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2007-583 SG , • •r 3040 Claremont Dr. Suite B San Diego,CA - 92117 APPLIED TEL (619)275-6577 CONSULTANTS FAX (619)275-6947 Civil Engineers& Geologists August 10, '2007 Mr. David Gafen D.G. Electric AN 16 2008 hydrogeology P.O. Box 22792 6 San Diego, California 92192 - -� geotechnical services "' Subject: Revised Geologic Investigation Report for the Subject Property Located at 2898 Lone Jack Road, Encinitas, California, Assessors Parcel Number(APN) 264- environmental services 151-28-00. Dear Mr. Gafen: structural engineering In accordance with your request, Applied Consultants has prepared the following report of our forensic engineering investigation of the underlying soils and geologic structure at 2898 Lone Jack Road, Encinitas, California (Figure 1). The purpose of this investigation was two-fold, first to identify any potential geologic features that could control the stability of the site and adjacent areas. Secondly, to determine the underlying soils' suitability for the proposed remodel of the existing single family residence and attached garage on the subject property. Applied Consultants reviewed Western Soil and Foundation Engineering Inc's "Geotechnical Investigation, Gafen Residence, 2898 Lone Jack Road, Encinitas, California" report dated September 13, 2004. Also, two 24-inch diameter borings were advanced at locations to the north and south of the existing single family residence (Figure 2). The open borings were physically inspected by a Professional Civil Engineer/Engineering Geologist to evaluate the depth of the compacted fill soils and the stability of the subject property and adjacent areas. After completion of the field and laboratory work, Applied Consultants reviewed our findings and prepared this report with the findings and recommendations. Upon completion of our investigation, Applied Consultants found that there are no significant geotechnical or geologic constraints that cannot be mitigated by proper planning, design, and the utilization of sound construction practices. Consequently it is our opinion that the development of the site is feasible from a geotechnical standpoint. We appreciate this opportunity to be of service. Should you have any questions please call our office at(619) 275-6577. Sincerely, Applied Consultants, Inc. Bernard J. Luther, RCE 63 56 �MAI10�, CEO No.tars cc: (3) cc * � * � CWTVW 7 ao�T r or OP CAOF 3040 Claremont Dr. Suite B -,' San Diego,CA 92117 APPLIED TEL (1619)275 6577 CONSULTANTS FAX (619)275-6947 Civil Engineers& Geologists REVISED GEOLOGIC INVESTIGATION REPORT hydrogeology FOR geotechnical services 2898 LONE JACK ROAD, ENCINITAS, CALIFORNIA environmental services APN 264-151-28-00 structural engineering forensic engineering Prepared for Mr. David Gafen D.G. Electric P.O. Box 22792 j San Diego, California 92192 By APPLIED CONSULTANTS 3040 Clairemont Drive, Ste. B San Diego, California 92117 August 10, 2007 TABLE OF CONTENTS INTRODUCTION ......................................................................................................................... 1 1.0 SCOPE OF WORK............................................................................................................ 1 2.0 GENERAL SITE CONDITIONS...................................................................................... 1 2.1 Site Description.............................................................................................................. 1 2.1.1 Exterior ..................................................................................................................2 2.1.2 Residence...............................................................................................................2 2.2 Surface and Ground Water.............................................................................................2 3.0 SITE HISTORY.................................................................................................................2 4.0 SITE GEOLOGY...............................................................................................................3 4.1 Geologic Literature Review...........................................................................................3 4.1.1 Geologic Map Review..........................................................................................4 4.1.2 Relative Landslide Susceptibility Map..................................................................4 4.1.3 Landslides and Steep Slope Map...........................................................................5 4.2 Tectonic Setting.............................................................................................................5 Table 1: Summary as Estimated Peak Horizontal Accelerations at Subject Property...........5 4.3 Seismic Design Parameters............................................................................................6 4.3.1 Uniform Building Code Design Information.........................................................6 Table 2: Seismic Design Parameters......................................................................................6 4.3.2 Maximum Bedrock Acceleration...........................................................................6 4.4 Aerial Photograph Review.............................................................................................7 Table 3: Summary of Aerial Photographs Reviewed ............................................................7 4.5 Potential Geologic Hazards............................................................................................7 5.0 FIELD WORK AND SOIL SAMPLING..........................................................................8 5.1 Site Reconnaissance.......................................................................................................8 5.2 Subsurface Investigation................................................................................................8 5.3 Soil Sampling.................................................................................................................8 6.0 FINDINGS.........................................................................................................................9 6.1 Boring Inspection Findings............................................................................................9 6.2 Laboratory Analyses.................................................................................................... 10 Table 4: Applied Consultants Soils Analyses Results......................................................... 10 6.3 Slope Stability Analysis............................................................................................... 11 7.0 CONCLUSIONS.............................................................................................................. 11 Gafen Revised 2898 Lone Jack Road Geotech Report ATH/BJL 8/9/07 i CONSTRUCTION INSPECTION AND LIMITATIONS.......................................................... 13 REFERENCES ............................................................................................................................ 14 FIGURES..................................................................................................................................... 15 APPENDIX A: SLOPE STABILITY ANALYSES.................................................................... 16 APPENDIX B: GENERAL EARTHWORK AND GRADING GUIDELINES......................... 17 Gafen Revised 2898 Lone Jack Road Geotech Report ATH/BJL 8/9/07 ll REVISED GEOLOGIC INVESTIGATION REPORT FOR 2898 LONE JACK ROAD, ENCINITAS.) CALIFORNIA, APN 264-151-28-00 INTRODUCTION The following report contains the procedures, findings, conclusions and recommendations of the geologic investigation for the proposed remodel of a single family residential with an attached garage located at 2898 Lone Jack Road, Encinitas, California, APN 264-151-28-00 (Figure 1) . 1.0 SCOPE OF WORK The scope of this study was limited to: ► Reconnaissance of the property and proposed area of construction; ► Identify the subsurface conditions at depths to be impacted by the proposed construction; ► Advance two 24-inch diameter boring to depths of 22 feet below grade (fbg) and 41 '/2 fbg respectively. Assess insitu soil conditions and placement of the fill material; ► Evaluation of the stability of the subject site and adjacent areas; ► Review investigation results and prepare a report containing our findings, conclusions, and recommendations. 2.0 GENERAL SITE CONDITIONS 2.1 Site Description The subject property is located in a residential community of Olivenhain, Encinitas, California. Specifically, the subject property is located on the north side of Lone Jack Road to the west of Jackie Lane. Review of the current topographic map for the site indicates that the subject property is at approximately 229 feet above average sea level mean (United States Geologic Survey [USGS] Rancho Santa Fe 7.5 Minute Quadrangle Map), please refer to Figure 1. Improvements to the subject property consist of a single family residence with an in-ground swimming pool. The current structure is proposed to be remodeled for a new attached garage. Gafen Revised 2898 Lone Jack Road Geotech Report ATH/BJL 8/9/07 1 2.1.1 Exterior The current structures on the subject property terrain lie on a graded cut:fill pad at the ridgeline of a south-southwesterly trending spur of low hills. The current structure on the subject property is constructed on structural fill soils to the north and south of the subject property. Slab cracking was observed in the garage slab and the adjacent pool decking to the north of the residence. The subject property slopes toward the northwest and southeast on opposite sides of the ridgeline. The adjacent property to the northeast is up-gradient from the subject property and is developed as a single family residence. The adjacent property to the southwest is down-gradient from the subject property and is also developed as a single family residence. Exposed surface geology consists of light-brown, dry, soft, fine sandy silt. 2.1.2 Residence The existing structure consists of a single story, concrete slab-on-grade, wood-framed single- family residence constructed on conventional footings. Interior slab cracking was observed to the southwest corner of the residence. 2.2 Surface and Ground Water No seeps or springs were noted on site in our investigation of the subject property. The surface drainage appeared to be sheet flow to the north and the south of the subject property. No ground water was observed in the test borings to a maximum depth of 22 and 411/2 feet below grade respectively. However it should be noted that changes in grades for site development and surface conditions may produce areas of ponded surface, or near-surface water where they previously did not exist. Minor corrective designs should be used to insure that positive drainage is maintained. 