C7 r 4 v, o ' M A W O C O Q co U C) k �w, t t%5 Y�. V (.0 Ski ";, rg � N Z LL r N yr U =3 o x € N U C P z. C C) ' U L N N a" C3 Cl N CD zs« a O U W cn � U) �a O ' uLO U cn n o �V o L U) LL a 7� 00 oo cti 11 _j LL C) �W N � U O .� a- 0 0 N O o II J U U ' o N i N ' O coo c N O a ( v N O co M M co M N N N N N [1;99j] UOIJeAG13 0 r v� C) Y O O C m N N o W ti O O O Z C7 v p a N N •, ,' �a .a k; CN N W .J Z .N co IR co co CD i C ' C6 U LL . 3 0 ' C) o Cl) LL o_ � ' Y � ° 00 CV O CC3 II J LL W N LL U O co Q 00 N O 1 o II O ' o N O O O O O O O O O O O O co m M cn M N N N N N [1;9@j] uoi}enaj�j 0 ' ° M O � r �U (L) o W co i N -� C ' O CL rl- ~ O O O U o Z (' o 6 C FL 1 N Z a C ) �+ C N U O O i N a o O 1 " N 1 ° N Y O p 1 ° � c� U LO W 1 ° co " cn cri 0 CD i 1 Co 1 ° C) c 1 ° _ o i � 0 1 ° i ° N 1 ° O O O O O O O O O O Cl M M M N N N N N r [199j] uOi}eA913 1 o 0 M MV-- N N O 't a O cn N ~ U U O uj ' N Q OO H ° o z C� ' N p C LL Z C r. C U :3 ' o N U N Q a ° N ' ° U O N U ° co Z O Cl M V W C0 Cl) C6 CO CD U ° r 0 cl O U O co � O N � ' o � v ' O N O O Cl O O O O Co O O O Cl Cl) M ccn N co N N N co r ' [Iaa j] u01leAG13 C) i �srs� Mr h Q C6 O Q I O �� ' C o Cl �t W P Q � O � 4 U O ' Z co 3 ,t" fv i. O ++ ' v LL Z . N ' N 00 a y v_ Q N� s U W Lo UL �a O Co u Cl Cfin U LL : L) a b t C) N 0 cd coo ' � U � O � U U O ' o N O O O O O O O Co O O O O M Cl) 0 Cl) M C) N N N N N [199j] uOi}ena13 Cl M Q CO v N N O It v , C6 0 O 4 W N CL li �. O D O Z C ' N IL 4 Z N •O N s{ � 4:,t N ' N D I..1 C> z O k zr: U W C LL Y+ Cl) U) CL p ' � u U Cj) A o U U I° (D 1 N C I.I . Q. Y � 00 N 'd w �-- cd o � LL U Cl) L.L •� ' 0o N U W O o N v C D ' o N ' O O O O O O O O O O O O Cco7 co cn M M N co N N N N co ' [199j] UO[JenaJ�j 1 0 cn CO ar v ag N O CD o tea° 4 Q O ' N y a� Oo W U o Z C7 N LL z =� U 7 t y N 0 CN CL CN ' O O N a ry e. O ' o Cl) LO (J) Cl) CL p ' u. LO �V o U a) N N I L Yti 00 N 'b ' 0 11I W +� r O O + • v� 0 OD LL O O L ' C) 00 N U u II _1 (1) � w O ' o � v rti o N ' O O O O O O O O O O O O cn co M M Cl) M N co N N N N [199j] u01lena13 i M z �s O O D O O CN CL r+ x Q ti O O O s U O O O Z /n M K Y N p LL {� O a N Mo CD a i c2 O . A /w ' , Y A / UL V'^I r CL O LO to A 0.4-, ° V Li V- N a) CD N Cl) LL Y � 00 N 7� ° o II J N w }, Cd O + O o LL N U LL 0o N U w O o N v ' o N O 0 ( O N O 0 ( N O 0 (h cn N N N N N ' [199j] uOljen91�] 1 O o w N CD ' r co O ' LLI O W CL s -fie U O Q D (O Q Q N CV s O O W N 1 v W O O N Cl) � CO a p Cl 11 Q � Cfjn U �U O Cd C) U C _ Cl � O a4 0 o a� 1 N O CD co ( O N O co C) N O co M Cl) N N N N N 0 t° M r s N o N p LL ~O W N N o 4 W / � r a';yti, Q rl� C, + O C) O O o oZ O � U . .0 �_ U v s ,ter a N N . ;. W O O r O W co d' Cl) O l Q. o U LL Cj)n a LL U OD O V N V'lll Y ' CN -i oo W L L LL o Q - N 00 (N w LL Q" � O p co � c 1� ' o N 1 O O O O O O O O O O O Cl co CO 'IT N O co to 'T N O O co Cl) Cl) co M N N N N N [199j] u01}enaIZI C) C) cl {� x / '.t o W O O co m O W CL O CL U O O O +r O Z O U. Z N N $ w K d O N :. O {. N a� W � 0 U co co cn ° O �a U) u c N � 0 Cj) 1 CL LL : C.) 00 04 0 O W LL N ':$ ° o Q N OD N Cl C) J O co W ts. .� O co U U � O °v N ' o N O O O O O O O O O O O O co CO 1 0 , N O Op O o0 m m co co M N N N N N [IGGJ] UOIJeAGJA ' o 0 N r F N O I.L. 0 O O i N O 4 W °o o D Co z LL coy .r at C r U =3 N .O L o N �Jr N �� sPb 2� 5s� o� CN N Ei- n U. CD O U c c n CL U) n U U U o ' o a� co c� o U O � O (O U �" 1 ' o N ' o G ( N O co c (DD R N O OD CO M A Cl) M N N N N N [199j] UOIIBAG13 C) M � ¢ M � N N �i � LL N CL O4 w 1� J U CO O D ' N LL Z U :3 C) N U o N° ti ^ x u N LL LL Z Co O W ' L ' U A r LL M (n Cl) a O ' n L U) n U V o N ° +) LL U) LL CL Y b 00 N 4-4 >) J CCi W O co O U O N � o N ' o N ' O C ( Q N O co O Cl Cl N O co O M M ('7 (h M N N N N N [}aaJ] U01jenal3 ' N C6 r LL C *j t� O N a N O 4 uj a a 1` C C) O D - s C) ►" O Z _V F t � co LL N "R � O L N ' O LL N � , z> O x O CD ui U M LL CO o. O I1 Cl Cj)n U Li O ' o o L U) LL CL Y 7d ° oo N 11 i Cd ?� w v� co U ' O � U � U � N � C) U ' o N O O O O O O O O O O O O M M m ( OM co N N N N co [199j] uoilenaIE] o � M r O LL co a� o W N � c) I.i. O o ... U oZ co LL Z o rP ' N N � 1 O any N LL U. O O LU U W)� Cl) (1) U) CL o O � U QL U •5 00 . N II J O �W 0 UL Q LL cd o co 00 N ' C) N ' o N ' O O O O O O O Cl O O O O co co Cl) Cl) Cl) 0 N N N N N co ' [199j] u0118A@13 I I O O co t N M r to Cti i� N �W U O 6 D C * O Z N L (7 1 ++ t 7 3 C) . N 6 O .. c O N I0 O N V O O O � W Co Lo U) V, C O a. u L vj A U I CD cd U-4 u o o U C) U V ' o N 1O O O O O O O O O O O O Co Co V N O Co to V N O 00 m M Co t'7 M N N N N N r [199j] uoijeA@jD 1 1 _ 3 � M r N r ' Goo = O N Q 9 W a C) O ° oZ 1 `° N Q LL a 1 C N U 7 N . � Q 1 " N a' Ky y' b �t ° x N T' i _ Z ° O CD U �� CO O Cj)V U LL: `/ 1 ° C) � cd 1 coo V . r. ' O c U U Cl ' N ° co c') m ° cn ( N co N N N N [199j] uOIJeA@13 ' o M �- N = o0 2 ' a� o v CL W Q n C) "O U O O D ° Cl Z Uf N +� o N U. Z S� w ' ° U CN � U O CN N y. O _ O N _ Z ' � O , W LO LL V/ C L cn L O �A U ti ° o .. ' S LL N � a c� ' co 00 04 U . 11 J ., W � O � .� v C� ' N O O O O O O O O O O 0 O C4 C� M Go M (cn m Cl) N N N N N [laaj] u01lena13 0 M n ti a CD W to a O P U O O Z C7 cD _ Z 6 U N N � wad N n O U C) LLI tn LL I-- (J) U) �' O ' n o LO vj A U C) ' o � a� cd ' s, C) Q co U 4i O CD N � ' o � v� �.J ' o N O O Co O O Cl O O O O O co co "It Cl O m M M m co N N N N co ' [1;9@j] UOi}eA913 Geotechnic s Incorporated Principals: Anthony F. Belfast Michael P. Imbriglio W. Lee Vanderhurst July 11, 2005 Bruce D. Wiegand, Inc. Project No. 0007 - 003 -12 760 Garden View Court, Suite 200 Document No. 05 -0753 Encinitas, California 92024 Attention: Mr. Bruce Wiegand SUBJECT: UPDATED CUT SLOPE RECOMMENDATIONS Copper Creek Estates, Lots 4 and 6 Olivenhain, California References: Geotechnics Incorporated (2004). Updated Slope Mitigation Recommendations (Revised), Copper Creek Estates, Lots 4 & 6, Olivenhain, California, Project No. 0007 - 003 -09, Document No. 04- 0741R, dated August 23. Geotechnics Incorporated (2000). Geotechnical Investigation for Grading, Copper Creek Estates, Lots 4 & 6, Encinitas, California, Project No. 0007 - 003 -09, Document No. 0 -0059, dated May 19. Pasco Engineering (2005). Remedial Grading and Slope Stabilization Plans for Lots 4 & 6 of Map 12644, Drawing No. 7095 -G, Sheets 4 through 6. Mr. Wiegand: This letter presents updated geotechnical recommendations for mechanical stabilization of the existing cut slope along the western side of Lots 4 and 6 of the Copper Creek Estates project in Olivenhain, California. The cut slope was investigated using two large diameter borings as described in the referenced report ( Geotechnics, 2000). These borings identified a highly weathered, intensely fractured greenish fat claystone within the proposed cut slope. Laboratory testing indicated that the strength of the claystone was relatively low, and that mitigation measures would be needed to improve cut slope stability. In the referenced update report, we provided recommendations for stabilizing the cut slope using grouted tie -back anchors and grade beams ( Geotechnics, 2004). The following recommendations supercede those provided in the referenced update, and are based on the actual cut slope conditions observed by our field personnel during grading. 9245 Activity Rd., Ste. 103 - San Diego, California 92126 Phone (858) 536 -1000 - Fax (858) 536 -8311 Bruce D. Wiegand, Inc. Project No. 0007 - 003 -12 July 11, 2005 Document No. 05 -0753 Page 2 A review of the boring logs presented in the referenced report indicates that the claystone within the proposed cut slope varied in thickness and consistency, and graded into a siltstone and then sandstone at depth (Geotechnics, 2000). For design purposes, we conservatively modeled the bed as massive and continuous between elevation 254 and 280 feet. The claystone bed is now clearly exposed in the cut slope, as shown in Figure 1. Field staking indicates that the contact between the fat claystone and the underlying siltstone is located at an elevation of between 267 and 268 feet. Our field observations suggested that the siltstone between 254 and 267 feet in elevation may be substantially stronger than initially assumed in our slope model. Consequently, we sampled the siltstone at an elevation of about 264 feet. The sample was returned to our laboratory, and remolded to approximate the in -situ moisture and density from the initial investigation. The remolded sample was soaked in water for several days, and then tested for direct shear in general accordance with ASTM D3080. The test results are presented in Figure 2, and suggest that the siltstone has an ultimate shear strength of 28 degrees with 300 lb /ft cohesion. This is substantially stronger than the strength initially assumed for this portion of the cut slope (24 degrees with 50 lb /ft cohesion). As a result of our testing and observation, we have revised our slope model to reflect the actual geologic conditions exposed in the cut slope, using a strength of 28 degrees with 100 lb/ft cohesion for the siltstone. The shear strengths of the other material exposed in the cut slope remain the same as those previously summarized in Figure 1 of the referenced update report (Geotechnics, 2004). Those shear strengths are reiterated in the attached Figure 3 for clarity. The stability of the revised cut slope model was analyzed using the program SLOPE /W, and the same assumptions described previously (Geotechnics, 2004). Cross sections of the cut slope above Lots 6 and 4 are shown in Figures 4 and 5, respectively. The first set of analyses (Figures 4.1 and 5.1) indicate that the cut slope still does not possess an adequate safety factor, and still requires mechanical stabilization. The second set of analyses (Figures 4.2 and 5.2) show that the upper grade beam and tie -back anchors are sufficient to raise the factor of safety of the cut slope to approximately 1.5. Our analyses further indicate that the lower grade beam and tie -back anchors are unnecessary, and do not contribute to improving slope stability. Based on our testing, observation, and analysis, we recommend that the grade beam and associated anchors at elevation 264 feet be eliminated. The upper grade beam and anchors (at elevation 274 feet) are still needed, and should be constructed in general accordance with the elevations, locations, details, and specifications shown on the referenced grading plans (Pasco Engineering, 2005). Geotechnics Incorporated Bruce D. Wiegand, Inc. Project No. 0007 - 003 -12 July 11, 2005 Document No. 05 -0753 Page 3 LIMITATIONS This report was prepared using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable soils engineers and geologists practicing in this or similar localities. No warranty, express or implied, is made as to the conclusions and opinions included in this report. We appreciate this opportunity to be of continued professional service. Please feel free to call the office if you have any questions or comments, or need anything further. GEOTECHNICS INCORPORATED oQ �DFESSro, r A Matthew A. Fagan, P.E. 57248 Exply ON civl\ Project Engineer q�OF CAL�Fp ED GFp� rv� KENNETH cf� tr SHAW No. 1251 k CERTIFIED �Ir ENGINEERING GEOLOGIST Kenneth W. Shaw, C.E.G. 1251 OF CA�� Anthony F. Belfast, P.E. 40333 Senior Geologist Principal Engineer Distribution: (4) Addressee, Mr. Bruce Wiegand (FAX: 760 - 635 -9074) (2) Geopacifica, Mr. Jim Knowlton (FAX: 760 - 721 -5539) Geotechnics Incorporated it N M T— o MO I _ O � { P p V i p C sr; N V O uj a co N 0 � CD W N s a co Z J uj r a A � Z 0 o. ,i U L 2 , U) Z W W LL cl O �' o F- U z U U O � Q 3000 - - - - -- - -- —� ^ - -- -- ■� f/ - -- -- , - - - - -- - LL a 2500 ■ ■17■■ ■e - -- - N 2000 L --■ � �� ■ -- -- ii t�tttf■ ■ ffffH� � s I I I LU 1500 -- - ■ • ® ® � 0® ® ■f■® ® ■M�W® ■aw®g W 1000 ■ -- ® - i,WTrrN - W WWR i iii; - -' <- - ■ y ■ ■ - . - -- -- - -i — - .i- - -- - - ■ ■ ■ ■ - -- Q ■' ■ ■■■■ ■ ■ ■ ■, ! w 500 --■ ® a � x cn ■ - 0 i j 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 STRAIN [ %] 4500 - - -- - - i I ® Peak Strength Test Results 4000 - 28 Degrees, 450 PSF Cohesion • Ultimate Strength Test Results 3500 - -- 2 Degrees, 300 PSF Co 3000 - -- - - T - - - -- - - - a. CO 2500 - - - - - - -- w Cn j H i 2000 2 - cn 1500 - / - - -- .