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Home My WebLink AboutCDP 07-12; Sears Residence; Soils Report; 2008-08-22RECORD COPY Initial ?M Date GEOTECHNICAL INVESTIGATION Proposed Single-Family Residence 4015 Sunnyhill Drive Carlsbad, California 1 RECEIVED AUG222GG8 ENGINEERING DEPARTMENT saensuaifc EHaucar M wps, ] 3 3 o J HETHERINGTON ENGINEERING, INC. HETHERINGTON ENGINEERING, INC. SOIL & FOUNDATION ENGINEERING • ENGINEERING GEOLOGY • HYDROGEOLOGY I 1 1 J I 1 1 1 September 18,2007 Project No. 5979.1 Log No. 11087 Mr. Tom Sears 13 87 Cynthia Lane Carlsbad, California 92008 Subject: GEOTECHNICAL INVESTIGATION Proposed Single-Family Residence 4015SunnyhillDrive Carlsbad, California References: Attached Dear Mr. Sears: In accordance with your request, Hetherington Engineering, Inc. has performed a geotechnical investigation for a proposed single-family residence to be located at the subject site. Our work was performed in August and September 2007. The purpose of the investigation was to evaluate geologic and soil conditions within the areas intended for new construction, and to provide grading and foundation recommendations for the proposed residential structure. With the above in mind, our scope of work included the following: • Research and review of available plans and geologic literature pertinent to the site vicinity (see References). • Subsurface exploration consisting of three hand-excavated exploratory test pits for soil sampling and geologic observation. • Laboratory testing of samples obtained from the subsurface exploration. • Engineering and geologic analysis. • Preparation of this report providing the results of our field and laboratory work, analyses, and our conclusions and recommendations. 5205 Avenida Encinas, Suite A • Carlsbad, CA 92008-4369 • (760) 931-1917 • Fax (760) 931-0545 32242 Paseo Adelanto, Suite C • San Juan Capistrano, CA 92675-3610 • (949) 487-9060 • Fax (949) 487-9116 www.hetheringtonengineering.com \ 1 1 1 GEOTECHNICAL INVESTIGATION Project No. 5979.1 Log No. 11087 September 18,2007 Page 2 SITE DESCRIPTION The subject property is located at 4015 Sunnyhill Drive within the city of Carlsbad, California (see Location Map, Figure 1). The site consists of a roughly triangular-shaped, approximately 0.5-acre undeveloped lot. Minor cut and fill grading has been performed in the past, creating a level pad area across the majority of the lot. Minor amounts of fill appear to have been placed in the west-central part of the lot, over a natural 5:1 (horizontal to vertical) slope that descends to the west. The property is bounded by similar residential parcels to the south and west, by a private driveway to the north, and by Sunnyhill Drive to the east. PROPOSED DEVELOPMENT Although no detailed development plans were available at the time of this report, we understand that the proposed construction consists of a two-story, single-family residence with attached garage. We anticipate the structure will be of relatively light wood-frame construction, founded on conventional continuous/spread footings with slab-on-grade ground floors. It is anticipated that the structure will be constructed at existing site grade and that grading will consist of minor remedial earthwork. SUBSURFACE EXPLORATION Subsurface conditions were explored by excavating three hand-excavated test pits to depths ranging from 2 to 5-feet below existing site grades. The approximate locations of the test pits are shown on the attached Plot Plan, Figure 2. The subsurface exploration was supervised by a geologist from this office, who visually classified the soil and bedrock materials, and obtained bulk and relatively undisturbed samples for laboratory testing. The soils were visually classified according to the Unified Soil Classification System. Soil classifications are shown on the attached Logs of Test Pits, Figures 3 and 4. LABORATORY TESTING Laboratory testing was performed on samples obtained during the subsurface exploration. Tests performed consisted of the following: • Dry Density and Moisture Content (ASTM: D 2216 and D 293 7) • Sulfate Content (EPA 903 8) HETHERINGTON ENGINEERING, INC. ,%%%*- ^Hf^&v/: YUfe. a ^^Sf^Li•fc V ' \S&' \ J ^.