3.0 SITE HISTORY In 2004, Western Soil and Foundation Engineering conducted a geotechnical investigation of the subject property (Western Soil and Foundation Engineering, Inc., 2004). The scope of their geotechnical investigation consisted of the following: ► Floor level survey performed to the inside the living space of the existing single family residence; ► Subsurface exploration performed to the depths that could be influenced by the proposed construction; ► Laboratory tests of the pertinent static physical properties of various soil and rock Gafen Revised 2898 Lone Jack Road Geotech Report ATH/BJL 8/9/07 2 stratigraphic units which could influence the development of this project; ► The provided recommendations for site preparation and grading; ► Furnishing soil parameters for foundation design, including bearing capacity, estimated settlements, lateral pressures, and expansion potential of the on-site soils. The results of Western Soil and Foundation Engineering Geotechnical Investigation found the following: • Floor level survey of the residence determined a 2%2 inch deflection from horizontal toward the south. A higher ridge in the slab appears to running east-west along the centerline of the structure with slight down-drop on the north side of the slab. The report states that the slab deflections appear to "mimic the pre-developed site terrain." • Western Soil and Foundation Engineering Geotechnical Investigation findings also state that a previous floor level survey was performed by another consultant in 1997 (no source stated). Comparison of the 1997 to 2004 results showed overall settlement increase '/2 inch, but that that movement trends were similar. • Four small diameter borings were advanced on July 15, 16, and 19, 2004. The borings encountered structural fill that varied in depth from 4 '/2 feet to 6 feet. Below the structural fill a pale yellow to grey fine silty sand was encountered to approximately thirteen feet below grade (fbg). Below 13 fbg, pale green, silty fine sandstone and green siltstone was encountered to the maximum depth of 31 feet in boring B-1. • Free groundwater was not observed in any of the borings. 4.0 SITE GEOLOGY The site is located in the Coastal Plains Geomorphic Province of San Diego County west of the San Diego Embayment. This province is known by rolling to steep marine terraces called mesas, some of which are level and dissected (United States Department of Agriculture Soil Survey, San Diego Area, California [USDA], 1973). Semi-consolidated sandstone, shale and unconsolidated material lie between the beach ridges and the foothills (USDA, 1973). The exposed surface geology consists of light to medium brown, soft, moist, medium to fine sandy clay (SC). 4.1 Geologic Literature Review Applied Consultants reviewed the Landslide Hazards in the Rancho Santa Fe Quadrangle, San Diego County, California, Landslide Hazard Identification Map No. 6 California Department of Conservation, Division of Mines and Geology 1987 (Siang Tan, 1987) for references concerning the geologic structure underlying the subject property and surrounding areas. Also Gafen Revised 2898 Lone Jack Road Geotech Report ATHBJL 8/9/07 3 reviewed were the more recent Geologic Maps of the Encinitas and Rancho Santa Fe 7.5" Quadrangles, Siang 1996, California Division of Mines and Geology (DMG) Open-File Report 96-02 (Tan & Kennedy, 1996). 4.1.1 Geologic Map Review Review of the 1987 and 1996 Geologic Maps for the Rancho Santa Fe 7.5' Quadrangle, shows that the subject property is located on the ridgeline of a spur of a southwesterly pointing low hills. The maps show that the subject property is overlooking the Escondido Creek to the southeast and an unnamed arroyo to the west. The 1987 Map shows the subject property being underlain by the middle Eocene-aged Scripps Formation (Tsc). The 1996 map shows the subject property being underlain by the upper middle Eocene-aged Santiago Formation (Tsa). The 1996 map legend explains that the Scripps Formation (Tsc) designation for the Encinitas and Rancho Santa Fe 7.5' Quadrangle Maps area were changed by Tan and Kennedy in 1996 to the Santiago Formation (Tsa). The Santiago Formation is described as consisting of"poorly bedded, poorly indurated, fine-to- medium-grained sandstone interbedded with landslide prone siltstone and claystone" (Siang Tan, 1986; Tan & Kennedy, 1996). The map shows that the Santiago Formation is underlain by the Delmar Formation (Td) member of the La Jolla Group. The Delmar Formation (Td) is characterized as consisting of "poorly bedded, poorly indurated, landslide-prone sandy claystone interbedded with medium-to-coarse grained sandstone" (Tan & Kennedy, 1996). The geologic maps also show that formational bedding strikes northwest to southeast with a 6° dip toward the southwest. Finally, the geologic map shows two landslides to west side of the hills on which the subject property is located. 4.1.2 Relative Landslide Susceptibility Map Review of the Relative Landslide Susceptibility Map in the Rancho Santa Fe Quadrangle Map, indicates that the subject property lies within the Relative Landslide Areas 2 and 4. Relative Landslide Area 2 is described as a "Marginally Susceptible Area". Marginally Susceptible Areas include "gentle to moderate slopes underlain by relatively competent material or colluvium that is considered unlikely to "remobilize under natural conditions". Also includes ridgetops and spur crests that are underlain by relatively competent material but flanked by steep, potentially unstable slopes. The stability of slopes within Area 2 may change radically in response to future natural or artificial alteration of the adjacent terrain" (Siang Tan, 1986). Relative Landslide Area 4 is described as a "Most Susceptible Area". Most Susceptible Areas are characterized as "naturally unstable, subject to failure even in the absence of activities of man" (Siang Tan, 1986). At the subject property, the residential pad and southeast facing slope are located within the Relative Landslide Area 2. All remodeling activities are to occur at these locations. The northwest facing slope of the subject property is located within the Relative Landslide Area 4. Gafen Revised 2898 Lone Jack Road Geotech Report ATH/BJL 8/9/07 4 No remodeling activities are planned for the northwest side of the subject property. 4.1.3 Landslides and Steep Slope Map Review of the Landslides and Steep Slopes Map in the Rancho Santa Fe Quadrangle Map, indicates that the subject property does not lie within a landslide deposit. A suspected landslide deposit (question-marked (?)) lies to the north of the subject property. Additionally the subject property does not lie within the steep-slope boundary (Siang Tan, 1986). The map shows the previously mentioned landslide approximately 1/8 mile to the southwest of the subject property. Both of these areas are located on the west facing slopes of the south- southwesterly pointing spur of low hills. 4.2 Tectonic Setting No visible evidence of faults or surface ruptures were observed traversing the subject property during the site investigation. However, it should be noted that Southern California, including Encinitas and surrounding areas are located in an area of late Tertiary to Quaternary-aged fault zones which strike to the northwest, conservatively (Kennedy, Tan et al, 1975). These fault zones are located in seismic zone IV and correspond to intensities up to 8.0 on the Modified Mercalli scale. According to the California Division of Mines and Geology, some of these fault zones are known to be active. "Active" faults are ones which have had faulting activity within the Holocene Epoch, or the last 11,000 years (Kennedy, Tan et al, 1975). Some of the faults in the area are considered to be active, while others are considered "potentially active", or "inactive" as stated by the California Division of Mines and Geology. According to the County of San Diego, Faults and Epicenters Map (Department of Public Works, Cartographic Services, 1993), the closest known or suspected fault is an unnamed inferred fault located approximately three miles to the east of the subject property. Accordingly, the subject property does not lie within an Alquist-Priolo Earthquake Fault Zone. The Rose Canyon Fault Zone lies approximately seven (8) miles to the west of the subject property. The La Nacion Fault Zone lies approximately twenty (20) miles to the southeast of the subject property. The Elsinore Fault Zone lies within 50-60 miles northeast of the property. The San Jacinto and San Andreas Fault Zones lie between 80 and 100 miles to the east of the subject property, respectively. Each of these faults is considered active and has ruptured within the last 11,000 years. The following table is a compilation of expected peak horizontal ground acceleration at subject property based upon distance and magnitude of rupture event (CDMG, 1987). Table 1: Summary as Estimated Peak Horizontal Accelerations at Subject Property Distance (Miles from Magnitude of Peak Horizontal Ground Fault Name Subject Property) Rupture Event FAcceleration at Subject Property Gafen Revised 2898 Lone Jack Road Geotech Report ATHBJL 8/9/07 5 Distance (Miles from Magnitude of Peak Horizontal Ground Fault Name Subject Property) Rupture Event Acceleration at Subject Property Unnamed Inferred 3 7.0 .08 g Rose Canyon 8 5.0 .27 g La Nacion 20 7.0 .15 g Elsinore 25 7.5 .13 g San Jacinto 49 8.0 .07 g San Andreas 74 8.0 .05 g An earthquake on any of these faults could cause mild to moderate damage at the subject property. 4.3 Seismic Design Parameters 4.3.1 Uniform Building Code Design Information Seismically related design parameters obtained from the Uniform Building Code (UBC) 1997 edition, Volume II, Chapter 16, are presented below. These design factors are based on subsurface soil and bedrock conditions and distance from known active faults. Table 2: Seismic Design Parameters UBC Chapter 16 Table No. Seismic Parameter Recommended Value 16-1 Seismic Zone Factor Z 0.40 16-J Soil Profile Type S, 16-Q Seismic Coefficient Ca 0.44 Na 16-R Seismic Coefficient Cv 0.64 Nv 16-S Near Source Factor Na 1.0 16-T Near Source Factor Nv 1.0 16-U Seismic Source Type B 4.3.2 Maximum Bedrock Acceleration Based upon a Maximum Magnitude Earthquake of 7.0 magnitude along the nearest portion of the Rose Canyon Fault Zone, the Maximum Bedrock Acceleration at the site is estimated to be 0.27 g. For structural design purposes, we recommend a dampening ratio not greater that 5 percent of critical dampening. Gallen Revised 2898 Lone Jack Road Geotech Report ATHBJL 8/9/07 6 4.4 Aerial Photograph Review On December 8, 2006, Applied Consultants reviewed aerial photographs of the subject property that are stored in the Cartography Department at the County of San Diego Operations Center located at 5201 Ruffin Road, San Diego, California 92123. Applied Consultants reviewed the aerial photographs with a stereoscope in order to better evaluate the potential slides or other types of slope creep that stability of the subject site and adjacent areas. The following table lists the photographs reviewed and a visual description of the subject property and adjacent area: Table 3: Summary of Aerial Photographs Reviewed Photograph Photograph Date Title Description Scarcely developed area. No properties exist on top of ridge. No visible signs 1953-1959 AXN 1M-17M of landslides. Scarcely developed area. No properties exist on top of ridge. No visible signs 1967 GS-VBTA of landslides. Area beginning development, Subject property and property to the southwest exist. Subject property appears to be fill lot from near the ridge of the hill. No 1978-1979 SDCO(West) visible signs of landslides. Area beginning development, Subject property and property to the southwest 1989 WAC(West) exist. Property to the northeast does not exist. No visible signs of landslides. Review of Google Earth satellite imagery from 4-14-04 shows that the subject property and surrounding properties are in their current configurations. The imagery also shows that the landslides to the southwest and northeast have been developed as single family, detached homes. 