- 1000 - - - - -- - 500 j - . ------ - - - -- - 0 500 1000 1500 2000 2500 3000 3500 4000 4500 NORMAL STRESS [PSF] SAMPLE: Elevation 264 Feet PEAK ULTIMATE DELMAR FORMATION �� 28 ° 28 Light gray brown sandy siltstone (ML). C. 450 PSF 300 PSF IN -SITU AS- TESTED STRAIN RATE: 10.0002 IN /MIN Yd 112.0 PCF 112.0 PCF (Sample was consolidated and drained) w 16.9 % 19.3 % =G e o t e c h n i c s Project No. 0007 - 003 -12 Incorporated DIRECT SHEAR TEST RESULTS Document No. 05 -0753 FIGURE 2 low 40 a w C-4 n / W z 9 G D m a 0 0 0 �° § \ / < r Cl o 2 / > © 6 £ 0 z E § 0 ® w 0 2 § § ) \ r q 04 •� 0 U- < I I g / ƒ o a) U- U 0 \ 0 0 \ 3 / ® / S w w } 2 a LLI ^ � « / w .0 S - to 2 Q) o LLI @ § 7 f 2 2 / t @ # \ z « 2 k § 7 3 7 7 (D � \ f § 2 U) co \ U k E « W 2 U) k � k k Z k q o / o 0 » \ \ \ Z g @ m Q m $ m m 1-4 Q 0 w tl t t t 2 0 / 0 0 } / 2 P¥ p R ¥ U < < < < Q \ \ -i E ? 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Wiegand, Inc INEERING SERVICES P m ject No. 0007 - 003 -12 ' 760 Garden View Court, Suite 200 ' ITIJ QAAN cument No. 05 -0741 Encinitas, California 92024 Attention: Mr. Bruce an Wie d ENGINEERING SERVICES Wiegand CITY OF ENCINMAS ' SUBJECT: AS- GRADED GEOTECHNICAL REPORT Copper Creek Estates, Lots 4 and 6 Olivenhain, California ' Gentlemen: ' This report summarizes the results of the testing and observation services performed by Geotechnics Incorporated during grading operations for Lots 4 and 6 of the Copper Creek Estates ' project in Olivenhain, California. The general contractor for this project was Bruce D. Wiegand, Incorporated. The site was graded by The Pahla Corporation. The tie -back anchor system was ' constructed by the J. C. Baldwin Construction Company. Our geotechnical services for this project were provided between June 1 and August 26, 2005. 1.0 PURPOSE AND SCOPE OF SERVICES This report and the associated geotechnical services were performed in general accordance with ' your Work Authorization dated May 31, 2005. Our field personnel were provided for this phase of the project in order to test and observe remedial earthwork, fill placement and compaction, and the implementation of mechanical slope stabilization measures. These observations and tests assisted us in developing professional opinions regarding whether or not the geotechnical aspects ' of earthwork construction were conducted in general accordance with our geotechnical recommendations. Our services did not include supervision or direction of the actual work of the contractor, his employees, or agents. Our services did include the following. 9245 Activity Road, Ste. 103 • San Diego, California • 92126 Phone (858) 536 -1000 • Fax (858) 536 -8311 ' Wiegand Neglia Corporation Project No. 0007 - 003 -12 August 31, 2005 Document No. 05 -0741 Page 2 ' • As- needed consultation during the construction of the improvements. Pertinent letters and reports are referenced in Appendix A. • Observation of the preparation of the existing ground, remedial excavation of landslide debris, the construction of subdrains and slope buttresses, and the implementation of mechanical slope stabilization measures. The as- graded conditions are shown on the As- Graded Geotechnical Map, Plate 1. ' • Performing laboratory and field tests on fill materials to support our geotechnical conclusions and recommendations. The laboratory test results are summarized in Appendix B. The field density test results are presented in Appendix C. Supplemental ' slope stability analyses which reflect the as- graded conditions are shown in Appendix D. • Preparation of daily field reports summarizing the day's activity with regard to earthwork, and documenting hours spent in the field by our technicians. ' 0 Preparation of this report which summarizes site preparation, remedial earthwork, drainage and slope mitigation measures, field and laboratory test results, fill placement, and the compaction operations. 2.0 SITE DESCRIPTION ' The subject �e t site consists of Lots 4 and 6 of the Copper Creek Estates residential development in ' Olivenhain, California. These lots are situated at the western edge of the development, as shown on the As- Graded Geotechnical Map, Plate 1. The site conditions were described in greater ' detail. in the referenced investigation (Geotechnics, 2000a). ' 3.0 GEOLOGY ' The subject site is located within the coastal plain section of the Peninsular Range Geomorphic Province of California. The building pad areas are now underlain primarily by a variable depth of compacted fill derived from the Delmar Formation and associated colluvial soils. Granular materials of the Delmar Formation are exposed in the lower portions of the western cut slope. The surficial soils throughout the site generally consist of sandy clay (CL to CH) with a medium to high expansion potential, and severe sulfate content. i Geotechnics Incorporated ' Wiegand Neglia Corporation Project No. 0007 - 003 -12 August 31, 2005 Document No. 05 -0741 Page 3 ' 4.0 GRADING AND IMPROVEMENT OPERATIONS Grading operations at the site began with the removal of deleterious vegetation and debris from areas to receive fill. Remedial grading was then conducted in order to reduce the potential for ' differential settlement and slope instability. Remedial grading included the excavation and compaction of the existing compressible colluvium and landslide debris throughout the site, and ' the over - excavation of the formational portions of the building pad areas. A series of slope buttresses and subsurface drains were then constructed to improve slope stability and drainage. After the remedial earthwork and slope buttressing was completed, cut and fill grading was used to attain design grades. Finally, grouted anchors were constructed to tie -back a buried grade beam along the western cut slope in order to complete the slope stabilization system. Additional details regarding each of these activities are presented below. 1 4.1 Remedial Excavations Remedial grading was conducted in order to excavate and compact potentially compressible colluvium and landslide debris throughout the site. Within the building pad areas, formational materials were also over - excavated to mitigate the cut /fill transitions ' created by excavation of these compressible materials. The excavation bottoms were observed by our geologist prior to placing compacted fill. In addition, the grading ' contractor surveyed the excavation bottoms. Selected remedial excavation bottom elevations are shown on the As- Graded Geotechnical Map, Plate 1. Note that the existing ' thickness of compacted fill may be estimated by subtracting these remedial excavation bottom elevations from the finish grades throughout the site. Our observations indicate that the proposed building pad areas for both Lots 4 and 6 are now underlain by a relatively uniform depth of compacted fill over formational materials. ' We estimate that the building pad areas are generally underlain by between approximately 25 and 30 feet of compacted fill. We anticipate that the proposed ' structures will experience relatively minor differential settlements. Foundation design will be controlled by the potential for expansive soil heave. i Geotechnics Incorporated Wiegand Neglia Corporation Project No. 0007 - 003 -12 August 31, 2005 Document No. 05 -0741 Page 4 ' 4.2 Subdrains t Subsurface drains were constructed throughout the site in general accordance with the recommendations presented in Section 7.4.6 of the referenced report in order to improve slope stability, and reduce the potential for future moisture related problems in the building and improvement areas ( Geotechnics, 2000a). The approximate locations of the ' drainage pipes associated with each subdrain are shown on the As- Graded Geotechnical Map, Plate 1. Each of these subdrains is described in greater detail below. An interceptor subdrain was constructed beneath the brow ditch at the top of the cut slope along the western edge of the site. This subdrain was constructed using TREMDrain t Total -Drain , an integrated composite panel drain with a drainage collector panel at the base. The bottom of this subdrain has a high point of approximately 280 feet near the property line between Lots 4 and 6. The subdrain drains at approximately a 1 percent gradient (or steeper) to gravity outlets on the north side of Lot 4 and the south side of Lot 6. The approximate location of the drainage panel is shown on Plate 1. ' Buttress backdrains were constructed along the toe of the temporary backcuts used to complete the remedial excavations. The temporary backcuts varied from 1:1 to 1' /2:1 (horizontal to vertical) in inclination, and extended down below the toe of the planned cut ' slope to an elevation of between 215 and 220 feet. The buttress backdrains consisted of 6 -inch diameter perforated PVC pipes surrounded by approximately 1 cubic foot per ' lineal foot of minus ' / 4 -inch crushed rock wrapped in filter fabric. The subdrains were connected to continuous composite drainage panels which extended from the remedial ' excavation bottoms up to an elevation of approximately 236 feet. Along the northern portions of Lot 6, the composite panel drains were extended up to near pad elevations. The buttress backdrains on Lots 4 and 6 drain south and north (respectively) at approximately a 1 percent gradient to a common collector subdrain. The PVC pipes in the buttress backdrains are connected in a "T" joint with the 6 -inch perforated PVC pipe in the collector subdrain near the property line between Lots 4 and 6. The collector 1 subdrain is surrounded by approximately 6 cubic foot per lineal foot of minus '/4 -inch crushed rock and wrapped in filter fabric. The collector subdrain transitions to a solid 6- inch diameter PVC along the eastern edge of the pad area, and outlets to Wiegand Street. Geotechnics Incorporated Wiegand Neglia Corporation Project No. 0007 - 003 -12 August 31, 2005 Document No. 05 -0741 Page 5 ' Two additional subdrains were constructed which were not anticipated in the referenced report (Geotechnics, 2000a). These subdrains were constructed at the toe of the temporary buttress backcut for the fill slope along the eastern edge of Lot 6, and along the toe of the off -site buttress backcut north of Lot 4. These subdrains consisted of 6- inch diameter perforated PVC pipes surrounded by approximately 1 cubic foot per lineal foot of minus 3 /4 -inch crushed rock, wrapped in filter fabric. These subdrains were ' connected to one 4 -foot wide row of composite panel drain. The approximate locations of these subdrain pipes are also shown on the As- Graded Geotechnical Map, Plate 1. 