••«.»-S—>. 4i—r-" ! "I •,/•«.. sr!! tt1, - =SUTT|R ^^Jjuw^aT^- ^l^^SL!,,NciR .5 -rtsf ^.'/-s— -15. \ ^ %« ojAKI*; A1 <i. w\%--- \ Wwi|^i •.<^a»- \ XAfiit. li?'* f**'"^_ 'i <i t-+-^i-f*> 1 &pG<vav-*«—t\^ 1W4\VX ^^^ ^fr>: "- X i_fV. \x' - * _L\^, ^ \ft> ADAPTED FROM: The Thomas Guide, San Diego County, 2006 Edition, Page 1106 i N I SCALE: T-2000' (1 Grid = 0.5x0.5 miles) LOCATION MAP HETHERINGTON ENGINEERING, INC. GEOTECHNICAL CONSULTANTS 4015 Sunnyhill Drive Carlsbad. California PROJECT NO. 5979.1 FIGURE NO.1 1 GEOTECHNICAL INVESTIGATION Project No. 5979.1 Log No. 11087 September 18, 2007 Page 3 • Direct Shear (ASTM: D 3080) • Expansion Index (ASTM: D 4829) • Maximum Dry Density/Optimum Moisture Content (ASTM: D 1557-02) Results of the dry density and moisture content determinations are presented on the Logs of Test Pits, Figures 3 and 4. The remaining laboratory test results are presented on the Laboratory Test Results, Figure 5. SOIL AND GEOLOGIC CONDITIONS 1. Geologic Setting The subject site is located within the coastal plain region of northern San Diego County, California. The site region is characterized by moderately to gently sloping hillsides and coastal bluffs composed of Eocene sedimentary bedrock that is capped at various elevations by relatively level to gently westward sloping Pleistocene regressive marine terraces. The subject property is contained within the southwestern portion of the U.S.G.S San Luis Rey 7-1/2 minute quadrangle. As observed in the subsurface excavations, the site is underlain by fill and Quaternary sedimentary marine and non-marine terrace deposits. No evidence of adverse geologic structure, faulting, or groundwater was observed in the test pits. 'i 2. Geologic Units a. Fill/Topsoil - Approximately 2 feet of fill/topsoil is present within the central 1 portion of the lot, consisting of brown, damp, loose, slightly gravelly silty fine sand. The fill is not considered suitable for support of the proposed improvements in its existing condition. y b. Topsoil - Up to approximately 2 feet of topsoil covers the entire site and consists of loose to medium dense, porous, light to dark brown silty fine sand. The topsoil jp ' is not considered suitable for the support of the proposed improvements in its y existing condition. c. Terrace Deposits - Encountered in all test pits below the fill and topsoil wastterrace deposits consisting of damp, dense to very dense, orange brown silty fine sand. The dense terrace deposits are considered suitable for support of structures and fill placement. I I I i I 1 1 HETHERINGTON ENGINEERING, INC. j 1 1 1 1 1 GEOTECHNICAL INVESTIGATION Project No. 5979.1 Log No. 11087 September 18,2007 Page 4 3. Groundwater No seepage or static groundwater was encountered in the exploratory test pits. It should be noted, however, that fluctuations in the amount and level of groundwater may occur due to variations in rainfall, irrigation, and other factors that might not have been evident at the time of our field investigation. SEISMICITY The site is located within the seismically active southern California region. There are, however, no known active or potentially active faults presently mapped that pass through the site nor is the site located within the presently defined limits of an Alquist-Priolo Earthquake Fault Zone. Active or potentially active fault zones within the site region include the Rose Canyon, Coronado Bank and Elsinore (Julian Segment). Strong ground motion could also be expected from earthquakes occurring along the San Jacinto and San Andreas fault zones, which lie northeast of the site at greater distances, as well as a number of other offshore faults. The following table lists the