4.5 Potential Geologic Hazards In our professional opinion, no geologic hazards of significant magnitude are present which would preclude the proposed new construction of a single family residence provided the recommendations in this report are followed. Ground Shaking is a likely hazard to the site. This is caused by the movement along active fault zones. The ground movement at the subject property could be mild to moderate depending on the distance from the epicenter of the seismic event. It is expected that the structure will have to endure this phenomenon to some degree. Liquefaction . The soils at the site and the ground water conditions are not conducive to liquefaction from earthquake activity. Liquefaction requires a shallow groundwater table and non-cohesive soils. The water table in this location is estimated to be greater than 50 feet below the ground surface and the underlying soil is very dense and cohesive. Gafen Revised 2898 Lone Jack Road Geotech Report ATH/BJL 8/9/07 7 Flooding . Given the location of the site, flooding is highly unlikely to occur. Landslide. Landsliding is a potential hazard in both the Santiago and the Del Mar formations. This was investigated by our firm through the advancing of two large-diameter borings and down-hole inspection of these borings. No visible slide planes were observed during the physical inspection of our borings AHC-B 1 and AHC-132 (boring logs). 5.0 FIELD WORK AND SOIL SAMPLING 5.1 Site Reconnaissance Prior to performing soil borings, Applied Consultants performed field reconnaissance of the subject property and adjacent properties. At that time, Applied Consultants representatives were told by the homeowner that a plumbing leak had existed unseen for an extended period of time. The plumbing leak was eventually located below the garage slab and pool decking. Additionally, Applied Consultants observed the perimeter of the subject property and observed no evidence of soil movement throughout the property. 5.2 Subsurface Investigation On November 1, 2006 Applied Consultants supervised Larive Drilling Co. in advancing two 24- inch diameter borings at locations to the south and north of the existing residence on the subject property (Figure 2). After drilling, a Registered Civil Engineer/ Engineering Geologist entered the borings cleaned all loose soils along the sidewall of the borehole using a metal scrapper to a maximum depth of 22 feet below grade (fbg) in boring AHC-B1 and 411/2 fbg in boring AHC- B2. After cleaning the boring walls, the Registered Civil Engineer / Engineering Geologist logged the boreholes from the bottom to the top. Applied Consultants obtained one in-place soil sample from ten feet below grade using a 4" diameter split spoon California sampler from boring AHC-B1. The in-place sample was collected in order to determine the conditions of the underlying structural fill soils within the building pad. During the down-hole logging, of the borings the Registered Civil Engineer / Engineering Geologist observed.no evidence of soil movement and or slide planes throughout the length of either boring. Additionally, the Registered Civil Engineer / Engineering Geologist did not observe fracturing or the presence /development of adverse features such as of bedding parallel shears or remolded clay surfaces in borings AHC-B 1 and AHC-132. 5.3 Soil Sampling Applied Consultants collected a drive soil sample from within test boring AHC-B 1. The soil sample Applied Consultants collected from 10 fbg in boring AHC-B 1 was laboratory-analyzed to determine the soil's physical characteristics. The soil sample was analyzed for the following: Gafen Revised 2898 Lone Jack Road Geotech Report ATH/BJL 8/9/07 8 Optimum Moisture Content and Maximum Density - ASTM D1557-91 - Natural Moisture Content& Field Density - ASTM D2216-92 Shear Resistance Value - ASTM D3080-90 Expansion Index - ASTM D4546-96 6.0 FINDINGS 6.1 Boring Inspection Findings The following soil structure was encountered in boring AHC-B 1 (see boring log): — 0 to 12 fbg: light brown, dry, soft, fine sandy silt (SM) appeared to be imported structural fill. — Drive Sample (DS 1) obtained at 10 fbg blow counts 1-1-1 using 3 500 pound sampler. — 12 fbg: contact between native and imported structural fill soils, observed flat, clean and dry. — 12 to 22 fbg: dark greenish grey, slightly damp, soft, fine sandy silt(SM). — Total depth: 22 fbg. — No ground water was encountered at a maximum depth of twenty two (22) feet below grade. Observation from the down hole logging observed that the bottom of the boring was dry and no seeps or springs were observed throughout the length of the boring. Additionally no slide planes were observed. The following soil structure was encountered in boring AHC-B2 (see boring log): — 0 to 8 fbg: light brown, dry, soft, fine sandy silt (SM) appeared to be structural fill. — 8 fbg: contact between native and imported fill soils, observed flat, clean and dry. — 8 to 10 fbg: medium brown, slightly damp, soft, fine clayey silt(ML). — 10 to 13 fbg: light brown, dry, soft, fine silty sand (SM). — 13 to 15 fbg: light brown, dry, medium dense fine silty sand(SM). — 15 to 20 fbg: greenish grey, dry, medium dense fine clayey silt (ML). — 20 to 31 fbg: dark grey, dry, dense, fine silty clayey silt(ML). Gafen Revised 2898 Lone Jack Road Geotech Report ATHBJL 8/9/07 9 — 31 to 35 fbg: grayish brown, dry, dense fine clayey silt(ML). 35 to 41Y2 fbg: grey, dry, dense, fine clayey sandy silt(SC/ML). total depth 41'/2 fbg. No ground water was encountered at a maximum depth of 41%2 fbg. Observation from the down-hole logging observed that the bottom of the boring was dry and no seeps or springs were observed throughout the length of the boring. Additionally no slide planes were observed. 6.2 Laboratory Analyses The following table (Table 4) is a compilation of Applied Consultants' soils analyses results from sample collected from the subject property and the soil analysis provided by the Western Soils and Foundation Engineering Inc. Report: Table 4: A plied Consultants Soils Analyses Results Dry Shear Testing Expansion Index Sample Field Field Max Opt. ID Moisture Density Density Moist Phi Cohesion EI Potential Content(%) (pcf) (pcf) (%) (angle) (p s f) Applied Consultants Drive Sample AHC B 1-DS 1 12.0% 111.3 115.0 14.0 28 600 115.0 High 10' Western Soil and Foundation En ineering Inc. B-3 g F-4' 115.0 14.0 B-1 DS 15' 26 280 B-2 DS 15' 13 500 B-2 DS 38' 26 250 B-3 DS 20' 30 300 B-4 DS 7' 23 500 B-1 F - 5' 34 Low B-2 @ 10' - 12%2' 108 High B-3 F - 4' 90 Medium B-3 @ 10'/2' - 109 High 12' B-1 DS 5' 9.1 89.1 B-1 DS 10' 9.8 113.8 B-1 DS 15' 21.4 100.4 B-1 DS 20' 21.2 110.9 13-1 DS @ 25'1 20.9 105.0 Gafen Revised 2898 Lone Jack Road Geotech Report ATHBJL 8/9/07 10 Dry Shear Testing Expansion Index Sample Field Field Max Opt. Phi Cohesion ID Moisture Density Density Moist an s EI Potential Content(%) ( cf) (pcf) (%) (angle)) (p B-1 DS g 30' 20.1 108.9 B-2 DS 5' 13.4 111.2 B-2 DS 15' 117.7 105.5 B-2 DS 38' 17.0 110.6 B-3 DS 2' 12.6 107.9 B-3 DS 7' 11.7 113.2 B-3 DS 15' 17.7 108.6 B-3 DS 20' 17.7 111.5 B-4 DS 2' 13.0 109.1 B-4 DS 7' 14.3 110.2 B-4 DS 10' 8.7 117.1 B-4 DS 14' 13.0 110.8 6.3 Slope Stability Analysis Applied Consultants has provided geologic cross-sections of the subject property (Figure 3) that include all of the soil boring data. The provided cross section matches the site plan and includes all geologic information. The geologic units are shown and labeled. Using the data contained in Figure 3, Applied Consultants performed slope stability analysis using bishops modified method for the cross section of the subject property. The slope stability analysis determined the minimum factor of safety of the slope to be greater than 1.5 see attached cross sections and slope stability analysis in figures. Copies of the slope stability analyses are contained in Appendix A 7.0 CONCLUSIONS After reviewing the results of our geotechnical investigation Applied Consultants concludes that the slab cracking observed to the swimming pool decking was due to the unseen plumbing leak described by the property owner. Applied Consultants also determined that the slab deflection observed in the interior of the residence is due to historical settlement of the structural fill soils in that area of the subject property. Additionally, Applied Consultants concludes that there are no significant geotechnical or geologic constraints that cannot be mitigated by proper planning, design, and the utilization of sound construction practices. It is our opinion that the proposed residential remodel and new construction of a garage is feasible from a geotechnical standpoint. Review of Geologic Literature for the subject property area found the following: 1. Nearby geologic bedding has been mapped as trending northwest to southeast with a 60 Gafen Revised 2898 Lone Jack Road Geotech Report ATHBJL 8/9/07 11 dip toward the southwest. Therefore, the exposed geology on the southeast side of the subject property dips "in-slope" increasing the relative stability of the southeastern facing slope. 2. At the subject property, the residential pad and southeast facing slope are located within the Relative Landslide Area 2. All remodeling activities are to occur at these locations. The northwest facing slope of the subject property is located within the Relative Landslide Area 4. No remodeling activities are planned for the northwest side of the subject property. Laboratory and visual analyses indicated the following: a. The depth of the fill soils was determined to be 12 fbg in the front of the residence (south) and 8 fbg in the rear of the residence (north). b. The native materials underlying the site are suitable for supporting the loads, including the proposed remodel of the residence and new construction of the garage for the subject property. C. No landslides were found throughout the lengths of the two test borings on the subject property and review of historical aerial photographs. d. When properly compacted, the native and fill have good load bearing capacities. e. Slope stability analysis determined the minimum factor of safety of the slope to be greater than 1.5. Gafen Revised 2898 Lone Jack Road Geotech.Report ATH/BJL 8/9/07 12 CONSTRUCTION INSPECTION AND LIMITATIONS The recommendations contained within this report are based upon Applied Consultants' field investigation. The interpolated subsurface conditions should be checked during construction by a representative of Applied Consultants. We recommend that all grading operations be observed by a representative of this firm. The recommendations contained within this report are based upon our field study, laboratory analyses, and our understanding of the proposed construction. If any soil conditions are encountered differing from those assumed in this report, Applied Consultants should be immediately notified so that we may review the situation and make supplementary recommendations. Additionally, if the scope of proposed work changes from that described in this report Applied Consultants should be notified. This report has been prepared in accordance with generally accepted soil and foundation engineering practices within the greater San Diego area. Professional judgments contained herein are based upon our evaluation of the technical information gathered, our understanding of the proposed work, and our general experience in the geotechnical field. Our engineering work and judgments rendered meet current professional standards. We do not guarantee the performance of the project in any respect. We do not direct the contractor's operations and we cannot be responsible for the safety of field personnel on the site; therefore, the safety of field personnel during construction