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2001-7090 G City 0 NGINEERING SERVICES DEPARTMENT Encinitas Capital Improvement Projects District Support Services Field Operations Sand Replenishment/Stormwater Compliance Subdivision Engineering Traffic Engineering June 4, 2003 Attn: San Diego County Credit Union 9985 Pacific Heights Blvd. San Diego, California 92121 RE: Ballerini/Couto 1312 Hymettus Avenue Grading Permit 7090-G ' A.P.N. 254-261-57 Final release of security Permit 7090-GI authorized earthwork, storm drainage, site retaining wall, and erosion control, all as necessary to build the described project. This project has been approved and finaled by the Field Inspector. Therefore, the final release of the security deposited is merited. Assignment of Account 66020522-02, in the original amount of$50,564.00,which was reduced by 50% to a remaining balance of$25,282.00, 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, U % Masih Maher J Le ach Senior Civil Engineer inance Manager Field Operations Financial Services CC: Jay Lembach,Finance Manager Debra Geishart Ballerini/Coto File TEL 760-633-2600 1 FAX 760-633-2627 505 S. Vulcan Avenue, Encinitas, California 92024-3633 TDD 760-633-2700 T41�1 recycled paper i -- E GINEERING SERVICES DEPARTMENT -- city b Capital Improvement Projects Encinitas District Support Services Field Operations Sand Replenishment/Stormwater Compliance Subdivision Engineering Traffic Engineering March 4, 2002 Attn: San Diego County Credit Union 9985 Pacific Heights Blvd. San Diego, California 92121 RE: Ballerini / Couto 1312 Hymettus Avenue 7090-G A.P.N. 254-261-57 Partial release of security Pen-nit 7090-GI authorized earthwork, storm drainage, site retaining wall, and erosion control, all as necessary to build the described project. This project is partially complete.Therefore, a partial release of the security deposited is merited. Assignment of Account 66020522-02, in the amount of$50,564.00, has been reduced by 50% by the Financial Services Manager therefore a balance of$25,282.00 remains. Should you have any questions or concerns, please contact Debra Geishart at (760) 633- 2779 or in writing, attention this Department. Sincerely, 111A � Masih Maher eslie Suelter Senior Civil Engineer Financial Services Manager Field Operations Financial Services CC: Leslie Suelter,Financial Services Manager Ballerini/Coto File A111"til \t'1111c 12.f_A(i .4W recycled paper JUN 13 2001 PRELIMINARY HYDROLOGY AND DRAINAGE STUDY DEVELOPMENT OF PARCEL 2, PM 14336 CITY OF ENCINITAS, CALIFORNIA Exp or Signed & sealed by RCE: art, RCE 28204 Registration expires 3-31-2002 RINEHART ENGINEERING 6431 Cleeve Way San Diego, California 92117-4246 (858) 268-8401 June 4, 2001 01201 HOI.DOC PRELIMINARY HYDROLOGY AND DRAINAGE STUDY DEVELOPMENT OF PARCEL 2, PM 14336 CITY OF ENCINITAS, CALIFORNIA The purpose of this drainage study is to calculate the peak drainage, before and after the proposed redevelopment of the subject parcel, Parcel 2, PM 14336 located at 1312 Hymettus Avenue, Leucadia, CA EXISTING DRAINAGE The Parcel is presently developed with a single family frame house and garage. There is an existing a/c driveway along the north boundary to access the parcel in back (west) of the subject parcel. The majority of the existing Parcel drains to the west and away from Hymettus Avenue. A small area drains east and into the road. For analysis,the existing parcel was divided into 4 areas, B 1 thru B4. Area B 1 drains the area east of the existing house to the adjacent road. The area of B 1 is 0.114 Ac and consists of approximately 0.052 Ac of hardscape. The peak 100 year frequency storm runoff from this area to the street is Q=0.454 cfs. Area B2 drains the southerly area of the lot, westerly to the boundary of the adjacent lot. The water sheet flows across the boundary. The area of B2 is 0.157 Ac and consists of approximately 0.038 Ac of hardscape. . The peak 100 year frequency storm runoff from this area to the adjacent lot is Q=0.567 cfs. Area B3 drains the north area of the lot, northerly to the existing driveway then westerly along the paved drive and into the adjacent lot west of the parcel. The storm runoff flows into an existing private storm drain within the adjacent property owners driveway. The area of B3 is 0.206 Ac and consists of approximately 0.080 Ac of hardscape. . The peak 100 year frequency storm runoff from this area to the adjacent lot is Q=0.797 cfs. The total peak 100 year storm water runoff from the lot is calculated to be approximately 1.82 cfs. Of that, 1.367 cfs flows onto the adjacent parcels to the west. DRAINAGE AFTER PROPOSED DEVELOPMENT The existing house and garage will be removed and a new house built on the parcel. To calculate the effects of the new structures, the parcel was divided into 5 areas Al-A5. Area A 1 through area A3 correspond roughly to the "before development" areas B 1 through B3. Areas B4 and B5 are areas within the lot parcel that will be diverted to the proposed underground reservoir and infiltration bed. Area A 1 is slightly smaller than B 1 and continues to drain most of the area in front of the house to the adjacent road. The area of Al is 0.090 Ac and consists of approximately 0.007 Ac of hardscape. The peak 100 year frequency storm runoff from this area to the street is Q=0.292 cfs. Area A2 is much smaller than the original area B2 and continues to drain the parcel westerly to the boundary and sheet flows onto the adjacent lot. The area of A2 has been reduced by 73%to 0.042 Ac. The balance of the original drainage area is to be diverted to the infiltration bed. The peak 100 year frequency storm runoff from this area to the adjacent lot has been reduced to 0.166 cfs from