4.3 Fill Slopes ' Fill slopes up to about 45 feet high were constructed at a gradient of approximately 3:1 (horizontal to vertical) or flatter. The specified relative compaction was achieved by overbuilding the slopes and cutting back to plan grade, as well as track rolling the finish surface of the slope faces. Keyways and benches for the fills slopes were mapped by our project geologist to evaluate potentially adverse geologic conditions which could affect the stability of the slopes. ' Select fill was placed within the lower portions of the fill slopes (from the keyways up to an elevation of approximately 216 feet) in order to improve slope stability. The buttress keyway bottoms were sloped to direct groundwater seepage back into the slope and toward the buttress backdrains which were described in Section 4.2. The select fill was generated by on -site excavations in the silty sandstone of the Delmar Formation (see Figure B -5.1 in Appendix B). Remedial excavations at the toe of the fill slope along the eastern edge of Lot 6 revealed massive, dense sandy siltstone of the Delmar Formation. This material was tested in our laboratory, and found to have sufficient in -situ shear strength for use in lieu of the select buttress fill initially proposed in that area (see Figure B -5.2 in Appendix B). ' Consequently, the fill slope buttress for Lot 6 was redesigned. Instead of the select fill buttress proposed in the referenced investigation, the revised buttress consisted of a ' uniform, 15 -foot wide select fill buttress which extended from the existing road grades up to an elevation of approximately 216 feet (Geotechnics, 2000a). The as -built fill slope ' buttress configurations are shown on the As- Graded Geotechnical Map, Plate 1. Geotechnics Incorporated ' Wiegand Neglia Corporation Project No. 0007 - 003 -12 August 31, 2005 Document No. 05 -0741 Page 6 4.4 Cut Slopes ' Cut slopes were graded at a slope ratio of approximately 2:1 (horizontal to vertical) or flatter up to a maximum height of approximately 40 feet. The cut slopes were mapped during grading by our geologist to locate potentially adverse geologic conditions, such as the fat claystone bed described in the referenced report (Geotechnics, 2000a). For design purposes, we had conservatively modeled the fat claystone bed as massive and continuous between elevations of 254 and 280 feet. However, once the claystone bed was exposed in the cut slope, the fat claystone was found to be underlain by a relatively strong siltstone bed below an elevation of 267 feet (see Figure B -5.3). The as- graded cut slope configuration was reanalyzed using SLOPE /W, as described in the referenced report (Geotechnics, 2005e). Our analysis indicated that the lower row of grade beam and tie -back anchors was unnecessary, and did not contribute to improving the cut slope stability. Consequently, we recommended it be removed. However, the upper grade beam and anchors (at elevation 274 feet) were still needed to improve cut slope stability, and were constructed as described in Section 6.3. 4.5 Off -Site Grading Remedial grading operations began with construction of the lower fill slope buttresses along Lots 4 and 6 (see Section 4.3). The existing landslide debris was first excavated ' along the eastern edge of the site in order to generate room for the select fill buttress proposed for the lower fill slope. The excavated soils were stockpiled along the 1 northwestern edge of the site. This grading activity (unloading the toe and loading the top of the existing landslide) resulted in a construction slope failure on Lot 4. The construction slope failure extended north and east of Lot 4 onto three adjacent properties. 1 As a result of the failure, we recommended that remedial excavations on Lot 4 be ' increased to remove the additional slide debris, and that a 30 -foot wide buttress and backdrain be constructed off -site to stabilize the failed area. The as -built configuration of the off -site buttress and backdrain is shown on the As- Graded Geotechnical Map, Plate 1. Details regarding the configuration and extent of the off -site failure and associated buttress and backdrain may be found in the referenced report (Geotechnics, 2005c). Geotechnics Incorporated Wiegand Neglia Corporation Project No. 0007 - 003 -12 August 31, 2005 Document No. 05 -0741 Page 7 4.6 Fill Soils ' The materials used as fill are described in Figure B -1. The maximum densities and optimum moisture contents of the soils were determined using ASTM method D1557 -00. 1 Where applicable, the maximum densities and optimum moisture contents were corrected for oversize fractions using ASTM method D4718 -87. The on -site fill soils ranged from ' fine to medium grained silty or clayey sand (SM or SC) to sandy clay (CL and CH). 4.7 Fill Placement Grading of the site was performed using typical grading techniques with heavy earthmoving equipment. In -place moisture and density tests were made in general accordance with ASTM D2922 -04 and D3017 -04 (Nuclear Gauge Methods). The results ' of these tests are presented in Appendix C. The approximate test locations are shown on the As- Graded Geotechnical Map. The test locations and elevations are based on field stakes and estimates from the grading plans, and should be considered rough estimates. The estimated locations and elevations should not be used for preparing cross sections, or in any case, for the purpose of after - the -fact evaluating of the sequence of fill placement. ' 5.0 LABORATORY TEST RESULTS ' A variety of laboratory tests were conducted on selected samples of the site soils. Testing was intended to aid in developing the geotechnical design parameters presented in this report, and to ' help refine the slope stability analyses. Laboratory testing included gradation, hydrometer, Atterberg Limits, expansion index, soluble sulfate content, and direct shear. The laboratory test results are described below, and are presented in detail in Appendix B. 5.1 Classification The particle size distributions of selected soil samples were determined in general accordance with ASTM D422 -63. Atterberg Limits were estimated using ASTM D4318- 00. The test results are shown in Figures B -2.1 and B -2.2. The classification tests aided in the development of the post- tension foundation design parameters presented herein. Geotechnics Incorporated Wiegand Neglia Corporation Project No. 0007 - 003 -12 August 31, 2005 Document No. 05 -0741 Page 8 ' 5.2 Expansion Index ' Expansion index tests were conducted on selected samples in general accordance with ASTM D4829 -95. The test results are presented in Figure B -3. The tests indicate the site 1 is underlain by soils with a medium expansion potential. The potential for soil expansion is incorporated into the recommendations provided in the following sections of this report. For design purposes, a high expansion potential has been incorporated into the foundation and slab recommendations provided in the following sections of this report. r 5.3 Soluble Sulfate Select samples were tested for water soluble sulfate content in general accordance with ASTM D516 -02. The test results are reported in Figure B -4 in terms of the percentage by weight of the water soluble sulfate in the soil. The tests indicate that the site soils present a severe sulfate exposure based on UBC criteria. According to Table 19 -A -4 of the 1997 ' UBC, all concrete which will come in contact with the pore fluid generated from the site soils (including foundations and slabs) should be designed to reduce the potential for long term sulfate degradation. Table 19 -A -4 of the UBC indicates that Type V cement should t be used along with a maximum water to cement ratio of 0.45, and a minimum 28 -day compressive strength of 4,500 psi. 5.4 Direct Shear In order to characterize the behavior of the site soils, selected samples of the various ' materials observed during grading were sampled, and transported to the laboratory for direct shear testing. The samples were remolded to approximate the as- graded densities, and then tested for shear strength in general accordance with ASTM D3080 -98. The ' results of the laboratory tests are presented in Figures B -5.1 through B -5.5. I Based on the shear test results (as well as direct shear testing conducted for the referenced investigation) lower bound shear strength parameters were estimated for use in the various slope stability analyses (Geotechnics, 2000a). A summary of the strength parameters used in the slope stability analyses is presented in Figure D -1. Geotechnics Incorporated ' Wiegand Neglia Corporation Project No. 0007 - 003 -12 August 31, 2005 Document No. 05 -0741 Page 9 6.0 CONCLUSIONS Based on our observations and testing, it is our professional opinion that grading operations at the site were performed in general accordance with the intent of the project geotechnical 1 recommendations, and with the geotechnical requirements of the City of Encinitas. Our conclusions are based on observations and testing performed between June 1 and August 25, ' 2005. No representations are made to the quality and extent of materials not observed. 