The URL can be used to link to this page

Home My WebLink AboutRP 00-07; Washington Street; Redevelopment Permits (RP) (5)Preliminary Geotechnical Investigation Residential Development 382 Christiansen Way Carlsbad, California Prepared For: Anastasi Development 1200 Aviation Boulevard Redondo Beach, California 90278 Attn: Mr. Chuck Springfield Project Number 8710-00 April 17, 2000 NorCal Engineering Soils and Geotechnical Consultants 10641 Humbolt Street Los Alamitos, CA 90720 (562) 799-9469 Fax (562) 799-9459 April 17, 1999 Project Number 8710-00 Anastasi Development 1200 Aviation Boulevard Redondo Beach, California 90278 Attn.: Mr. Chuck Springfield RE: Preliminary Geotechnical Investigation - Proposed Residential Development - Located at 382 Christiansen Way, in the City of Carlsbad, California Dear Mr. Springfield : Pursuant to your request, this firm has performed a Geotechnical Investigation for the above referenced project in accordance with your authorization of our verbal proposal. The purpose of this investigation is to evaluate the geotechnical conditions of the subject site and to provide recommendations for the proposed project. This geotechnical engineering report presents the finding of our study along with conclusions and recommendations for development. We appreciate this opportunity to be of service to you. If you have any further questions, please do not hesitate to contact the undersigned. Respectfully submitted NORCAL ENGINEE Keith D. Tucker II UJ i I mJJ Troy D. Norrell Project Engineer \\*^V ^P-^^/^'^^ President R.G.E. 841 April 17, 1999 Project Number 8710-00 Page 2 Project Description The purpose of the investigation was to explore the subsurface conditions and to provide preliminary geotechnical engineering design parameters for evaluation of the site with respect to the proposed development. It is proposed to construct a unit condominium development of the subject site. Other improvements will comprise of concrete and asphalt pavement areas. Site Description The subject project is situated within a residential tract within the 300 block of Christiansen Way, immediately west of Washington Street, in the City of Carlsbad. The lot is 60' by 200', rectangular shaped, elongated in a north to south direction. The site is relatively level with topography descending gradually from front to rear on the order of a few feet. The property contains a single-family residence, sheds, wood fencing, trees and associated improvements. The open areas of the site is covered with a heavy growth of vegetation. Field Investigation The investigation consisted of the placement of six (6) borings to maximum depth of 15 feet placed strategically in proposed areas of development. The explorations were visually classified and logged by a field engineer with locations of the subsurface explorations shown on the attached Site Plan. The exploratory excavations revealed the existing earth materials to consist of a fill and native soil. A detailed description of the subsurface conditions are listed on the excavation logs in Appendix A. These soils are described as follows: NorCal Engineering Apnl 17, 1999 Project Number 8710-00 Page 3 Fill: A fill soil to a depth of 1 to VA feet was encountered consisting predominately of a brown, fine to medium grained, slightly silty SAND which was noted generally to be loose and damp. These soils were noted to contain some small gravel, vegetation and root structure. Natural: An undisturbed native material was encountered directly beneath the upper fill soils consisting predominately of a brown to red brown, fine to medium grained, slightly silty SAND which were noted to be dense and moist. Deeper soils consisted of dense to very dense sands to silty sands. The overall engineering characteristics of the earth material were relatively uniform with each boring. Groundwater was not encountered and no caving occurred to the depths of our excavations. Laboratorv Tests Relatively