the original 0.567 cfs. Area A3 has been reduced in area from the original 0.206 Ac of B3 to 0.098 Ac and now largely consists of the adjacent a/c driveway that provides access to the lot west of the subject parcel. The storm runoff continues to flow along the adjacent property owners driveway and into a private drain at the westerly end of the driveway. The area of A3 consists of approximately 0.0760 Ac of hardscape. . The peak 100 year frequency storm runoff from this area to the adjacent lot is Q=0.443 cfs, reduced from the original B3 flow of 0.797 cfs, a 45%reduction. Area A4 consists of the area around the south and east side of the house that flows into the proposed storm drain pipe and into the new infiltration bed. The area is 0.121 acres and contains 0.086 Ac of hardscape. This area contributes a peak flow of 0.533 cfs to the infiltration bed. Area A5 consists of the area around the north side of the house that flows into the proposed infiltration bed . The area is 0.103 acres and contains 0.042 Ac of hardscape. This area contributes a peak flow of 0.400 cfs to the infiltration bed. The total peak 100 year storm water runoff from the lot after development is calculated to be approximately 0.901 or a reduction of approximately one-half the existing runoff of 1.82.sfs. Of that, 0.277 cfs flows onto the adjacent parcels to the west, a reduction of 80% of the existing 1.367 cfs flow. The proposed infiltration bed is a 10'x30'x5' deep excavation lined with filter cloth and filled with clean, crushed rock. The structure is completely underground. The volume of the reservoir is designed to hold the majority of the runoff from areas A4 and A5 within the interstitial voids, approximately 30% of the total volume. The bed will empty by infiltration into the surrounding soil and into the ground water. Some evapo- transporation will occur. The reservoir is designed to reduce the storm water runoff into the surrounding lots and decrease the impact of the increased hardscape area. APPENDIX 1► r--in /II/-"--�IMMII��- Zmm��Wz/SIWS WAN�. I=M��AFAIFAWMAW" mm I/,I/Alm PANA IFAUNFAMFAWAWA ■■I/V,Y/i�Ii�if-i■■��A�� ■I/L/S1II�/Ii�IS1��■■■■�� z � BUG/■/■I�� ■■■■■■� ■■■■■� NONE . .. . r ,l ii IAJ / w CJ L • _ __o�_ == o �-? �� r, '-- ��.�r, WAFAW CL F-D IILIIWAI��II��I�� /II//"---Im�II��- AVAIAW AV mmmWAV -mm WAPWAWA A��I��I�� z -===F/III.//AWMF �M MMWWAIAVAFAVA �■M//!I/1 AI/f��1��■■��A�� i' �■■/III//I//II--�■■■■■■�� - �iFAURNAWAWAWA m■■■mmm� z �/�/�y►/ly/III/I�/��■��■■�� . . . .. . . .. . WAREVAMF" E INN lip All , So OR A L �j A ■ . 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Z ~ � dux ouio viou < < C) M w C) W —1 < c� oLL. i Xa r•` ' a I J u µ a Y II-A-7 JOB-- — _.-- RINEHART ENGINE[ NG SHEET NO OF F. Dan Rinehart, R.C.L. 6431 Cleeve Way CALCULATED BY_ DATE SAN DIEGO, CALIFORNIA 92117-4246 (619) 268-8401 CHECKED BY DATE SCALE 4 Z )C- �-�. x — �- ds— _.d -CT 2041IS,ngie ShMS,2151 iPAdedi®._inr ;iris Mail".197'Td 0,de�H,NE rlEE'-dF7-225-E38i JOB RINEHART ENGINEL .NG SHEET NO �- OF F. Dan Rinehart, R.C.E. 6431 Cleeve Way CALCULATED BY DATE SAN DIEGO, CALIFORNIA 92117-4246 (619) 268-8401 CHECKED BY DATE SCALE t5 t � ;",,.CT 204 1 S,qP Snoets 205 'Padded. nCa r- _-V Mass 0'.4 Skit'PKNE 71:_L=SEE 801i-225-6'.81, PEAK RUNOFF US THE 70 60 - 0.993 CFS = 59.58 CFM 50 40 30 v O � v 0.354 CFS = 21.24 CFM 20 h W 10 LL --FO-75 0 TIME (MIN) SGC South/and Geotechnical Consultants - ' JUN 13 1001 SOILS INVESTIGATION PROPOSED BALLERINI/COUTO RESIDENCE 1312 HYMETTUS AVENUE ENCINITAS, CALIFORNIA Project No. 1471333 January 15, 2001 Prepared for: BETH BALLERINI AND DREW COUTO 1312 Hymettus Avenue Encinitas, California 92024 . 1238 GREENFIELD DRIVE, SUITE A EL CAJON, CALIFORNIA 92021 • (619)442-8022 • FAX(619)442-7859 SGC Southland Geotechnical Consultants January 15, 2001 Project No. 1471333 To: Beth Ballerini and Drew Couto 1312 Hymettus Avenue Encinitas, California 92024 Subject: Soils Investigation, Proposed Ballerini/Couto Residence, 1312 Hymettus Avenue, Encinitas, California Introduction Southland Geotechnical Consultants has performed a soils investigation for the proposed residential development to be constructed at 1312 Hymettus Avenue in the Leucadia area of Encinitas. This report presents the results of our soils investigation and provides our conclusions and recommendations, from a geotechnical standpoint, relative to the proposed development. Purpose and Scope The purpose of our soils investigation was to evaluate the soil conditions at the property and provide recommendations, from a geotechnical standpoint, relative to the proposed development. The scope of our investigation included the following: - Review of geologic maps and literature pertaining to the site and general vicinity. A list of the documents reviewed is presented in Appendix A. - Review of preliminary project plans indicating the approximate locations of the proposed site improvements. - Field reconnaissance to observe the existing surficial soil conditions at the subject property and nearby vicinity. - Investigation of the subsurface soil conditions by manually excavating, logging and sampling six exploratory borings at the site. - Laboratory expansion index and sulfate content testing of a representative sample of the onsite soils. - Geotechnical analysis of the data obtained. . 