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Home My WebLink AboutCDP 11-15; BARELMANN JUNIPER RESIDENCE; LIMITED GEOTECHNICAL INVESTIGATION; 2011-06-14C/OP It - EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 (619)258-7901 Fax 258-7902 Robert Barelmann June 14, 2011 P.O. Box 1698 Project No. 1 1-1 106E7 Carlsbad, California 92008 Subject: Limited Geotechnical Investigation Proposed Single-Family Residence andDetached Garage 150 Juniper Avenue Carlsbad, California 92008 Dear Mr. Barelmann: In accordance with your request, we have performed a limited geotechnical investigation at the subject site to discuss the geotechnical aspects of the project and provide recommendations for the proposed development. Our investigation has found that the subject site is underlain by topsoil to a depth of approximately 18 inches below existing grade. Dense sandstone of the Terrace Deposits Formation was underlying the topsoil to the explored depth of 10 feet. It is our opinion that the proposed development is geotechnically feasible provided the recommendations herein are implemented in the design and construction. Should you have any questions with regard to the contents of this report, please do not hesitate to contact our office. Respectfully submitted, No. GE 2704 wi in Exp: L-i-" ik Mamadou Saliou Diallo, P.E. RCE 54071, GE 2704 MSD\md C61 1 4(° I ROBERT BARELMANN/JUNIPER AVENUE PROJECT NO. 11-1106E7 TABLE OF CONTENTS INTRODUCTION...............................................................................................................................................3 SCOPE OF SERVICES......................................................................................................................................3 SITE DESCRIPTION AND PROPOSED CONSTRUCTION ........................................................................3 FIELD INVESTIGATION AND LABORATORY TESTING........................................................................4 GEOLOGY.........................................................................................................................................................4 GeologicSetting ......................................................................... ........................................................... 4 SiteStratigraphy ............... . ..................................................................................................................... 4 SEISMICITY......................................................................................................................................................5 RegionalSeismicity ......................................................................... ...................................................... 5 SeismicAnalysis ...................................................................................................................................5 2010. CBC Seismic Design Criteria ......................................................................................................5 Geologic Hazard Assessment................................................................................................................6 GEOTECHNICALEVALUATION ................................................................................................. . ................ 6 CompressibleSoils .................................................................................................................................7 ExpansiveSoils......................................................................................................................................7 Groubdwater........................................................................................................................................ . .7 CONCLUSIONS AND RECOMMENDATIONS ............................................................................................ 7 GRADINGAND EARTHWORK......................................................................................................................7 Clearingand Grubbing ..........................................................................................................................8 Structural Improvement of Soils ............................................................................................................... 8 Transitions Between Cut and Fill .... ...................................................................................................... 8 Method and Criteria of Compaction......................................................................................................9 ErosionControl ...................................................................................................................................... 