undisturbed samples of the subsurface soils were obtained to perform laboratory testing and analysis for direct shear, consolidation tests, and to determine in- place moisture/densities. These undisturbed samples consisted of one-inch rings with inside diameter of 2.5 inches. Bulk bag samples were obtained in the upper soils for expansion index tests, maximum density tests, atterberg limits and sulfate tests. All test results are included in Appendix B, unless noted otherwise. A. The field moisture content (ASTM:D 2216) and the dry density of the ring samples were determined in the laboratory. This data is listed on the log of excavations. NorCal Engineering April 17, 1999 Project Number 8710-00 Page 4 B. Maximum density tests (ASTM: D-1557-91) were performed on typical samples of the upper soils. Results of these tests are shown on Table I. C. Expansion index tests in accordance with the Uniform Building Code Standard No. 29-2 were performed on remolded samples of the upper soils to determine the expansive characteristics. Results of these tests are provided on Table II. D. Determination of Atterberg limits (ASTM: D 4318-84) consisting of liquid limit, plastic limit and plasticity index of soils were performed on representative samples. Results are shown on Table III E. Soluble sulfate tests in accordance with EPA Method 9038 were performed on representative soils samples. Results are provided in Table IV. F. Direct shear tests (ASTM: D-3080) were performed on undisturbed and disturbed samples of the subsurface soils. The test is performed under saturated conditions at loads of 500 Ibs./sq.ft., 1,000 Ibs./sq.ft., and 2,000 Ibs./sq.ft. with results shown on Plate A. G. Consolidation tests (ASTM: D-2435) were performed on undisturbed samples to determine the differential and total settlement which may be anticipated based upon the proposed loads. Water was added to the samples at a surcharge of one KSF and the settlement curves are plotted on Plate B. NorCal Engineering Apnl 17, 1999 Project Number 8710-00 Page 5 Conclusions and Recommendations Based upon our evaluations, the proposed development is acceptable from a geotechnical engineering standpoint. By following the recommendations and guidelines set forth in our report, the structures will be safe from excessive settlements under the anticipated design loadings and conditions. The proposed development shall meet all requirements of the City Building Ordinance and will not impose any adverse effect on existing adjacent structures. It is recommended that site inspections be performed by a representative of this firm during all grading and construction of the development to verify the findings and recommendations documented in this report. The following sections present a discussion of geotechnical related requirements for specific design recommendations of different aspects of the project. Seismicitv Evaluation There are no known active or potentially active faults trending toward or through the site. The proposed development lies outside of any Alquist Priolo Special Studies Zone and the potential for damage due to direct fault rupture is considered very remote. The site is located in an area of high regional seismicity and a peak horizontal ground acceleration of 0.40 may occur from a Magnitude 6.3 earthquake along the Rose Canyon fault zone, which is located approximately 5 miles away. Ground shaking originating from earthquakes along other active faults in the region is expected to induce lower horizontal accelerations due to smaller anticipated earthquakes and/or greater distances to other faults. The following table provides information on nearby major active faults along with peak horizontal ground accelerations. NorCal Engineering Apnl 17, 1999 Page 6 Project Number 8710-00 Estimated Maximum Probable Ground Motion Parameters Fault Zone Rose Canyon Coronado Bank Elsinore San Andreas Approximate Distance Maximum Probable From Site (Miles) Magnitude (Richter) 5 NW 20 SW 23 NE 73 NE 6.3 6.8 6.8 8.2 Peak Horizontal Acceleration (g) 0.40 0.23 0.19 0.10 CDMG Open File Reports 92-03 and 96-08 The following earthquake design parameters are based upon the 1997 Uniform Building Code (UBC) for a Seismic Zone 4 with a Z factor of 0.40 and a Soil Profile Type of So, based on a stiff soil profile. Earthguake Fault 1. Distance from Site 2. Seismic Source Type 3. Seismic Coefficient = Ca 4. Seismic Coefficient = Cv 5. Near-Source Factor Na 6. Near-Source Factor Nv Rose Canvon 8 km B (0.44) Na (0.64) Nv 1.0 1.2 Site Grading Recommendations Any vegetation or demolition debris shall be removed and hauled from proposed grading areas pnor to the start of grading operations. Any removed soils may be reutilized as compacted fill once any deleterious material or oversized materials (in excess of eight inches) is removed. All grading operations shall be performed in accordance with the attached "Specifications for Compacted Fill Operations". The upper disturbed/fill soils (upper 1 to 1/2 feet) shall be removed to expose native soils, the exposed surface shall be scarified to a depth of 12 inches, brought to the proper moisture content and compacted to a minimum of 90% of the laboratory standard prior to placement of any additional compacted fill soils, foundations and concrete slabs. This fill shall extend a minimum of five horizontal feet or to the depth of vertical overexcavation, whichever is greater, beyond the outside edge of the perimeter foundation. NorCal Engineering Apnl 17, 1999 Project Number 8710-00 Page 7 Temporarv Excavations Temporary unsurcharged excavations in the existing site materials less than 4 feet high may be made at a vertical gradient unless cohesionless soils are encountered. Temporary unsurcharged excavations from 4 to 8 feet high may be trimmed at a 1 to 1 (horizontal to vertical) gradient. In areas where soils with little or no binder are encountered, where adverse geological conditions are exposed, or where excavations are adjacent to existing structures, shoring, slot-cutting, or flatter excavations may be required. The temporary cut slope gradients given do not preclude local raveling and sloughing. All excavations shall be made in accordance with the requirements of CAL-OSHA and other public agencies having jurisdiction. Care should be taken to provide or maintain adequate lateral support for all adjacent improvements and structures at all times during the grading operations and construction phase. Foundation Design All foundations may be designed utilizing a safe bearing capacity of 2,000 psf for an embedded depth of 18 inches into approved compacted fill soils or competent native soils. The bearing value may be increased by 500 psf for each additional foot of depth in excess of the 18 inch minimum depth, up to a maximum of 3,000 psf A one third increase may be used when considering short term loading and seismic forces. Lateral Resistance The following values may be utilized in resisting lateral loads imposed on the structure. Requirements of the current Uniform Building Code should be adhered to when the coefficient of friction and passive pressures are combined: Coefficient of Friction - 0.40 Equivalent Passive Fluid Pressure = 250 Ib./cu.ft. Maximum Passive Pressure = 2,500 Ibs./sq.ft. The passive pressure recommendations are valid only for compacted fill soils and/or competent native soils. NorCal Engineering April 17, 1999 Project Number 8710-00 Page 8 Settlement Analvsis Resultant pressure curves for the consolidation tests are shown on Plate B. Computations utilizing these curves and the recommended safe bearing capacities reveal that the foundations will experience settlements on the order of 3/4 inch and differential settlements of less than 1/4 inch. Retaining Wall Design Parameters Active earth pressures against retaining walls will be equal to the pressures developed by the following fluid densities. These values are