1238 GREENFIELD DRIVE, SUITE A EL CAJON, CALIFORNIA 92021 . (619)442-8022 • FAX(619)442-7859 Project No. 147833 Preparation of this report summarizing the results of our geotechnical investigation and presenting recommendations, from a geotechnical standpoint, for the proposed residential development. Project Description - The subject property is located at 1312 Hymettus Avenue, in the Leucadia area of the City of Encinitas, California (see Figure 1 ). The site is bounded by existing residential lots to the north, west and south. Overall, the lot slopes gently towards the west. The eastern portion of the lot is currently developed with a single-family residence and detached garage. The western portion of the lot is occupied by an orchard. The site is vegetated with grass and trees. We understand that the existing residence will be razed and a new one-story, single- family residence, pool and associated improvements will be constructed. We anticipate that building loads will be typical for residential structures. Some site grading may be performed to prepare the site and attain design finished grades. Subsurface Investigation On December 28, 2000, six exploratory borings were manually excavated at the site. The exploratory borings were drilled to a maximum depth of approximately 5.5 feet below the existing ground surface. The borings were logged by a geologist from our firm. Samples of the soils encountered during the subsurface investigation were obtained for visual soils classification and laboratory testing. Subsequent to logging and sampling, the borings were backfilled. The approximate locations of the exploratory borings are shown on Figure 2 (Exploratory Boring Location Map). Logs of the exploratory borings are presented on Figure 3. Soil/Geologic Units As encountered in our soils investigation, the subject property appears to be underlain by topsoil and the geologic unit known as terrace deposits. Brief descriptions of these units follow: Topsoil - Topsoil, developed on and gradational with the underlying terrace deposits, appears to mantle the site and was encountered in all of our exploratory borings at the site. As encountered, the topsoil generally consisted of brown and light brown, silty fine and fine to medium sand. The topsoil 2 SGC Project No. 147B33 encountered ranged in depth from approximately 13 inches to a maximum of 28 inches below the existing ground surface (Boring 5). However, localized deeper accumulations of topsoil may exist at the site. The topsoil is considered potentially compressible and, in its present state, should not be relied upon for the support of fill and/or structural loads. The topsoil is similar to soils in the general site vicinity found to have a very low expansion potential when tested in general accordance with UBC test standard 18-2. Terrace Deposits - Quaternary-aged terrace deposits were encountered underlying the topsoil in all of the exploratory borings. As encountered in our exploratory borings, the terrace deposits generally consisted of yellow and orange-brown, silty fine to medium sand. The terrace deposits generally exhibit favorable bearing characteristics. A sample of the terrace deposits (Boring 1 , sample at 18 to 48 inches) was tested in general accordance with UBC test standard 18-2 and was found to have a very low expansion potential (expansion index = 0) Groundwater and Surface Water Indications of a static, near-surface groundwater table were not observed during our geotechnical investigation. Groundwater is not anticipated to be a constraint to the proposed development. However, our experience indicates that near-surface groundwater conditions can develop in areas where no such groundwater conditions previously existed, especially in areas where a substantial increase in surface water infiltration results from landscape irrigation or unusually heavy precipitation. It is anticipated that site development will include appropriate drainage provisions for control and discharge of surface water runoff. 3 SGC Project No. 147B33 Conclusions and Recommendations Based on the results of our soils investigation, it is our opinion that construction of the proposed residential development is feasible from a geotechnical standpoint. The following sections provide recommendations, from a geotechnical standpoint, which should be considered for design and construction of the proposed project. Earthwork From our understanding of the project, some site grading may be performed to prepare the site and attain finished design grades. Site earthwork should be performed in accordance with the following recommendations and the Recommended Earthwork Specifications included in Appendix B. - Site Preparation - Prior to grading and construction activities, the site should be cleared of vegetation, debris and loose soils. Vegetation and debris should be properly disposed of off site. Holes resulting from removal of buried obstructions which extend below finished site grades should be filled with properly compacted fill soils. Removal/Recomgaction of Potentially Compressible Soils - The existing topsoil is considered potentially compressible and unsuitable for the support of fill and/or structural loads in its present condition. We recommend that these soils be removed in areas planned for structures, surface improvements or fill ' placement. As encountered in our exploratory borings, these soils apparently underlie the entire and were encountered to a maximum depth of approximately 28 inches below the existing ground surface. Localized deeper accumulations ' of the topsoil may exist at the site. The thickness and extent of these soils may vary and should be evaluated by the geotechnical consultant during removal of these unsuitable soils. These soils are considered suitable for re-use as compacted, structural fill provided they are free of organic material, deleterious debris and oversized materials (rocks with a maximum dimension greater than 6 inches). Excavations - It is anticipated that excavation of the onsite soils can be accomplished by conventional grading equipment in good operating