known active faults that would have the most significant impact on the site: Fault Newport-Inglewood/Rose Canyon (9-kilometers SW) Elsinore (Julian Segment) (37-kilometersNE) Coronado Bank (40-kilometers SW) Maximum Probable Earthquake (Moment Magnitude) 7.2 7.1 7.6 Slip Rate (mm/year) 1.5 5 3 Fault Type B A B SEISMIC EFFECTS 1. Ground Accelerations The most significant probable earthquake to affect the site would be a 7.2 magnitude earthquake on the Rose Canyon fault zone. Depiction of probabilistic seismic hazard analysis utilizing a consensus of historical seismic data and the respective regional geologic conditions that are shown on the "Probabilistic Seismic Hazards Assessment HETHERINGTON ENGINEERING, INC. I I I I 1 1 1 1 GEOTECHNICAL INVESTIGATION Project No. 5979.1 Log No. 11087 September 18,2007 PageS Model" (April 2003) and the "The Revised 2002 California Probabilistic Seismic- Hazard Maps" indicate that peak ground accelerations of about 0.27 to 0.29g are possible with a 10% probability of being exceeded in 50-years (References 2 and 4). 2. Ground Cracks The risk of fault surface rupture due to active faulting is considered low due to the absence of known active faulting on site. Ground cracks due to shaking from seismic events in the region are possible, as with all of southern California. 3. Landsliding Due to the absence of slopes in the immediate site vicinity, the risk of landsliding is considered negligible. 4. Liquefaction The risk of seismically induced liquefaction within the site is considered low due to lack of shallow ground water and the dense nature of the underlying terrace deposits. I 5. Tsunamis Due to the elevation of the property and its distance to the coast, the potential for seismically generated ocean waves impacting the site is considered negligible. CONCLUSIONS AND RECOMMENDATIONS 1. General The proposed development is considered feasible from a geotechnical standpoint. Grading and foundation plans should take into account the appropriate geotechnical features of the site. The proposed construction is not anticipated to adversely impact the adjacent properties from a geotechnical standpoint provided the recommendations presented in this report and good construction practices are implemented during design and construction. HETHERINGTON ENGINEERING, INC. I I I I 1 1 1 1 1 GEOTECHNICAL INVESTIGATION Project No. 5979.1 Log No. 11087 September 18, 2007 Page 6 2. Seismic Parameters for Structural Design Seismic considerations that should be used for structural design at the site include the following: a. Ground Motion - The proposed structure should be designed and constructed to resist the effects of seismic ground motions as provided in Chapter 16, Division IV-Earthquake Design of the 2001 California Building Code (CBC). The basis for the design is dependent on and considers seismic zoning, site characteristics, occupancy, configuration, structural system and building height. b. Soil Profile Type - In accordance with CBC Section 1629.3.1, Table 16-J, and the underlying geologic conditions, a site Soil Profile of Type SD is considered appropriate for the subject property. c. Seismic Zone - In accordance with CBC Section 1629.4.1 and Figure 16-2, the subject site is situated within Seismic Zone 4. d. Seismic Zone Factor (z) - A Seismic Zone Factor of 0.40 is assigned based on CBC Table 16-1. Since the site is within Seismic Zone 4, CBC Section 1629.4.2 requires a Seismic Source Type and Near Source Factors. I e. Near-Source Factors (Na and Nv) - Based on the known active faults in the region and distance of the faults from the site, a Seismic Source Type of B per CBC Table 16-U, and Near Source Factors of Na = 1.0 per Table 16-S and Nv = I 1.04 per Table 16-T are provided. f. Seismic Coefficients (Ca and Cv) - Using the Soil Profile Type and Seismic ZoneIFactor along with CBC Tables 16-Q and 16-R, the Seismic Coefficients Ca = 0.44 /"Mo"* on/-1 rV = C\ 6.A rXT-iT1* a»v» nrnij\Aar\ nv C'r* = f\ A A oti/1 C^ir = (\ £.7(Na) and Cv = 0.64 (Nv) are provided, or Ca = 0.44 and Cv = 0.67. 