for granular free draining backfill material placed adjacent to the walls at various ground slopes above the walls. Surface Slope of Retained Materials Equivalent Fluid (Horizontal to Vertical) Densitv (Ib./cu.ft.) Level 30 5 to 1 35 4 to 1 38 3 to 1 40 2 to 1 45 Any applicable short-term construction surcharges and seismic forces should be added to the above lateral pressure values. A backfill zone of non-expansive material shall consist of a wedge beginning a minimum of one horizontal foot from the base of the wall extending upward at an inclination no less than 1/4 to 1 (horizontal to vertical). All walls shall be waterproofed as needed and protected from hydrostatic pressure by a reliable permanent subdrain system. Slab Recommendations All concrete slabs shall be a minimum of four inches in thickness and placed on approved subgrade soils. A vapor barrier sandwiched between four inches of select sand shall be utilized beneath floor slabs which would be sensitive to the infiltration of moisture. All concrete slab areas to receive floor coverings should be moisture tested to meet all manufacturer requirements prior to placement. NorCal Engineering April 17, 1999 Project Number 8710-00 Page 9 Corrosion Design Criteria Representative samples of the surficial soils, typical of the subgrade soils expected to be encountered within foundation excavations were tested for sulfate concentration. According to the '1994 Uniform Building Code (UBC) Table 19-A-3 - Requirements for Concrete Exposed to Sulfate-Containing Solutions', these contents revealed negligible levels of sulfate exposure. Therefore, a Type li cement according to latest UBC specifications may be utilized for building foundations at this time. Additional sulfate tests shall be performed at the completion of rough grading to assure that these soils are consistent with the recommendations stated in this design. Sulfate test results may be found on the attached Table IV. Limitations The recommendations and conclusions contained in this report are based upon the soil conditions uncovered in our test excavations. No warranty of the soil condition between our excavations is implied. NorCal Engineering should be notified for possible further recommendations if unexpected to unfavorable conditions are encountered during construction phase. Any unusual conditions which may be encountered in the course of the project development may require the need for additional study and revised recommendations. It is the responsibility of the owner to ensure that all information within this report is submitted to the Architect and appropriate Engineers for the project. This firm should have the opportunity to review the final plans to verify that all our recommendations are incorporated. This report and all conclusions are subject to the review of the controlling authorities for the project. NorCal Engineering April 17, 1999 Project Number 8710-00 Page 10 A preconstruction conference should be held between the developer, general contractor, grading contractor, city inspector, architect, and geotechnical engineer to clarify any questions relating to the grading operations and subsequent construction. Our representative should be present during the grading operations and construction phase to certify that such recommendations are complied within the field. This geotechnical investigation has been conducted in a manner consistent with the level of care and skill exercised by members of our profession currently practicing under similar conditions in the Southern California area. No other warranty, expressed or implied is made. NorCal Engineering April 17, 1999 Project Number 8710-00 Page 11 SPECIFICATIONS FOR PLACEMENT OF COMPACTED FILL Preparation Any existing low density soils and/or saturated soils shall be removed to competent natural soil under the inspection of the Soils Engineering Firm. After the exposed surface has been cleansed of debris and/or vegetation, it