condition. Structural Fill Placement - Areas to receive fill and/or other surface improvements should be scarified to a minimum depth of 6 inches, brought to near-optimum moisture conditions, and recompacted to at least 90 percent relative compaction, based on laboratory standard ASTM D1557. Fill soils should be brought to near-optimum moisture conditions and compacted in 4 SGC Project No. 147833 uniform lifts to at least 90 percent relative compaction (ASTM D1557). The optimum lift thickness to produce a uniformly compacted fill will depend on the size and type of construction equipment used. In general, fill should be placed in loose lift thicknesses not exceeding 8 inches. Placement and compaction of fill should be observed and tested by the geotechnical consultant. In general, placement and compaction of fill should be performed in accordance with local grading ordinances, sound construction practices, and the Recommended Earthwork Specifications included in Appendix B. Transition (Cut/Fill) Condition - The potential for a transition (cut-fill) condition underlying the area of the proposed structure should be checked when project plans are finalized and in the field during grading so that appropriate recommendations can be provided to reduce the potential damage due to differential settlement of the structure across the transition. Typically, we recommend that the cut (or natural) portion of the building area be overexcavated to a minimum depth of 3 feet and replaced with moisture- conditioned fill soils compacted to at least 90 percent relative compaction (ASTM D1557). The overexcavation and recompaction typically extends for a distance of at least 5 feet beyond the perimeters of the proposed structures. - Trench Backfill - The onsite soils are generally suitable as trench backfill provided they are screened of organic matter and clasts over 6 inches in diameter. Trench backf ill should be compacted by mechanical means to at least 90 percent relative compaction (ASTM D1557). Top-of-Slope Structural Setback A minimum horizontal setback distance from the faces of slopes is recommended for all structural footings and settlement-sensitive structures located near the tops of slopes. The recommended minimum setback is 7 feet for slopes less than 15 feet in height and 10 feet for slopes higher than 15 feet. This distance is measured from the outside edge of the footing, horizontally to the slope face (or to the face of a retaining wall). For footings founded in dense formational materials, the recommended minimum setback may be reduced to 5 feet. Soils within the setback zone possess poor lateral stability, and improvements (such as sidewalks, fences, etc) constructed within this area may be subject to damage due to lateral movement and/or differential settlement. 5 SGC Project No. 147633 Foundations and Slabs Foundations and slabs should be designed in accordance with structural considerations and the recommendations included in the following sections. These recommendations are provided assuming the following: 1) The existing topsoil has been removed and recompacted in accordance with the preceding recommendations and the proposed residence will be supported on continuous and/or spread footings founded entirely in dense natural soils or founded entirely in properly compacted fill soils. Concrete slab-on-grade floors and/or raised floors may be used with this option. OR 2) The proposed residence will utilize a foundation system consisting of a combination of continuous and/or spread footings that extend through the existing topsoil and are embedded a minimum of 6 inches into the underlying dense terrace deposits. Raised- wood floors or a concrete structural slab system may be used. The potentially compressible topsoil should not be relied upon for support of the structural slab (or other fill/structural loads). Footings - Footings for the proposed structure should be designed in accordance with structural considerations and the following recommendations. These recommendations assume that the footings will be excavated entirely into dense, formational soils or entirely into properly compacted fill soils with very low to low expansion potential. The proposed structure may be supported by continuous or spread footings bearing at a minimum depth of 12 inches below the lowest adjacent grade. At this depth, footings may be designed using an allowable bearing capacity of 2,000 pounds per square foot. This value may be increased by one-third for loads of short duration including wind and seismic loads. Continuous footings should have a minimum width of 12 inches and be reinforced, at a minimum, Y with two No. 4 rebars (one near the top and one near the bottom). Spread footings should be designed in accordance with structural considerations and have a minimum width of 24 inches. Slabs - Concrete slab-on-grade floors (i.e. garage) underlain entirely by dense formational soils or entirely by properly compacted fill soils with a very low to low expansion potential should have a minimum thickness of 4 inches and be reinforced at midheight with No. 3 rebars at 18 inches on center each way (or 6 SGC Project No. 147B33 No. 4 at 24 inches on center each way). Care should be taken by the contractor to insure that the reinforcement is placed at slab midheight. Slabs should be designed with crack control joints at appropriate spacings for the anticipated loading. Slabs should be underlain by a 4-inch layer of clean sand (sand equivalent greater than 30). In moisture-sensitive areas or if floor coverings are planned, a 10-mil moisture barrier is recommended midheight within the sand blanket. The potential for nuisance cracking may be lessened by careful