9 StandardGrading Guidelines ................................................................................................................. 9 FOUNDATIONSAND SLABS ........................................................................................................................9 SETTLEMENT................................................................................................................................................. 10 PRESATURATION OF SLAB SUBGRADE.................................................................................................10 TEMPORARYSLOPES ...................................................................................................................................10 TRENCHBACKFILL......................................................................................................................................10 DRAINAGE ... ................... .................................................................................................................................. II FOUNDATION PLAN REVIEW .................................................................................................................... 11 LIMITATIONS OF INVESTIGATION .........................................................................................................11 ADDITIONAL SERVICES ............................................................................................................................12 PLATES . Plate I - Location of Exploratory Boreholes Plate 2 - Summary Sheet (Exploration Borehole Logs) Plate 3 - USCS Soil Classification Chart PAGE L-1, LABORATORY TEST RESULTS ...................... . ........................................................................ 14 REFERENCES............................................................................................................. . .................................... 15 ROBERT BARELMANN/ JUNIPER AVENUE PROJECT NO. 1I-1106E7 INTRODUCTION This is to present the findings and conclusions of a limited geotechnical investigation for a proposed two-story, single-family residence and a detached garage/ shop to be located on the north side of Juniper Avenue, in the City of Carlsbad, California. The objectives of the investigation were t0 evaluate the existing soils conditions and provide recommendations for the proposed development. SCOPE OF SERVICES The following services were provided during this investigation: Site reconnaissance and review of published geologic, seismological and geotechnical reports And maps pertinent to the project area Subsurface exploration consisting of three (3) boreholes within the limits of the proposed area of development. The boreholes were logged by our Staff Geologist. Collection of representative soil samples at selected depths. The obtained samples were sealed in moisture-resistant containers and transported to the laboratory for subsequent analysis. Laboratory testing of samples representative of the types of soils encountered during the field investigation Geologic and engineering analysis of the field and laboratory data, which provided the basis for our conclusions and recommendations 0 Production of this report, which summarizes the results of the above analysis and presents our fmdings and recommendations for the proposed development SITE DESCRIPTION AND PROPOSED CONSTRUCTION The subject site is a rectangular-shaped residential lot located on the north side of Juniper Avenue, in the City of Carlsbad, California. The property, which encompasses an area of approximately. 6,300 square feet, includes a one-story structure that will be removed. The site is relatively level with general drainage to the southwest. Vegetation consisted of shrub and grass. Site boundaries include Juniper Avenue to the south and residential parcels to the remaining directions. No architectural plans were available at the time of this investigation. It is our understanding that the proposed construction will include a single-family residence and a detached garage! shop. The residence will be two-story, wood-framed and founded on continuous footings with raised-wood and slab-on-grade floors. ROBERT BA REL MA NNI JUNIPER A VENUE PROJECT NO. 11-1106E7 FIELD INVESTIGATION AND LABORATORY TESTING On June 1, 2011, three (3) boreholes were excavated to a maximum depth of approximately 10 feet below existing grade with a hand auger. The approximate locations of the boreholes are shown on the attached Plate No 1, entitled "Location of Exploratory Boreholes" A continuous log of the soils encountered was recorded at the time of excavation and is shown on Plate No 2 entitled "Summary Sheet" The soils were visually and texturally classified according to the filed identification prôcedures.sét forth on Plate No. 3 entitled "USCS Soil Classification". Following thefield exploration,: laboratory testing was, performed to evaluate the pertinent engineering properties of the foundation materials. The laboratory-testing program included moisture and density, maximum dry density and optimum moisture content, particle size analysis and expansion index tests. These tests were 'performed in general accordance with ASTM standards and other accepted methods Page L-1 and Plate No 2 provide a summary of the laboratory test results. GEOLOGY GeolOgic Setting . The subject site is located within the southern portion of what is known as the Peninsular Ranges Geomorphic Province of California The geologic map pertaining to the area indicates that the site is underlain by Pleistocene manne terrace deposits (Qt) Site Stratiranh The subsurface descriptions provided are interpreted 'frprn cohditions' exposed during the field. investigation andlor inferred from the geologic literature Detailed descriptions of the subsurface materials encountered during the field investigation are presented on the exploration logs provided on Plate No 2 The following paragraphs provide general descriptions of the encountered soil types Topsoil Topsoil is the surficial soil material that mantles the ground, usually containing roots and other organic -matenals, which supports vegetation Topsoil was observed inall boreholes_withathickness of approximately 18 inches It consisted of dark brown, silty sand that was damp to moist, loose and porous in consistency with some organics (roots and rootlets) / Marine Terrace Deposits (Ot) Manne terrace deposits were observed below the topsoil layer. They generally consisted of reddish brown, silty sand thàtwas moist and medium dense to dense inconsistency. 4 ROBERT BARELMANN/JUN!PER A VENUE PROJECT NO. I1-1106E7 SEISMICITY Regional Seismicity Generally, Seismicity within California can be attributed to the regional tectonic movement taking place along the San Andreas Fault Zone, which includes- the San Andreas Fault and most parallel and subparallel faults within the state. The portion' of southern California where the subject site is located is considered seismically active. Seismic hazards are attributed to groundshaking from earthquake events along nearby or more distant Quaternary . faults. The primary factors in evaluating the effect an earthquake has on a site are the magnitude of the event, the distance from the epicenter to the site and the near surface soil profile. According to the Fault-Rupture Hazard Zones Act of 1994 (revised Aiquist-Priolo Special Studies Zones Act), quaternary faults have been classified as "active" faults, which show apparent surface rupture during the last 1.1,000 years (i.e., Holocene time). "Potentially-active" faults are those faults with evidence of displacing Quaternary sediments between 11,000 to 16,000 years old. Seismic Analysis Based on our evaluation, the closest known "active" fault . is the Rose Canyon Fault located approximately 4.4 miles (7 kilometers) to the west. The Rose Canyon Fault is the design fault of the project due to the predicted credible fault magnitude and ground acceleration. The Seismicity of the site was evaluated utilizing deterministic methods (Eqseachl Eqfault ver 3.0, Blake, 2008) for active Quaternary faults within the regional vicinity. The site may be subjected to a Maximum Probable Earthquake of 6.9 Magnitude along the Rose Canyon fault, with a corresponding Peak Ground Acceleration of 0.47g. The maximum Probable Earthquake is defined as the maximum earthquake that is considered likely to occur within a 100-year time period. The effective ground acceleration at the site is associated with the 'part of significant ground motion, which contains repetitive strong-energy shaking, and which may produce structural deformation. As such, the effective or "free field" ground acceleration is referred to as the Repeatable High Ground Acceleration (RHGA). It has been determined by Ploessel and Slosson (1974) that the RHGA is approximately equal to 65 percent of the Peak Ground Acceleration for earthquakes occurring within -20 miles of a site. Based on the above, the calculated Credible RHGA at the site is 0.30g. 2010 CBC Seismic Design Criteria 'A review of the active fault maps pertaining to the site indicates the existence of the Rose Canyon Fault Zone approximately 7 km to the west. Ground shaking from this fault or one of the major active faults, in the region is the most likely happening to affect the site. With. respect to this hazard, the site ,is comparable to others in the general area. The proposed residential structures should be .designed in accordance with seismic design requirements of the 2010 California.Building Code or the Structural' Engineers Association of California using the following seismic design parameters: 5 ROBERT BARELMA NNI JUNIPER AVENUE PROJECT NO. II-1106E7 PARAMETER VALUE . 