shall be scarified until it is uniform in consistency, brought to the proper moisture content and compacted to a minimum of 90% relative compaction (in accordance with ASTM: D-1557-91). Materiai For Fill The on-site soils or approved import soils may be utilized for the compacted fill provided they are free of any deleterious materials and shall not contain any rocks, brick, asphaltic concrete, concrete or other hard materials greater than eight inches in maximum dimensions. Any import soil must be approved by the Soils Engineering firm a minimum of 24 hours prior to importation of site. Placement of Compacted Fill Soils The approved fill soils shall be placed in layers not in excess of six inches in thickness. Each lift shall be uniform in thickness and thoroughly blended. The fill soils shall be brought to within 15% of the optimum moisture content, unless otherwise specified by the Soils Engineering firm. Each lift shall be compacted to a minimum of 90% relative compaction (in accordance with ASTM: D-1557-91) and approved prior to the placement of the next layer of soil. Compaction tests shall be obtained at the discretion of the Soils Engineering firm but at a minimum of one test for every 500 cubic yards placed and/or for every two vertical feet of compacted fill placed. NorCal Engineering April 17, 1999 Project Number 8710-00 Page 12 The minimum relative compaction shall be obtained in accordance with accepted methods in the construction industry. The final grade of the structural areas shall be in a dense and smooth condition prior to placement of slabs-on-grade or pavement. No fill soils shall be placed, spread or compacted during unfavorable weather conditions. When the grading is interrupted by heavy rains, compaction operations shall not be resumed until approved by the Soils Engineering firm. Grading Observations The controlling governmental agencies should be notified prior to commencement of any grading operations. This firm recommends that the grading operations be conducted under the observation of a Soils Engineering firm as deemed necessary. A 24 hour notice must be provided to this firm prior to the time of our initial inspection. Observation shall include the clearing and grubbing operations to assure that all unsuitable materials have been properly removed; approval of the exposed subgrade in areas to receive fill and in areas where excavation has resulted in the desired finished grade and designate areas of overexcavation; and performance of field compaction tests to determine relative compaction achieved during fill placement. In addition, all foundation excavations shall be observed by the Soils Engineering firm to confirm that appropriate bearing materials are present at the design grades and recommend any modifications to construct footings. NorCal Engineering AVN\ N' N3SNVIlSmHO I j "1t- z g o -J Q. X ^ UJ -J a. UJ (0 00 c a; QJ c < J Z o u X u o UJ o 13 o ^ 5^ o cn ® z lU S OL O -I UJ > UJ o < < Z < Appendices (In order of appearance) Appendix A - Log of Excavations Log of Borings B-1 to B-6 Appendix B - Laboratorv Tests Table I - Maximum Dry Density Tests Table II - Expansion Index Tests Table III - Atterberg Limits Table IV - Sulfate Tests Plate A - Direct Shear Tests Plate B - Consolidation Tests NorCal Engineering Appendix A NorCal Engineering MAJOR DIVISION GRAPHIC SYMBOL LETTER SYMBOL TYPICAL DESCRIPTIONS COARSE GRAINED SOILS MORE THAN 50% OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZE GRAVEL AND GRAVELLY SOILS MORE THAN 50% OF COARSE FRACTION RETAINED ON NO. 4 SIEVE SAND AND SANDY SOILS MORE THAN 50% OF COARSE FRACTION PASSING ON NO. 4 SIEVE CLEAN GRAVELS (LITTLE OR NO FINES) GW WELL-GRADED GRAVELS, GRAVEL. SAND MIXTURES, LITTLE OR NO FINE GP POORLY-GRADED GRAVELS, GRAVEL-SAND MIXTURES, LITTLE OR NO FINES GRAVELS WITH FINES (APPRECIABLE AMOUNT OF FINES) GM SILTY GRAVELS. GRAVEL-SAND- SILT MIXTURES GC CLAYEY GRAVELS, GRAVEL-SAND- CLAY MIXTURES CLEAN SAND (LITTLE