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Home My WebLink AboutCT 81-06B; POINSETTIA VILLAGE; PRELIMINARY SOILS & GEOLOGIC INVESTIGATION; 1981-08-31I I I . I I I U I I o PRELIMINARY SOILS .& GEOLOGIC INVESTIGATION, PROPOSED 22.89-ACRE SITE FOR INDUSTRIAL-COMMERCIAL DEVELOPMENT CARLSBAD, CALIFORNIA FOR R. C. JEWETT COMPANY PROJECT NO. SD1992(2) AUGUST 31, 1981 Medall, Aragon, Worswick & Associates, Inc. t R.'C. Jewett Company A1st 31, 1981 Project No. SD1992(2) TABLE OF CONTENTS Page No. 1.0 INTRODUCTION ..................... 2.0 PROPOSED DEVELOPMENT ............. . 1-2 3.0 SITEINVESTIGATION ..................2 3.1 Site Description ..............2-3 LOCATION MAP - FIGURE 1 3.2 Subsurface Conditions .............3 3.3 Geology ..................... 4.0 GENERAL SEISMICITY . . . . . . . . . . . . . . . . 4-6 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 General .....................6 5.2 Earthwork ........................6-8 5.3 Foundations ...................8-9 5.4 Floor Slabs ...................9-10 5.5 Sulphate Content ...............10 5.6 Pavement ...................10 5.7 Temporary Construction Cuts .........10 5.8 Surface Drainage ...............11 6.0 SUMMARY .......................11-12 APPENDIX A - Field Investigation APPENDIX B - Laboratory Testing APPENDIX C - Suggested Items to Include In Standard Grading Specifications GEOLOGIC MAP - Figure 2 (In Pocket) dated August 31, 1981 O I Medall, Aragon, Worswick & Associates. Inc. Consulting Engineers and Geologists #AW 2044 Cotner Ave. Los Angeles, California 90025 213/477-8507 U 2168 South Hathaway Street, Santa Ana, California 92705 714/546-6602 16882 Van Buren Blvd., Riverside (Woodcrest), California 92504 714/780-7482 11300 Sorrento Valley Rd. San Diego, California 92121 714/4520160 U August 31, 1981 Project No. SD1992(2) U R. C. Jewett Company 7215 Daffodil Place Carlsbad, CA 92008 Attention: Mr. Mike Jewett U Subject: Preliminary Soils and Geologic Investigation, Proposed 22.89 Acre Industrial-Commercial Site, Southwest Corner of San Diego Freeway and Poinsettia Lane, Carlsbad, California. U Gentlemen: 1.0 INTRODUCTION U This report presents the findings and conclusions of a geotechnical I investigation of the subject site. The purpose of this investigation was to evaluate the geotechnical conditions and provide recommenda- tions for the proposed development of the site. Recommendations given in this report are intended for use in preparation of grading and con- struction plans. A tentative tract map prepared by Buccola Engineer- ing, Inc. at .a scale of one inch equals one hundred feet dated Febru- ary 3, 1981, a U.S.G.S. topographic map dated 1967, and aerial photo- graphs flown in 1939 and 1975 were used as references for this investigation. 2.0 PROPOSED DEVELOPMENT No specific development plans are available at this time, but it is assumed that future structures will consist of light industrial and/or NMI -_------,,--------,-.---------"--.-.----------"--------- --.-- I R. C. Jewett Company August 31, 1981 U SD1992(2) Page 2 commercial buildings of wood-frame or.concrete tilt-up design up to 2 stories in height. For purposes of this investigation it is assum- ed that isolated structural loads (dead plus live) will not exceed 50 kips, and that continuous footing loads will be less than 10 kips per lineal foot. It is our understanding that grading of the site will consist of nominal cuts and fills to establish grades for 10 lots on the site. It is recommended that final grading plans be reviewed by this office when they become available so that their adequacy from a geotechnical view point may be evaluated. 3.0 SITE INVESTIGATION Our field investigation of the site consisted of a geologic reconnais- sance of the property, interpretation of aerial photographs and the excavation, sampling and logging of four exploratory borings on the site. Details of the field studies performed, as well as logs of the borings are presented in Appendix A. Laboratory studies and test re- suits are presented in Appendix B, while earthwork specifications are contained in Appendix C. A description of the site and conditions encountered are presented below. 3.1 Site Description I The subject site is located at the southwest corner. of Poinsettia Lane and the San Diego Freeway . (1-5) in the City of Carlsbad, San Diego County, California. The approximately 23-acre site is irregularly- shaped; bounded on the north by Poinsettia Lane, on the east by the San Diego Freeway and on the west and south by Avenida Encinas (see Figure 1, Location Map). Medall, Aragon. Worswick & Associates, inc. PROJ. NAME R C Jewett Company PROJ. NO. sn 1992(2) .\jJ7 1\ \PA \\ X S \\\\ if \ \ -to Water if If - . - \ I\ 24 \ - \( 1 / 10 ij 7, Ell Fl I P \ Oa \ \P0 )c, (f7 Ponto \' C\ \\ \ \ \\\ 7 L \\ BAIQUITOS 33 H LOCATION MAP - MAP REFERENCE: U.S.G.S., Encinitas 7½' Topographic Quadrangle, 1968. fAW Medal. Aragon. Worswick & Associates. Inc. By RH DATE 8-31-81 Consulting Engineers and Geologists C 1 1t ..'ca.je.