2010 CBC REFERENCE Site Class D Table 1613.5.2 Mapped Spectral Acceleration. For Short Periods, S, 1.339 Figure 1613.5(3) Mapped Spectral Acceleration For a 1-Second Period, S1 0.502 Figure 1613.5(4) Site Coefficient, F. 1.0 Table 1613.5.3(1) Site Coefficient, F 1.5 Table 1613.5.3(2) Geologic Hazard Assessment Ground Rupture Ground rupture due to active faulting is not considered likely due to the absence of known fault traces within the ''icinity of the project, however, this possibility cannot be completely ruled out. The unlikely hazard of ground rupture should not preclude consideration of "flexible" design for on-site utility lines and connections. Liquefaction Liquefaction involves the substantial loss of shear strength in saturated soils, usually sandy soils with a loose consistency when subjected to earthquake shaking. Based on the absence of shallow groundwater and consistency of the underlying terrace deposits, it is our opinion that the potential for liquefaction is very low. . Landsliding There is no indication that landslides or unstable slope conditions exist on or adjacent to the project site. There are no obvious geologic hazards related to landsliding to the proposed development or adjacent properties. . Tsunamis and Seiches The site is not subject to inundation by tsunamis due to its elevation. The site is also not subject to seiches (waves in-confined bodies of water). - ------------------- ................................. GEOTECHNICAL EVALUATION Based on our investigation and evaluation of the collected information, we conclude that the proposed construction is feasible from a geotechnical standpoint provided the recommendations provided herein will be properly implemented during structural development. In order to provide a uniform support for the proposed structures, footings should be excavated into properly compacted fill soils or extended to the dense terrace deposits. The new foundations may consist of reinforced continuous and/ or spread footings with the proposed raised-wood and slab-on- .6 ROBERT BARELMANNI JUNIPER AVENUE PROJECT NO. 11-I1 06E7' grade floors. Recommendations and criteria for foundation design are provided in the FOundation and Slab recommendations section of this report. Compressible Soils Our field observations and testing indicate low compressibility within the terrace deposits, which underlie the site. However, loose topsoil was typically encountered to a depth, of approximately 18 inches below surface grades. These soils are compressible. Due to the potential for soil compression upon loading, remedial grading of these loose soils, including overexcavation and tecompaction will be required unless footings are extended to the dense terrace deposits. Following implementation of the earthwork recommendations presented herein, the potential for soil compression resulting from the new development has been estimated to be low. The low-settlement assessment assumes a well-planned and maintained site drainage system. Recommendations regarding mitigation by earthwork construction are presented, in the Grading and Earthwork recommendations section' of this report. . Expansive Soils An expansion index test was performed on a representative sample of the formational soils to determine volumetric change characteristics with change in moisture content. An expansion index of 0 was obtained which.indicates a very low expansion potential for the foundation soils. Groundwater Static groundwater was not encountered to the depths of the boreholes. The subject site is located at an. elevation of approximately 50 'feet above Mean Sea Level. We do not expect groundwater to affect the proposed construction. Recommendations to prevent or mitigate the effects of poor surface drainage are presented in the Drainage section of this report. CONCLUSIONS AND RECOMMENDATIONS The following conclusions and recommendations are based upon the analysis of the data and information obtained from our soil investigation. This includes site reconnaissance; field --investigation;laboto