OR NO FINES) sw WELL-GRADED SANDS, GRAVELLY SANDS. LITTLE OR NO FINES SP POORLY-GRADED SANDS, GRAVEL- LY SANDS, LITTLE OR NO FINES SANDS WITH FINE (APPRECIABLE AMOUNT OF FINES) SM SILTY SANDS, SAND-SILT MIXTURES SC CLAYEY SANDS, SAND-CLAY MIXTURES FINE GRAINED SOILS MORE THAN 50% OF MATERIAL IS SMALLER THAN NO. 200 SIEVE SIZE ML INORGANIC SILTS AND VERY FINE SANDS, ROCK JLOUR, SILTY OR CLAYEY FINE SANDS OR CLAYER SILTS WITH SLIGHT PLASTICITY SILTS AND CLAYS LIQUID LIMIT LESS THAN 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 MH INORGANIC SILTS. MICACEOUS OR DIATOMACEOUS FINE SAND OR SILTY SOILS SILTS AND CLAYS LIQUID LIMIT GREATER THAN 50 CH INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY. ORGANIC SILTS HIGHLY ORGANIC SOILS PT PEAT, HUMUS. SWAMP SOILS WITH HIGH ORGANIC CONTENTS NOTE: DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATIONS UNIFIED SOIL CLASSIFICATION SYSTEM NorCal Engineering KEY: m E • n Indicates 2.5-inch Inside Diameter. Ring Sample. Indicates 2-inch OD Split Spoon Sample (SPT). Indicates Shelby Tube Sample. Indicates No Recovery. Indicates SPT with 140# Hammer 30 in. Drop. Indicates Bulk Sample. Indicates Small Bag Sample. Indicates Non-Standard Indicates Core Run. COMPONENT PROPORTIONS COMPONENT DEFINITIONS COMPONENT SIZE RANGE Boulders Larger than 12 in Cobbles 3 in to 12 in Gravel 3 in to No 4 (4.5mm ) Coarse gravel 3 in to 3/4 in Fine gravel 3/4 in to No 4 ( 4.5mm ) Sand No. 4 ( 4.5mm ) to No. 200 ( 0.074mm ) Coarse sand No. 4 ( 4.5 mm ) to No. 10 ( 2.0 mm ) Medium sand No. 10 ( 2.0 mm ) to No. 40 ( 0.42 mm ) Fine sand No. 40 ( 0.42 mm ) to No. 200 ( 0.074 mm ) Silt and Clay Smaller than No. 200 ( 0.074 mm ) DESCRIPTIVE TERMS RANGE OF PROPORTION Trace 1 - 5% Few 5-10% Little 10-20% Some 20 - 35% And 35 - 50% MOISTURE CONTENT DRY Absence of moisture, dusty. DRY dry to the touch. DAMP Some perceptible DAMP moisture; below optimum MOIST No visible water; near optimum MOIST moisture content WET Visible free water, usually WET soil is below water table. RELATIVE DENSITY OR CONSISTENCY VERSUS SPT N -VALUE COHESIONLESS SOILS COHESIVE SOILS Density N (blows/fl) Consistency N (blows/ft) Approximate Undrained Shear Strength (psf) Very Loose Oto 4 Very Soft Oto 2 <250 Loose 4 to 10 Soft 2 to 4 250 - 500 Medium Dense 10 to 30 Medium Stiff 4 to 8 500- 1000 Dense 30 to 50 Stiff Sto 15 1000-2000 Very Dense over 50 Very Stiff 15 to 30 2000 - 4000 Hard over 30 >4000 NorCal Engineering Log of Boring B-1 Project: Anastasi/Carlsbad Dateof Drilling: 4/13/00 Groundwater Depth: None Encountered Drilling Method: Hand Auger Hammer Weight: Drop: Samples Depth (feet) Geotechnical Description Surface Elevation: Not Measured Lith-ology 0) Q. S c O 3 Laboratory JS— o tn 2? 10 15 20 25 30 35 FILL SOILS SAND fine to mediunn grained slightly silty ^Brown, loose, damp with small gravel, upper 6" with small rootlets NATURAL SOILS SAND fine to medium grained slightly silty Brown to red/brown, dense to very dense, damp SAND fine to medium grained Light brown, medium dense, damp I Boring completed at depth of 15' 4.5 6.7 4.0 115.4 116.7 111.7 2.9 106.1 NorCal Engineering Project No. 8710-00 Project: Anastasi/Carlsbad Dateof Drilling: 4/13/00 Groundwater Depth: None Encountered Drilling Method: Hand Auger Hammer Weight: Drop: Log of Boring B-2 Samples Depth (feet) 0 Geotechnical Description Surface Elevation: Not Measured Lith-ology 0) a sl O 3 Laboratory 3^ Q in 10 15 20 25 30 35 FILL SOILS SAND fine to medium grained slightly silty ^Brown, loose, damp with small gravel, upper 6" with small rootlets NATURAL SOILS SAND fine to medium grained slightly silty Brown to red/brown, dense to very dense, damp SAND fine to medium grained Light brown, medium dense, damp 7.3 115.9 •f-'J-' mi 3.7 107.6 Boring completed at depth of 15' 2.6 109.8 NorCal Engineering Project No. 8710-00 Project: Anastasi/Carlsbad Dateof Drilling: 4/13/00 Groundwater Depth: None Encountered Drilling Method: Hand Auger Hammer