• . - 2 000 Figure 1 I R C Jewett Company August 31, 1981 Project No. SD1992(2) Page 3 The property is bisected by a north-south trending swale. Maximum relief of the site is approximately 28 feet. At the time of the field investigation the site was in an undeveloped state and appear- ed to have been used for agricultural purposes'. A storm drain collec- tor box was observed in the southerly portion of the site adjacent to Avenida Encinas. Drainage within the subject property consisted of sheet flow collecting within the north-south trending swale which drains in a southerly direc- tion. Vegetation was composed of a thick growth of grasses and weeds. A row of well established eucalyptus trees was observed along the western edge of the site. - 3.2 Subsurface Conditions Our subsurface investigation indicates that the site is mantled by approximately one to one-and-one-half feet of loose, dry, silty sand, sandy silt and sand. This material is underlain in the central portion of the site by loose to medium dense, moist, fine grained silty sand, silt and sandy silt. The eastern and western portions of the site were underlain by similar materials which were found to be medium dense to dense. Groundwater was encountered in borings B-2-and B-3 at depths of 10 and 12 feet, 'respectively. The approximate locations of the exploratory borings are indicated on Figure 2. A more detailed description of materials and conditions encountered during the investigation is pre- sented in Appendix A. Medall, Aragon, Worswick & Associates, Inc. . R. C. Jewett Company , '. Project No. SD1992(2) I August 31, 1981 Page 3.3 Geology The subject site is underlain by Pleistocene marine terrace deposits. These deposits have been mapped as two geologic units. The older unit exposed on the western and eastern portions of the site is correlated with the upper Pleistocene age Bay Point Formation found further south along the coast. Younger materials were observed within the central portion of the site and are considered to be late Pleisto- cene valley-fill deposits. As indicated in boring B-4, these terrace deposits overlie moderately indurated mudstone of the Santiago Forma- tion of Eocene age. 4.0 GENERAL SEISMICITY The subject property, situated in earthquake-prone Southern California, has experienced earthquake induced ground-shaking in the past and can be expected to experience occasional ground shaking in the future. Future ground shaking can be expected as a result of continuing, perio- dic movement along known active faults, or, as a more remote possibility, renewed movement along potentially active faults. The subject site is located within about 4 miles of the offshore Newport-Inglewood-Rose Canyon structural (fault) zone, 24 miles from the Whittier-Elsinore fault, 47 miles from the San Jacinto fault and 73 miles from the San Andreas fault.. These faults are considered to be active or poteiitál1y active and could generate earthquakes which could cause damage to the site. The Newport-Inglewood-Rose Canyon zone of faulting parallels the coast- line a few miles offshore, west of the property. This fault zone is MedaJi, Aragon. Worswick & Associates, Inc. Acceleration for Firm Ground 0.05 - 0.09 0.10 - 0.14 0.15 - 0.19 0.20 - 0.24 0.25 - 0.29 0..30 - 0.34 0.35 %Probability of One Occurrence per 50-Year Period 99 88 64 40 22 10 4.4 I R. C. Jewett Company August 31, 1981 Project No. SD1992.(2) Page 5 reported to continue northwestward and connect with the Newport- Inglewood fault zone. No conclusive, direct evidence of Holocene age (the last 10,000 years) fault activity has been reported along the offshore segment of the fault, such as offset Holocene deposits, recent., geomorphic features or associated recorded seismicity. On that basis, the offshore fault zone is not considered to be active by State Division of Mines and Geology criteria. However, there is evidence for at least Quáternary age (the last 2-3 million years) fault offsets across offshore fault segments. Therefore, the fault zone opposite the property is considered to be potentially active for this study. Housner (1970), has computed the statistical probabilities of any site in California experiencing various levels of acceleration within pre- scribed periods. Assuming a 50-year design life for structures .within the development, the following probabilities for acceleration could be anticipated: STATISTICAL PROBABILITIES Medati, Aragon. Worswick & Associates, Inc. - I. R. C. Jewett Company August 31, 1981 Project No. SD1992(2) Page Considering this data, it is reasonable to assume that during a 50- year life, structures within the property will probably be subjected to a ground acceleration of 0.15g to 0.20g, for a duration of 18-30 seconds with a predominant site periodof .25 to .35 seconds. 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 General Based upon the information obtained during this investigation, it is concluded that the geotechnical conditions at the site can be improved to render the site suitable for the proposed development, provided recommendations presented herein are incorporated into the design plans and specifications. In summary, the in-place density of the soils in the north-south trend- ing swale areas was relatively low Removal and recompaction of these materials to an approximate depth of 9 feet is considered appropriate for the support of structures or additional fill materials. In general, our field data indicates that in the remaining areas of the site, the upper 2-3 feet of topsoil/alluvium is loose and disturbed and will re- quire 'removal and recopaction. Some variation in these estimates should be anticipated as isolated deeper zones of unsuitable material may exist. 