is the responsibility of the contractor. The contractor shall notify the owner if he considers any of the recommended actions contained herein to be unsafe. Gafen Revised 2898 Lone Jack Road Geotech Report ATH/BJL 8i9i07 13 REFERENCES County of San Diego, Faults and Epicenters Map, 1993, Department of Public Works, Cartographic Services. Geologic Maps of the Encinitas and Rancho Santa Fe 7.5' Quadrangles, Siang and Kennedy, 1996, California Division of Mines and Geology (DMG) Open-File Report 96-02 Geology of the San Diego Metropolitan Area, California, Kennedy and Tan et al, 1975, Bulletin 200 California Division of Mines and Geology Landslide Hazards in the Rancho Santa Fe Quadrangle, San Tan 1986, San Diego County, California, Landslide Hazard Identification Map No. 6 California Department of Conservation, Division of Mines and Geology 1987. United States Department of Agriculture Soil Survey, San Diego Area, California [USDA], 1973). United States Geologic Survey [USGS] Rancho Santa Fe 7.5 Minute Quadrangle Map Western Soil and Foundation Engineering, Inc., 2004, "Geotechnical Investigation, Gafen Residence, 2898 Lone Jack Road, Encinitas, California', September 13. Gafen Revised 2898 Lone Jack Road Geotech Report ATH/BJL 8/9/07 14 FIGURES Gafen Revised 2898 Lone Jack Road Geotech Report ATH/BJL 8/9/07 15 117'014 .000' W WGS34 117`13.000' W CD . r a' � jr- Of I 1 J IL I L 1 rl°� � • �� 'r'�sra 1�1�, r Subj°c C Property • 020 �1 1 .rF M.Y w x fr • •�� . rf+ i• ~ O 4$ 117'014 .000' W WGS34 117c'13.000' Ifs 0 1000 FEET 0 1 � ` tif3dlsv<<IC�1 OP�� NaCicml Gec!yr3'�?k 4vn-, v.nat-icnal Figure 1: MAPPLIED Site Location Map for Date : 8/10/07 CONSULTANTS Lone Jack Road, Drawn by: ATH Encinitas, California SITE MAP u O B-1 A 0• , HM FOU / S no CVN YK -30 "M wow� N 30' 0 30' 60' 120' O Test Boring I B-3 0 Applied Consultants Boring SCALE AHC B-1 David GafFen Residence Date: 8/10/07 APPLIED APN#264-151-28-00 CONSULTANTS 2898 Lone Jack Road . - - Drawn by: ATH Encinitas, California �uuu �IINNNNNN 9 IM EO CU M OZS C: CA-ti CD CO UJ • 2 F4 Boring Log : B-1 Location : APN 264-151-28-00 2898 Lone Jack Road, Encinitas, California Depth Soil Description Moisture goring Details (feet) Content 0 2411 Dia. 0-12' Light brown, dry, soft, fine sandy silt (SM) 10 DS1 @10' 1 blow for each 6"to 18" MC1 @10' 12.0% i 12' - 22' Dark greenish grey, slightly damp, soft, fine sandy silt (SM) 20 Bottom of Boring @ 22fbg LEGEND 30 Silty Sand (SM) Sandy Silt (SM) DS1 @ 10' - Drive Sample MC-1 @10' - Moisture Can Sample 40 fbg -feet below ground surface 50 60 (Driller: Larive Drilling) (Logged By: Bernard J. Luther) Note: Hammer Weight 3,500lbs @ 0 - 27fbg , 2,400lbs @ 27- 55fbg Drilled and Logged on Nov 1, 2006 David Gaffen Residence Date: 12/13/06 APPLIED APN#264-151-28-00 Job#: SD6700.06 CONSULTANTS 2898 Lone Jack Road Drawn by: ATH Encinitas, California Boring Log : B-2 Location : APN 264-151-28-00 2898 Lone Jack Road, Encinitas, California Depth Soil Description Moisture Boring Details (feet) Content 0 0-8' Light brown, dry, soft, fine sandy silt (SM) 24" fill soils Dia. Light brown to dark brown, slightly amp, so , 10 1 fine clayey silt ML 10' - 15' Light-brown to light-orange, dry, soft-to-medium dense, fine silty sand (SM) 15' - 20' greenish grey, dry, medium dense, 20 clayey-silt(ML) 20' - 31' dark grey, dry, dense, clayey-silt (ML) 30 31' - 35' grey brown, dry, dense, clayey-silt (ML) 35' -41.5' grey, dry, dense, clayey-fine sandy silt 40 (SC-ML) Bottom of Boring @ 41.5fbg LEGEND Silty Sand (SM) 50 Clayey Silt (ML) Clayey-Sandy Silt (SC-ML) 60 fbg -feet below ground surface (Driller: Larive Drilling) (Logged By: Bemard J. Luther) Note: Drilled and Logged on Nov 1, 2006 David Gaffen Residence Date: 12/13/06 MAPPLIED APN#264-151-28-00 Job#: SD6700.06 CONSULTANTS 2898 Lone Jack Road Drawn by: ATH Encinitas, California APPENDIX A SLOPE STABILITY ANALYSES Gafen Revised 2898 Lone Jack Road Geotech Report ATHBJL 8/9/07 16 STABL for Windows 3.0 - Results Name: 2898 Lone Jack Road Southeast to Northwest DATA SUMMARY Problem: 2898 Lone Jack Road Southeast to Northwest 320 Soils Cohesion Friction --- ---- ---- --- 310 A — -- - —--- -:- • fiN Sods 600.0 28.0 ^----- o Native 1 500.0 13.0 - __ I ---- --- o Native 2 300.0 30.0 280 • Native 300.0 30.0. -- -- --- --- --- --- ---- --- --------------------------------- 270 -- ------------ --- ----- -- --- --- 260 ---------- --- --- ---- --- --- --- --- --- -— --- -- --- --- --- 240 ------ — Z 3; # S s — 9 .. 10 y1 230 - --- `12 220 ---'-----'--- 210 - ---- 200 -- - -- 190 180 z3 170 --- 160 — 160 --------- 140 -- 130 ---- -- 120 -- 110 --- 100 ---:-----' Bo -- 70 ------ --- 3 60 -- - -20 0 20 40 6o so 100 120 140 160 160 200 220 240 260 260 300 320 340 350 (Stele in Feet) I I Profile Data i. ,�. � ,a� ,��.�� ° - �€ •emu .�; ;H: 1 0 214 21 224 1 2 21 224 31.5 228 1 3 31.5 228 40.5 228.9 1 4 40.5 228.9 54 234 1 - 5 54 234 57 237 1 - 6 57 237 70.5 240 1 7 70.5 240 175.5 240 1 8 175.5 240 189 234 1 9 189 234 204 228 1 10 204 228 207 226.5 1 16-Jan-08 Page 1 STABL for Windows 3.0 - Results Name: 2898 Lone Jack Road Southeast to Northwest 11 207 226.5 231 224 1 12 231 224 249 216 1 13 249 216 270 212 1 14 270 212 282 208.5 1 15 282 208.5 306 207 1 16 306 207 328.5 204 ] 17 0 208 75 233.5 2 18 75 233.5 160.5 233.5 2 19 160.5 233.5 328.5 190 2 20 160.5 230.5 274.5 200.5 3 21 274.5 200.5 328.5 184 3 22 208.5 211 268.5 188.5 2 23 268.5 188.5 328.5 164.5 2 24 208.5 211 328.5 154 3 25 0 205 76.5 230.5 4 4 26 76.5 230.5 91.5 230.5 4 27 91.5 230.5 160.5 230.5 4 28 160.5 230.5 268.5 176.5 4 29 268.5 176.5 328.5 143.5 4 Soil Properties 1 109.7 120.4 600 28 0 0 0 Fill Soils 2 107 123.7 500 13 0 0 0 Native 1 3 107 126.5 300 30 0 0 0 Native 2 4 113.5 132 300 30 0 0 0 Native 3 16-Jan-08 Page 2 STABL for Windows 3.0 - Results Name: 2898 Lone Jack Road Southeast to Northwest _____________ All Surfaces Generated =____________ Problem: 2898 Lone Jack Road Southeast to Northwest-FS Min-Bishop=5 761 320 i Sofls Cohesion Frktion 310 Maple --- --- - --:__-:---------- - - ---- .. 300 FA Sills 600D 280 -.Native 1 500 0 130 .---- - : : - Native 2 300.0 30.0 280 Native 3000 30.0 .'---.--------------- ...........'_—...__...-__...__._... .. 270 CribcalSurtece .:.----'- -1-----'- - __._-_-.Svtece 2 Sur/ece 3 250 Surfece4 -- ---- -'- -- '- 240 -.- Surlece 220 _5,�ixe 8 210 g 200 —� 180 1110 — — 170 -..:-...- 160 -- - -- ,,: - --- 150 140 — —. 130 1211 — --- ---:.._- 110 ---'------ ' 100 - ---- -- _-`. 70 60 - I 20 0 20 40 60 80 100 120 140 180 100 200 220 240 250 280 300 320 340 360 ? (Scale in Fed) 10 Most Critical Surfaces Problem. 2898 Lone Jack Road Southeast to Northwest-FS Mn-Bishop=5 761 320 ------ --- -- Sots Cohesion Frfetlon -.- - - - . 310 Angle .-...- ---.:._._;_.._:_...-:. 300 F/Sills 600.0 280 ..- - _. - ..:. .--: •-- - - •-.. . --- 290 - Nafive 1 500.0 13.0 Native 2 300.0 30.0 280 �Native 3 3000 300 --------------------- . 270 CrbcalSixlwe 280 _.11--Svtace2 ..-:- -- ._- , Suriace 3 � � �.. ' 250 _-_.__Surface 4 __-. . 240 —Surfece5 230 Surlsce6 --'.---=— —;--- -----`---.-`—.. 220 - -- —..- - 210 _.... 200 �--- 190 - --- -- --- 180 170 - �,------ -.... —. 160 _ -—- •5k:z - 150 140 130 — - 110 --- 60 -— - --I ---5---- 70 - -20 0 20 40 80 80 100 120 140 160 160 200 220 240 280 280 300 320 340 380 (Scab in Fed) 16-Jan-08 Page 3 STABL for Windows 3.0 - Results Name: 2898 Lone Jack Road Southeast to Northwest Factor of Safety Histogram Distribution of Factors of Safety 9 --- ---- ----- ------- --- - -- ----— --- ------------------ ---- 8 1----------- ---- - -------- ---- --- --- ---- ---- -- 7 --- ----- ----------------- ----------- ----- --- ---- - 6 1---- ---- --- I----- --- ----- ---- 5 ------------ , .. ------ I--- --------- -------- 4 --- — ------- - -- ----- ----- - 3 ----- ---- — ---------- —-- ----- --- 2 ----- — ---- - --- 1 — — ------ ---- ------ — ---- ,---— ----- 0 02 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 (FS) Factors of Safety of 10 Most Critical Surfaces 1 5.761 2 5.988 3 6.166 4 6.409 5 6.419 6 6.51 7 6.526 8 6.708 9 6.735 10 7.031 16-Jan-08 Page 4 _ STABL for Windows 3.0 - Results Name: 2838 Lone Jack Road Northwest to Southeast DATA SUMMARY Problem: 2838 Lone Jack Road Northwest to Southeast 320 Soils Cohesion Frletion'---------------------- — ------------------ -----I I------ 310 Angle -- —-- ---- --- --- --- —- --- -- ---- ---- --- 300 • fiN Soils 600.0 28.0 -- ---- o Native 1 500.0 13.0 290 o Native 2 300.0 30.0 ------ --- .. .... 280 • Native 3 300.0 30.0. — 270 - ---- - ---- -- ---- --- --------- - ----- ----- --- --- ----- ---- ---- 260 --- - ---- -— --- -- -- ---- -- - ---- -- -- -— --- 240 — — — 220 - --- ---- 0 ,3 10 11 1.2 13 �� ----- -- --d-- --s-- s- ,7 ---- 210 - -------- z~ 3 200 190 a. 160 ---- 22 n — 170 - ------ 160 --- ';' -- 150 -- --- --- 140 -- -- — 130 120 - ----- -- ---- 110 --- 100 ---�- ---�----- 80 70 -- ----- GO -20 0 20 40 60 80 100 120 140 160 180 200 220 240 280 280 300 320 340 360 (Scale in feet) Profile Data �. � �� F� .___ � gar: ,, ,� ?� �z�, ,��r, a .�_• .<> .� 1 0 204 22.5 207 1 2 22.5 207 46.5 208.5 1 3 46.5 208.5 58.5 212 1 4 58.5 212 79.5 216 1 5 79.5 216 97.5 224 1 6 97.5 224 121.5 226.5 1 7 121.5 226.5 124.5 228 1 8 124.5 228 139.5 234 1 9 139.5 234 153 240 1 10 153 240 258 240 1 09-Aug-07 Page 1 STABL for Windows 3.0 - Results Name: 2838 Lone Jack Road Northwest to Southeast Ei h 11 258 240 271.5 237 1 12 271.5 237 274.5 234 1 13 274.5 234 288 228.9 1 14 288 228.9 297 228 1 15 297 228 307.5 224 1 16 307.5 224 328.5 214 1 17 0 190 168 233.5 2 18 168 233.5 253.5 233.5 2 19 253.5 233.5 328.5 208 2 20 0 184 54 200.5 3 21 54 200.5 168 230.5 3 22 0 164.5 60 188.5 2 23 60 188.5 120 211 2 24 0 154 120 211 3 25 0 143.5 60 176.5 4 26 60 176.5 168 230.5 4 27 168 230.5 237 230.5 4 28 237 230.5 252 230.5 4 29 252 230.5 328.5 205 4 Soil Properties 1 109.7 120.4 600 28 0 0 0 Fill Soils 2 107 123.7 500 13 0 0 0 Native 1 3 107 126.5 300 30 0 0 0 Native 2 4 113.5 132 300 30 0 0 0 Native 3 09-Aug-07 Page 2 STABL for Windows 3.0 - Results Name: 2838 Lone Jack Road Northwest to Southeast All Surfaces Generated Problem 2838 Lone Jack Road Northwest to Southeast-FS Min-Bishop=3 773 320 soft cohesion Frktlon"- '-— ---------- --- —--:...-- -- -----..:..--- ..._ 310 AnDe — ---: ._:.--- -- --- --- ---- :..— -- --- 300 f1,Fill Sods 600.0 290 J--_:.....:— _...:._-- — -- ----- ---- --- --- 290 x Native 1 500 0 13.0 Native 2 3000 300 290 fl!)'Native3 3000 300 -'......1---.:..--'.- ---1"---'- ---:. 270 CrticalSartoce -'-----------------------1----',- -- -_. Snrlace2 - ---- - --- Svtace 3 250 -----------Surface 4 --- .. -- -- -- -- - -- ........... - ----- -- - -- -.. 240 —Surfsoe5 .-.-' Surface6 url ---Sece 7 220 —Svlece8 210 —Surtace9 ---- 200 —' 190 190 170 --.-... .. 160 150 140 --- - - -.. 130 120 _.:_.... 110 — 90 —------ - --- - -- 70 — - 20 0 20 40 80 80 100 120 140 160 190 200 220 240 290 280 300 320 340 390 (Scab in Feel) 10 Most Critical Surfaces Problem. 2838 Lone Jack Road Northwest to Southeast-FS Min-Bishop=3 773 320 Sots Cohesion Friction ---""1"-"-"l - 310 Ande -- ---:.._-•-----:._ - ---__:.._..:_--- ---.---------- 300 [i Fit Sods 6000 290 -- Native 1 500.0 13.0 Native 2 3000 30.0 260 Native 3000 30.0 ---------------- _.... 270 GticalSutace -•-----'- 1-----',- --.:.