3. Slope Stability The site is relatively flat and no significant cut or fill slopes are anticipated. 4. Site Grading a. Clearing and Grubbing - Existing vegetation and miscellaneous debris within the limits of proposed grading should be removed to an appropriate offsite disposal area. Holes resulting from the removal of buried obstructions, which extend HETHERINGTON ENGINEERING, INC. 1 1 1 1 1 1 GEOTECHNICAL INVESTIGATION Project No. 5979.1 Log No. 11087 September 18, 2007 Page 7 below finished site grades, should be replaced with compacted fill. In the event that abandoned cesspools, septic tanks or storage tanks are discovered during the excavation of the site, they should be removed and backfilled in accordance with local regulations. Existing utility lines to be abandoned should be removed and capped in accordance with the local requirements. i i m '••'fctsjas*'"' I 1 b. Removal of Unsuitable Soils - In the area of proposed structures, driveways, and I appurtenances; all fill and topsoil and other material deemed unsuitable by the J Geotechnical Consultant should be removed to dense terrace deposits. Removals are anticipated to extend approximately 2 to 4-feet below existing site grades and I should extend to at least 5-feet beyond the limits of all proposed improvements and structures. Final removal depths should be determined by the Geotechnical Consultant during site grading. I c. Scarification - After the required removals have been made, all areas to receive fill should be scarified to a minimum depth of 6 to 8-inches, brought to near 1 optimum moisture content, and compacted to at least 90 percent relative compaction (ASTM: D 1557-02). I d. Compacted Fill - Fill soils should be moisture conditioned to about optimum moisture content and compacted by mechanical means in uniform horizontal lifts of 6 to 8-inches in thickness. All fill should be compacted to a minimum relative 1 compaction of 90 percent based upon ASTM: D 1557-02. The on-site materials are suitable for use as compacted fill. Rock fragments over 6-inches in dimension and other perishable or unsuitable materials should be excluded from the fill. All 1 grading and compaction should be observed and tested by the Geotechnical * Consultant. 5. Foundation and Slab Recommendations The proposed structure may be supported on conventional continuous/spread footings founded at least 12-inches below adjacent grade for one-story structures and 18- inches below adjacent grade for two-story structures and bearing into approved terrace deposits and/or compacted fill. Continuous footings should be at least 12- inches wide for one-story structures and 15-inches wide for two-story structures, and reinforced with a minimum of two #4 bars, one top and one bottom. Foundations located adjacent to utility trenches should extend to below a 1:1 plane projected upward from the bottom of the trench. HETHERINGTON ENGINEERING, INC. I I I I I 1 1 I 1 I 1 1 1 1 ir l GEOTECHNICAL INVESTIGATION Project No. 5979.1 Log No. 11087 September 18,2007 PageS Foundations bearing as recommended may be designed for a dead plus live load bearing value of 2000-pounds-per-square-foot. This value may be increased by one- third for loads including wind and seismic forces. A lateral bearing value of 250- pounds-per-square-foot per foot of depth and a coefficient of friction between foundation soil and concrete of 0.35 may be assumed. These values assume that footings will be poured neat against the foundation soils. Footing excavations should be observed by the Geotechnical Consultant prior to the placement of reinforcing steel in order to verify that they are founded in suitable bearing materials. Slab-on-grade floors should have a minimum thickness of 4-inches (actual) and should be reinforced with #3 bars spaced at 18-inches, center-to-center, in two directions, and supported on chairs so that the reinforcement is at mid-height hi the slab. Floor slabs should be underlain by a 4-inch layer of clean sand with at least a 10-mil visqueen vapor barrier placed in the middle of the sand layer. Consideration should be given to providing contraction joints to control shrinkage cracking. 