testing and our general knowledge of the soils-native .to-the site. -The ..site. is - suitable for the proposed residential development provided the recommendations set forth are implemented during construction. GRADING AND EARTHWORK Based upon the proposed construction and the information obtained during the field investigation, we anticipate that the proposed structures will be founded on continuous and/ or spread footings, which are supported by properly compacted fill ordense sandstone of the Terrace Deposits Formation. The following grading and earthwork recommendations are based upon the limited geotechnical investigation performed, and should be verified during construction by our field representative. 7 ROBERT BARELMANNIJUNIPER AVENUE PROJECT NO. 11-1106E7. Clearing and Grubbing All areas to be graded or to receive fill and/or structures should be cleared of vegetation. Vegetation and the debris from the clearing operation should be properly disposed of off-site. The area should be thoroughly inspected for any possible buried objects, which need to be rerouted or removed prior to the inception of, or during grading. All holes, trenches, or pockets left by the removal of these objects should be properly backfilled with compacted fill materials as recommended in the Method and Criteria of Compaction section of this report. Structural Improvement of Soils Information obtained from our field and laboratory analysis indicates that loose topsoil covers the site to a depth of approximately 18 inches below existing grade. These surficial soils are susceptible to settlement upon loading. Based upon the soil characteristics, we recommend the following: * All topsoil and other loose natural soils should be completely removed from areas, which are planned to receive compacted fills and/or structural improvements. The bottom of the removal area should expose competent materials as approved by ECSC&E geotechnical representative. Prior to the placement of new fill, the bottom of the removal area should be scarified a minimum depth of 6 inches, moisture-conditioned within 2 percent above the optimum moisture content, and .then recompacted to at least 90 percent relative compaction (ASTM D1557 test method). * Overexcavation should be completed for the structural building pads to a minimum depth of 3 feet below finish pad grades. The limit of the required areas of overexcavation should be extended a minimum of 5 feet laterally beyond the perimeter footing (building footprint). * Soils utilized as fill should be moisture-conditioned and recompacted in conformance with the following Method and Criteria of Compaction section of this report. The depth and extent of any overexcavation and recompaction should be evaluated in the field by a representative of ECSC&E. * An alternative to the overexcavation and recompaction of the existing topsoil is to extend the footings to the dense sandstone of the Terrace Deposits Formation. However, for slab ...................support....we recommend overexcavation and. .recompaction._of...the.upp.er ,two feeLpf.. subgrade. Foundation excavations should be observed by a representative of this firm to verify competent bearing soils. Transitions Between Cut and Fill The proposed structures are anticipated to be founded in either properly compacted fill or dense sandstone of the Terrace Deposits Formation. Cut to fill transitions below the proposed structures should be completely eliminated during the earthwork construction as required in the previous section. 8 ROBERT BARELMANN/ JUNIPER AVENUE PROJECT NO. 11-1106E7 Method and Criteria of Compaction Compacted fills should consist of approved soil material, free of trash debris, roots, vegetation or other deleterious materials. Fill soils should be compacted by suitable compaction equipment in uniform loose lifts of 6 to 8 inches. Unless otherwise specified, all soils subjected to recompaction should be moisture-conditioned within 2 percent over the optimum moisture content and compacted to at least 90 percent relative compaction per ASTM test method Dl 557. The on-site granular and non-expansive soils, after being processed to delete the aforementioned deleterious materials, may be used for recompaction purposes. Should any importation of fill be planned, the intended import source(s) should be evaluated and approved by ECSCE prior to delivery to the site. Care should be taken to ensure that these soils are not detrimentally expansive. Erosion Control Due to the granular characteristics of the on-site soils, areas of recent grading or exposed ground may be subject to erosion. During