control of water/cement ratios. The use of low slump concrete is recommended. Appropriate curing precautions should be taken during placement of concrete during warm weather. The upper 12 inches of soil beneath the floor slabs should be moistened prior to placement of the sand blanket, moisture barrier and concrete. We recommend that a slip-sheet (or equivalent) be utilized if grouted tile or other crack-sensitive flooring is planned directly on the concrete slabs. Please note that the recommendations provided for slabs are minimums. They do not represent an adequate lesser substitute for those that may be recommended by the structural consultant. In addition, our recommendations are not intended to eliminate the possibility of cracks due to concrete shrinkage. Shrinkage cracks develop in nearly all slabs which are not specifically designed to prevent them. We recommend that a structural consultant or qualified concrete contractor be consulted to provide appropriate design and workmanship requirements for mitigation of shrinkage cracks. Lateral Resistance and Retaining Wall Design Parameters Footings and slabs founded in firm, natural soils or properly compacted fill soils may be designed for a passive lateral bearing pressure of 350 pounds per square foot per foot of depth. A coefficient of friction against sliding between concrete and soil of 0.35 may be assumed. These values may be increased by one-third when considering loads of short duration, such as wind or seismic forces. Cantilever (yielding) retaining walls may be designed for "active" equivalent fluid pressure of 35 pounds per cubic foot. Retaining walls which are rigid or restrained at their upper ends (non-yielding) may be designed for an "at-rest" equivalent fluid pressure of 50 pounds per cubic foot. Walls subject to surcharge loading of vehicular traffic within a distance behind the wall equal to the wall height should be designed for an additional uniform pressure of 75 psf. If walls are surcharged by adjacent structures, the wall design should take into account the surcharge load. These values assume horizontal, nonexpansive granular backfill and free-draining conditions. 7 SGC Project No. 147B33 Retaining wall footings should be designed in accordance with the previous foundation recommendations. We recommend that retaining walls be provided with appropriate drainage provisions. Appendix B contains a typical detail for drainage of retaining walls. The walls should also be appropriately waterproofed. Waterproofing treatments and alternative, suitable wall drainage products are available commercially. Design of waterproofing and its protection during construction should be provided by the project architect. Wall backfill should be compacted by mechanical means to at least 90 percent relative compaction (ASTM D1557). Care should be taken when using compaction equipment in close proximity to retaining walls so that the walls are not damaged by excessive loading. Seismic Considerations The principal seismic considerations for most structures in southern California are damage caused by surface rupturing of fault traces, ground shaking, seismically- induced ground settlement or liquefaction. The seismic hazard most likely to impact the site is ground shaking resulting from an earthquake on one of the major active regional faults. The possibility of damage due to ground rupture is considered minimal since no active faults are known to cross the site. The potential for liquefaction or seismically-induced ground settlement due to an earthquake is considered low because of the dense nature of the underlying terrace deposits and anticipated lack of a near- surface groundwater table. The effects of seismic shaking can be reduced by adhering to the most recent edition of the Uniform Building Code and current design parameters of the Structural Engineers Association of California. Based on our understanding of the onsite geotechnical conditions, the seismic design parameters from the 1997 Uniform Building Code, Section 1636, Tables 16-J, 16-S, 16-T and 16-U are provided below. UBC Table 16-J - Based on our understanding of the onsite geotechnical conditions and our review of UBC Table 16-J, the soil profile type for the subject property is So ("Stiff Soil Profile"). UBC Table 16-U - Based on our review of the Active Fault Near-Source Zones maps (0-36) prepared by the California Division of Mines and Geology, the nearest known active fault is the Rose Canyon fault zone located offshore to the west of the site. The site is located within approximately 5.5 kilometers of the Rose Canyon fault. The fault is considered a seismic source type B based on UBC Table 16-U. 8 SGC Project No. 147B33 UBC Table 16-S - Based on our understanding of the onsite geotechnical conditions and minimum distance to the nearest known active fault (Rose Canyon fault zone), the Near-Source Factor (N.) is 1 .0. - UBC Table 16-T - Based on our understanding of the onsite geotechnical conditions and minimum distance to the nearest known active fault (Rose Canyon fault zone), the Near-Source Factor (Nv) is 1 .2. Sulfate Content A sample (Boring 6, sample at 36 to 48 inches) of the onsite soils was tested to assist in an evaluation of the degree of sulfate attack on ordinary (Type II) concrete. The test was performed in general accordance with California Test Method No. 417 and yielded a soluble sulfate content of 142 ppm. The test result indicates a "negligible" degree of sulfate attack based on UBC Table 19-A-4 criteria. The type of concrete specified and used should be determined by the structural engineer. Site Drainage Drainage at the site should be directed away from foundations, collected and tightlined to