6. Concrete Flatwork Concrete flatwork should be at least 4-inches thick and reinforced with at least No. 3 bars placed at 18-inch on center (two directions) and placed on chairs so that the reinforcement is in the center of the slab. Slab subgrade should be thoroughly moistened prior to placement of concrete. Contraction joints to control concrete shrinkage should have a maximum spacing of 10-feet. Joints should create square panels where possible. For rectangular panels (where necessary), the long dimension should be no more than 1.5 tunes the short dimension. Joint depth should be at least 0.25 the flatwork thickness. Flatwork subgrade should be scarified to a depth of 6 to 8-inches, brought to near optimum moisture content, and compacted to at least 90-percent relative compaction (ASTM: D 1557-02). All subgrade should exhibit a firm and unyielding condition prior to the placement of the concrete. 7. Soluble Sulfate Representative samples of the on-site soils were submitted for sulfate analyses. The results of the soluble sulfate tests per EPA 9038 methods are presented on the attached Laboratory Test Results, Figure 5. The sulfate content of the on-site soils is consistent with a negligible sulfate exposure classification per Table 19-A-4 of the HETHERINGTON ENGINEERING, INC. i i I i i 3 1 1 1 1 1 1 GEOTECHNICAL INVESTIGATION Project No. 5979.1 Log No. 11087 September 18, 2007 Page 9 2001 California Building Code. Consequently, special provisions for sulfate resistant concrete are not considered necessary 8. Retaining Walls Retaining walls free to rotate (cantilevered walls) should be designed for an active pressure of 35-pounds-per-cubic-foot (equivalent fluid pressure) assuming level backfill consisting of the granular on-site soils and 43-pounds-per-cubic-foot for backfill sloping at 2:1 (horizontal to vertical). Walls restrained from movement at the top should be designed for an additional uniform soils pressure of 8xH pounds per square foot where H is the height of the wall in feet. Any additional surcharge pressure behind retaining walls should be added to these values. Retaining wall footings should be designed in accordance with the previous building foundation recommendations. Retaining walls should be provided with adequate drainage to prevent buildup of hydrostatic pressure and should be adequately waterproofed. The subdrain system behind the retaining wall should consist of at least 4-inch diameter Schedule 40 (or equivalent) perforated (perforations down) PVC pipe embedded in at least 1-cubic-foot of 3/4 inch crushed rock per lineal foot of pipe all wrapped in approved filter fabric. Recommendations for wall waterproofing should be provided by the project Architect and/or Structural Engineer. 9. Trench and Retaining Wall Backfill All utility trench and retaining wall backfill should be compacted to at least 90 percent relative compaction (ASTM: Dl557-02) and tested by the Geotechnical Consultant. 10. Site Drainage The following recommendations are intended to minimize the potential adverse effects of water on the structure and appurtenances. Surface drainage should be designed by the project Architect and/or Civil Engineer. a. Consideration should be given to providing the structure with roof gutters and downspouts that discharge to an area drain system and/or to suitable locations away from the structure. b. All site drainage should be directed away from the structure. The on-site soils are generally sandy in nature and considered moderately credible if exposed to concentrated drainage. HETHERINGTON ENGINEERING, INC. GEOTECHNICAL