6.1 Compaction Based on our testing and observations, it is our opinion that structural fill was placed in substantial accordance with the minimum compaction criteria of 90 percent of the maximum dry density based on ASTM D1557 guidelines. ' 6.2 Slope Stability The stability of the cut and fill slopes constructed throughout the site was re- analyzed during grading to reflect the as- graded geologic conditions, as described in Sections 4.3, ' 4.4 and 4.5. Our analyses are summarized in Appendix D. It is our opinion that the graded slopes throughout the site are stable with regard to deep seated failure with a ' factor of safety of 1.5 or more, which is generally accepted for long -term slope stability. Note that our slope stability analyses were based on our best estimate of the prevailing geologic and groundwater conditions and soil strength. Site conditions can be complex and variable due to changes in stratigraphy, geologic structure, and groundwater. It is possible that conditions may differ from those anticipated in our analyses. Any future changes to constructed slope heights, ratios, retaining walls, or addition of surcharge ' should be evaluated by Geotechnics Incorporated. Man -made and natural slopes will weather over time as a result of wetting and drying, biologic forces and gravity. As a result, the outer 5 feet of the slope faces may undergo 1 minor down -slope creep over the years. While it is not possible to completely eliminate this effect, it can be reduced by establishing deep- rooted vegetation on the slope, maintaining the drainage patterns established during construction, and by rodent control. Geotechnics Incorporated ' Wiegand Neglia Corporation Project No. 0007 - 003 -12 August 31, 2005 Document No. 05 -0741 Pag 1 ' 6.3 Mechanical Stabilization System In our initial geotechnical investigation for the project, we noted that the proposed cut slope along the western edge of the site was marginally stable, and would require buttressing (Geotechnics, 2000a). However, suitable buttress fill material was unavailable, and lime stabilization of the on -site clays was deemed impractical by the ' property owner. Consequently, mechanical measures were developed for stabilizing the claystone bedding near the top of the cut slope, as described in the referenced report (Geotechnics, 2004c). When the cut slope was excavated during grading, the geologic r conditions were substantially better than anticipated. Consequently, the lower row of tie- back anchors was removed, as described in the referenced update (Geotechnics, 2005e). Geotechnics Incorporated provided observation services during construction of the upper ' grade beam and tie -back system (at elevation 274 feet). The mechanical stabilization system was constructed by J.C. Baldwin Construction Company between July 27 and ' August 24, 2005. Our observations indicate that the tie -back anchors were installed at the plan locations with the recommended dimensions and embedment. A summary of the anchor configurations and construction sequence is presented in Table 1. The approximate anchor locations are shown on the As- Graded Geotechnical Map, Plate 1. Geotechnics Incorporated also observed grouting, tensioning, and testing of the tie -back anchors (these tests were performed by J.C. Baldwin Construction), as well as construction, backfill and compaction of the grade beam. All 27 anchors were tested to at least 1' /2 times the design load of 80 kips. The average, upper, and lower bound of the load versus deflection measurements are shown in Figure 1. The maximum load on all 27 anchors was held for 10 minutes in order to estimate creep. The maximum recorded creep was 0.002 inches (well below the specified allowable creep of 0.040 inches). In general, our observations indicate that the mechanical stabilization system was constructed in general accordance with the elevations, locations, details, and specifications shown on the referenced grading plans (Pasco Engineering, 2005). The grade beam dimensions and reinforcement met project specifications. The results of our 28 -day compressive strength tests on the tie -back anchor grout and grade beam shotcrete will be presented in an addendum report once the testing is completed. 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Z=l ::D Z:) Z Z:� .7 m W LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL U_ LL LL LL ) J Q o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CO M M M M M M M M M M M M M co M co M M M M M m co M M M i N N N N N N N N N N N N N N N N N N N N N N N N N N N Q a) a) a) (D a) a) a) a) a) a) a) a) a) a) a) a) a) a) Q) (D a) a) (V a) a) a) a) w Z L L L L L L L L L L L t L L L L L L L L L L L L L L L C U U U U U U U U U U U U U U U U U U U U U U U U U U U G O c c c c c c _c c c c c c c c c c c c c c c c c c c c c = w Q (0 co (D (0 (0 0 co (D (0 (D (D c0 (D (D 0 0 CD c0 (0 (D c0 (0 CD 0 (D (D O N w W � N L L L L L L t L L L L L L L L L L L L L L L L L L L L m Q 0 C C C C C C C C C _C C c _C C _C C C C C C C _C C C C C _C ' v O O (0 O 0 W (D (0 (D (D 0 0 (D 0 (0 (0 0 0 0 0 0 (D W (0 0 0 0 Z Q Q LO l[') LO lf) L1") LO LO LO LO Ln LO LO LO Ln Ln LO LO LO LO LO Lr) LO LO Ln LO Ln LO W W O O O O O O O O O O O O O O O O O O O O O O O O O O O U Q m m m m m m m m 00 00 M 00 V' V V IY V V' 00 00 00 ICT qq' V V V Q W r r �- r r �- r �- r N N N N N N — — — N N N N N N — — — 00 00 00 00 M 00 00 00 O 00 00 O DD 00 00 00 00 CO 00 00 00 uj Q w W LO LO Ln LO LO LO u') LO LO LO LO Lr) LO LO Lr) LO U') LO LO LO LO Lr) LO L() LO LO Ln F_ 0 0 0 0 0 0 0 0 0 0 ' Q Q 00 00 O O N M O O LO In to L[ ) qq N - r cD (D (0 (0 CD N O N N N N N N� w" - - - -- � � - -- •-- Q r- ti r- t- i r- cc) w w w 0 o 0 o ao 00 w w w co w 00 00 o 0 0o 00 i Q U') U 0 Ln LO LO LO Lr) LO LO LO LO LO LO LO LO Ln LO LO Ln L LO Ln LO Lr) C) LO W W O o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 J -- — O O O — — — — — — O O O O O ~ J 1` P.- 00 W 00 O M - N M O O L n U) LO 0 a j j -- -- (0 (0 (D (D 0 N Cd N Q N N N N N N— QO ao o 00 00 00 co 00 00 ao ao OO a0 a0 OD 00 00 OD co Q r - r` ti r` r r - r` ao ao ao co ao ao ao ao ao OD 00 00 I/) p U � a a a a a a a a - o a a a a a -a a a a a a a a a a a a O w C c C C C c c c c C C c c c C C C c C C C C C c C c c p i - - - - - - - - - - - - - - - �m m m m m m m m m m m Y Y Y ++ Y Y Y Y Y Y Y Y Y Y U U) fn (n In (n (n fn N (n (1) U) (n (n (n fn (� (n (n (n (n cn fn rn fn (n U1 (n U Q M M M M M M M M M M M M M M M M M M M M M M M M M M M Z J J J J J J J J J J J J J J _1 J J J J a d a a a a a a ~ ' a a a a a a a a a a a a a a a a a p 0 0 0 0 0 0 0 0 w w w w w = F= 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 � U V (n (n (n (n (n (n (n (n U) Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z CY �t �t ;T ;T : ;t : ;t � cD (D LO � cM N N N N (V N N N N N �-- O V Q 00 1` (D LO v' M N �- v C0 — N M qT LO O 1` 00 L0) O �- N M V Ln O 1` O = e N M Iq LO (0 r_ 00 O O— N CO v LO (D ti 00 M O— N M d LO 10 � U Z — — — — — — — — -- N N N N N N N N Q 5.0 4.5 4.0 3.5 3.0 z c 2.5 m 0 2.0 Average - - - - - Upper Bound 1.5 - - - - _Lower Bo ' 1.0 0.5 0.0 0 20 40 60 80 100 120 140 Load [K] TEST AVERAGE MINIMUM MAXIMUM LOAD DEFLECTION DEFLECTION DEFLECTION KIPS INCHES INCHES INCHES 0 0.000 0.000 0.000 27 0.563 0.255 0.796 52 1.419 1.071 1.677 80 2.290 1.901 2.607 ' 105 3.161 2.773 3.556 132 4.174 3.760 4.681 ' NOTE All 27 anchors were proof tested. The maximum 10 minute creep was 0.002 inches (the average creep was 0.000 inches). G e o t e c h n i c s Project No. 0007 - 003 -12 I n c o r p o r a t e d LOAD TEST RESULTS Document No. 05 -0741 FIGURE 1 Wiegand Neglia Corporation Project No. 0007 - 003 -12 August 31, 2005 Document No. 05 -0741 Page 11 ' 7.0 RECOMMENDATIONS The remainder of this report presents geotechnical parameters for design of future retaining walls and foundations at the site, as well as recommendations to help reduce the potential for future ' slope failures. These recommendations are based on empirical and analytical methods typical of the standards of practice in southern California. If these recommendations do not to cover a ' specific feature of the project, please contact our office for additions or revisions. ' 7.1 Retaining Walls It is our understanding that several retaining walls may be constructed at the site. Retaining walls are proposed at the toe of the cut slope along the western edge of the building pad areas. We have previously evaluated the cut slope stability with an assumed ' retaining wall at the toe with a maximum exposed height of 8 feet. The results of our analyses were presented in the referenced reports, and remain applicable to the as- graded ' conditions (Geotechnics, 2005ab). Our analyses indicate that an 8 foot high retaining wall may be constructed anywhere along the toe of the cut slope without adversely impacting slope stability. Retaining walls constructed along the toe of the cut slope ' should be designed by a structural engineer for an active pressure approximated by a fluid with a unit weight of 70 lb/ft'. In addition to the walls described above, we understand that a retaining wall is proposed ' along the top of the fill slope along the eastern edge of Lot 4. A San Diego Regional Standard Type C -3 retaining wall is proposed for use in that area. The wall will have a ' maximum retained height of 8 feet, with a maximum exposed height of 6 feet (the lower 2 feet of the wall and the 1 -foot thick footing will be buried by the 3:1 fill slope backfill). The proposed configuration will satisfy our minimum recommended slope setback for wall foundations on descending slopes (the wall will have a 9 -foot setback as measured from the bottom outside edge of the footing to the slope face). We have analyzed the impact of the proposed retaining wall on the stability of the ' existing 3:1 fill slope along the eastern edge of Lot 4 (see Figures D -7.1 and D -7.2 in Appendix D). Our analyses indicate that the proposed wall and slope system have an ' adequate safety factor against slope failure. ' Geotechnics Incorporated ' Wiegand Neglia Corporation Project No. 0007 - 003 -12 August 31, 2005 Document No. 05 -0741 Page 12 ' For general retaining wall design, an allowable bearing capacity of 2,500 lbs /ft a coefficient of friction of 0.30, and a passive pressure of 300 psf per foot of depth is ' recommended. Wall footings should be embedded at least 24 inches below lowest adjacent soil grade (and at least 3 feet for the Type C -3 wall proposed on Lot 4). All ' retaining walls should contain a backdrain to relieve hydrostatic pressures, as shown in Figure 6 of the referenced report (Geotechnics, 2000a). ' Backfilling retaining walls with expansive soil can increase lateral pressures well beyond normal active or at -rest pressures. We recommend that retaining walls be backfilled with ' granular soil or crushed rock having an expansion index of 30 or less (the sandy on -site soils may meet this criterion). The low expansion fill area should include the zone ' defined by a 1:1 sloping plane, back from the base of the wall. Retaining wall backfill should be compacted to at least 90 percent relative compaction, based on ASTM D1557. ' Backfill should not be placed until walls have achieved adequate structural strength. Heavy compaction equipment which could cause distress to walls should not be used. ' 7.2 Foundations ' The following design parameters were developed in general accordance with the procedures described by the Post - Tensioning Institute. Foundation design should be ' performed by the project structural engineer using the following geotechnical parameters. The following parameters are considered appropriate for the proposed buildings which will be underlain by compacted fill with a medium to high expansion potential. Edge Moisture Variation, e,,,: Center Lift: 5.8 feet ' Edge Lift: 2.7 feet Differential Swell, y Center Lift: 4.3 inches ' Edge Lift: 1.0 inch Differential Settlement: 3 /4 inch Allowable Bearing: 1,500 lb /ft (at slab subgrade) ' Minimum Footing Depth: 24 inches below lowest adjacent soil grade for any conventional foundations tied into the post- tension ' slab foundation system. ' Geotechnics Incorporated Wiegand Neglia Corporation Project No. 0007 - 003 -12 ' August 31, 2005 Document No. 05 -0741 Page 13 7.3 Pavements ' It is our understanding that the proposed driveways for Lots 4 and 6 will be paved with Portland cement concrete (PCC) using an integral curb and gutter. Concrete pavement i design was conducted in general accordance with the simplified 20 year design procedure of the Portland Cement Association. For design, it was assumed that aggregate interlock would be used for load transfer across control joints. The subgrade materials were assumed to provide "low" subgrade support based on our experience with similar soils in the site vicinity. The concrete was assumed to have a minimum flexural strength of 600 psi. Based on these assumptions, we recommend that the PCC pavement sections consist of 6'/2 inches of concrete reinforced with No. 4 bars on 18 -inch centers (each way) or 6x6 W6 /W6 welded wire fabric placed securely at mid - height of the pavement section. Immediately prior to constructing the pavement section, the upper 12 inches of pavement subgrade be scarified, brought to slightly above optimum moisture content, and compacted to at least 90 percent of the maximum dry density based on ASTM D1557. 