construction, surface water. should be controlled via berms, gravel/ sandbags, silt fences, straw wattles, siltation basins, positive surface grades or other method to avoid damage to the finish work or adjoining properties. All site entrances and exits must have coarse gravel or steel shaker plates to minimize offsite sediment tracking. Best Management Practices (BMPs) must be used to protect storm drains and minimize pollution. The contractor should take measures to prevent erosion of graded areas until such time as permanent drainage and erosion control measures have been installed. After completion of grading, all excavated surfaces should exhibit positive drainage and eliminate areas where water might pond. Standard Grading Guidelines Grading and earthwork should be conducted in accordance with the standard-of-practice methods for this local, the guidelines of the current edition of the Uniform Building Code, and the requirements of the jurisdictional agency. Where the information provided in the geotechnical report differs from the Standard Grading Guidelines, the requirements outlined in the report shall govern. FOUNDATIONS AND SLABS Continuous and spread footings are suitable for use and should extend to minimum- depths of 1.8 and 12 inches for the proposed residence and garage respectively below the lowest adjacent grade into the properly compacted fill soils or dense sandstone of the Terrace Deposits Formation. Continuous footings should be at least 15 and 12 inches in width respectively and reinforced with four #4 steel bars; two bars placed near the top of the footings and the other two bars placed near the bottom of the footings. Isolated or spread footings should have a minimum width of 24 inches. Their reinforcement should consist of a minimum of #4 bars spaced 12 inches on center (each way) and placed horizontally near the bottom. - The garage floor slabs should be a minimum 4 inches thick. Reinforcement should consist of #3 bars placed at 1.8 inches on center each way within the middle third of the slabs by supporting the steel on chairs or concrete blocks "dobies". The slabs should be underlain by 2 inches of clean ROBERT BARELMANNI JUNIPER A VENUE PROJECT NO 11-1106E7 sand over a 1 0-mil visqueen moisture bamer. The effect of concrete shrinkage will result in cracks in virtually all-concrete slabs To reduce the extent of shrinkage, the concrete should be placed at a maximum of 4-inch slump The minimum steel recommended is not intended to prevent shrinkage cracks. c Where moisture sensitive floor coverings are anticipated over the slabs, the lO-mil plastic moisture barrier should be underlain by a capillary break at least 2 inches thick, consisting of coarse sand, gravel or crushed rock not exceeding 3/4 inch in size with no more than 5 percent passing the #200 sieve- d.' An allowable soil bearing value of 2,000 pounds per square foot may be used for the design of continuous and spread footings at least 12 inches wide and founded a minimum of 12 inches into properly compacted fill soils or the dense sandstone of the Terrace Deposits Formation as set forth in the 2010 California Building Code, Table 180.4.2. This value may be increased by 400 psf for each additional foot of depth or width to a maximum value of 4,000 lb/ft2 e Lateral resistance to horizontal movement may be provided by the soil passive pressure and the friction of concrete to soil An allowable passive pressure of 250 pound 4per square foot per foot of depth may be used A coefficient of friction of 0.3.5 is recommended The soils passive pressure as well as the bearing value may be increased by 1/3 for wind and seismic loading SETTLEMENT Settlement of compacted fill soils is normal and should be anticipated Because of the type and minor thickness of the fill soils anticipated under the proposed footings and Ithe light building loads, total and differential settlements should be within acceptable limits PRESATURATION OF SLAB SUBGRADE Because of the granular characteristics of the existing soils, presoaking of the subgrade prior to concrete pour is not required However, subgrade soils in areas receiving concrete should be watered prior to concrete placement to mitigate any drying shrinkage, which may occur following site grading TEMPORARY SLOPES For the excavation of foundations and utility trenches, temporary vertical cuts to ,.