Weight: Drop: Log of Boring B-3 Depth (feet) Geotechnical Description Surface Elevation: Not Measured Lith-ology Samples o Q. O 3 3^ Laboratory Q 10 15 20 25 30 35 FILL SOILS SAND fine to medium grained slightly silty Brown, loose, damp with small gravel, heavy dried vegetation and roots to ^2.5' NATURAL SOILS SAND fine to medium grained slightly silty Brown to red/brown, dense to very dense, damp SAND fine to medium grained Light brown, medium dense, damp Boring completed at depth of 10' 6.8 116.7 NorCal Engineering Project No. 8710-00 Project: Anastasi/Carlsbad Dateof Drilling: 4/13/00 Groundwater Depth: None Encountered Drilling Method: Hand Auger Hammer Weight: Drop: Log of Boring B-4 Samples Depth (feet) Geotechnical Description Surface Elevation: Not Measured Lith-ology 0) Q. >« sl O 3 3.^ Laboratory Q Ss Q tn 10 15 20 25 30 35 FILL SOILS SAND fine to medium grained slightly silty ^rown, loose, damp with small gravel, upper 6'^with snnall rootlets NATURAL SOILS SAND fine to medium grained slightly silty Brown to red/brown, dense to very dense, damp SAND fine to medium grained Light brown, medium dense, damp 5.9 114.6 3.4 110.8 Boring completed at depth of 12' NorCal Engineering Project No. 8710-00 Project: Anastasi/Carlsbad Dateof Drilling: 4/13/00 Groundwater Depth: None Encountered Drilling Method: Hand Auger Hammer Weight: Drop: Log of Boring B-5 Samples Depth (feet) Geotechnical Description Surface Elevation: Not Measured Lith-ology 0) a sl O 3 Laboratory 3^ Q S Q tn 2? 10 15 20 25 30 35 FILL SOILS SAND fine to medium grained slightly silty Brown, loose, damp with small gravel and heavy roots and dried \vegetation NATURAL SOILS SAND fine to medium grained slightly silty Brown to red/brown, dense to very dense, damp 7.8 112.6 Boring completed at depth of 8' NorCal Engineering Project No. 8710-00 Project: Anastasi/Carlsbad Dateof Drilling: 4/13/00 Groundwater Depth: None Encountered Drilling Method: Hand Auger Hammer Weight: Drop: Log of Boring B-6 Samples Depth (feet) Geotechnical Description 0 Surface Elevation: Not Measured Lith-ology 0) a >« I- sl O 3 3^ Laboratory ^<2 Q Ss Q (A 2^ 10 15 20 25 30 35 FILL SOILS SAND fine to medium grained slightly silty ^Brown, loose, damp with small gravel, upper 18" with small rootlets NATURAL SOILS SAND fine to medium grained slightly silty Brown to red/brown, dense to very dense, damp Boring completed at depth of 8' 6.9 112.8 NorCal Engineering Project No. 8710-00 Appendix B NorCal Engineering April 17, 1999 Page 13 Project Number 8710-00 TABLE I MAXIMUM DENSITY TESTS (ASTM: D-1557-91) Sample Classification 81 @ 1-2' SAND, fine to medium grained, slightly silty Optimum Moisture 10.5 Maximum Dry Densitv (Ibs./cu.ft.) 124.5 Soil Type B1 @ 1-2' TABLE II EXPANSION INDEX TESTS (U.B.C. STD. 29-2) Classification SAND, fine to medium grained, slightly silty Expansion Index 03 Sample B1 (d> 1-4' Liquid Limit 21 TABLE III ATTERBERG LIMITS Plastic Limit 16 Plasticitv Index 5 Sample Composite SULFATE TESTS Sulfate (%1 0.019 % by weight NorCal Engineering 2500 2000 u. 1500 t/i 1000 1500 2000 MORmi STRESS (PSF) 3000 SYMBOL BORING NUNBER DEPTH (FEET) (DEGREES) C (PSF) DRY DENSin (PCF) MOISTURE CONTEITT (X) X 1 2.5 34 125 115.4 4.5 O 2 3.0 37 75 115.9 7.3 A 6 2.0 32 125 112.1 6.9 • NOTE: TESTS PERFORMED ON SATURATED SAMPLES UNLESS SHOWN BELOW. (FM) FIELD MOISTURE TESTS PERFORMED ON UNDISTURBED SAMPLES UNLESS SHOWN BELOW. (R) SAMPLES REMOLDED AT 90X OF MAXIMUM DRY DENSITY NorCal Engineering SOILS AND GEOTECHNICAL CONSULTANTS PROJECT 8710-00 OATE DIRECT SHEAR TEST RESULTS Plate A 1.0 5 NORMAL PRESSURE (KSF) SYMBOL BORING NUMBER DEPTH (FEET) ORY DENSITY (PCF) MOISTURE CONTENT (X) LicyjiD LIMIT it) PUSTICITY INDEX it) X 1 4 116.7 6.7 O 1 12 108.1 2.9 A 2 8 108.6 3.7 • COMPRESSION (FN) FIELO MOISTURE - NO MTER ADOEO REBOUND (R) SMPLE RENOLOEO AT 90S OF NMINUN ORY DENSITY NorCal Engineering SOILS AND GEOTECHNICAL CONSULTANTS PROJECT 8710-00 DATE CONSOLIDATION TEST RESULTS Plate B