7.4 Slopes Our analyses indicate that the site slopes are stable with regard to deep seated failure. ' However, heavy seepage and deep saturation of the slope faces may result in surficial slope failure and erosion. We recommend that the slopes be planted with vegetation that will increase their stability. Vegetation should include woody plants and ground cover. All plants should be adapted for growth in semi -arid climates with little irrigation. A landscape architect should be consulted to develop planting suitable for stabilization. i 7.5 Off -Site Improvements Geotechnics Incorporated has not evaluated the stability of the off -site slopes beyond the buttress area, and makes no representations to slope stability in that area ( Geotechnics, 2005c). A geotechnical engineer should provide recommendations for future grading, structures, or settlement sensitive improvements proposed within the off -site slope areas. Geotechnics Incorporated ' Wiegand Neglia Corporation Project No. 0007 - 003 -12 August 31, 2005 Document No. 05 -0741 Page 14 8.0 LIMITATIONS ' Our services were performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable soils engineers and geologists practicing in this or similar localities. No warranty, express or implied, is made as to the conclusions and professional advice included in this report. The samples used for testing, the observations made, and the in- 1 place field testing performed are believed to be representative of the project. However, soil and geologic conditions can vary significantly between tested or observed locations. ' The findings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether due to natural processes or the works i of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or broadening of knowledge. Accordingly, the ' findings of this report may be invalidated by changes outside our control. This report is subject to review and should not be relied upon after a period of three years. GEOTECHNICS INCORPORATED Q RpFESSlON�� C0 CD m cc C5724 * Exp Q IEC / N CIVIL Q �� P ' AL� FC O Matthew A. Fagan, P.E. 57248 Project Engineer G EQ G KENNET ¢ sHAW ' N 125 CERTIF � ENGiNEER1N'G GEOLOGIS 1 Kenneth W. Shaw, C.E.G. 1251 OF C�,L Anthony F. Belfast, P.E. 40333 Senior Geologist Principal Engineer Distribution: (8) Addressee, Mr. Bruce Wiegand (FAX: 760 - 635 -9074) ' Geotechnics Incorporated 1 APPENDIX A REFERENCES American Society for Testing and Materials (2000). Annual Book ofASTM Standards, Section 4, Construction, Volume 04.08 Soil and Rock (1); Volume 04.09 Soil and Rock (II); Geosynthetics, ASTM, West Conshohocken, PA, 1624 p., 1228 p. Geopacifica Geotechnical Consultants (2004a). Third Party Review, Copper Creek Estates, Lot 4 and 6 of Map No. 12644, Olivenhain Area, City of Encinitas, California, August 12. ' Geopacifica Geotechnical Consultants (2004b). Third Party Review, Drawing #7095 -G, Copper Creek Estates, Lot 4 and 6 of Map No. 12644, Olivenhain Area, City of Encinitas, California, APN 264- 240 -08, dated September 10. Geotechnics Incorporated (2000a). Geotechnical Investigation for Grading, Copper Creek Estates, Lots 4 & 6, Encinitas, CA, Project 0007 - 003 -09, Document 0 -0059, May 19. ' Geotechnics Incorporated (2000b). Supplementary Slope Analysis, Copper Creek Estates, Lots 4 & 6, Carlsbad, California, Project 0007 - 003 -09, Document 0 -0719, July 13. Geotechnics Incorporated (2000c). Response to Geotechnical Review Comments, Copper Creek Estates, Lots 4 & 6, Carlsbad, CA, Project 0007 - 003 -09, Document 0 -0883, August 24. Geotechnics Incorporated (2004a). Updated Slope Mitigation Recommendations, Copper Creek Estates, Lots 4 & 6, Olivenhain, California, Project 0007 - 003 -09, Document 04- 0741R, dated August 23. Geotechnics Incorporated (2004b). Response to Third Party Review Comments, Copper Creek Estates, Lots 4 & 6, Olivenhain, California, Project 0007 - 003 -09, Document 04- 0894R, dated September 16. Geotechnics Incorporated (2004c). Response to Geopacifica Review Comments, Copper Creek ' Estates, Lots 4 & 6, Olivenhain, California, Project 0007 - 003 -09, Document 04 -1012, dated September 23. Geotechnics Incorporated (2005a). Retaining Wall Recommendations, Copper Creek Estates, Lots 4 & 6, Olivenhain, California, Project 0007 - 003 -09, Document 05 -0215, March 4. ' Geotechnics Incorporated APPENDIX A REFERENCES Continued 1 Geotechnics Incorporated (2005b). Supplemental Retaining Wall Recommendations, Copper Creek Estates, Lots 4 & 6, Olivenhain, California, Project 0007 - 003 -09, Document 05- 1 0334, dated April 6. ' Geotechnics Incorporated (2005c). Updated Buttress Recommendations, Copper Creek Estates, Lots 4 & 6, Olivenhain, California, Project 0007 - 003 -12, Document 05 -0674, June 14. ' Geotechnics Incorporated (2005d). Revised Temporary Backcut Recommendations, Copper Creek Estates, Lots 4 & 6, Olivenhain, California, Project 0007 - 003 -12, Document 05- j 0708, dated June 23. Geotechnics Incorporated (2005e). Updated Cut Slope Recommendations (Revised), Copper Creek Estates, Lots 4 & 6, Olivenhain, California, Project 0007 - 003 -12, Document 05- 0753R, dated July 13. 1 Pasco Engineering (2005). Remedial Grading and Slope Stabilization Plans for Lots 4 & 6 of Map 12644, Drawing No. 7095 -G, Sheets 1 through 6. San Diego Soils Engineering (1989). Slope Stability Evaluation, 8 Lot Subdivision, Lone Jack ' Road, Encinitas, California, Job No. 04- 3864 - 002- 01 -00, Log No. 9 -1721, dated June 8. 1 Sowers & Brown Engineering (2004). Slope Stabilization for Copper Crest Lots 4 & 6, Job No. 04 -085, Sheets 1 and 2, dated August 25. 1 United States Department of Agriculture. (1953). Aerial Photographs, Flight No. AXN -4M -72 and 73, dated March 31, Scale 1:20,000. i 1 1 1 Geotechnics Incorporated APPENDIX B LABORATORY TESTING 1 Selected samples were tested using generally accepted standards. Laboratory testing was conducted in a manner consistent with the level of care and skill ordinarily exercised by members of the profession currently practicing under similar conditions and in the same locality. ( No warranty, express or implied, is made as to the correctness or serviceability of the test results or the conclusions derived from these tests. Where a specific laboratory test method has been referenced, such as ASTM, Caltrans, or AASHTO, the reference applies only to the specified laboratory test method and not to associated referenced test methods or practices, and the test method referenced has been used only as a guidance document for the general performance of the test and not as a "Test Standard." A brief description of the tests performed follows: Classification Soils were classified visually according to the Unified Soil Classification ' System as established by the American Society of Civil Engineers in general accordance with the procedures outlined in ASTM test method D D2487 -00. 1 Maximum Density /Optimum Moisture The maximum density and optimum moisture of selected soil samples were determined by using test method ASTM D1557 -00. For samples with ' more than 10 percent plus 3 /4 -inch material, the maximum densities and optimum moisture contents were corrected using ASTM D4718. The test results are summarized in Figure B -1. Particle Size Analysis Particle size analyses were performed in general accordance with ASTM test method D422 -63. The results are presented in Figures B -2.1 and B -2.2. Atterberg Limits ASTM D4318 -00 was used to determine the liquid and plastic limits, and plasticity index of selected soils. The results are also presented in Figures B -2.1 and B -2.2. ' Expansion Index The expansion potentials of selected soil samples were estimated using the laboratory procedures in ASTM test method D4829 -95. The results are summarized in Figure B- 3 along with the UBC criteria for evaluating the expansion potential. 1 Sulfate Content: To assess the potential for reactivity with concrete, soil samples were tested for water soluble sulfate. The sulfate was extracted from the soil under vacuum, typically using a 20:1 (water to dry soil) dilution ratio. The extracted solution was tested for water soluble sulfate in general accordance with ASTM D516 -02. The test results are presented in Figure B -4 along with the UBC criteria for evaluating soluble sulfate content. ' Direct Shear: To supplement shear tests conducted previously for the site, the shear strength of selected soil samples was assessed using direct shear testing performed in general accordance ' with ASTM D3080 -98. The results are shown in Figures B -5.1 through B -5.5. Geotechnics Incorporated MAXIMUM DENSITY /OPTIMUM MOISTURE CONTENT ' (ASTM D1557) ' Maximum Optimum Sample Description Density Moisture [PCF] [ %] 1 Light reddish brown clayey sand (SC) with 10% gravel. 127'/2 10 ' 2 Olive brown sandy lean clay (CL). 109'/2 17'/2 3 Light yellow brown fine to medium silty sand (SM). 118'/2 12'/2 4 Dark brown sandy fat clay (CH). 114 16 ' 5 Light reddish brown fine to medium clayey sand (SC). 1 117'/2 14'/2 6 Light olive brown fine to medium clayey sand (SC). 116'/2 14'/2 Admkh- G e o t e c h n i c s Project No. 0007 - 003 -12 Inco rporated LABORATORY TEST RESULTS Document No. 05 -0741 FIGURE B -1 C) ' O N Cq O y N v N M O O m W o O LO U J o W J J Z O CD Z Ur m ° U w W d ' a a y �_ v J ° Q a � 1 0 o ° Z a F J J U y ai E 0 - o Z o r (n cn S _O o Q N O L v+ E # E Z J z U N C " < O (/� N N S Z o ° C ° O ' � Z U J C/) a L U C6 LL N Z M y a C W U) w U J 1 uj J Z O O � U) a o � W W U y U. v U it 4-j U7 O co O () ^ M V . ,••I i+� z C7 z o LL J LL O v U U wz J m o U � af z o O w W J N J a LU � CL a a O a U) < in y Cl O O O O O O O O O O O O O m oo i� CO Ln � Cl) N lg6ia/A Aq aaui }uaaaad i 0 O N T N O N MO Oi m 9 p LU W C) O O a m 0 U Z O Z C9 H F p c Li z E U J ~ U Q d N a) U r J i C) ° Z QQ � J J U i ar E 0 a Z r O F' C V r '^ O VI IL ' # E z J LL U r U ) C/) O N = N U) Z F N o c O O cn cu z a r "2 (� U (Q LL U C T ? y z . CU, ° Q u! � J O D O y a o � r w W U) LL of Z W O = ° � U � r � O U ' M T w fO z o FL J " O v U U ui z J m o N ui D o O ' w w J ui J Lu < 'J d J O co Q r ° Co O O O O O O O O O O O T O O OO 1— (O LO M N T T ;U6iaAA Aq jauid Iuaaaad 1 EXPANSION INDEX TEST RESULTS ' (ASTM D4829) LOT DESCRIPTION EXPANSION INDEX Lot 4 Fill: Olive brown lean clay with sand (CL). 