-a maximum height of 4 feet may be constructed in fill or natural soil Any temporary cuts beyond the above height constraints should be shored or further laid back following a 1:,l (horizontal to vertical) slope ratio OSHA guidelines for trench excavation safety should be implemented during construction TRENCH BACKFILL . . . Excavations for utility lines, which extend under structural areas should be properly backfilled and compacted Utilities should be bedded and backfilled with clean sand or approved granular soil to a depth of at least one foot over the pipe. This backfill, should be uniformly watered and '10' ROBERT BARELMANNI JUNIPER AVENUE PROJECT NO. 1I-1106E7 compacted to a firm condition for pipe support. The remainder of the backfill should be on-site soils or non-expansive imported soils, which should be placed in thin lifts, moisture-conditioned and compacted to at least 90% relative compaction. DRAINAGE Adequate measures should be undertaken to properly finish grade the site after the structures and other improvements are in place, such that the drainage water within the site and adjacent properties is directed away from the foundations, footings, floor slabs and the tops of slopes via rain gutters, downspouts, surface swales and subsurface drains towards the natural drainage for this area. A minimum gradient of 1 percent is recommended in hardscape areas. For earth areas, a minimum gradient of 5 percent away from the structures for a distance of at least 5 feet should be provided. Earth swales should have a minimum gradient of 2 percent. Drainage should be directed to approved drainage facilities. Proper surface and subsurface drainage will be required to minimize the potential of water seeking the level, of the bearing soils under the foundations, footings and floor slabs, which may otherwise result in undermining and differential settlement of the structures and other improvements. FOUNDATION PLAN REVIEW Our firm should review the foundation plans during the design phase to assure conformance with the intent of this report. During construction, foundation excavations should be observed by our representative prior to the placement of forms, reinforcement or concrete for conformance with the plans and specifications. LIMITATIONS OF INVESTIGATION Our investigation was performed using the skill and degree of care ordinarily exercised, under similar circumstances, by reputable soils engineers and geologists practicing in this or similar localities. No other warranty, expressed or implied, is made as to the conclusions and professional advice included in this report. This report is prepared for the sole use of our client and may not be assigned to others without the written consent of the client and ECSC&E, Inc. The samples collected and used for testing, and the observations made, are believed representative of site conditions; however, soil and geologic conditions can vary significantly between exploration trenches, boreholes and surface exposures. As in most major projects, conditions revealed by construction excavations may vary with preliminary findings. If this. occurs, the changed conditions must be evaluated by a representative of ECSC&E and designs adjusted as required or alternate designs recommended. This report is issued with the understanding that it is: the responsibility of the owner, or of his representative to ensure that the information and recommendations contained herein are brought to the attention of the project architect and engineer. Appropriate recommendations should be incorporated into the structural plans. The necessary steps should be taken to see that the contractor and subcontractors carry out such recommendations in the field. 11 ROBERT BARELMANNI JUNIPER AVENUE PROJECT NO. II-1106E7 The findings of this report are valid as of this present date. However, changes in the conditions of a property can occur with the passage of time, whether they are due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may, occur from legislation or the broadening of knowledge. Accordingly, the findings of'this report may be invalidated wholly-or partially by changes outside of our control. Therefore, this report is subject to review and should be updated after a period of two years. ADDITIONAL SERVICES The review of plans and specifications, field observations and testing under our direction are integral parts of the recommendations made in this report. If East County Soil Consultation and Engineering, Inc. is not retained for these services, the client agrees to assume our responsibility for any'potential claims that may, arise during construction. Observation 'and testing are additional services, which are provided by our firm, and should be budgeted within the cost of development. Plates No. 1 through 3, Page L-1 and References are parts of this report. 