— 260 _ Surtxe 2 : -- Surlace 3 250 Surface4 _. __. ___. -----t--- 240 Svlsce5 230 Sirlace 6 ' Svtsce 7 - -- 220 —Surfece8 --- -'---- 210 —Surface 9 - 200 190 180 - - -" ,xi• - 170 160 ---- 1S0 - - -- --- — 140 130 - --- 120 1f0 100 --- 90 80 ------- ---'-- -20 0 20 40 60 90 100 120 140 180 180 200 220 240 280 280 300 320 340 380 (Scab in Feet) 09-Aug-07 Page 3 STABL for Windows 3.0 - Results Name: 2838 Lone Jack Road Northwest to Southeast Factor of Safety Histogram Distribution of Factors of Safety 4 ------------------------- ------------—------- ------- -------------------------- 3.5 — ----------------------------- -------------------------- 3 ------------------------ ------—------— 2.5 --------------------------------------------------------- ----------------------- 2 ------------------- ------- ---------..------ ----.------ ,--------------------—---- 1.5 -------------------------------------- ------- -------- ------------`--------- 1 ------------—------ —-- ----------------- ----------- --------------- ---------- 0.5 --------------------—---- ---------------- ——------- --------- ---------—— 0 1 2 (FS) Factors of Safety of 10 Most Critical Surfaces a i su 1 3.773 2 3.776 3 3.804 4 3.813 5 3.847 6 3.849 7 3.859 8 3.865 9 3.891 10 3.916 09-Aug-07 Page 4 APPENDIX B GENERAL EARTHWORK AND GRADING GUIDELINES Gafen Revised 2898 Lone Jack Road Geotech Report ATH/BJL 8/9/07 17 GENERAL EARTHWORK AND GRADING GUIDELINES I. EARTHWORK OBSERVATION AND TESTING Prior to commencement of grading, a qualified geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. The consultant is to provide adequate testing and observation so that he may determine that the work was accomplished as specified. It should be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes so that the consultant may schedule his personnel accordingly. The contractor is to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes or agency ordinances,these specifications, and the approved grading plans. If in the opinion of the consultant, unsatisfactory conditions are resulting in a quality of work less than required in these specifications,the consultant may reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to determine the degree of compaction should be performed in accordance with the American Society for Testing and Materials Test Method ASTM: D 1557-82. II. PREPARATION OF AREAS TO BE FILLED 1. Clearing and Grubbing : All brush, vegetation, and debris shall be removed and properly disposed of. The Geotechnical Consultant shall evaluate the extent of removal of these items depending on site conditions. Fill material shall not contain more than 1 percent of organic material by volume. No fill should contain more than 5 percent organic matter. No fill shall contain hazardous materials or asphalt pavement. If asphalt pavement is removed it should be disposed of at an appropriate location. Concrete fragments which are free of reinforcing steel may be placed in the fills. 2. Processing : the existing ground which is evaluated to be satisfactory for support of fill shall be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory shall be over-excavated as specified in the following section. Scarification shall continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform and free of uneven features which would inhibit uniform compaction. 3. Overexcavation : Soft, dry, spongy, or otherwise unsuitable ground, extending to Gafen Revised 2898 Lone Jack Road Geotech Report ATHBJL 8/9/07 18 such a depth that surface processing cannot adequately improve the condition, shall be over-excavated down to firm ground as approved by the consultant. 4. Moisture Conditioning : Over-excavated and processed soils shall be watered, dried-back, blended, and/or mixed, as necessary to attain a uniform moisture content approximately 2 percent over optimum. 5. Recompaction : Over-excavated and processed soils which have been properly mixed and moisture-conditioned shall be compacted to a minimum relative compaction of 90 percent according to ASTM: D1557-82. 6. Benching : Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical units), the ground shall be benched. The lowest bench shall be: a minimum of 15 feet wide, at least 2 feet deep with a minimum 2% slope into the fill bank for horizontal stability, expose firm materials, and be approved by the consultant. Other benches shall excavated into firm material for a minimum width of 4 feet. Ground sloping flatter than 5:1 shall be benched or otherwise over- excavated when considered necessary by the consultant. 7. Approval : All areas to receive fill, including processed areas, removal areas, and toe-of-fill benches shall be approved by the consultant prior to fill placement. III. FILL MATERIAL 1. General : Material to be placed as fill shall be free of organic matter and other deleterious substances, and shall be approved by the consultant. Soils of poor gradation, expansion, or strength characteristics shall be placed in areas designated by the consultant or mixed with other soils until suitable to serve as satisfactory fill material. 2. Oversize : Oversize material defined as rock, or other irreducible material, with a maximum dimension of greater than 12 inches, shall not be buried or placed in fill unless the location, materials, and disposal methods are specifically approved by the consultant. Oversize disposal operations shall be such that nesting of oversize material does not occur, and such that the oversize material is completed surrounded by compacted or densified fill. Oversize material shall not be placed within the range of future utilities or underground construction, unless specifically approved by the consultant. 3. Import : If import fill is necessary for grading, the import material shall be approved by the geotechnical consultant. Gafen Revised 2898 Lone Jack Road Geotech Report ATH/BJL 8/9/07 19 IV. FILL PLACEMENT AND COMPACTION 1. Fill Lifts : Approved fill material shall be placed in areas prepared to receive fill in near-horizontal layers not exceeding 6 to 8 inches in compacted thickness. The consultant may approve thicker lifts if testing indicates that the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer shall be spread evenly and shall be thoroughly mixed during spreading to attain uniformity of material and moisture in each layer. 2. Fill Moisture : Fill layers at a moisture content less than optimum shall be watered and mixed, and wet fill layers shall be aerated by scarification or blended with drier materials. Moisture conditioning and mixing of fill layers shall continue until the fill material is at a uniform moisture content at or near two percent over optimum. 3. Compaction of Fill : After each layer has been evenly spread, moisture conditioned, and mixed, it shall be uniformly compacted to not less than 90 percent of maximum dry density in accordance with ASTM: D1557-82. Compaction equipment shall be adequately sized and either specifically designed for soil compaction or of proven reliability,to efficiently achieve the specified degree of compaction. 4. Fill Slopes : Compacting of slopes shall be accomplished, in addition to normal compaction procedures, by backrolling of slopes with sheepsfoot rollers at frequent intervals of 2 to 3 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading,the relative compaction of the slope out to the slope face shall be at least 90 percent. 5. Compaction Testing : Field tests to check the fill moisture and degree of compaction will be performed by the consultant. The location and frequency of tests shall be at the consultants discretion. In general,the tests shall be taken at an interval not exceeding 2 feet in vertical rise and/or every 1000 cubic yards of embankment. V. SUBDRAIN INSTALLATION Subdrain systems, if required, shall be installed in approved ground to conform to the approximate alignment and details shown on the plans or shown herein. The subdrain location or materials should not be changed or modified without the approval of the consultant. The consultant, however, may recommend and upon approval, direct changes in subdrain line, grade or material. All subdrains shall be surveyed for line and grade after installation and sufficient time allowed for surveys, prior to commencement of filling over the subdrains. Gafen Revised 2898 Lone Jack Road Geotech Report ATHBJL 8/9/07 20 VI. EXCAVATIONS Excavations and cut slopes shall be examined during grading. If directed by the consultant, further excavation or overexcavation and refilling of cut areas shall be performed, and/or remedial grading of cut slopes performed. Where fill-over-cut slopes are to be graded, unless otherwise approved, the cut portion of the slope shall be made and approved by the consultant prior to placement of the fill portion of the slope. Excavations may require the consultant to produce an alternate sloping plan if the excavation VII. TRENCH BACKFILL 1. The Contractor shall follow all OSHA and CAL/OSHA requirements for maintaining safety of trench excavations. 2. The bedding and backfill of utility trenches should be done with the applicable provisions of Standard Specifications of Public Works Construction. Bedding material should have a sand equivalent of(SE )30). Bedding should be placed to 1 foot above the top of pipe. All backfill should be compacted to 90 percent form 1 foot above the pipe to the surface. 3. The geotechnical consultant should test the trench backfill for relative compaction. At least one test should be performed for every 300 feet of trench and every two feet of trench fill. 4. The lift thickness of the trench backfill shall not exceed what is allowed in the Specifications of Public Works Construction unless the contractor can demonstrate that the fill can be compacted by an alternative means to the minimum relative compaction. VIII. FOUNDATIONS NEAR TOP OF SLOPES Where foundations, footings, walls and other similar proposed structures are to be located seven feet and further away from the top of slopes standard design may take place in conformance with the recommended soil bearing value. In situations where foundations, footings, walls et cetera are located closer than seven feet from the top of slope shall be deepened so that the bottom edge of the footing is 7 feet horizontally from daylight in the slope. Gafen Revised 2898 Lone Jack Road Geotech Report ATWBJL 8/9/07 21 3040 Ciairemont Dr. �\ Suite B San Diego..CA c� �o y I ^}} 92117 AP LED EL (619)275-6577 CONSULTANTS 1\ � FAX (619)275-6947 Civil Engineers & Geologists J, Dec er 13 , 2006 ,4 'A 92 133 Mr. David Gafen D.G. Electric hydrogeology P.O. Box 22792 San Diego, California 92192 geotechnical services Subject: Geotechnical Investigation for the Subject Property Located at 2898 Lone Jack Road, Encinitas, California Assessors Parcel Number(APN) 264-151-28-00. environmental services Dear Mr. Gafen: structural engineering In accordance with your request, Applied Consultants has prepared the following report of our study the site soils and geology to a depth sufficient to encounter any potential geologic features that may forensic engineering control the stability of the site and adjacent areas and determine the soil's suitability for construction. Applied Consultants' investigation consisted of advancing two 24-inch diameter borings at locations on the subject property to evaluate the depth of the compacted fill soils and to determine the stability of the subject property and adjacent areas. After completion of the field and laboratory work, Applied Consultants reviewed our findings and prepared this report with the findings and recommendations. Upon completion of our investigation, Applied Consultants found that there are no significant geotechnical or geologic constraints that cannot be mitigated by proper planning, design, and the utilization of sound construction practices. Consequently it is our opinion that the development of the site is feasible from a geotechnical standpoint. We appreciate this opportunity to be of service. Should you have any questions please call our office at (619) 275-6577. Sincerely, Applied Consultants, Inc. Aaron T. Hill Bernard J. Luther, RCE 63653, CEG 1356 Project Geologist President cc: (3) cc 4t#4 IN.is" • swim-1—wo • } Gafen �' 2898 Lone Jack Road Geotech Report.v pd ATH/BJL 12/13/06 TABLE OF CONTENTS INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Paye 4 of 17 1.0 SCOPE OF WORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4 of 17 2.0 GENERAL SITE CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4 of 17 2.1 Site Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4 of 17 2.2 Surface and Ground Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 5 of 17 3.0 SITE GEOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 5 of 17 3.1 Geologic Literature Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 5 of 17 3.2 Aerial Photograph Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 6 of 17 3.3 Tectonic Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 6 of 17 3.4 Seismic Design Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 7 of 17 3.4.1 Uniform Building Code Design Information . . . . . . . . . . . . . . . . . . Page 7 of 17 3.4.2 Maximum Bedrock Acceleration . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 8 of 1.7 3.5 Potential Geologic Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 8 of 17 Ground Shaking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 8 of 17 Liquefaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 9 o 17 Flooding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page of 17 Landslide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page8 of 17 4.0 FIELD WORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 8 o 17 5.0 FINDINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 9 of 17 6.0 CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 10 of 17 CONSTRUCTION INSPECTION AND LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . Page 10 of 17 FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 12 of 17 GENERAL EARTHWORK AND GRADING GUIDELINES . . . . . . . . . . . . . . . . . . . . Page 14 of 17 EARTHWORK OBSERVATION AND TESTING . . . . . . . . . . . . . . . . . . . . . . Page 14 of l 7 PREPARATION OF AREAS TO BE FILLED . . . . . . . . . . . . . . . . . . . . . . . . . . Page 14 of 17 Clearing and Grubbing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 14 of 17 Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 14 of 17 Overexcavation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15 of 17 Moisture Conditioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15 of 17 Recompaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15 of 17 Benching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15 of 17 Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15 of 17 FILL MATERIAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15 of 17 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15 of 17 Oversize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15 of 17 Import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15 of 17 FILL PLACEMENT AND COMPACTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pave 16 of 17 Fill Lifts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 16 of 17 Fill Moisture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 16 of 17 Compaction of Fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 16 of 17 Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 2 of 17 Fill Slopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 16 of 17 Compaction Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 16 of 17 SUBDRAIN INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 16 of 17 EXCAVATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 16 of 17 TRENCH BACKFILL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 17 of 17 FOUNDATIONS NEAR TOP OF SLOPES . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 17 of 17 Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 3 of 17 REPORT OF GEOTECHNICAL INVESTIGATION APN 264-151-28-00, 2898 LONE JACK ROAD, ENCINITAS, CALIFORNIA INTRODUCTION This report contains the findings, conclusions and recommendations of the geotechnical investigation for the proposed single family residential remodel at the subject property located at APN 264-151-28-00 at 2898 Lone Jack Road, Encinitas, California(Figure 1). 1.0 SCOPE OF WORK The scope of this study was limited to: ► Reconnaissance of the property and proposed area of construction; ► Identify the subsurface conditions at depths to be impacted by the proposed construction; ► Advancing two 24-inch diameter boring to depths of 22 feet below grade (fbg) and 41 %2 fbg respectively in order to assess the soil conditions and placement of the fill material; ► Evaluation of the stability of the subject site and adjacent areas; ► Review investigation results and prepare a report containing our findings, conclusions, and recommendations. 2.0 GENERAL SITE CONDITIONS 2.1 Site Description The subject property is located in a residential neighborhood of Olivenhain in Encinitas, California. Specifically, the subject property is located on the north side of Lone Jack Road to the west of Jackie Lane at an elevation of approximately 229 feet above sea level (Topo! Interactive Maps on CD-Rom 1997). The subject property currently has a single family residence and swimming pool on it that are proposed to be remodeled. The terrain on the subject property lies flat with slopes from the north to the south counter Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 4 of 17 clockwise with a residence located up-gradient from the subject property to the northeast. The subject property appears to be a cut lot that was graded on an existing ridge top. The lot appears to have been overexcavated, with a fill being built to support the residence footings. Exposed surface geology consists of a light brown, dry, soft, fine sandy silt. 2.2 Surface and Ground Water No seeps or springs were noted on site in our investigation of the subject property. No ground water was observed in the test borings to a maximum depth of twenty two (22) and forty one and a half(41%2) feet below grade respectively. However it should be noted that changes in grades for site development and surface conditions may produce areas of ponded surface, or near-surface water where they previously did not exist. Minor corrective designs should be used to insure that positive drainage is maintained. 3.0 SITE GEOLOGY The site is located in the Coastal Plains Geomorphic province of San Diego County west of the San Diego Embayment. This province is known by rolling to steep marine terraces called mesas, some of which are level and dissected (United States Department of Agriculture [USDA], 1973). Semi-consolidated sandstone, shale and unconsolidated material lie between the beach ridges and the foothills (USDA, 1973). The exposed surface geology consists of light to medium brown, soft, moist, medium to fine sandy clay(SC). 3.1 Geologic Literature Review Applied Consultants reviewed the Geologic Map of the Oceanside 30' X 60' Quadrangle, California(Kennedy & Tan, 2005) for references concerning the geologic structure underlying the subject property and surrounding areas. Review of the Geologic Map of the Oceanside 30' X 60' Quadrangle, indicates that the subject property lies a transitional zone of two geologic formations. The two geologic formations consist of the middle eocene Del Mar Formation (Td), the middle eocene Santiago Formation (Tsa), respectively. The Del Mar Formation (Td) is described as a dusky yellowish-green sandy claystone interbedded with medium- gray, coarse grained sandstone. The Del Mar formation is considered part of the La Jolla group. The Santiago Formation (Tsa) is described as consisting of three distinctive parts. A basal member that consists of buff and brownish- gray, massive, coarse-grained,poorly sorted arkosic sandstone and conglomerate (sandstone generally predominating). In some areas the basal member is overlain by gray and brownish gray(salt and pepper) central member that consists of soft, medium- grained, moderately well sorted arkosic sandstone. An upper member consists of gray, coarse - grained arkosic sandstone and grit. Throughout the formation are vertical interbeds, tongues and lenses often fossiliferous, lagoonal claystone and siltstone. The lower part of the Santiago Gafen 2898 Lone.lack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 5 of 17 formation interfingers with the Del Mar formation. (Kennedy&Tan, 2005). 3.2 Aerial Photograph Review On December 8, 2006, Applied Consultants reviewed aerial photographs of the subject property that are stored in the Cartography Department at the County of San Diego Operations Center located at 5201 Ruffin Road, San Diego, California 92123. Applied Consultants reviewed the aerial photographs in order to help to evaluate the stability of the subject site and adjacent area. The following table lists the photographs reviewed and a visual description of the subject property and adjacent area: Table 1: Summary of Aerial Photographs Reviewed Photograph Photograph Description Date Title 1953-1959 AXN 1M- Scarcely developed area. No properties exist on top of ridge. No visible signs of 17M landslide. 1967 GS-VBTA Scarcely developed area. No properties exist on top of ridge. No visible signs of landslide. 1978-1979 SDCO Area beginning development, Subject property and property to the southwest exist. (West) Subject property appears to be cut lot from near the ridge of the hill. No visible signs of landslide. 1989 WAC Area beginning development, Subject property and property to the southwest exist. (West) Property to the northeast does not exist. No visible signs of landslide. 3.3 Tectonic Setting There was no evidence of faults traversing the subject property observed during the site investigation. However, it should be noted that Southern California, including Encinitas and surrounding areas are located in an area of late Tertiary to Quaternary-aged fault zones (Kennedy 1975) which strike to the northwest conservatively. These fault zones are located in seismic zone N and correspond to intensities up to 8.0 on the Modified Mercalli scale. Some of these fault zones are known to be active according to the California Division of Mines and Geology. "Active" faults are ones which have had faulting activity within the Holocene Epoch, or the last 11,000 years (California Division of Mines and Geology). Some of the faults in the area are considered to be active, while others are considered "potentially active", or"inactive" as stated by the California Division of Mines and Geology. According to the County of San Diego, Faults and Epicenters Map (Department of Public Works, Cartographic Services, 1993), the closest known or suspected fault is an unnamed inferred fault Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 6 of 17 located approximately three miles to the east of the subject property. Accordingly, the subject property does not lie within an Alquist-Priolo Earthquake Fault Zone. The Rose Canyon Fault Zone lies approximately seven (8) miles to the west of the subject property. The La Nacion Fault Zone lies approximately twenty(20) miles to the southeast of the subject property. The Elsinore Fault Zone lies within 50-60 miles north east of the property. The San Jacinto and San Andreas Fault Zones lie between 80 and 100 miles to the east of the subject property, respectively. Each of these faults is considered active and has ruptured within the last 11,000 years. The following table is a compilation of expected peak horizontal ground acceleration at subject property based upon distance and magnitude of rupture event. Table 2: Summary as Estimated Peak Horizontal Accelerations at Subject Property Fault Name Distance Magnitude of Rupture Peak Horizontal Ground (Miles from Event Acceleration at Subject Property Subject Property) Unnamed Inferred 3 7.0 .08 g Rose Canyon 8 5.0 .27 g La Nacion 20 7.0 .15 g Elsinore 25 7.5 .13 g San Jacinto 49 8.0 .07 g San Andreas 74 8.0 .05 g An earthquake on any of these faults could cause mild to moderate damage at the subject property. 