59 Lot 6 Fill: Olive brown lean clay with sand (CL). 59 UBC TABLE NO. 18 - 1 - B, CLASSIFICATION OF EXPANSIVE SOIL EXPANSION INDEX POTENTIAL EXPANSION ' 0 -20 Very low 21 -50 Low 51 -90 Medium 91 -130 High Above 130 Very high Project No. 0007 - 003 -12 : � e o t e c h n i c s LABORATORY TEST RESULTS Document No. 05 -0741 Inc orporated FIGURE B-3 i r r r r SOLUBLE SULFATE TEST RESULTS r (ASTM D516) r LOT DESCRIPTION SULFATE r Lot 4 Fill: Olive brown lean clay with sand (CL). 0.75 r Lot 6 Fill: Olive brown lean clay with sand (CL). 0.90 _ Y r r ' UBC TABLE NO. 19 -A -4, RE UIREMENTS FOR CONCRETE EXPOSED TO SULFATE SULFATE CONTENT % SULFATE EXPOSURE CEMENT TYPE r 0.00 -0.10 Negligible - r 0.10 -0.20 Moderate II, IP(MS), IS(MS) 0.20 -2.00 Severe V r Above 2.00 Very Severe V plus pozzolan r r r r Project No. 0007 - 003 -12 : �G e o t e c h n i c s LABORATORY TEST RESULTS Document No. 05 -0741 Incorporated FIGURES -4 r ' 3000 - - -- ■ - _- mogul y 2500 - - - - ■ ■ r- -- - - ■ -a ■1N1■!_0 - -- - -- - - - -- - - U) 2000 ■ ■ W ON ■■ 1500 ■ -� ® t ® ®® Mia sma a Me - -- -- - 1000 ■- ® 1 ® ®' ■■■ ■ ■ ■ ■>r ■1■�� ■ ■r■`■rrrii� ��W� iiO iiie = 0 ®® �■ � N ■ ■ ' 0 ■ -- - - - - -- - - - -- - -- - - - - 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 STRAIN [ %] - - -- - - - - -- — 4500 - - — -- - - - - - ® Peak Strength Test Results 4000 -- 32 Degrees, 300 PSF Cohesion • Ultimate Strength Test Results ' 3500 - - - 32 Degrees, 150 PSF Coh -- i ^' f - - - - - - - - -- - - - - - 3000 - - a � 2500 - -- -- LU 2000 - !- - -- - -- - -- - Q W 1500 - - - -- - - . - - - -- - - - - -- - ' 1000 - -- - - - -- - -- - - - - - -- 500 - �- -- - - - - -- ' 0 500 1000 1500 2000 2500 3000 3500 4000 4500 NORMAL STRESS [PSF] ' SAMPLE: Lower Buttress Fill (Lot 4) PEAK ULTIMATE 1 SELECT FILL: Yellow brown fine to 32 32 ° medium grained silty sand (SM). C. 300 PSF 150 PSF IN -SITU AS- TESTED STRAIN RATE: 1 0.0020 IN /MIN Y 105.4 PCF 105.4 PCF (Sample was consolidated and drained) w, 8.7 % 19.9 % ' A=6.G e o t e c h n i c s Project No.0007- 003 -12 Incorporated DIRECT SHEAR TEST RESULTS Document No. 05 -0741 FIGURE B -5.1 3000 - a 2500 k- - ■�� ■ ■ ■ ■ ■� ■��. ■- ■ ■ ■��i ■ ■i�■�■■■�, u f ■ ' Cn 2000 1500 - ■' ® ® ��® ■ate ■ ® -®■ ® ■� ® ® ■ ® ® ® ® ®t� ® ■ ■ ■, ' 1000 -- -� -- — - �- - +- -- - W_ ® ■■ - f■ f t N 0 _ ® OB- -- -- - -- _ -- -� .0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 STRAIN [ %] - - -- - 4500 - - -- I I ' I ' ■ Peak Strength Test Results 4000 - - - -- -- - - 30 Degrees, 400 PSF Cohesion • Ultimate Strength Test Results 3500 -- -- - -- - - - -- 28 Degrees, 10 PSF Cohesion U 3000 - - - - - _- - - -- -- - U) - N 2500 -- - W 2000 a w 1 1500 - -- - - = -- -- -- 1 1000 - -- -- i ' 500 - - :> - - - - -- - -- - - - -- - - 0 - - - - 1_ - -- - - - -- - - -- - -- -- -- -_ 0 500 1000 1500 2000 2500 3000 3500 4000 4500 NORMAL STRESS [PSF] SAMPLE: Lower Buttress Backcut (Lot 6) PEAK ULTIMATE DELMAR FORMATION (Td): �' 30 ° 28 ° Light gray sand siltstone (ML). C' 400 PSF 100 PSF IN -SITU AS- TESTED STRAIN RATE: 1 0.0020 IN /MIN Yd 117.7 PCF 117.7 PCF (Sample was consolidated and drained) w, 14.4 % 17.3 % �G e o t e c h n i c s Project No. 0007 - 003 -12 Incorporated DIRECT SHEAR TEST RESULTS Document No. 05 -0741 FIGURE B -5.2 3000 - - - -- - -- - - - - - -- -- LL CA) 2500 IL - -- - ■■■ ff77o/ it N ttte■ifftffiftif - ■■ ' y 2000 - -- - - - -t -- - - - -- - - - - - -- ■ W 1500 ®■ tf ® -9t� 10 ■ ■-a ■ -wfsf aesswe anew-m on 0 MGM Q W 1000 -- ® ■'■ - ■� ■ ■ ■E ■ ■�� ■� ■� ■ ■ ■ ■ ■ ■■ ® ®� � - Ttttftf ftif ■ ■ -- -- i --- - - ■ U ' — — — — -- -- — -- — -- 500 ~ ■ • — ■ -- x ■ c� il■ �I 0 0 0 1.0 -2.0 ._ 3.0 4.0 5.0 6.0 - 7.0 ` -- - -- - 8.0 9.0 10.0 STRAIN [ %] 4500 ® Peak - -- Strength - -- -- -- - - 1 I k th Test Results j 4000 28 Degrees, 450 PSF Cohesion ♦ Ultimate Strength Test Results 3500 -- 28 Degrees, 30 PSF Cohesion -- - -- - - -- - ^ 3000 - - _. -- -- - — - a y 2500 -- - - - - -- UJ N 2000 - - -- - - -- - 2 N 1500 - - - - -- - I i 1000 - -- - - - - ��- -- -- - - - - - - -- 500 - ri' ✓,, - - - - - -- - -- - 0 - - - . - -- - -- - -- - - - -- - - _ -- - - -- - ' 0 500 1000 1500 2000 2500 3000 3500 4000 4500 NORMAL STRESS [PSF] 1 SAMPLE: Upper Cut Slope (EL. 264 Feet) PEAK ULTIMATE DELMAR FORMATION (Td) V 28 ° 28 ° Light gray brown sandy siltstone (ML). C 450 PSF 300 PSF IN -SITU AS- TESTED ' STRAIN RATE: 1 0.0002 IN /MIN Yd 112.0 PCF 112.0 PCF (Sample was consolidated and drained) w, 16.9% 19.3 % =G e o t e c h n i c s Project No. 0007 - 003 -12 Incorporated DIRECT SHEAR TEST RESULTS Document No. 05 -0741 FIGURE B -5.3 1 800 N 700 -- ■ ■�� ■ - - - -- - T - -� 600 - -- s f�l�ti■��- c 500 - -- w 400 300 - ■ ■ ■ ■� ■■■■is■ ■ ■ ■ ■ ■ ■ ■� ■ ■■ ■�� ®' a 200 = 100 - ---- - - -�.. - - - - -- y 0�� ■' -- - - 1 -- - -- - -- ! - -- - J 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 STRAIN [ %] 4500 - - - - - - - - -- ® Upper Bound Residual Strength 4000 -_ - - -- - 11 Degrees, 0 PSF Cohesion • Lower Bound Residual Strength 1 3500 _ - - - -- - -- -- - 9 Degrees, 0 PSF C ohesion U ^ 3000 - -- - _- - - - - - -- - - - - co a u N 2500 - - -- -- - - -- - -- - -- - - w 2000 a w u) 1500 - -- -- 1000 0 10 0 500 -. - - - -- - - -- -_ -- - -- - - - - -- - ' 00 1500 2000 2500 3000 3500 4000 4500 NORMAL STRESS [PSF] SAMPLE: Slide Plane (EL. 218 Feet) UPPER BOUND LOWER BOUND DELMAR FORMATION (Td): Remolded �' 11 ° 9 ° g reen fat clay (CH). Sheared 6 cycles. C' 0 PSF 0 PSF IN -SITU AS- TESTED ' STRAIN RATE: 1 0.0002 IN /MIN Yd 110.0 PCF 110.0 PCF (Sample was consolidated and drained) w 19.3 % 36.5 =G e o t e c h n i c s Project No. 0007 - 003 -12 Incorporated DIRECT SHEAR TEST RESULTS Document No. 05 -0741 FIGURE B -5.4 2500 - T - - - - - - -- -- U T 2000 - - — - - -_ - -- _ -_ - -_ 1500 UJ ■ ■ -■ ■ ■ -m! _� r# ■ k ■ ■■ U) 1000 ■�* - -- - - - t - - - - -- -- - � � ® ® ® 'I , m ■ ■ ■ ® ■ ■ ■ ■� ■ ■m ■�m ■ ® ®i ® ®® ® gy m ® � ■ ® ■ ® ® ® ® ■m ■ I w 500 ■ ,n■■ ■ ■ ■■ ■ � - -� x �■ N i 0 0� - _ 1.0_ -- - 2.0 - 3.0- - 4.0 - -- 5.0 -- 6.0 7.0 - - 8.0 - 9.0 10.0 STRAIN [ %] 4500 - - -- - - -- - - I I 1 ' ■ Peak Strength Test Results 4000 - - - - - 24 Degrees, 150 PSF Cohesion • Ultimate Strength Test Results 3500 - - -- - 24 Degrees, 5 PSF Cohesion 3000 -- - — - -- -- - -- - - - - N CL U) 2500 - - — - - - -- - -- - - -- -- W Cn F- 2000 w I W 1500 1000 - - - '- - - - -- - - - - T - - I 500 G -- - - -- - -- - - -- - -- ' 0 0 : 500 1000 15 00 -- -- -- _ - - - -- - 2000 2500 3000 3500 4000 4500 NORMAL STRESS [PSF] SAMPLE: Non - Select Fill (Lot 6) PEAK ULTIMATE FE, LL: Olive gray sandy fat clay (CH). �' 24 24 C' 150 PSF 50 PSF IN -SITU AS- TESTED STRAIN RATE: 1 0.0002 IN /MIN rd 105.5 PCF 105.5 PCF (Sample was consolidated and drained) w, 14.3 % 22.8 % A06,G e o t e c h n i c s Project No. 0007 - 003 -12 Incorporated DIRECT SHEAR TEST RESULTS Document No. 05 -0741 FIGURE B -5.5 APPENDIX C FIELD TEST RESULTS The results of the field density g grading p tests taken durin radin operations at the subject site are presented in the following Figures C -1 through C -5. Note that the elevations and locations of the field tests were determined by hand level and pacing relative to field staking done by others. The precision of the field density test and the maximum dry density test is not exact and variations should be expected. For example, the American Society for Testing and Materials has recently researched the precision of ASTM Method No. D1557 and found the accuracy of the maximum dry density to be plus or minus 4 percent of the mean value and the optimum moisture content to be accurate to plus or minus 15 percent of the mean value; the Society specifically states the "acceptable range of test results expressed as a percent of mean value" is the range stated above. In effect, an indicated relative compaction of 90 percent has an acceptable range of 86.6 to 92.8 percent based on the maximum dry density determination. The precision of the field density test ASTM D1556 has not yet been determined by the American Society for Testing and Materials. However, it must be recognized that it also is subject to variations in accuracy. The following abbreviations were used to describe the tests reported in this appendix. NU = Nuclear Density Test 1 SB = SuBdrain Backfill Density Test Geotechnics Incorporated G e o t e c h n i c s Project No. 0007 - 003 -12 I n c o r p o r a t e d DENSITY TEST RESULTS Document No. 05 -0741 FIGURE C -1 Test Test Elevation/ Soil Max. Dry Moisture Field Relative Required Retest Test No. Date Station Type Density Content Density Compaction Compaction Number Method [ftl [Pct] [ %l [Pctl [ %] [ %] 1 6/2/05 218 2 109.5 23.5 101.5 93 90 NU 2 6/2/05 223 2 109.5 22.6 104.9 96 90 NU ' 3 6/2/05 247 2 109.5 20.7 104.1 95 90 NU 4 6/2/05 230 2 109.5 23.0 99.6 91 90 NU 5 6/6/05 196 3 118.5 13.5 107.2 90 90 NU 6 6/6/05 209 3 118.5 12.1 107.1 90 90 NU 7 6/6/05 206 3 118.5 13.0 107.2 90 90 NU 8 6/6/05 200 3 118.5 12.8 115.2 97 90 NU 9 6/6/05 216 3 118.5 12.9 109.6 92 90 NU 1 10 6/7/05 215 3 118.5 14.0 113.1 95 90 NU 11 6/7/05 194 3 118.5 12.7 108.3 91 90 NU 12 6/7/05 193 3 118.5 14.5 109.0 92 90 NU 13 6/7/05 195 3 118.5 11.8 107.2 90 90 NU 14 6/7/05 210 3 118.5 10.2 104.6 88 90 16 NU 15 6/7/05 197 3 118.5 13.3 108.1 91 90 NU 16 6/8/05 210 3 118.5 17.4 109.0 92 90 NU 1 17 6/8/05 205 3 118.5 16.6 113.4 96 90 NU 18 6/8/05 198 3 118.5 17.3 108.8 92 90 NU 19 6/9/05 206 3 118.5 12.3 110.9 94 90 NU ' 20 6/9/05 197 3 118.5 13.1 110.1 93 90 NU 21 6/9/05 209 3 118.5 14.1 108.6 92 90 NU 22 6/9/05 210 3 118.5 14.0 109.7 93 90 NU 23 6/9/05 208 3 118.5 16.8 106.5 90 90 NU 1 24 6/9/05 209 3 118.5 12.9 111.8 94 90 NU 25 6/9/05 213 3 118.5 16.3 108.5 92 90 NU 26 6/9/05 215 3 118.5 14.5 108.7 92 90 NU ' 27 6/9/05 212 3 118.5 17.3 106.4 90 90 NU 28 6/9/05 216 3 118.5 15.8 106.9 90 90 NU 29 6/9/05 216 3 118.5 12.9 108.2 91 90 NU 30 6/16/05 219 2 109.5 22.9 98.8 90 90 NU 31 6/16/05 220 5 117.5 21.3 105.3 90 90 NU 32 6/16/05 221 2 109.5 19.5 101.7 93 90 NU 33 6/16/05 221 3 118.5 16.2 109.1 92 90 NU 34 6/16/05 222 6 116.5 18.0 105.6 91 90 NU 35 6/17/05 223 6 116.5 18.9 106.7 92 90 NU 36 6/17/05 225 6 116.5 17.1 107.7 92 90 NU ' 37 6/17/05 227 6 116.5 17.3 110.3 95 90 NU 38 6/17/05 229 6 116.5 18.9 105.7 91 90 NU 39 6/17/05 234 6 116.5 18.7 108.2 93 90 NU 40 6/17/05 233 6 116.5 21.0 106.0 91 90 NU 41 6/17/05 231 6 116.5 19.2 107.0 92 90 NU 42 6/17/05 237 6 116.5 19.5 107.7 92 90 NU 43 6/20/05 238 6 116.5 21.4 105.9 91 90 NU ' 44 6/20/05 241 6 116.5 19.5 105.4 90 90 NU 45 6/20/05 225 4 114.0 21.3 103.5 91 90 NU 46 6/20/05 229 4 114.0 18.9 103.2 91 90 NU 47 6/20/05 240 4 114.0 20.2 106.6 94 90 NU 48 6/20/05 240 4 114.0 23.1 102.6 90 90 NU 49 6/21/05 232 6 116.5 19.3 106.2 91 90 NU 50 6/21/05 242 6 116.5 19.2 106.5 91 90 NU G e o t e c h n i c s Project No. 0007 - 003 -12 In corporated DENSITY TEST RESULTS Document No. 05 -0741 FIGURE C -2 ' Test Test