5.2 Earthwork 5.2.1 Detailed recommendations for treatment of existing ground and preparation of ground surface to receive fill are contained in the applicable portions of the earthwork specifications presented in Appendix C. Medall, Aragon, Worswick & Associates. Inc. R. C. Jewett Company August 31, 1981 Project No. SD1992(2) Page 7 5.2.2 In areas to be graded, the subject site will re- quire removal of all vegetation, debris and all other deleterious materials. 5.2.3 During clearing operations, an attempt. should be made to locate, remove or relocate any underground utility lines which may be encountered. Irrigation lines if encountered should be followed out and removed. 5.2.4 Removal of any existing eucalyptus trees will result in disturbance of subsurface soils in root areas. These disturbed soils should be removed and recompact- ed under the inspection of the soils engineer. 5.2.5 Within the boundaries of the proposed structures (and 5-feet beyond), a minimum 3-foot thick mat of compacted fill should be provided below the bottom of the footings. In the proposed streets and parking areas, a minimum re- moval and recompaction of 24 inches is recommended to pro- vide a firm subgrade. 5.2.6 Prior to placing fills, the exposed surfaces should be scarified to a depth of 12 inches and watered or dried to near-optimum moisture conditions, then compacted with heavy equipment to provide a firm base for support of the replacement compacted fill. 5.2.7 Our evaluations indicate that most of the excavated materials will be suitable for reuse as engineered fill provided that all unsuitable materials (roots, etc.) be Medall, Aragon, Worswick & Associates. Inc. U .R . C. Jewett Company August 311 1981 Project No. SD1992(2) Page 8 removed from these materials. This should be U verified by the Soils Engineer at the time of grading. 5.2.8 Soils may then be replaced as engineered fill in accordance with the recommendations presented in Appendix C. 5.3 Foundations 5.3.1 The proposed structures may be supported on continuous or isolated spread footings. The footings should be founded directly on compacted fill. 5.3.2 For design purposes, maximum allowable bearing capacities of 1500 pounds per square foot are recommended for all continuous or spread footings founded on approved com- pacted fill. Minimum footing embedment for one and two-story build- ings is 12 and 18 inches, respectively. These embedment depths are to be measured below the lowest adjacent final grade. 5.3.3 The site soils are considered to have low expansion po- tential, thus no special footing reinforcement is re- quired. Footing reinforcement should be designed by the Structural Engineer based on anticipated loading conditions. Final expansion potential of the subgrade soils should, however, be 'verified by the Soils Engineer upon completion of rough grading. Medall, Aragon. Worswick & Associates, Inc. c-'::. N R. C. Jewett Company August 311 1981 Project No. SD1992(2) Page 9 5.'3.4 In designing to resist horizontal loads, lateral bearing of 200 pounds per square foot of embedment. to the maximum allowable bearing value and a fric- tion factor of 0.35 may be used where slabs or foot- ings arecast against compacted fill or natural materials. 5.3.5 For footings designed as recommended herein, total post-construction settlement of similarly loaded foot- U ings is expected to be less than 1 inch. Similarly, differential settlements of less than ½-inch are estimated. 5.3.6 All foundation excavations should be inspected and approved by the Soils Engineer prior to placement of. forms, reinforcement or concrete. The excavations should be trimmed, neat, level and square. All loose, sloughed and moisture softened materials should be U removed prior to the placement of concrete. Materials 'from footing excavations should not be spread in pave- ment subgrades or slab-on-grade areas unless they are compacted and tested. 5.4 Floor Slabs Concrete slab-on-grade floors should be supported by a pad of pro- cessed and recompacted natural soil at least 24-inches thick. Slabs should be designed by the Structural Engineer on the basis of antici- pated loading conditions. Site soils are considered nonexpansive, therefore, expansion characteristics do not dictate reinforcement. Medall, Aragon, Worswick & Associates. Inc. U 0 R. C. Jewett Company August 31, 1981 Project No SD1992(2) Page 10 For crack control, however, (assuming there are no structural load- ing constraints), it. is recommended that slabs be reinforced with 6" x .6", lOgax lOga welded-wire mesh placed at slab midheight. Final expansion potential of slab subgrade soils should, however, be verified by the Soils Engineer upon completion of rough grading. U If moisture migration through on-grade slabs is undesirable, slabs should be underlain by a vapor barrier such as visqueen, covered with at least an inch of protective sand. U 5.5 Sulphate Content A representative sample of the foundation soils, typical of the build- ing pad materials was tested to determine the sulphate content. The laboratory test results indicate the onsite soils have an approximate . sulphate content of 177 parts per million and as such, Type II cement is anticipated. . . 