3.4 Seismic Design Parameters 3.4.1 Uniform Building Code Design Information Seismically related design parameters obtained from the Uniform Building Code (UBC) 1997 edition, Volume II, Chapter 16, are presented below. These design factors are based on subsurface soil and bedrock conditions and distance from known active faults. Table 3: Seismic Design Parameters UBC Chapter 16 Table No. Seismic Parameter Recommended Value 16-I Seismic Zone Factor Z 0.40 16-J Soil Profile Type S, 16-Q Seismic Coefficient Ca 0.44 Na Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 7 of 17 UBC Chapter 16 Table No. Seismic Parameter Recommended Value 16-R Seismic Coefficient Cv 0.64 Nv 16-5 Near Source Factor Na 1.0 16-T Near Source Factor Nv 1.2 16-U Seismic Source Type B 3.4.2 Maximum Bedrock Acceleration Based upon a Maximum Magnitude Earthquake of 7.0 magnitude along the nearest portion of the Rose Canyon Fault Zone, the Maximum Bedrock Acceleration at the site is estimated to be 0.27 g. For structural design purposes, we recommend a dampening ratio not greater that 5 percent of critical dampening. 3.5 Potential Geologic Hazards In our professional opinion, no geologic hazards of significant magnitude are present which would preclude the proposed new construction of a single family residence provided the recommendations in this report are followed. Ground Shaking is a likely hazard to the site. This is caused by the movement along active fault zones. The ground movement at the subject property could be mild to moderate depending on the distance from the epicenter of the seismic event. It is expected that the structure will have to endure this phenomenon to some degree. Liquefaction. The soils at the site and the ground water conditions are not conducive to liquefaction from earthquake activity. Liquefaction requires a shallow groundwater table and non- cohesive soils. The water table in this location is estimated to be greater than 50 feet below ground surface and the underlying soil is very dense and cohesive. Flooding. Given the hilltop location of the site, flooding is highly unlikely to occur. Landslide. Potential at the subject property was noted as a potential hazard due to the topography, underlying material and overall geology in the area. Our down-hole logging of the borings at the site revealed that no visible slide planes were observed in the sidewalls of the down hole boring. The formation was massive and undisturbed. Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 8 of 17 4.0 FIELD WORK On November 1, 2006 Applied Consultants supervised Larive Drilling Co. advancing two 24- inch diameter borings at locations to the south and north portions of the subject property. Applied Consultants logged the boreholes to a maximum depth of twenty two(22) and forty one and a half (41'/2) feet respectively in the borings. Following the completion of the boring a Registered Civil Engineer/Engineering Geologist logged the borehole from the bottom to the top to verify the findings. 5.0 FINDINGS The following soil structure was encountered in boring B-1 (see boring log): — zero to twelve fbg: light brown, dry, soft, fine sandy silt (SM) appeared to be structural fill. — drive sample (DS 1) obtained at 10 fbg blow counts 1-1-1. — twelve to twenty two fbg: dark greenish grey, slightly damp, soft, fine sandy silt (SM). — total depth twenty two fbg. — No ground water was encountered at a maximum depth of twenty two (22) feet below grade. Observation from the down hole logging observed that the bottom of the boring was dry and no seeps or springs were observed throughout the length of the boring. Additionally no slide planes were observed at the contacts of differing soil types. The following soil structure was encountered in boring B-2 (see boring log): — zero to eight fbg: light brown, dry, soft, fine sandy silt (SM) appeared to be structural fill. — eight to ten fbg: medium brown, slightly damp, soft, fine clayey silt (ML). — ten to thirteen fbg: light brown, dry, soft, fine silty sand (SM). — thirteen to fifteen: light brown, dry, medium dense fine silty sand(SM). — fifteen to twenty fbg: greenish grey, dry, medium dense fine clayey silt (ML). — twenty to thirty one fbg: dark grey, dry, dense, fine silty clayey silt (ML). Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 9 of 17 thirty one to thirty five fbg: greyish brown, dry, dense fine clayey silt (ML). thirty five to forty one and a half fbg: grey, dry, dense, fine clayey sandy silt(SC/ML). total depth 41'/2 fbg. No ground water was encountered at a maximum depth of forty one and a half(41'/2) feet below grade. Observation from the down hole logging observed that the bottom of the boring was dry and no seeps or springs were observed throughout the length of the boring. Additionally no slide planes were observed at the contacts of differing soil types. 6.0 CONCLUSIONS After reviewing the results of our geotechnical investigation Applied Consultants concludes that the slab cracking observed in the residence and the swimming pool is due to a plumbing leak that was unnoticed for an extended period of time. Additionally, Applied Consultants concludes that there are no significant geotechnical or geologic constraints that cannot be mitigated by proper planning, design, and the utilization of sound construction practices. It is our opinion that the proposed residential remodel is feasible from a geotechnical standpoint. Laboratory and visual analyses indicated the following: a. The depth of the fill soils was determined to be twelve feet below grade in the front of the residence (southeast) and eight feet in the rear of the residence (north). b. The native materials underlaying the site are suitable for supporting the loads, including the proposed remodeled residence for the subject property. C. No landslides were found throughout the lengths of the two of the boreholes on the subject property and review of historical aerial photographs. d. When properly compacted, the native and fill have good load bearing capacities. CONSTRUCTION INSPECTION AND LIMITATIONS The recommendations contained within this report are based upon Applied Consultants' field investigation. The interpolated subsurface conditions should be checked during construction by a representative of Applied Consultants. We recommend that all grading operations be observed by a representative of this firm. The recommendations contained within this report are based upon our field study, laboratory Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 10 of 17 analyses, and our understanding of the proposed construction. If any soil conditions are encountered differing from those assumed in this report, Applied Consultants should be immediately notified so that we may review the situation and make supplementary recommendations. Additionally, if the scope of proposed work changes from that described in this report Applied Consultants should be notified. This report has been prepared in accordance with generally accepted soil and foundation engineering practices within the greater San Diego area. Professional judgments contained herein are based upon our evaluation of the technical information gathered, our understanding of the proposed work, and our general experience in the geotechnical field. Our engineering work and judgments rendered meet current professional standards. We do not guarantee the performance of the project in any respect. We do not direct the contractor's operations and we cannot be responsible for the safety of field personnel on the site; therefore, the safety of field personnel during construction is the responsibility of the contractor. The contractor shall notify the owner if he considers any of the recommended actions contained herein to be unsafe. Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 11 of 17 FIGURES Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 12 of 17 N Alf 41 ACO, Tr�Ixl Nh �k Q /PSc 49 Geographic Location 2898 Lone Jack Road, Encinitas, CA Lat. 33 Deg. 03 min. 32 sec. Long. 117 Deg. 13 min. 29 sec. Elevation: 229ft MSL Site Location Map 2898 Lone Jack Road Fig: 1 Encinitas, California, USA SITE MAP N71.1g 3�E TB-2 APN: 264-151-28-00 z ° N TB-1 f 4+ 1W N 30 0 30' 60' 120' 0 Test Boring SCALE David Gaffen Residence ® APPLIED APN#264-151-28-00 Date: 12/13/06 0.06 CONSULTANTS 2898 Lone Jack Road Job#: SD670 670 Drawn by: ATH Encinitas California t Boring Log B-1 Location : 2898 Lone Jack Road, Encinitas, California Depth Boring Soil Description (fe0et) NOTES: 0-12' Light brown, dry, soft, fine sandy silt(SM) ` 10 12' - 22' Dark greenish grey, slightly damp, soft, fine sandy silt (SM) 20 Total Depth 22' 30 ��%�r%��%��%��r%�%�%�%�%�%�\��%r%�% \��i\NZiNIi N�i��i��i�ii�ii��i��i�ii�ii��i�ii� r\\ryr\ 160 ��r�� N �� LEGEND V�\EARTH� David Gaffen Residence Date: 12/13/06 APN# 264-151-28-00 Job #: SD6700.06 ONSLt ;A y t S 2898 Lone Jack Road Drawn by: ATH Encinitas, California Boring Log B-2 Location : 2898 Lone Jack Road, Encinitas, California Depth Boring (feet) Soil Description NOTES: 0 � 0-8' Light brown, dry, soft, fine sandy silt (SM) � � �� \ fill soils 8'-10' Light brown to dark brown, slightly damp, soft, fine clayey silt (ML) 10 10' - 13' Light brown, dry, soft, fine silty sand SM \/NN/�\\/XN/\\\ 13" - 15' Light orange brown, dry, medium dense, /\/,\� / fine silty sand (SM) 15' - 20 greenish grey, dry, medium dense, fine clayey silt(ML) 20' - 31' dark grey, dry, dense, fine silty clayey silt (ML) 31' - 35' grey brown, dry, dense, fine clayey silt (ML) 35' -41.5' grey, d ry, dense, fine clayey sandy silt 40 (SC/M L) Total Depth 41.5' j\x \j/\\�j\I\\I/I \/\�\/\/\�\/\�\/\�\/ N,X\111 IMII iN N I Z M 1 //\\/,\\/, LEGEND EARTH David Gallen Residence Date: 12/13/06 D'D : '=, APN# 264-151-28-00 Jab#: SD6700.06 Vr` A SUL , T 2898 Lone Jack Road Drawn by: ATH Encinitas, California APPENDIX A GENERAL EARTHWORK AND GRADING GUIDELINES Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 13 of 17 GENERAL EARTHWORK AND GRADING GUIDELINES I. EARTHWORK OBSERVATION AND TESTING Prior to commencement of grading, a qualified geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechnical report and these specifications. The consultant is to provide adequate testing and observation so that he may determine that the work was accomplished as specified. It should be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes so that the consultant may schedule his personnel accordingly. The contractor is to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes or agency ordinances, these specifications, and the approved grading plans. If in the opinion of the consultant, unsatisfactory conditions are resulting in a quality of work less than required in these specifications, the consultant may reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to determine the degree of compaction should be performed in accordance with the American Society for Testing and Materials Test Method ASTM: D 1557-82. H. PREPARATION OF AREAS TO BE FILLED 1. Clearing and Grubbing: All brush, vegetation, and debris shall be removed and properly disposed of The Geotechnical Consultant shall evaluate the extent of removal of these items depending on site conditions. Fill material shall not contain more than 1 percent of organic material by volume. No fill should contain more than 5 percent organic matter. No fill shall contain hazardous materials or asphalt pavement. If asphalt pavement is removed it should be disposed of at an appropriate location. Concrete fragments which are free of reinforcing steel may be placed in the fills. 