Elevation/ Soil Max. Dry Moisture Field Relative Required Retest Test No. Date Station Type Density Content Density Compaction Compaction Number Method Ift] IPcq ] %] [Pctl 1 %] [ %] 51 6/21/05 235 6 116.5 20.7 104.5 90 90 NU 52 6/21/05 242 6 116.5 17.9 109.5 94 90 NU 53 6/21/05 220 6 116.5 20.5 106.4 91 90 NU 54 6/21/05 225 6 116.5 16.2 105.7 91 90 NU 55 6/21/05 236 6 116.5 18.0 107.3 92 90 NU 56 6/21/05 240 4 114.0 19.8 105.3 92 90 NU 57 6/22/05 220 6 116.5 19.2 109.7 94 90 NU 58 6/22/05 225 4 114.0 19.6 103.0 90 90 NU 59 6/22/05 230 4 114.0 21.7 102.8 90 90 NU 60 6/22/05 235 4 114.0 22.9 102.2 90 90 NU 61 6/24/05 218 6 116.5 20.1 107.8 93 90 NU 62 6/24/05 226 6 116.5 13.8 109.7 94 90 NU 1 63 6/24/05 232 6 116.5 18.9 104.3 90 90 NU 64 6/24/05 227 6 116.5 18.5 106.9 92 90 NU 65 6/24/05 233 6 116.5 18.5 109.4 94 90 NU 66 6/24/05 239 6 116.5 18.1 104.8 90 90 NU 67 6/24/05 220 4 114.0 18.6 102.8 90 90 NU 68 6/24/05 223 6 116.5 18.1 107.0 92 90 NU 69 6/24/05 217 4 114.0 21.0 103.7 91 90 NU ' 70 6/24/05 226 6 116.5 19.4 107.5 92 90 NU 71 6/24/05 239 4 114.0 20.8 104.5 92 90 NU 72 6/27/05 238 4 114.0 20.9 105.0 92 90 NU 73 6/27/05 217 3 118.5 12.1 107.2 90 90 NU 74 6/27/05 213 6 116.5 19.2 106.3 91 90 NU 75 6/27/05 236 6 116.5 20.5 104.8 90 90 NU 76 6/27/05 230 4 114.0 22.1 104.0 91 90 NU 1 77 6/28/05 232 6 116.5 23.0 106.5 91 90 NU 78 6/28/05 229 4 114.0 22.4 103.3 91 90 NU 79 6/28/05 216 4 114.0 21.3 104.5 92 90 NU 80 6/28105 221 4 114.0 20.9 106.7 94 90 NU 81 6/28/05 225 6 116.5 18.8 108.9 93 90 NU 82 6/28/05 219 6 116.5 18.8 108.3 93 90 NU 83 6/28/05 219 6 116.5 19.9 105.7 91 90 NU 84 6/28/05 225 6 116.5 18.6 109.7 94 90 NU 85 6/28/05 222 6 116.5 18.8 106.0 91 90 NU 86 6/28/05 225 6 116.5 19.9 104.8 90 90 NU 87 6/28/05 228 6 116.5 20.4 108.4 93 90 NU 88 6/28/05 232 6 116.5 16.0 109.1 94 90 NU 89 6/28/05 237 6 116.5 19.0 106.7 92 90 NU 90 6/28/05 237 6 116.5 15.0 106.2 91 90 NU 91 6/28/05 243 6 116.5 18.4 109.0 94 90 NU 92 6/29/05 232 6 116.5 20.2 107.6 92 90 NU 93 6/29/05 238 6 116.5 20.6 105.8 91 90 NU 94 6/29/05 234 6 116.5 19.6 105.1 90 90 NU 95 6/29/05 240 6 116.5 22.1 104.7 90 90 NU 96 6/30/05 226 6 116.5 19.4 106.4 91 90 NU I 97 6/30/05 221 6 116.5 20.6 106.4 91 90 NU 98 7/1/05 229 6 116.5 19.0 109.6 94 90 NU 99 7/1/05 231 6 116.5 18.2 105.0 90 90 NU 100 7/1/05 233 6 116.5 17.1 110.0 94 90 NU ' G e o t e c h n i c s Project No. 0007 - 003 -12 - I n c o r p o r a t e d DENSITY TEST RESULTS Document No. 05 -0741 FIGURE C -3 Test Test Elevation/ Soil Max. Dry Moisture Field Relative Required Retest Test No. Date Station Type Density Content Density Compaction Compaction Number Method IN [pcq 1 %] [pcq [°iol [viol 101 7/1/05 238 6 116.5 19.1 106.1 91 90 NU 102 7/1/05 240 6 116.5 21.7 104.2 90 90 NU I 103 7/1/05 231 6 116.5 20.7 107.2 92 90 NU 104 7/1/05 244 6 116.5 20.0 106.4 91 90 NU 105 7/1/05 242 6 116.5 22.6 104.4 90 90 NU 106 7/1/05 233 6 116.5 21.2 106.1 91 90 NU 107 7/1/05 241 6 116.5 20.2 104.8 90 90 NU 108 7/1/05 238 6 116.5 19.1 105.8 91 90 NU 109 7/5/05 212 6 116.5 20.7 104.5 90 90 NU 110 7/6/05 215 4 114.0 23.3 104.4 92 90 NU 111 7/6/05 221 6 116.5 18.6 106.0 91 90 NU 112 7/6/05 223 6 116.5 18.5 105.2 90 90 NU 113 7/6/05 220 4 114.0 23.3 102.2 90 90 NU 114 7/6/05 222 4 114.0 21.5 103.9 91 90 NU 115 7/6/05 224 4 114.0 22.7 104.4 92 90 NU 116 7/6/05 221 6 116.5 20.6 107.5 92 90 NU 117 7/6/05 225 4 114.0 23.2 103.1 90 90 NU 118 7/7/05 225 4 114.0 25.2 102.6 90 90 NU 119 7/7/05 227 4 114.0 24.3 102.6 90 90 NU ' 120 7/7/05 229 4 114.0 24.2 102.2 90 90 NU 121 7/7/05 230 4 114.0 23.0 104.8 92 90 NU 122 7/7/05 234 4 114.0 22.6 104.0 91 90 NU 123 717/05 230 4 114.0 21.9 103.2 91 90 NU 124 7/7/05 227 4 114.0 21.3 105.1 92 90 NU 125 7/7/05 224 4 114.0 21.1 103.9 91 90 NU 126 7/7/05 225 4 114.0 22.3 105.2 92 90 NU 127 7/7/05 230 4 114.0 21.9 105.8 93 90 NU 128 7/7/05 221 4 114.0 21.4 103.5 91 90 NU 129 7/7/05 222 6 116.5 20.0 105.3 90 90 NU ' 130 7/7/05 225 6 116.5 19.7 105.5 91 90 NU 131 7/7/05 226 4 114.0 19.8 103.4 91 90 NU 132 7/8/05 227 6 116.5 19.8 106.7 92 90 NU 133 7/8105 233 4 114.0 23.1 104.1 91 90 NU 134 7/8/05 239 6 116.5 20.2 106.9 92 90 NU 135 7/8/05 240 4 114.0 19.6 104.4 92 90 NU 136 7/8/05 234 4 114.0 21.5 102.5 90 90 NU 137 7/8/05 224 4 114.0 21.5 102.1 90 90 NU 138 7/8/05 223 4 114.0 21.8 104.5 92 90 NU 139 7/11/05 225 6 116.5 21.1 107.5 92 90 NU 140 7/11/05 226 6 116.5 20.5 105.4 90 90 NU 141 7/11/05 224 6 116.5 17.2 107.5 92 90 NU 142 7/11/05 227 6 116.5 19.0 107.7 92 90 NU 143 7/11/05 226 6 116.5 20.3 105.8 91 90 NU ' 144 7/11/05 228 6 116.5 18.8 106.7 92 90 NU 145 7/11/05 228 6 116.5 19.3 107.6 92 90 NU 146 7/11/05 226 3 118.5 15.5 111.7 94 90 NU 147 7/11/05 229 4 114.0 15.7 103.3 91 90 NU 148 7111/05 230 6 116.5 21.1 105.9 91 90 NU 149 7/11/05 233 6 116.5 19.4 108.7 93 90 NU 150 7/11/05 237 6 116.5 21.0 107.7 92 90 NU i G e o t e c h n i c s Project No. 0007 - 003 -12 n c o r p o r a t e d DENSITY TEST RESULTS Document No. 05 -0741 FIGURE C-4 i Test Test Elevation/ Soil Max. Dry Moisture Field Relative Required Retest Test No. Date Station Type Density Content Density Compaction Compaction Number Method [ft] [pcfl 1 %] [pctl N N ' 151 7/12/05 238 6 116.5 21.3 106.3 91 90 NU 152 7/12/05 240 6 116.5 20.7 108.8 93 90 NU 153 7/12/05 240 6 116.5 20.2 107.0 92 90 NU 154 7/12/05 244 6 116.5 20.4 107.6 92 90 NU 155 7112/05 236 6 116.5 22.1 106.0 91 90 NU 156 7/12/05 247 6 116.5 17.2 108.4 93 90 NU 157 7/12/05 244 6 116.5 17.6 109.2 94 90 NU 158 7/12/05 244 6 116.5 21.7 105.1 90 90 NU 159 7/12/05 248 6 116.5 19.2 105.8 91 90 NU 160 7/12/05 248 6 116.5 19.6 105.6 91 90 NU 161 7/13/05 250 6 116.5 18.7 112.1 96 90 NU 162 7/13/05 251 6 116.5 17.6 111.7 96 90 NU 163 7/13/05 250 1 127.5 14.7 114.6 90 90 NU 164 7/13/05 254 6 116.5 15.1 113.4 97 90 NU 165 7/13/05 252 1 127.5 14.6 120.8 95 90 NU 166 7/13/05 253 1 127.5 15.1 118.2 93 90 NU 167 7/13/05 250 6 116.5 15.7 114.5 98 90 NU 168 7/13/05 243 1 127.5 14.6 119.2 93 90 NU 169 7/13/05 232 6 116.5 19.7 107.4 92 90 NU ' 170 7/13/05 233 6 116.5 19.3 107.3 92 90 NU 171 7/13/05 234 6 116.5 17.8 110.2 95 90 NU 172 7/13/05 234 6 116.5 16.7 106.7 92 90 NU 173 7/13/05 233 6 116.5 20.1 105.0 90 90 NU 174 7/13/05 234 6 116.5 19.7 105.4 90 90 NU 175 7/13/05 247 6 116.5 19.5 108.5 93 90 NU 176 7/13/05 238 6 116.5 16.5 107.8 93 90 NU ' 177 7/13/05 241 6 116.5 17.2 110.3 95 90 NU 178 7/13/05 243 6 116.5 18.0 106.1 91 90 NU 179 7/13/05 244 6 116.5 17.7 110.3 95 90 NU 180 7/13/05 249 6 116.5 17.0 107.6 92 90 NU 181 7/13/05 247 6 116.5 18.9 105.3 90 90 NU 182 7/13/05 247 6 116.5 19.2 106.6 92 90 NU 183 7/13/05 247 6 116.5 18.4 106.8 92 90 NU 184 7113/05 250 6 116.5 17.4 105.4 90 90 NU 185 7/14/05 238 6 116.5 17.1 107.5 92 90 NU 186 7/14/05 230 6 116.5 16.5 109.5 94 90 NU 187 7/14/05 240 6 116.5 11.9 107.0 92 90 NU 188 7/14/05 228 6 116.5 17.7 105.4 90 90 NU 189 7/14/05 220 6 116.5 12.6 108.1 93 90 NU 190 7/14/05 240 6 116.5 17.1 104.8 90 90 NU 191 7/14/05 235 6 116.5 16.0 106.5 91 90 NU 192 7/14/05 241 6 116.5 14.5 109.1 94 90 NU 193 7/14/05 225 6 116.5 14.7 106.1 91 90 NU 194 7/14/05 240 6 116.5 15.6 106.8 92 90 NU 195 7/14/05 245 6 116.5 16.0 108.2 93 90 NU 196 7/14/05 244 6 116.5 14.9 104.4 90 90 NU ' 197 7/14/05 244 6 116.5 19.4 105.1 90 90 NU 198 7/14/05 216 6 116.5 13.9 105.8 91 90 NU 199 7/14/05 206 6 116.5 20.2 99.9 86 90 209 NU 200 7/14/05 212 6 116.5 15.9 108.6 93 90 NU t G e o t e c h n i c s Project No. 0007 - 003 -12 I n c o r p o r a t e d DENSITY TEST RESULTS Document No. 05 -0741 FIGURE C-5 Test Test Elevation/ Soil Max. Dry Moisture Field Relative Required Retest Test No. Date Station Type Density Content Density Compaction Compaction Number Method Ift] Pct] (°io] [Pct] N [ %] 201 7/14/05 205 6 116.5 21.1 100.4 86 90 210 NU 202 7/15/05 215 3 118.5 12.5 108.0 91 90 NU ' 203 7/15/05 208 3 118.5 14.4 110.1 93 90 NU 204 7/15/05 200 3 118.5 10.9 106.7 90 90 NU 205 7/15/05 197 3 118.5 13.7 107.6 91 90 NU 206 7/18/05 218 3 118.5 10.8 106.6 90 90 NU ' 207 7/18/05 228 6 116.5 12.7 106.0 91 90 NU 208 7/18/05 236 6 116.5 13.7 105.6 91 90 NU 209 7/18/05 206 6 116.5 15.8 105.7 91 90 NU ' 210 7/18/05 205 6 116.5 19.4 104.6 90 90 NU 211 7/18/05 247 6 116.5 15.0 108.4 93 90 NU 212 7/18/05 247 6 116.5 16.4 109.7 94 90 NU 213 7/18/05 247 6 116.5 16.4 112.2 96 90 NU 214 7/18/05 247 6 116.5 18.7 110.0 94 90 NU 215 7/18/05 247 6 116.5 19.3 110.6 95 90 NU 216 7/18/05 247 6 116.5 18.1 109.3 94 90 NU ' 217 7/21/05 244 6 116.5 16.8 109.2 94 90 NU 218 7/21/05 244 6 116.5 17.4 110.4 95 90 NU 219 7/21/05 244 6 116.5 16.9 108.1 93 90 NU ' 220 7/21/05 244 6 116.5 20.8 107.6 92 90 NU 221 7/21/05 244 6 116.5 16.3 112.7 97 90 NU 222 7/21/05 244 6 116.5 14.6 107.1 92 90 NU 223 8/23/05 269 6 116.5 18.6 109.2 94 90 NU ' 224 8/23/05 266 6 116.5 21.0 105.5 91 90 NU 225 8/23/05 275 2 109.5 20.5 93.3 85 90 227 NU 226 8/24/05 276 2 109.5 18.8 99.9 91 90 NU ' 227 8/24/05 275 2 109.5 20.9 101.3 93 90 NU 228 8/24/05 276 2 109.5 22.8 98.5 90 90 NU 229 8/25/05 276 2 109.5 23.4 98.7 90 90 NU 230 8/25/05 275 2 109.5 23.7 98.9 90 90 NU 231 8/25/05 275 2 109.5 23.2 104.3 95 90 NU 232 8/25/05 278 2 109.5 17.4 98.6 90 90 NU 233 8/25/05 277 2 109.5 17.7 98.0 90 90 NU ' 234 8/25/05 277 2 109.5 20.4 99.4 91 90 NU 235 8/25/05 277 6 116.5 15.3 105.0 90 90 NU 236 8/26/05 274 2 109.5 16.3 99.8 91 90 NU 237 8/26/05 278 2 109.5 17.7 100.1 91 90 NU SB 1 6/8/05 273 2 109.5 18.8 98.8 90 90 NU SB -2 6/8/05 279 2 109.5 23.2 98.2 90 90 NU ' SB -3 6/8/05 286 2 109.5 18.2 99.3 91 90 NU SB -4 6/8/05 286 5 117.5 18.0 105.3 90 90 NU SB -5 6/8/05 285 5 117.5 17.4 106.0 90 90 NU ' SB -6 6/23/05 214 4 114.0 16.7 105.2 92 90 NU ' APPENDIX D SLOPE STABILITY ANALYSIS The slope stability analyses performed for this project are presented in the following appendix. ' The shear strength parameters used for the analysis are shown in Figure D -1. In general, shear strengths were chosen to approximate the lower bound envelop for each geologic unit. The ' analyses are intended to approximate worst -case long term strength conditions. Gross Stability The gross stability of the proposed slopes was analyzed using SLOPE /W ' software. Cross sections of the slopes are presented in Figures D -2 through D -7. The approximate cross section locations are shown on the Geotechnical Map, Plate 1. Analyses were ' conducted using Spencer's method of slices to identify the critical failure surfaces. The analyses indicate that the as -built cut and fill slopes possess an adequate factor of safety against deep seated slope failure (F.S. >1.5) for the heights shown on the Geotechnical Map. Surficial Stability Surficial stability was analyzed using an idealized infinite slope composed ' of a cohesive, frictional material. Steady state seepage forces were applied parallel to the slope surfaces using an idealized flow net. The analysis procedure is based on that presented in the referenced text (Abrahamson et al., 1996). The factor of safety against surficial failure is plotted ' versus the depth of the wetted zone in Figures D -8 through D -10. A factor of safety of 1.5 is typically deemed acceptable against surficial failure. A factor of safety of 1.0 would indicate failure given a particular depth of wetted zone. The analysis indicates that all of the slopes at the site may be susceptible to surficial slope failure given substantial wetting of the slope faces. Geotechnics Incorporated N � r 1 � , Cr) O � z W z ° o a � LO o o� � to LO U') p Z O > OU O c z Z ' U) ZO W- U 7 O U J N N N M N N N N CO O o 0 LL Q a 0 Ll N N LL y LL N 0) ' Ll r- N U- 00 U- 2 Li 00 N N LO M N N - N f0 U CO N O O N J N C N O w f0 LLJ w co ' Z 0) N N N Lo N N 3 3 J 3 Q CN N 0 U O O J J J J O O J O m W W W W J m N N Q W m M U U 2 U J N m N W w o 0 c o o N F- o ° c � U O p N N C .2 Z O W N = N f0 d f9 0) C w 'y N N > d 0 > UN X En > > > ' (0 N c f0 M 0) to f0 w f0 � f6 Q W co N p W W W W W W W Z Z Z Z Z Z Z ' J p 0 p 0 0 0 0 0 > 2 } U) N U g U) U g Q F 0 >- U >- H U UA a J g J Q g g � a� U) U) U U U U ' t7-t t t Z Z Z z Z Z z z O a 0 0 0 0 0 0 0 0 LL J v U 2 2 U LL 0 0 0 0 0 0 0 0 �w J o W Q Q Q Q Q Q Q Q 0 U 2 2 2 2 2 2 2 Z O w w w O D w O 1 1 N CN C4 r � I 0 3 00 ' N o C o ui ' o O Z CD N p N Z E N U N � Q CL ' o N N O Q N j Q Lo Z ' O CD 'W^ V+ VI C) c � ,0 U v .. N � (U r � c v t ° o LL 00 U 0 ' � O 0 U ' o o N CD A N O 000 w v 0 O 00 ((0 ' M Cl) N N N N N [189j] uOiJena13 ' C) M J N N r- r cli (A r .... 