5.6 Pavement Representative samples of the surf icial soils, typical of the subgrade materials within the planned streets, parking areas and driveways should be collected for laboratory "R" (resistance) Value testing near the completion of grading. These tests would determine "R" values for pavement design. . 5.7 Temporary Construction Cuts To be in conformance with CAL-OSHA safety requirements, it is recom- mended that vertical construction cuts over 5-feet high be braced, or that they be cut back to an inclination of 1:1 (horizontal:vertical), or flatter, if field conditions dictate. . . Medall, Aragon, Worswick & Associates, Inc. . __ .. . I - R. C. Jewett Company August 31, 1981 Project No. SD1992(2). . Page 11 5.8 Surface Drainage I Positive drainage should be provided around the proposed buildings to reduce surface water infiltration into the underlying soils. N Open planter boxes adjoining the exterior walls shOuld be avoided unless they are constructed -with closed bottoms. Finished subgrade U. adjacent to. exterior footings should be sloped away to facilitate surface drainage. The entire site should be graded to allow water - to drain to appropriate disposal areas. 6.0 SUMMARY This report was prepared to provide goetechnical information and aid the project designers,.reviewing agencies, grading contractor, owner and other concerned parties. The findings and recommendations con- tamed herein were prepared in accordance with generally accepted professional engineering principles and practices. No other warranty, either expressed or implied is made. When development, grading and foundation plans become available, they should be forwarded to our office for review. The findings and recommendations herein are based on the specific exploration borings, and observations as noted. If conditions are encountered that are different, than those noted in our field investi- gation, this office should be notified. The opportunity to work with you on this project is appreciated. If you should have any questions regarding the information contained Ii- I Medafi, Aragon, Worswick & Associates, Inc. I.. a a R. C. Jewett August 31, 1981 Project No. SD1992(2) Page 12 herein, or other questions, please contact our office at your convenience. Respectfully submitted, By: _____________________________________ en y'bg, gaff Engineer for DALL,ARAGON,WORSWICK & ASSOCIATES, INC. By: Richard T. Higley, r'ect Geologist for MEDALL,ARAGON,WORSWICK & ASSOCIATES, INC. Reviewed by: Claude Corvino, R.C.E. 31072 for MEDALL,ARAGON,WORSWICK & ASSOCIATES, INC. Reviewed by: Paul Davis, C.E.G. 320, Chief Geologist for MEDALL,ARAGON,WORSWICK & ASSOCIATES, INC. FY:RTH:CC:PD:eab c: (4) Addressee Medall, Aragon, Worswick & Associates, Inc. APPENDIX A FIELD INVESTIGATION Medafl, Aragon, Worswick & Associates, Inc R. C. Jewett Company August 31, 1981 Project No. .SD1992(2). APPENDIX A FIELD INVESTIGATION The field investigation consisted of a reconnaissance of the subject property, drilling of four exploratory borings, and interpretation of aerial photo stereo pairs. The exploratory borings were drilled with a truck-mounted 74-inch diameter bucket auger drill rig. The borings were excavated to depths of 15 to 21 feet. Locations of the borings are shown on the enclosed Geologic Map, Figure 2. During this investigation, the soil materials encountered were con- tinuously logged by our field geologist and were classified in accordance with visual and tactile procedures. The final logs of the exploratory borings are presented in Figures A-1 through A-4. Representative bulk and "intact", samples of the soils encountered were recovered for laboratory testing and analysis. Relatively un- disturbed samples were obtained by driving a sampler lined with steel sampling rings into the desired strata. The drive energy for each 12 inch drive was recorded and is presented in the Boring Logs, Figures A-i through A-4. The soil samples were sealedin moisture resistant containers prior to transporting to our laboratory for testing. Medall, Aragon, Worswick & Associates. Inc. BORING LOG Logged By: Date Drilled: Drill Rig: Boring ameter: jBoring Number: RH 1 6-18-81 Bucket Auger 24". 1 B-i This log is a representation of subsurface conditions at the time and place of drilling. With the passage of time or at any other location there may be consequential changes in conditions. - Boring Elevation: . 65 SAMPLE 0(, e /,•/ G EOLOG I CALIENG IN EER I NG Description and Remarks Q. 41, 6u Cj TOPSOIL: SM Silty SAND - V Loose, orange-brown, dry, porous, _roots. — T 25 3.7 108 TERRACE DEPOSITS (Qto): - - SM Silty SAND - 29 4.4 112 Medium dense todense, orange-brown, • * dry, fine to medium grained. SAND - SP Medium dense to dense, orange brown, dry, fine to medium grained, trace of silt. ±22 4.8 105 10 1 16 6.2 100 :-- • Dark brown. - T -15 J_19 4.7 110 - = TOTAL DEPTH 16 FT. HOLE BACKFILLED. NO GROUNDWATER. Medall, Aragon, Worswick & Associates, Inc. LOS ANGELES SANTA ANA Consulting Engineers and Geologists - RIVERSIDE PROJECT NO.: 5D1992 FIGURE NO.: A—i - V-.