INVESTIGATION Project No. 5979.1 Log No. 11087 September 18, 2007 Page 10 c. No landscaping should be allowed against the structure. Moisture accumulation j or watering adjacent to foundations can result in deterioration of wood/stucco and may affect foundation performance. I d. Irrigated areas should not be over-watered. Irrigation should be limited to that required to maintain the vegetation. Additionally, automatic systems must be (seasonally adjusted to minimize over-saturation potential particularly in the winter (rainy) season. I e. All yard and roof drains should be periodically checked to verify they are clear and flow properly. This may be accomplished either visually or, in the case of subsurface drains, by placing a hose at the inlet and checking the outlet for flow. I 11. Recommended Observations and Testing During Construction I The following tests and/or observations by the Geotechnical Consultant are recommended: I a. Observation and testing of all fill bottom cleanouts and grading. b. Foundation excavations prior to placement of forms and reinforcing steel. » c. Interior and exterior utility trench backfill, i d. Flatwork subgrade. e. Retaining wall backfill and drain placement. 12. Grading and Foundation Plan Review I Grading and foundation plans should be reviewed by the Geotechnical Consultant to confirm conformance with the recommendations presented herein or to modify the recommendations as necessary. I 1 1 I LIMITATIONS The analyses, conclusions and recommendations contained in this report are based on site conditions, as they existed at the time of our investigation and further assume the excavations to be representative of the subsurface conditions throughout the site. If HETHERINGTON ENGINEERING, INC. I I I 1 1 I 1 1 1 1 GEOTECHNICAL INVESTIGATION Project No. 5979.1 Log No. 11087 September 18, 2007 Page 11 different subsurface conditions from those encountered during our exploration are observed or appear to be present in excavations, the Geotechnical Consultant should be promptly notified for review and reconsideration of the recommendations. Our investigation was performed using the degree of care and skill ordinarily exercised, under similar circumstances, by reputable Geotechnical Consultants practicing in this or similar localities. No other warranty, express or implied, is made as to the conclusions and professional advice included in this report. This opportunity to be of service is sincerely appreciated. If you have any questions, please call this office. Sincerely, Hetherington Engineering, Inc. Micher-ArVascbncellos Professional Geologist 793 Certified Engineering Ge (expires 1/31/09) MV/DC/dkw Distribution: 4-Addressee Attachments: Location Map Plot Plan Logs of Test Pits Laboratory Test Results Danny Cohen Registered Civil Engi Geotechnical Enim (expires 3/31/08) Figure 1 Figure 2 Figures 3 and 4 Figure 5 HETHERINGTON ENGINEERING, INC. I 1 I I I REFERENCES 1. Aerial Photographs, Flight GS-VBTA, Photos 1-143 and 1-444, dated May 8, 1967. 2. California Geological Survey "Probabilistic Seismic Hazards Assessment Model," 2002 (Revised April 2003). 3. California Division of Mines and Geology, "Planning Scenario for a Major Earthquake, San Diego - Tijuana Metropolitan Area," Special Publication 100, dated 1990. 1 4. Cao, Tianging, et al "The Revised 2002 California Probabilistic Seismic Hazard Maps," dated June 2003. 5. ICBO, "California Building Code," 2001 Edition. 6. ICBO, "Maps of Known Active Faults Near-Source Zones in California and Adjacent Portions of Nevada," dated February 1998. 7. Jennings, Charles W., "Fault Activity Map of California and Adjacent Areas," California Data Map Series, Map No. 6, dated 1994. 1 8. Kennedy, Michael P., "Geology of the San Diego Metropolitan Area, California," California Division of Mines and Geology, Bulletin 200, dated 1975. 9. Kennedy, Michael P., "Geologic Maps of the Northwestern Part of San Diego I County, California" California Division of Mines and Geology, Open File Report 96- 1 02, dated 1996. 