2. Processing: the existing ground which is evaluated to be satisfactory for support of fill shall be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory shall be over-excavated as specified in the following section. Scarification shall continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform and free of uneven features which would inhibit uniform compaction. Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 14 of 17 3. Overexcavation: Soft, dry, spongy, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, shall be over- excavated down to firm ground as approved by the consultant. 4. Moisture Conditioning: Over-excavated and processed soils shall be watered, dried- back, blended, and/or mixed, as necessary to attain a uniform moisture content approximately 2 percent over optimum. 5. Recompaction: Over-excavated and processed soils which have been properly mixed and moisture-conditioned shall be compacted to a minimum relative compaction of 90 percent according to ASTM: D1557-82. 6. Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical units), the ground shall be benched. The lowest bench shall be: a minimum of 15 feet wide, at least 2 feet deep with a minimum 2% slope into the fill bank for horizontal stability, expose firm materials, and be approved by the consultant. Other benches shall excavated into firm material for a minimum width of 4 feet. Ground sloping flatter than 5:1 shall be benched or otherwise over-excavated when considered necessary by the consultant. 7. Approval: All areas to receive fill, including processed areas, removal areas, and toe- of-fill benches shall be approved by the consultant prior to fill placement. III. FILL MATERIAL 1. General: Material to be placed as fill shall be free of organic matter and other deleterious substances, and shall be approved by the consultant. Soils of poor gradation, expansion, or strength characteristics shall be placed in areas designated by the consultant or mixed with other soils until suitable to serve as satisfactory fill material. 2. Oversize: Oversize material defined as rock, or other irreducible material, with a maximum dimension of greater than 12 inches, shall not be buried or placed in fill unless the location, materials, and disposal methods are specifically approved by the consultant. Oversize disposal operations shall be such that nesting of oversize material does not occur, and such that the oversize material is completed surrounded by compacted or densified fill. Oversize material shall not be placed within the range of future utilities or underground construction, unless specifically approved by the consultant. 3. Import: If import fill is necessary for grading, the import material shall be approved by the geotechnical consultant. Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 15 of 17 IV. FILL PLACEMENT AND COMPACTION l. Fill Lifts: Approved fill material shall be placed in areas prepared to receive fill in near-horizontal layers not exceeding 6 to 8 inches in compacted thickness. The consultant may approve thicker lifts if testing indicates that the grading procedures are such that adequate compaction is being achieved with lifts of greater thickness. Each layer shall be spread evenly and shall be thoroughly mixed during spreading to attain uniformity of material and moisture in each layer. 2. Fill Moisture: Fill layers at a moisture content ed blescarif scarification or blended with drier and mixed, and wet fill layers shall be aerated y materials. Moisture conditioning and mixing of fill layers shall continue until the fill material is at a uniform moisture content at or near two percent over optimum. 3. Compaction of Fill:_ After each layer has 9,0 moisture conditioned percent of maxim m and mixed, it shall be uniformly compa cted to not less than dry density in accordance with ASTM: D1557-82. Compaction equipment shall be adequately sized and either specifically designed for soil compaction or of proven ve the specified degree of compaction. reliability, to efficiently achie 4. Fill Slopes_ Compacting of slopes shall be accomplished, in addition to normal compaction procedures,by backrolling of slopes with sheepsfoot rollers at frequent intervals of 2 to 3 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of the slope out to the slope face shall be at least 90 percent. 5. Compaction Testing: Field tests to check the fill moisture and degree of compaction will be performed by the consultant. Thslocation hall be taken at an interval nohex eedinge consultants discretion. In general, the to 2 feet in vertical rise and/or every 1000 cubic yards of embankment. V. SUBDRAIN INSTALLATION Subdrain systems, if required, shall be installed in approved ground to conform to the approximate alignment and details shown a the od plans eed without the herein. pproval sub he in location or materials should not be changed consultant. The consultant, however, may recommend and upon approval, direct changes in subdrain line, grade or material. All subdrains shall be surveyed for line and grade after installation and sufficient time allowed for surveys, prior to commencement of filling over the subdrains. VI. EXCAVATIONS Gafen 2898 Lone Jack Road Geotech Report.wpd page 16 of 17 ATH/BJL 12/13/06 Excavations and cut slopes shall be examined during grading. If directed by the consultant, further excavation or overexcavation and refilling of cut areas shall be performed, and/or remedial grading of cut slopes performed. Where fill-over-cut slopes are to be graded, unless otherwise approved, the cut portion of the slope shall be made and approved by the consultant prior to placement of the fill portion of the slope. Excavations may require the consultant to produce an alternate sloping plan if the excavation VII. TRENCH BACKFILL 1. The Contractor shall follow all OSHA and CAL/OSHA requirements for maintaining safety of trench excavations. 2. The bedding and backfill of utility trenches should be done with the applicable provisions of Standard Specifications of Public Works Construction. Bedding material should have a sand equivalent of(SE )30). Bedding should be placed to 1 foot above the top of pipe. All backfill should be compacted to 90 percent form 1 foot above the pipe to the surface. 3. The geotechnical consultant should test the trench backfill for relative compaction. At least one test should be performed for every 300 feet of trench and every two feet of trench fill. 4. The lift thickness of the trench backfill shall not exceed what is allowed in the Specifications of Public Works Construction unless the contractor can demonstrate that the fill can be compacted by an alternative means to the minimum relative compaction. VIII. FOUNDATIONS NEAR TOP OF SLOPES Where foundations, footings, walls and other similar proposed structures are to be located seven feet and further away from the top of slopes standard design may take place in conformance with the recommended soil bearing value. In situations where foundations, footings, walls et cetera are located closer than seven feet from the top of slope shall be deepened so that the bottom edge of the footing is 7 feet horizontally from daylight in the slope. Gafen 2898 Lone Jack Road Geotech Report.wpd ATH/BJL 12/13/06 Page 17 of 17 3040 Clairemont Dr. Suite B San Diego,CA — ------------ c 92117 APPLIED TEL 1619!275-6577 CONSULTANTS FAX (619)275-6947 Civil Engineers& Geologists January 9, 2007 Mr. David Gafen D. G. Electric hydrogeologyP.O. BOX 22792 San Diego, California 92192 geotechnical services Subject: Laboratory Determined Load Bearing Capacity and Active and Passive Pressures from the Geotechnical Investigation for the Subject Property Located at 2898 Lone Jack environmental services Road, Encinitas, California Assessors Parcel Number(APN) 264-151-28-00. Dear Mr. Gafen: structural engineering In accordance with your request,Applied Consultants has preformed the following soils analysis forensic engineering on the soil sample obtained during the geotechnical investigation that was performed on November 1, 2006. The following table is a compilation of Applied Consultants' soils analyses results from samples collected from locations near the proposed new: Applied Consultants Soils Analyses Results Dry Shear Testing Expansion Index Sample Field Field Max Opt.Moist. ID Moisture Density Density (%) Phi Cohesion (%) Potential Content(%) ( cfl ( cfl (angle) ( sfl DS IA IO'bg 12.0% 1 111.3 115.0 14.0 28 1 600 From the determined soil parameters, Applied Consultants calculated the load bearing capacity of the underlying soils to be the following: Sample ID Depth(in.) Width(in.) Load Bearing Capacity(psfl DS-1 18 12 3,500 In addition to the load bearing capacity Applied Consultants has determined the following for any proposed earth retaining structures a. Active Pressures It is recommended that structures be able to withstand an active fluid pressure of 41.52 pcf for unrestrained walls. The retaining structure should have a granular backfill with a level surface and adequate drainage to prevent the build up of hydrostatic pressures. The architect should provide details for the drainage and waterproofing of the retaining Gafen 2898 Lone Jack Road Soils Analysis Letter.wpd ATH/BJL 1/09/07 structures. b. Passive Pressures Passive pressures for the soil conditions at the subject site should be 318.5 pounds per square foot per foot of depth. The pressure may be increased by .25 for seismic loading. The coefficient of friction for concrete against soil should be.35 for the lateral resistance. Upon completion of our investigation, Applied Consultants found that there are no significant geotechnical or geologic constraints that cannot be mitigated by proper planning, design, and the utilization of sound construction practices. Consequently it is our opinion that the development of the site is feasible from a geotechnical standpoint. We appreciate this opportunity to be of service. Should you have any questions please call our office at (619) 275-6577. Sincerely, Applied Consultants, Inc. Z141 � Aaron T. Hill -- B and J. Luther, RCE 63653, CEG 1356 Project Geologist President cc: (3) cc �� o4. is" �' Gafen 2898 Lone Jack Road Soils Analysis Lettenwpd ATH/BJL 1/09/07 Page 2 of 2 3040 Clairemoi « San Died ;A 9- 1 APPLIED TEL (619)275-�,5 CONSULTANTS FAX n619) Civil Engineers & Geologists June 23, 2008 hydrogeology Mr. Norbert Lohse, Architect geotechnical services Lohse2 1270 Morena Boulevard San Diego, California 92110 environmental services Subject: Grading at Gafen Residence, 2898 Lone Jack Road, Encinitas, California. structural engineering Dear Mr. Lohse: forensic engineering In accordance with your request we have supervised the grading along the southern side of the above-mentioned property. All keys were inspected and approved by our geotechnical engineer and the fill was tested in two foot lifts throughout the grading process. All work was performed in complete conformance with our geotechnical recommendations. Please feel free to call our offices if you have any questions. Sincerely, �]Ternard J. Luther, RCE 63653, CEG 1356 CEO No.cam. n"°.