--, ----_.--_-•- ' -T:T"'' '.--rr--*,-..--- ._-,.._..- ...,-. 'V... •. -. W BORING LOGE F Logged By: pH 1Date Drilled: 6-18-81 1Drill Ri9:ucket Auger Boring Diameter: 24" Boring Number: B-2 This log is a representation of subsurface conditions at the time and place of drilling. With the Boring Elevation: 62 passage of time or at any other location there may be Consequential changes in conditions. SAMPLE.// G EO LOG I CAUENG IN EERI N G Description and Remarks .00 __ SM TOPSOIL: ___ SAND-- e, brown, damp, slightly I - 12.1 . \ y, roots, porous. TERRACE DEPOSITS (Qty): \ Clayey SILT with SAND - ML T 3 18.7 102 \ Soft, light brown to brown, moist, \ slightly porous, very fine grained \ lenses ofsandy silt. _5 \. SiltyCLAY -- I 6 19.5 105 CL Soft, gray-brown, moist, slightly \layy.__________ \ Sandy CLAY - Soft, brownish gray, moist, rootlets, \j.z1ie, mottled.. • Clayey SAND - SC Loose to medium dense, brownish gray, fine to medium grained. Silty CLAY - -1- Stiff, brown to gray-brown, moist. 13 20.2 106 - - CL Stiff to very stiff, firmer drilling. — 14.3 15.. Clayey SAND - SC Medium dense, gray to light brown, — 20- damp, very fine, micaceous. 28 12.4 126 . • • TOTAL DEPTH 21 FT. - - ___ ___ ____ ____ . • HOLE BACKFILLED. SEEPAGE AT 10 FT. Medall, Aragon, Worswick & Associates, Inc. LOS ANGELES PROJECT NO.: FIGURE NO.: SANTA Consulting Engineers and Geologists • RIVERSIDEA SD1992 A-2 BORING LOG Logged By: Date Drilled: Drill Rig: Boring Diameter: Boring Number: RH 6-18-81 Bucket Auger 24" B-3 This log is a representation of subsurface conditions at the time and place of drilling. With the passage of time or at any other location there may be consequential changes In Conditions. Boring Elevation: 70 - SAMPLEj// /,./ / / GEOLOGICALIENGINEERING / - to / /J/ Description and Remarks - TOPSOIL: SM - porous. Silty SAND FT TERRACE DEPOSITS (Qto): 16 2.9 108 - - SM Silty SAND - • Medium dense, light orange brown,- dry - - - _ - ____ • - to damp, fine grained. SP SAND- Medium dense, light brown, dry, fine 19 3.9 105 T grained, slightly silty. Clean, orange, light gray, mottled. Orange brown, moist, fine to medium 10- grained. 16 10.1 117 - - Moist to very moist, rapid seepage, - : : SC clayey. Fine to coarse grained. I T - 33 =_ 14.8 126 - 1. - IT— - Fne grained. TOTAL DEPTH 15 FT. HOLE BACKFILLED. • RAPID SEEPAGE AT 12 FT. Medal[, Aragon, Worswick & Associates, Inc. LOS ANGELES PROJECT NO.: FIGURE NO.: SANTA ANA Consulting Engineers and Geologists RIVERSIDE SD1992 A-3 77 ,.-- - 'S -S •••S__.S• - -S•• •••.•-S-'S - -:' '--*• .55- -.•--•----.---.•"-...-.-.5--S•.----.-..--•• ........-. •••_••• _•••••••• , BORING LOf Logged By:RH 1Date Drilled: 6- 11W jDrill Riucket Auger BorinJeter: 24" Boring Number: B-4 This log is a representation of subsurface conditions at the time and place of drilling. With the Boring Elevation: 62 passage of time or at any other location there may be consequential changes in conditions. SAMPLEj// /*•/ 1 06~q GEOLOGICAL/ENGINEERING Description and Remarks ML TOPSOIL: 3.9 107 -Nj an SILT 16 t, light gray-brown, dry, roots, ous. TERRACE DEPOSIT (Qty):. - - CL Sandy CLAY -I-- 1 125 14.2 109 Stiff,.light grey brown to brownish- gray, damp, slightly porous to 2½ ft. -5- Clayey SAND - • I 28 11 5 122 SC Medium dense to dense, gray brown, 10 damp, fine to medium grained. BEDROCK: T 22 17.5 109 - CL MIJDSTONE - ± Stiff, brown to light gray, orange, - mottled, moist, blocky fracture, - massive. SAND-- I 15 S Light gray, moist, very fine grainec 25 11.4 122 trace of silt. TOTAL DEPTH 16 FT. HOLE BACKFILLED. - NO GROUNDWATER. Medail, Aragon, Worswick & Associates, inc. LOS ANGELES PROJECT NO.: FIGURE NO.: Consulting Engineers and Geologists SANTA ANA SD1992 A-4 -••'.• .-,.. APPENDIX B LABORATORY TESTING .Medan, Aragon, Worswick & Associates. Inc. R C Jewett Coma Project No. SD1992(2) APPENDIX B LABORATORY TESTING Moisture-Density Field moisture content and dry density were determined for each undisturbed sample obtained. This information was an aid to classification and permitted recognition of variations in mate- rial consistency with depth. The dry weight was determined in pounds per cubic foot, and the field moisture content was expressed as a percentage of the, soil's dry weight. The results are presen- ted in the Boring Logs (Figures A-1 through A-4). Compaction Tests The maximum dry density and optimum moisture content of a typical soil was determined in the laboratory in accordance with ASTM Method of Test D1557-70, the five-layer method. For this test, soil is compacted in five layers within a 4-inch diameter 1/30 cubic foot mold. Each layer is compacted by 25 blows with a 10- pound hammer falling 18 inches. The results of the test is pre- sented below: Sample Maximum Dry Optimum Moisture Boring Depth Soil Density (Pounds Content (Percent No. (feet) Description Per Cubic Foot) of Dry Weight) B-2 2' Sandy SILT 124 13 8-4 2' Sandy SILT 124 11 Direct Shear Tests A direct shear test was performed on a representative undisturbed sample. The shear box was designed to accommodate a sample having Medall. Aragon Worswick & Associates. Inc. -'-"--5' R C Jewett Company August 31, 1981 Project No. SD1992(2) a diameter of 2.375 inches and a height of 1 inch. The sample was