1 10. Kennedy, Michael P., et al., "Character and Recency of Faulting, San Diego Metropolitan Area, California," Special Report 123, dated 1975 11. Peterson, M., Beeby, W., Bryant, W., et al., "Seismic Shaking Hazard Maps of I California," California Division of Mines and Geology, Map Sheet 48, dated 1999. 12. Tan, Siang S., "Landslide Hazards in the Northern Part of the San Diego Metropolitan (Area, San Diego County, California, Landslide Hazard Identification Map No. 35", dated 1995. 13. Weber, F. Harold, "Recent Slope Failures, Ancient Landslides and Related Geology of the North-Central Coastal Area, San Diego County, California" California Division of Mines and Geology, Open File Report 82-12, dated 1982. I I 1 I I I I 1 Project No. 5979.1 Log No. 11087 HETHERINGTON ENGINEERING, INC. .1 p •j j i \. '\ TERRACE DEPOSITS \ TP-2Bf TERRACE DEPOSITS HiTP-1 '''••'- •''\-":-."~&-'' .->'-" ' •fff ^M O *=~j=-.r T^T^gs. TERRACEDEPOSITS 1 D 10 20 30 i I 40 LEGEND TP-3 H APPROXIMATE LOCATION OF TEST PIT X ^ -^ *S APPROXIMATE GEOLOGIC CONTACT \ C/' / PLOT PLAN HETHERINGTON ENGINEERING, INC. GEOTECHNICAL CONSULTANTS 4015SunnyhillDrive Carlsbad, California PROJECT NO. 5979.1 FIGURE NO. 2 O I •o I I I I I I I I 1 BACKHOE COMPANY: HEI BUCKET SIZE: Hand Pit DATE: 08/21/07 H aa. HW bSiu.u 5.0— _ ; •in n BULKSAMPLEX X DENSITYTEST>d DRYDENSITY(pcf)131 113 120 MOISTURECONTENT(%)3.2 10.0 8.9 CO ^w • «C CO CJ CJ J CO H SM SOIL DESCRIPTION TESTPITNO.TP-1 ELEVATION: 239 + FILUTOPSOIL: Medium to dark brown, slightly gravelly, silty fine A sand, damp, medium dense, few fine root hairs, slight porosity f TERRACE DEPOSITS: Light brown silty fine sand, damp, medium dense, massive, moderately weathered @ 1 .75': Orange brown silty fine sand, damp, dense to very dense, massive Total depth 3.5 feet No groundwater No caving — IU.U TESTPITNO.TP-2 ELEVATION: 239 t 0.0 7\ -X m m m 111 109 119 6.9 5.6 19.6 SM SM FILUTOPSOIL: Light brown, slightly gravelly, silty fine sand, damp, loose to medium dense few roots, slight porosity TOPSOIL: Dark brown silty fine sand, damp to moist, medium dense, fine root hairs TERRACE DEPOSITS: Orange brown silty fine sand, damp, dense to very dense, massive Total depth 5 feet No groundwater No caving — — — LOG OF TEST PITS 4015 Sunnyhill Drive HETHERINGTON ENGINEERING, INC. Carlsbad, California GEOTECHNICAL CONSULTANTS PROJECT NO. 5979.1 FIGURE NO. 3 1 ] I] BACKHOE COMPANY: HEI BUCKET SIZE: Hand Pit DATE: 08/21/07 EH Wcu aw faQ — hO.O • 1 ] 5.0 10.0-BULKSAMPLEDENSITYTESTDRYDENSITY(pcf)H 02 EH 3 2EH H CO EHM 2 —O O c*>s u — CO -~ rt co u u t-3 CO M O => CO ~ SM SOIL DESCRIPTION TESTPITNO.TP-3 ELEVATION: 232 FILL/TOPSOIL: Light to medium brown, slightly gravelly, silty fine sand, damp, loose TERRACE DEPOSITS: Orange brown silty fine sand, damp, dense to very dense, massive Total depth 2 feet No groundwater No caving f i LOG OF TEST PITS HETHERINGTON ENGINEERING, INC. GEOTECHNICAL CONSULTANTS 4015Sunnyhill Drive Carlsbad, California PROJECT NO. 5979.1 FIGURE NO. LABORATORY TEST RESULTS 1'1] 1 DIRECT SHEAR (ASTM: D 3080) Sample Location TP-l@1.5'-2.5' Angle of Internal Friction (°) 31 Cohesion (psf) 100 Remarks Remolded to 90% of maximum dry density, consolidated, saturated, drained SULFATE TEST RESULTS (EPA 9038) Sample Location Soluble Sulfate in Soil (%) TP-2 @ 0 - 0.5'0.0289 1 1 Jc I EXPANSION INDEX (ASTM: D 4829) Sample Location TP-l®1.5'-2.5' TP-2 @ 0.5' -1.0' Initial Moisture (%) 10.4 9.6 Compacted Dry Density (pcf) 119.0 112.6 Final Moisture (%) 17.6 14.6 Expansion Index 17 0 Expansion Potential Very low Very low i I I I I IfI MAXIMUM DRY DENSITY/OPTIMUM MOISTURE CONTENT (ASTM: D 1557-02) Sample Location TP-l@1.5'-2.5' TP-2 @ 0-2' Description Orange brown silty fine sand Brown silty fine sand Maximum Dry Density (pcf) 122.0 125.5 Optimum Moisture Content (%) 13.0 9.5 Figure 5 Project No. 5979.1 Log No. 11087