appropriate discharge points. Consideration may be given to collecting roof drainage by eave gutters and directing it away from foundations via non-erosive devices. Water, either natural or from irrigation, should not be permitted to pond, saturate the surface soils or flow over the tops of slopes. Landscape requiring a heavy irrigation schedule should not be planted adjacent to foundations or paved areas. Plan Review/Construction Observation and Testing The recommendations provided in this report are based on our understanding of the project and subsurface conditions exposed in our widely-spaced exploratory borings. Final project drawings for the proposed development should by reviewed by Southland Geotechnical Consultants prior to construction to check that the recommendations contained in this report are incorporated into the project plans. Subsurface conditions should be checked in the field during construction. Geotechnical observation during site grading and field density testing of compacted fill should be performed by Southland Geotechnical Consultants. Geotechnical observation of footing excavations should also be performed by the geotechnical consultant to check that construction is in accordance with the recommendations of this report. 9 SGC Project No. 147B33 If you have any questions regarding our report, please contact our office. We appreciate the opportunity to be of service. Sincerely, SOUTHLAND GEOTECHNICAL CONSULTANTS s� Susan E. Tanges,, C 86 Charl s R. Corbin, RCE 36302 Managing Principal/En i ing Geologist Project Engineer ESS/0* 0- 0 1386 CERTIFIE[? ENGIi�EERI!NG No. 36302 " GEOLOGIST - Cf CAL%" Attachments: Figure 1 - Site Location Map Figure 2 - Exploratory Boring Location Map Figure 3 - Logs of Exploratory Borings Appendix A - References Appendix B - Recommended Earthwork Specifications Distribution: (1 ) Addressee (3) Safdie Rabines Architects, Mr. Kevin Nivinskus 10 SGC 1 It J BA TIC U TO —_ Nz F 1 1SC ` t4 TI •�_ •.y •tiI •h �• Zen„ I t R ;SITE Qsbr • ^ '..� Oft •• f.� l�'1 ` /• ' •` _-_ ..` r r -' " Tia �' # ,•' J�r. W1Y t'•1 WASP. S� , 0 a an. G�,TI,a-� s x �rJ lit�% County P 1 ..��3..\ ° . 1 "',.•,'�. ,'� . a ' 9 '°" 5 Diu v �. ,cantle Garden s_ � x.:c L �.�:. I',k' /. ? ■. � _4 �,.. •� �. f,n: 7 B pi, �r "'' County Perk \. 1. .�_.�.� S ._ �'�', - F •l i, ..?�:�Sd - SITE LOCATION MAP N Project No. 147B33 Proposed Ballerini/Couto Residence 1312 Hymettus Avenue Encinitas, California Scale (approximate): 1 inch = 2,200 feet Base Map: Pleistocene Marine Terrace and Eocene Geology Encinitas and Ranch Santa Fe Quadrangles San Diego County, California by L. Eisenberg, 1983. FIGURE 1 SGC | _ - - � / � � � - � � � � � - / / / � -1W OF - / � � � � � � - SHKO' ) \ � / ^ / N,=^" I-M.W . ~ EXPLORATORY BORING LOCATION ON MAP ' N LEGEND Project No. 1471333 0 Approximate location of . Proposed BaUerini/CoutoRmaidence 0'6 exploratory boring 1312HynnettuoAvenue Encinitas, California - Not to Scale Base Map: Site Plan for 8aUorini/Couto Residence, ` provided by Safdio Rabinuo Architects, dated December 22, 2000 FIGURE 2 . SGC Project No. 1471333 LOGS OF EXPLORATORY BORINGS BORING NO. DEPTH DESCRIPTION B-1 0-18" Topsoil - Dark brown, dry, loose, silty fine sand (SM); with roots, gradational with: 18-60" Terrace Deposits - Mottled yellow and orange-brown, moist, dense, silty fine to medium sand (SM) Total depth = 60 inches No groundwater encountered Bulk sample at 18-48 inches Excavated and backfilled 12-28-00 ------------------------------- B-2 0-13" Topsoil - Light brown, dry, loose, fine to medium sand (SP); with roots, gradational with: 13"-60" Terrace Deposits-Orange-brown,moist,dense,fine to medium sand (SP) Total depth = 60 inches No groundwater encountered Bulk sample at 36-60 inches Excavated and backfilled 12-28-00 ------------------------------- B-3 0-21" Topsoil - Light brown, dry, loose, silty fine sand (SM); with roots, gradational with: 21"-66" Terrace Deposits - Orange-brown, dry to moist, dense, fine to medium sand (SP) Total depth = 66 inches No groundwater encountered Excavated and backfilled 12-28-00 FIGURE 3c^/� .. 4J V 4./ Project No. 1471333 LOGS OF EXPLORATORY BORINGS (continued) BORING NO. DEPTH DESCRIPTION B-4 0-15" Topsoil - Brown, dry, loose, fine to medium sand (SP); with roots 15"-48" Terrace Deposits - Orange-brown, dry, dense, silty fine to medium sand (SM) Total depth = 48 inches No groundwater encountered Bulk sample at 0-15 inches Bulk sample at 17-48 inches Excavated and backfilled 12-28-00 ------------------------------- B-5 0-28" Topsoil - Brown, dry, loose, silty fine to medium sand (SM); with roots 28"-48" Terrace Deposits - Yellow and orange-brown, dry, dense, silty fine to medium sand (SM) Total depth = 48 inches No groundwater encountered Bulk sample at 0-28 inches Excavated and backfilled 12-28-00 ------------------------------- B-g 0-18" Topsoil - Brown, dry, loose, fine to medium sand (SP); with abundant roots 18-48" Terrace Deposits - Orange-brown, dry, dense, silty fine to medium sand (SM) Total depth = 48 inches No groundwater encountered Bulk sample at 18-48 inches Excavated and backfilled 12-28-00 FIGURE 3 SGC .. . . . .. ........ t r APPENDIX A SG b Project No. 147B33 APPENDIX A REFERENCES 1 . California Division of Mines and Geology, 1994, Fault activity map of California and adjacent areas: CDMG Geologic Data Map No. 6. 2. City of San Diego, 1995, Seismic Safety Study, Dated December 3. Eisenberg, L., 1983, Pleistocene and Eocene geology of the Encinitas and Rancho Santa Fe quadrangles, in Abbott, P.L., ed., On the manner of deposition of the Eocene strata in northern San Diego County: San Diego Association of Geologists, fieldtrip guidebook. 