tested at various normal loads and at increased moisture con- tents. The shear stress was applied at a constant rate of strain of approximately 0.05 inches per minute. The result of the test is presented below and shown graphically on Figure B-l. Coulomb Angle of Cohesion Internal Boring Depth Soil (Pounds per Friction No. (feet) Description Square Foot) (Degrees) B-1 3 Silty SAND 36 150 Consolidation The apparatus used for the consolidation tests is designed to receive the brass ring of soil as it comes from the field. Loads were applied to the test specimen in several increments, and the resulting deformations were recorded at selected time intervals. Porous stones were placed in contact with the top and bottom of the specimen to permit the ready addition or release of water. Samples were tested at the field and saturated moisture contents. The test results are shown on Figures B-2 through B-S. Expansion Index A typical surface soil was collected in the field for classifica- tion and expansion index testing (Section 2904-B, UBC Standard 29-2). The result of the test and the expansive, nature is presen- ted in the following table: Sample Boring Depth Soil Expansion Expansion No. (Feet) Description Index Potential Sandy SILT B-4 2 w/trace of clay 15 Very Low MedaH, Aragon, Worswick & Associates, Inc. DJrOT SHEAR TES DIAGRAM Project NQ SD1992 (2) Project Name_R C. Jtt aflY Plotted by__F Y 8] Location Check by _ _____ Dote .Bor.N9. B-i - Sample • _ _ _ DEPTH ___1-L_ Soil Clossificaiion Silty SAND 3.0 1 2.5 _ E.2.0 1.5 p LO 1 _ LIZ 05,7 3.0 0 05 1.0 15 2.0 2.5 Normal Pressure, KSF I 36 emars Undisturbed and C=.15 K.SE Saturated MedaH,ArBQorVikrswIck&Assocjates,pnc. - Consultants in the Earth Sciences 2O41COIneqA,e Los Angeles. CA9O 3I3I477.507 21158o aySt.. Santa Ana. CA927O5 741546-602 B-i .0I .02 .03 .04 .05 .06 .07 2 .08 U C .09 .10 2 2 I- C .12 2 .13 0 .14 .15 .16 .17 .18 .19 .20 4PONSOLIDATI.ON TEj0F NORMAL PRESSURE kips/sq ft 0.1 0.2 03 0.5 10 .2.0 3.04:050 10... 20 3040 , -. } ;4'iJ.;.. 6 _FET4. EE::. ___ _ t: -rt 41- ~4_ _ i4iE 44 i :t Lr 44 P pi __;___..:..i TT ir ..._..1 H±1 1i Boring Depth 0 Field Moisture Undisturbed V 0 Readings After Adding Moisture Remolded Rebound Meda!1,Aragon, Worsvjck & Associates, Inc. fNSOLIDATION TF1 'NORMAL PRESSURE kips/sq. ft. 0.1 0.2 0.3 0.5 1.0 2.0 3.0 4;0 5.0 10 .. 20 30 40 .01 - .02 - .03 .04 - .05 .06 H. .07 .08 tH L7 C) C 09 __________ ______ C., .10- 777 2 P2 _J ~4 0 .14 -77 .15 .16 14 ip _____ .18 .19 rl r .20 11 Boring Depth 0' 0 Field Moisture ITT Undisturbed x • Readings After Adding Moisture Remolded Rebound Medal!, Aragon, Worsvjjck & Associates, Inc. Project No. SD1992(2) rPlate B-4 !4. ____ j:l_ fti H1........... - _____ .R, tE :tT tJ h L4 _ L::; :: :::J::::!:.i: ;j: :::: i!3 I....__._.......__..t_._....- ....1 j:L.: :.. T • :3:!..'f.j:: t :i- .i ••f -.I. :H........ I: :::::::: —•-- —, , ,-."t.-t fl -- . ._-_ ---a.. -----S-- ....-..c?... .- --- - - .- .- -a— ...--. -• - - - .-•- - 0ONSOLIDATION Ti NORMAL PRESSURE kips/sq.ft. 0.1 0.2 0.3 0.5 1.0 2.0 3.0 4.0 5.0 10 20 30 40 I f Ft 7 It" _55F. .01 .02 .03 .04 _____ : .05 .06- 14 17 .07 -j- .08 U C 0 .10. o .11- I- 12- _J 77 f4q 0 T-j .14 .15 -I .16 .17 .18 .19 _____ I. .20 - ________ ________ ____________________ _____________________________________ Boring Depth 0 Field Moisture PH- at Undisturbed • Readings After Adding Moisture Remolded --- Rebound Medalj,Aragon, Worswck & Associates, Inc. (Project No. SD1992(2) J?ite B-5 ..._. . —...L4 .., ..... ...,... .., .].. .... .. : I . . kfi-i ____ IJfLLL; -H4 v[1 IEi1 _____________-T ..-... ._.1.__ _________________________ T I •1 - :. .. 4±.J • . .---- :::;" LHI..... -Hi_L J± * Ttf r1-' L i'E: IT --.... ............. - ---- 46 APPENDIX STANDARD GRADING SPECIFICATIONS jP~ R C Jewett CoInpan 31, 1981 Project No. SD1992(2) I APPENDIX C SUGGESTED ITEMS TO INCLUDE IN STANDARD GRADING SPECIFICATIONS These specifications present the usual and minimum require- ments for grading operations performed under the observation I and testing of Medall,Aragon,Worswick & Associates, Inc. No deviation from these specifications will be allowed, except where specifically superseded in the preliminary geology and soils report, or in other written communication signed by the Soils Engineer or Engineering Geologist. I GENERAL The Soils Engineer and Engineering Geologist are the Owner's or Builder's representative on the project. For the purpose of these specifications, observation and testing by the Soils Engineer includes that observation and testing performed by any person or persons employed by, and responsible to, the licensed Civil Engineer signing the soil report. All clearing, site preparation or earthwork performed on the project shall be conducted by the Contractor under the observation of the Soils Engineer. It is the Contractor's responsibility to prepare the ground surface to receive the fills to the satisfaction of the Soils Engineer and to place, spread, mix, water and compact the fill in accordance with the specifications of the Soils Engineer. The Contractor shall also remove all material considered unsatisfactory by the Soils Engineer. It is also the Contractor's responsibility to have suitable and sufficient compaction equipment on the jobsite to handle the amount of fill being placed. If necessary, excavation equipment will be shut down to permit completion of compaction. Sufficient water- ing apparatus will also be provided by the Contractor, with due consideration for the fill material, rate of placement and time of year. Medall, Aragon, Worsw,ck & Assoc., Inc. 