0 o H Z OI O N W �/ 0 LL U pZ ' o N Q � Z U. U r ' ° O O N L-0 a_ O N N ' O W Cl 1 W o Z C 0 U LU ai U) 0 0 � 0 v ' «s N O O � � O Cd O O � O C � O o O U U CO O G� O c3 L O :3 N Z O O O O O O O O O O O C M co M c N N N N N [1aa _d] UOIIBA913 i O O Cl) J N C%4� N C14 , M co O I 1 N N a o LO W o Z 5 ' N o N Z a) LL .� U � 1 °v O O N a 1 ° N N O /y N 1 z 1 C ° W Cl) Cl Cl) � Cl) C) O O V � L N � � i Y ° o N N -� 4-A 3 cd CD U O ' O U U _ 4-A LL U `/ O 1 N O Z O O O O O O O O O O O M M M Cl) co N N N N N 1 [1;9@j] uOi}ena13 ' o 0 M ^ N � N � N N ti i � 00 N C p ui OL ° ° o D C) U pZ i o I.L. Z E CD U � N ° 0 CL ' O N N C O N N 1 LO o U U Z ! O I' Q i = W m (1) Cl) cn G O rn v � m 00 LL N ' o N a.. U O � 0 O Cd C) U co i L N y _ � o a� 0 U N � 0 - -- 0 0 0 0 0 0 0 0 0 0 0 m m M N N N N N r ' [109j] uOIJeA913 i N e— !" rl L6 N 0 ao � lU N O Z r � . W o O o �, oo Z 1 ° n �.. N Q C 0 Z d) V- U 7 ° O O O N ap o N N O N �1 C) O ui � U i ° U) ° 4- 0 U) LL o Q� N L Y � 00 N ° L W \ a� cd C) U O 4 U o F 3 4..+ O ° p v U 1 C, cfl t N O � O O O O O O O O O� O O M M M Cl) O N N N N O N i [199 = 1] uOIJenaJ�] 1 N N N N C6 O 1 O O,o N Z O Lo C) W O O o C O CL - 1.' N Oa O C U Z a) LL U O O U N O O 1 0 I^ N v/ r i ° N 0 O O 1 r / r 1 LL Q Q LL 1 N G Yti V 00 N m J "C7 1 U- W a� o � — — !-4 1 0 0 -- ~ 1 w 4, C ) N ' 0 0 0 0 0 0 0 0 0 0 0 M M M M M co N N N 0 N co [199j] uOIJenaJ�] i 1 C) ° i N M N 3 b U 0 CD O W ° (1) O Z CL N n O CX. C U Z E LL CD 1 N *+► L .'^ CL 1 O N (n O a O v� N ' W O 1 o � U 1 W I I co LL W O aL U 1 Y� C OD N \ 7b 1 0 W Cd 1 co N � v CO co U U H O 0 1 � N O ; O O O O O O O O O O O O co (h M M M M O N N O N N N ' [199j] UOIJena13 ' " N N N � O 0 1 ' N 3 0L 0 CD o z W w °o o w C oZ N a o c VI J : U Z LL U O N 0 O O N O N � v a - 1 0 N W .' W �r } O c o � ' W ' W CO U) U) o 0 1 -- V u- 1 L G Oo N J W "d ' o LL G. U Cd �O 0 co O o mo w, C, N p 0 0 0 0 0 0 0 0 0 0 0 0 00 (O 'IT N O c0 O V N O 00 M Cl) Cl) Cl) M N N N N N ' [199j] uOIJEA913 1 1 CD - -- 0 M LL ° 3 CO ° ' N 'p (1) O M I - Q ti O W O b p �_ C) o Z N Z LL N . I..L O N N N EL LL. CD � O n U cn cn cn o L U N U. VO r O � � �o CD U N r -- C) G� v C) N o - -- O Cl O O O Co O O O O O M M O M N N N N N ' [199j] UOIJen913 O - - 0 M N N N as M ti N N ,a O I t Q ti O LLB A U O p C) pZ D Z N LL. V ' N U N O D a O N N �a Cl O U- N v rt r O r" U -- cn M N r V. W 0 ' o L C '�/�) a y/ 03 co 4 �1 0 � V U N � ' C3 N ' o N O O O O O O O O Cl O O M co M co co N N N CD - — [1aa j] U01jen913 INPUT PARAMETERS - 3:1 SELECT FILL SLOPE WITH SATURATED FACE ' Friction Angle CD 32 DEGREES Cohesion (CD) 50 [PSF] Dry Unit Weight 105 [PCF] Water Content 20 [ %] Slope Surface Z Hs i n p cosp Specific Gravity 2.65 Slope Angle X 3.00 X CALCULATED PARAMETERS Void Ratio 0.57 s tangy' F.S. Moist Unit Weight 126 [PCF] sat Saturated Unit Weight 128 [PCF] Friction Angle 0.56 [RADIANS] Slope Angle 0.32 [RADIANS] SURFICIAL STABILITY ' (After Abrahamson et. al, 1996) 4.0 H F F.S. ' 0.50 3.99 1.00 2.53 3.5 -- - -� - = 1.25 2.24 ' 1.50 2.05 1.75 1.91 3.0 2.00 1.80 ' 2.25 1.72 LL 2.50 1.66 .� - -- - -__ - - -- - - - -- - -- 2 .5 - 2.75 1.60 ' 3.00 1.56 3.25 1.52 2.0 - -- - - - - - - - -- - - 3.60 1.49 Q - - - -- - - - -- - - -- 3.75 1.46 4.00 1.44 JT 1.5 4.25 1.42 N ' 4.50 1.40 ° L 4.75 1.38 4- 0 1.0 - -- - - - -- -- - - - - -- - - - ' 5.00 1.36 - - . 5.50 1.34 6.00 1.32 ' 0.5 - - -- - -- - 6.50 1.30 7.00 1.28 - -- - ± - - - 7.50 1.27 8.00 1.26 0.0 8.50 1.24 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Depth of Wetted Zone (H) [Feet] e o t e c h n i c s Project No. 0007 - 003 -12 I n c o rp o r at e d SURFICIAL SLOPE STABILITY Document No. 05 -0741 FIGURE D -8 INPUT PARAMETERS - 2:1 CUT SLOPE WITH SATURATED FACE ' Friction Angle (CD) F'15.5 2 [DEGREES] Cohesion (CD) 0 [PSF] ' Dry Unit Weight [PCF] Water Content 20 [ %] Slope Surface E s,t Specific Gravity 2.65 ' Slope Angle X 2.00 X � ✓ CALCULATED PARAMETERS Void Ratio 0.57 S 2 ( p) tan0' F.S. _ Moist Unit Weight 126 [PCF] cosp Saturated Unit Weight 128 [PCF] Friction Angle 0.56 [RADIANS] Slope Angle 0.46 [RADIANS] SURFICIAL STABILITY ' (After Abrahamson et. al, 1996) 4.0 H F F.S. 0.50 2.74 1.00 1.71 3.5 - -- - -- 1.25 1.50 1.50 1.36 1.75 1.26 3.0 2.00 1.19 ' 2.25 1.13 2.50 1.09 2. 2.75 1.05 0 - - -- - 3.00 1.02 3.25 0.99 2.0 3.50 0.97 a - ' 3.75 0.95 4.00 0.93 1.5 ' 4.25 0.92 4.50 0.90 ° 4.75 0.89 ° 1.0 - -- - - - - -- - - - -- - 5.00 0.88 5.50 0.86 6.00 0.85 ' 6.50 0.83 0.5 - -- -- - - - - - - - - - -- -- -- - ;_- 7.00 0.82 7.50 0.81 ' 8.00 0.80 0.0 8.50 0.80 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Depth of Wetted Zone (H) [Feet] G e o t e c h n i c s Project No. 0007 - 003 -12 - I n c o r p o r a t e d SURFICIAL SLOPE STABILITY Document No. 05 -0741 FIGURE D -9 INPUT PARAMETERS - 3:1 FILL SLOPE WITH SATURATED FACE Friction Angle (CD) 24 [DEGREES] Cohesion (CD) 50 [PSF] Dry Unit Weight 106 [PCF] Water Content 14 [ %] Slope Surface E ot H Specific Gravity 2.80 Slope Angle X 3.00 X CALCULATED PARAMETERS Voi d Ratio 0.65 F s tangy' .S. _ Moist Unit Weight 121 [PCF] cosR Saturated Unit Weight 131 [PCF] Friction Angle 0.42 [RADIANS] Slope Angle 0.32 [RADIANS] i SURFICIAL STABILITY ' (After Abrahamson et. al, 1996) 4.0 H F TI F.S. 0.50 3.38 1.00 2.05 3.5 - -- - - y - - - - - - I - - - - - -- -- - 1.25 1.78 ' 1.50 1.61 1.75 1.48 3.0 2.00 1.39 2.25 1.31 LL 2.50 1.25 2.5 2.75 1.21 3.00 1.17 Cn 3.25 1.13 2.0 3.50 1.10 Q 3.75 1.08 w 4.00 1.06 4.25 1.04 N 1.5 4.50 1.02 L. 4.75 1.00 5.00 0.99 1.0 -- - - - - - -- - -; -- -- - LL 5.50 0.97 6.00 0.95 6.50 0.93 7.00 0.91 7.50 0.90 ' 8.00 0.89 0.0 8.50 0.88 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Depth of Wetted Zone (H) [Feet] G e o t e c h n i c s Project No. 0007 - 003 -12 - Incorporated SURFICIAL SLOPE STABILITY Document No. 05 -0741 FIGURE D -10 1 Geotechnics Incorporated ' Principals: Anthony F. Belfast Michael P. Imbriglio W. Lee Vanderhurst April 6, 2004 Wiegand Neglia Corporation Project No. 0007 - 010 -02 760 Garden View Court, Suite 200 Document No. 04 -0350 Encinitas, California 92024 Attention: Mr. Bruce Wiegand SUBJECT: AS- GRADED GEOTECHNICAL REPORT ' Double LL Ranch, Lots 5, 6, 7 and 10 Olivenhain, California Gentlemen: This report summarizes the results of the testing and observation services performed by Geotechnics Incorporated during grading operations for Lots 5, 6, 7 and 10 of the Double LL Ranch residential development in Olivenhain, California. The general contractor for this project ' was the Wiegand Neglia Corporation. The site was graded by Bert Sims Grading. Our geotechnical services for this phase of the Double LL Ranch project were provided between ' December 9, 2003 and April 6, 2004. 1.0 PURPOSE AND SCOPE OF SERVICES This report and the associated geotechnical services were performed in accordance with your verbal authorization provided on December 9, 2003. Our field personnel were provided for this project in order to test and observe remedial earthwork, fill placement and grading operations. These observations and tests assisted us in developing professional opinions regarding whether or not the geotechnical aspects of earthwork construction were conducted in general accordance with our geotechnical recommendations and the geotechnical requirements of the City of ' Encinitas. Our services did not include supervision or direction of the actual work of the contractor, his employees, or agents. Our services did include the following. 9245 Activity Rd., Ste. 103 - San Diego, California 92126 Phone (858) 536 -1000 - Fax (858) 536 -8311 Wiegand Neglia Corporation Project No. 0007 - 010 -02 ' April 6, 2004 Document No. 04 -0350 Page 2 t • Observation of remedial grading operations to determine whether these tasks were performed in general accordance with the intent of our geotechnical recommendations. • Performing field and laboratory tests on fill materials to support our geotechnical recommendations and conclusions. • Preparation of daily field reports summarizing the day's activity with regard to earthwork, and documenting hours spent in the field by our technicians. ' • Preparation of this report which summarizes site preparation, field and laboratory test results, fill placement, and the compaction operations. ' 2.0 SITE DESCRIPTION The subject site consists of Lots 5, 6, 7 and 10 of the Double LL Ranch residential development ' in Olivenhain, California. The site conditions were described in detail in the referenced investigation (Geotechnics, 2001). Grading operations for the subdivision began with construction of Via Monte Verde, the main access road into the site (formerly called Edward Lloyd Lane). These grading operations were reported previously (Geotechnics, 2002c). Grading ' operations continued with development of Lots 8 and 9 which were also reported previously (Geotechnics, 2002abd). The approximate layouts of the four lots graded for this recent phase of site development site are shown on the Geotechnical Maps, Plates 1 through 4. ' 3.0 GEOLOGY The subject site is located within the coastal plain section of the Peninsular Ranges geomorphic province of southeM California. Our grading observations indicate that the building pad areas of ' the site are now underlain primarily by claystone of the Delmar Formation, which is covered with a variable depth of compacted fill derived from the formation and associated colluvial soils. Granular materials of the Torrey Sandstone are exposed in the upper portions of the Lot 7 cut slope. Weathered Santiago Peak metavolcanic rock is believed to underlie the entire site at depth, and was observed at lower elevations during remedial excavations within Lots 5, 6 and 10. The surficial soils throughout the site generally consist of sandy clay (Unified Soil Classification System CL to CH) with a medium to high expansion potential, and severe sulfate content. 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