4. Hart, E.W., 1997, Fault-rupture hazard zones in California: California Division of Mines and Geology, Special Publication 42, revised. 5. Tan, S.S., 1995, Landslide hazards in the northern part of the San Diego metropolitan area, San Diego County, California: California Division of Mines and Geology, Open-File Report 95-04. 6. Southland Geotechnical Consultants, in-house geologic/geotechnical information. PLANS Safdie Rabines Architects, 2000, Proposed Site Plan for Ballerini/Couto Residence, 1312 Hymettus Avenue, Leucadia, dated December 22. SGC APPENDIX B d �� SGC APPENDIX B RECOMMENDED EARTHWORK SPECIFICATIONS 1 .0 General Intent These specifications are presented as general procedures and recommendations for grading and earthwork to be used in conjunction with the approved grading plans. These general earthwork specifications are considered a part of the recommendations contained in the geotechnical report and are superseded by recommendations in the geotechnical report in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these specifications or the recommendations of the geotechnical report. It shall be the responsibility of the contractor to read and understand these specifications, as well as the geotechnical report and approved grading plans. 2.0 Earthwork Observation and Testinq Prior to grading, a qualified geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing fill placement for conformance with the recommendations of the geotechnical report and these specifications. It shall be the responsibility of the contractor to keep the geotechnical consultant apprised of work schedules and changes, at least 24 hours in advance, so that he may schedule his personnel accordingly. No grading operations shall be performed without the knowledge of the geotechnical consultant. The contractor shall not assume that the geotechnical consultant is aware of all site grading operations. It shall be the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes and agency ordinances, recommendations of the geotechnical report, and the approved grading plans. If, in the opinion of the geotechnical consultant, unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than recommended in the geotechnical report and the specifications, the consultant will be empowered to reject the work and recommend that construction be stopped until the conditions are rectified. 3.0 Preparation of Areas to be Filled 3.1 Clearing and Grubbing: Sufficient brush, vegetation, roots, and all other deleterious material should be removed or properly disposed of in a method acceptable to the owner, design engineer, governing agencies and the geotechnical consultant. SGC The geotechnical consultant should evaluate the extent of these removals depending on specific site conditions. In general, no more than one percent (by volume) of the fill material should consist of these materials. In addition, nesting of these materials should not be allowed. 3.2 Processing: The existing ground which has been evaluated by the geotechnical consultant to be satisfactory for support of fill, should be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory should be overexcavated as specified in the following section. Scarification should continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform, flat, and free of features which would inhibit uniform compaction. 3.3 Overexcavation: Soft, dry, organic-rich, spongy, highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overexcavated down to competent ground, as evaluated by the geotechnical consultant. For purposes of determining pay quantities of materials overexcavated, the services of a licensed land surveyor or civil engineer should be used. 3.4 Moisture Conditioning: Overexcavated and processed soils should be watered, dried, or blended as necessary to attain a uniform near- optimum moisture content as determined by test method ASTM D1557. 3.5 Recompaction: Overexcavated and processed soils which have been properly mixed, screened of deleterious material, and moisture- conditioned should be recompacted to a minimum relative compaction of 90 percent as determined by test method ASTM D1557. 3.6 Benching: Where fills are placed on ground sloping steeper than 5:1 (horizontal to vertical), the ground should be stepped or benched. The lowest bench should be a minimum of 15 feet wide, excavated at least 2 feet into competent material as evaluated by the geotechnical consultant. Ground sloping flatter than 5:1 should be benched or otherwise overexcavated when recommended by the geotechnical consultant. 3.7 Evaluation of Fill Areas: All areas to receive fill, including processed areas, areas of removal, and fill benches should be evaluated by the geotechnical consultant prior to fill placement. SGG 4.0 Fill Material 4.1 General: Material to be placed as fill should be sufficiently free of organic matter and other deleterious substances, and should be evaluated by the geotechnical consultant prior to placement. Soils of poor gradation, expansion, or strength characteristics should be placed as recommended by the geotechnical consultant. 4.2 Oversize Material: Oversize fill material, defined as material with a maximum dimension greater than 6 inches should not be buried or placed in fills unless the location, materials, and methods are specifically recommended by the geotechnical consultant. 4.3 Import: If grading operations include importing of fill material, the import material should meet the requirements of Section 4.1 . Sufficient time should be given to allow the geotechnical consultant to test and evaluate proposed import as necessary, prior to importing to the site. 5.0 Fill Placement and Compaction 5.1 Fill Lifts: Fill material should be placed in areas properly prepared and evaluated as acceptable to receive fill. Fill should be placed in near- horizontal layers approximately 6 inches in compacted thickness. Each layer should be spread evenly and thoroughly mixed to attain uniformity of material and moisture content throughout. 