'S Suggested. Items to Include in Standard Grading Specifications Page 2 E. A final report will be issued by the Soils Engineer . and Engineering Geologist attesting to the Contractor's conformance with these specifications. II SITE PREPARATION All vegetation and deleterious material such as rubbish shall be disposed of offsite. This removal must be concluded prior to placing fill. The Soils. Engineer shall locate all houses, sheds, sewage disposal systems, large trees or structures on the site or on the grading plan to the best of his knowledge prior to preparing the ground surface. Soil, alluvium or rock materials determined by the Soils Engineer as being unsuitable for placement in compacted fills shall be removed and wasted from the site. Any material incorporated as a part of a compacted fill must be approved by the Soils Engineer. After the ground surface to receive fill has been cleared, it shall be scarified, •disced or bladed by the Contractor until it is uniform and free from ruts, hollows, hummocks or other uneven features which may prevent uniform compaction. The scarified ground surface shall then be brought to optimum moisture, mixed as required, and compacted as specified. If the scarified zone is greater than twelve inches in depth, the excess shall be removed and placed in lifts restricted to six inches. Prior to placing fill, the ground surface to receive fill shall be inspected, tested and approved by the Soils. Engineer. Any underground structures such as cesspools, cisterns, minimum shafts, tunnels, septic tanks, wells, pipe lines or others not located prior to grading are •to be removed or treated in a manner prescribed by the Soils Engineer. . MedaH, Aragon, Worswick & Assoc., Inc. a Suggested Items to Include in Standard Grading Specifications Page 3 III COMPACTED FILLS A. Any material imported or excavated on the property may be utilized in the fill, provided each material has been determined to be suitable by the Soils Engineer. Roots, tree branches and other matter missed during clearing shall be removed from the fill as directed by the Soils Engineer. B. Rock fragments less than six inches in diameter may be utilized in the fill, provided: They are not placed in concentrated pockets. There is a sufficient percentage of fine-grained material to surround the rocks. The distribution of the rocks is observed by the Soils Engineer. C. Rocks greater than six inches in diameter shall be taken offsite, or placed in accordance with the recommendations of the Soils Engineer in areas designated as suitable for rock disposal. Details for rock disposal such as location, moisture control, percentage of rock placed, etc., will be referred to in the "Conclusions and Recommendations" section of the soils report. If rocks greater than six inches in diameter were not anticipated in the preliminary soils and geology report, rock disposal recommendations may not have been made in the "Conclusions and Recommendations" section. In this case, the Contractor shall notify the Soils Engineer if rocks greater than six inches in diameter are encountered. The Soils Engineer will then prepare a rock disposal recommendation or request that such rocks be taken offsite. D. Material that is spongy, subject to decay, or other- wise considered unsuitable shall not be used in the compacted fill. Nedall, Aragon, Worswick & Assoc., Inc. ...-,- - - Suggested Items to Include in Standard Grading Specifications Page 4 Representative samples of materials to be utilized as compacted fill shall be analyzed in the laboratory by the Soils Engineer to determine their physical properties. If any material other than that previously tested is encountered during grading, the appropriate analysis of this material shall be conducted by the Soils Engineer as soon as possible. Material used in the compacting process shall be evenly spread, .watered or dried, processed and compacted in thin lifts not to exceed six inches in thickness to obtain a uniformly dense layer. The fill shall be placed and compacted on a horizontal plane, unless otherwise approved by the Soils Engineer. If the moisture content or relative compaction varies from that required by the Soils Engineer, the Contractor shall rework the fill until it is approved by the Soils Engineer.. Each layer shall be compacted to 90 percent of the maximum density in compliance with the testing method specified by the controlling governmental agency. (In general, ASTM D1557-70T will be used.) If compaction to a lesser percentage is authorized by the controlling governmental agency because of a specific land use or expansive soil conditions, the area to receive fill compacted to less than 90 percent shall either be delineated on the grading plan or appropriate reference made to the area in the soil report. I. All fills shall be keyed and benched through all topsoil, colluviuin, alluvium or creep material, into sound bedrock