12 /Iko/Aib•. I 14WI,P,4f ,4f1f4 EAST COUNTY SOIL CONSULTATION & ENGINEERING, INC. IO925HARThEYRD SUITE LSANTEE.CA9207I 4 W'V/'/Af'ø't m (619)258.7901 Fax (6I9)25X79O2 I ROBERT BARELMANN/ JUNIPER AVENUE PROJECT NO. I1-1106E7 PLATE NO.2 SUMMARY SHEET BOREHOLE NO. 1 DEPTH SOIL DESCRIPTION Y M Surface TOPSOIL dark brown, damp to moist, loose, porous, silty sand with rootlets 1.5' TERRACE DEPOSITS (Qt) reddish brown, moist, medium dense to dense, silty sand 10.0' bottom of borehole, no caving, no groundwater borehole backfihled 6/1/11 BOREHOLE NO. 2 DEPTH SOIL DESCRIPTION Y M Surface TOPSOIL dark brown, damp to moist, loose, porous, silty sand with rootlets 1.5' TERRACE DEPOSITS (Qt) reddish brown, moist, medium dense to dense, silty sand 112.5 6.3 3.5' " " 110.2 6.9 4.0' bottom of borehole, no caving, no groundwater borehole backfilled 6/1/11 BOREHOLE NO.3 DEPTH SOIL DESCRIPTION Y M Surface TOPSOIL dark brown, damp to'moist, loose, porous, silty sand with rootlets 1.5' TERRACE DEPOSITS (Qt) reddish brown, moist, medium dense to dense, silty sand 5.0' bottom of borehole, no caving, no groundwater borehole backfihled 6/1/11 Y = DRY DENSITY IN PCF M= MOISTURE CONTENT IN % 13 MAJOR DIVISIONS SYMBOL DESCRIPTION GW WELL GRADED GRAVELS OR GRAVEL- SAND MIXTURES. LITTLE OR NO FINES. GP POORLY GRADED GRAVELS OR GRAVEL-SAND MIXTURES, LITTLE OR NO FINES GRAVELS (MORE THAN " OF COARSE FRACTION >NO. 4 SIEVE GM SILTY GRAVELS, GRAVEL-SAND-SILT MIXTURES COARSE GRAINED SOILS SIZE) GC CLAYEY GRAVELS, GRAVEL-SAND-CLAY MIXTURES (MORE THAN Yz OF SOIL > NO. 200 SIEVE SIZE) SW WELL GRADED SANDS OR GRAVELLY SANDS, LITTLE OR NO FINES SANDS (MORETHAN'/2 OF COARSE FRACTION < NO. 4 SIEVE SP POORLY GRADED SANDS OR GRAVELLY SANDS, LITTLE ORNOFINES SM SILTY SANDS, SILT-SAND MIXTURES SIZE) SC CLAYEY SANDS, SAND-CLAY MIXTURES SILTS & ML INORGANIC SILTS AND VERY FINE SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS OR CLAYEY SILTS WITH SLIGHT PLASTICITY FINE GRAINED SOILS (MORE THAN Y: OF SOIL <NO. 200 SIEVE SIZE) CLAYS LIQUID LIMIT <50 CL INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS OL ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY SILTS & MH INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE SANDY OR SILTY SOILS, ELASTIC SILTS CH INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS • • CLAYS LIQUID LIMIT >50 OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTY CLAYS, ORGANIC SILTS HIGHLY ORGANIC SOILS. Pt PEAT AND OTHER HIGHLY ORGANIC SOILS CLASSIFICATION CHART (UNIFIED SOIL CLASSIFICATION SYSTEM) CLASSIFICATION RANGE OF GRAIN SIZES U.S. STANDARD GRAIN SIZE IN SIEVE SIZE MILLIMETERS BOULDERS Above 12 Inches Above 305 COBBLES 12 Inches To 3 Inches 305 To 76.2 GRAVEL 3 Inches to No. 4 76.2 to 4.76 Coarse 3 Inches to 'h Inch 76.2 to 19.1 Fine 'flInch to No. 4 19.1 to 4.76 SAND No. 4 to No. 200 4.76 to 0.074 Coarse No. 4toNo. 10 4.76 to 2.00 Medium No. 10 to No. 40 2.00 to 0.420 Fine No. 40 to No. 200 0.420 to 0.074 SILT AND CLAY I Below No. 200 Below 0.074 GRAIN SIZE CHART EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC. 10925 HARTLEY ROAD, SUITE "I" SANTEE, CALIFORNIA 92071 - - E NIH 1LL I MLOL I '4WO L'MI ILLI PLASTICITY CHART ROBERT BARELNANN/ JUNIPER AVENUE PROJECT NO. 11-1106E7 PLATE NO. 3 6/14/11 U.S.C.S. SOIL CLASSIFICATION ROBERT BARELMANN/ JUNIPER A VENUE PROJECT NO Il-I 106E7 PAGE L-4, LABORATORY TEST RESULTS MAXIMUM DRY DENSITY AND OPTIMUM MOISTURE CONTENT (ASTM D1557) The maximum dry density and optimum moisture content of the fill materials as determined by ASTM D1557, Procedures A and B which use 25 blows of 'a 10-pound slide hammer falling from a height 6f-] 8 inches on each of 5 equal 'layers in a 4-inch diameter 1/30 cubic foot compaction cylinder and Procedure C which uses 56 blows of a 10-pound slide hammer falling from a height of 18 inches on each of 5-equal layers in a 6-inch diameter, 1/13.3 cubic foot compaction cylinder are presented as follows OPTIMUM MAXIMUM -• MOISTURE SOIL TYPE/ DRY bENsrry. CONTENT PROCEDURE DESCRIPTION (PCF) (%) LOCATION 1/A REDDISH BROWN SILTY SAND 1220 94 BH-1 @25' H EXPANSION INDEX TEST(ASTM D4829) INITIAL - SATURATED. INITIAL DRY MOISTURE MOISTURE DENSITY EXPANSION -- -- CONTENT(%) CONTENT(%) (.PCF) INDEX - LOCATION 90 172 1111 0 BH-1@25' PARTICLE SIZE ANALYSIS (ASTM 1)422) WRL ThSStandard -,çj' Percent Passmg' BFI @ -Topsoit Mm PercentPassin - 2 Terracé Depbsits ' -00 Perent Pasmg. TeceDesits rPercent Passing 5 ' Tenice Deposits 1/2" - - - - 3/8" - - - - - #4 - - - -. #8 - - - -- - #16 1-00 100 -- 100 100 - #30 93 .92 -. -.90 - - . 89 -. #50 .. . 44 . -44 . 43 : 39 #100. - 21 - 22 - 20 •. 17 #200 15 16 14 12.2 USCS • • SM SM - 1. SM -. SM