5.2 Moisture Conditioning: Fill soils should be watered, dried or blended as necessary to attain a uniform near-optimum moisture content as determined by test method ASTM D1557. 5.3 Compaction of Fill: After each layer has been evenly spread, moisture conditioned, and mixed, it should be uniformly compacted to not less than 90 percent of maximum dry density as determined by test method ASTM D1557. Compaction equipment should be adequately sized and be either specifically designed for soil compaction or of proven reliability to efficiently achieve the specified degree and uniformity of compaction. 5.4 Fill Slopes: Compaction of slopes should be accomplished, in addition to normal compaction procedures, by backrolling slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of the fill, including the embankment face should be at least 90 percent as determined by test method ASTM D 1557. SGC 5.5 Compaction Testin-g: Field tests of the moisture content and degree of compaction of the fill soils should be performed by the geotechnical -- consultant. The location and frequency of tests should be at the consultant's discretion based on observations of the field conditions. In general, the tests should be taken at approximate intervals of 2 feet in elevation gain and/or each 1 ,000 cubic yards of fill placed. In addition, on slope faces, as a guideline, one test should be taken for each 5,000 square feet of slope face and/or each 10-foot interval of vertical slope height. 6.0 Subdrain Construction Subdrain systems, if recommended, should be constructed in areas evaluated for suitability by the geotechnical consultant. The subdrain system should be constructed to the approximate alignment in accordance with the details shown on the approved plans or provided herein. The subdrain location or materials should not be modified unless recommended by the geotechnical consultant. The consultant may recommend modifications to the subdrain system depending on conditions encountered. Completed subdrains should be surveyed for line and grade by a licensed land surveyor or civil engineer. 7.0 Excavations Excavations and cut slopes should be evaluated by the geotechnical consultant during grading. If directed by the geotechnical consultant, further excavation, overexcavation, and/or remedial grading of cut slopes (i.e., stability fills or slope buttresses) may be recommended. 8.0 Quantitv Determination • The services of a licensed land surveyor or civil engineer should be retained to determine quantities of materials excavated during grading and/or the limits of overexcavation. SGG RETAINING WALL DRAINAGE DETAIL SOIL BACKFILL. COMPACTED TO 90 PERCENT RELATIVE COMPACTION* ------------ Typ.: ----------- RETAINING WALL ------------ IN. FILTER FABRIC ENVELOPE WALL WATERPROOFING OVERLAP PER ARCHITECT'S 0 (MIRAFI 140M OR APPROVED SPECIFICATIONS EQUIVALENT) 1' MIN. 314'-1-1/20 CLEAN GRAVEL FINISH GRADE o 48 (MIN.) DIAMETER PERFORATED 0 PVC PIPE (SCHEDULE 40 OR EQUIVALENT) WITH PERFORATIONS ORIENTED DOWN AS DEPICTED ------------------------------- MINIMUM I PERCENT GRADIENT TO SUITABLE OUTLET OMPACTED FILL------ WALL FOOTING 3' MIN. NOT TO SCALE COMPETENT BEDROCK OR MATERIAL AS EVALUATED BY THE GEOTECHNICAL CONSULTANT SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard *BASED ON ASTM D1557 Sieve Size Z Passing I" 100 *IF CALTRANS CLASS 2 PERMEABLE MATERIAL 3/411 90-100 (SEE GRADATION TO LEFT) IS USED IN PLACE OF 3/4'-1-1/2' GRAVEL, FILTER FABRIC MAY 13E 3/8" 40-100 DELETED. CALTRANS CLASS 2 PERMEABLE No. 4 25-40 MATERIAL SHOULD BE COMPACTED TO 90 No. 8 18-33 PERCENT RELATIVE COMPACTION No. 30 5-15 No. 50 0-7 No. 200 0-3 NOTE:COMPOSITE DRAINAGE PRODUCTS SUCH AS MIRADRAIN Sand Equivalent>75 OR J-GRAIN MAY BE USED AS AN ALTERNATIVE TO GRAVEL OR CLASS Z INSTALLATION SHOULD BE PERFORMED IN ACCORDANCE WITH MANUFACTURER'S SPECIFICATIONS, a 9% _L7 Lr TRANSITION LOT DETAILS CUT-FILL LOT EXISTING GROUND SURFACE MIN MIN.* (OVEREXCAVATE 0 AND RECOMPACT ------- COMPETENT BEDROCK OR MATERIAL EVALUATED SY THE GEOTECHNICAL CONSULTANT CUT LOT EXISTING GROUND SURFACE --�REMOVE U N S U I TA S L E MIN. MATERIAL , ------ ---------------------- ----------- ---- 36' MIN* I L L-------- ----------------- ------- OVEREXCAVATE AND RECOMPACT ------ ------- COMPETENT BEDROCK 10 �OBR MATERIAL EVALUATED--� Y THE GEOTECHNICAL CONSULTANT *NOTE: Deeper or laterally more extensive overexcavation and recompaction may be recommended by the geotechnical consultant based on actual field conditions encountered and locations of proposed improvements G- C KEY AND BENCHING DETAILS N FILL SLOPE PRO,JECT 1 TO 1 LINE iA7PAZ-t FROM TOE OF SLOPE TO COMPETENT MATERIAL EXISTING GROUND SURFACE -- --- --- REMOVE UNSUITABLE MATERIAL BENCH MIN 2' MIN is, MIN KEY I LOWEST DEPTH BENCH (KEY) -- --------- FILL-OVER-CUT I SLOPE KA E& EXISTING GROUND SURFACE BENCH -2 RE-MOVE MIN UNSUITABLE 2- LOWEST MATERIAL MIN. ENC BH KEY (X EY) DEPTH CUT SLOPE (TO BE EXCAVATED PRIOR TO FILL PLACEMENT) EXISTING GROUND SURFACE %4 CUT SLOPE W (TO BE EXCAVATED CUT-OVER-FILL SLOPE PRIOR TO FILL PLACEMENT) REMOVE UNSUITABLE 'MATERIAL PROJECT i TO I LINE FROM TOE -'` OF SLOPE TO C1JWP C COMPETENT --FI MATERIAL ------- BENCH a MIN 2' MIN. LOWE3-r� KEY DEPTH BENCH • (KEY) nded by the geotechnical Consultant based on NOTE: Sack drain may be recommended May actUal field conditions enco untered. Sench dimenSict? also be altered based an field candon3 encountered. SGC