or firm material where the slope receiving fill exceeds a ratio of five horizontal to one vertical, in accordance with the recommendations of the Soils Engineer. J. The key for side hill fills shall be a minimum of 15 feet within bedrock or firm materials, unless otherwise specified in the soils report. (See detail on Plate GS-l.) Medall, Aragon, Worswick & Assoc., Inc. - I, Is Suggested Items to Include in Standard Grading Specifications Page 5 K. Drainage terraces and subdrainage devices shall be constructed in compliance with the ordinances of the controlling governmental agency, or with the recommendations of the Soils Engineer and Engineering Geologist. The Contractor w111 be required to obtain a minimum relative compaction of 90 percent out to the finish slope face of fill slopes, buttresses and stabiliza- tion fills. This may be achieved by either over- building the slope and cutting back to the compacted core, or by direct compaction of the slope face with suitable equipment, or by any other procedure which produces the required compaction.. The Contractor shall prepare a written detailed description of the method or methods -he will employ to obtain the required slope compaction. Such documents shall be submitted to the Soils Engineer for review and comments prior to the start of grading. If a method other than overbuilding and cutting.back to the compacted core is to be employed, slope tests will be made by the Soils Engineer during construction of the slopes to determine if the required compaction is being achieved. Where failing tests occur or other field problems arise, the Contractor will be notified by the Soils Engineer.. If the method of achieving the required slope. compaction selected by the Contractor fails to produce the necessary results, the Contractor shall rework or rebuild such slopes until the required degree of compaction is obtained, at no additional cost to the Owner or,Soils Engineer. All fill slOpes should be planted or protected from - erosion by methods specified in the soils report or by means approved by the governing authorities. Fill-over-cut slopes shall be properly keyed through topsoil, colluvium or creep material into rock or firm materials; and the transition shall be stripped of all soil prior to placing fill. (See detail - Plate GS-2.) Medall, Aragon, Worswjck & Assoc., Inc. -• - ••- •--.- .•-•-- -•-,-.-••. --. -- . Suggested Items to Include in Standard Grading Specifications Page 6 IV CUT SLOPES A. The Engineering Geologist shall inspect all cut slopes excavated in rock, lithified or formation material at vertical intervals not exceeding ten feet. B. If any conditions not anticipated in the preliminary report such as perched water, seepage, lenticular or confined strata of a potentially adverse nature, unfavorably inclined bedding, joints or fault planes are encountered during grading, these conditions shall be analyzed by the Engineering Geologist and Soils -Engineer; and recommendations shall be made to treat these problems. Cut slopes that face in the same direction as the prevailing drainage shall be protected from slope wash by a nonerosive interceptor swale placed at • the top of the slope. Unless otherwise specified in the soils and geological report, no cut slopes shall be excavated higher or steeper than that allowed by the ordinances of controlling governmental agencies. - - E. Drainage terraces shall be constructed in compliance with the ordinances of controlling governmental • agencies, or with the recommendations of the Soils Engineer or Engineering Geologist. V GRADING CONTROL Inspection of the fill placement shall be provided by the Soils Engineer during the progress of grading. In general, density tests should be made at inter- vals not exceeding two feet of fill height of every 500 cubic yards of fill placed.' This criteria will vary depending on soil conditions and the size of the job. In any event, an adequate number of field density tests shall be made to verify that the required compaction is being achieved. Medall, Aragon, Worawick & Assoc., Inc. s-s-•.• .5 444.s- Of . suggested Items to Include in Standard Grading Specifications Page 7 N Density tests should also be made on the surface material to receive fill as required by the Soils Engineer. All cleanout, processed ground to receive fill, key excavations, subdrains and rock. disposal must be inspected and approved by the Soils Engineer (and often by the governing authorities) prior to placing any fill. It shall be the Contractor's responsibility to notify the Soils Engineer and governing authorities when such areas are ready for inspection. . VI CONSTRUCTION CONSIDERATIONS Erosion control measures, when necessary, shall be provided by the Contractor during grading and prior to the completion and construction of permanent drainage controls. Upon completion of grading and termination of observations by the Soils Engineer, no further filling or excavating, including that necessary for footings, foundations, large tree wells, retaining walls, or other features shall be per- formed without the approval of the Soils Engineer or Engineering Geologist. Care shall be taken by the Contractor during final grading to preserve any berms, drainage terraces, interceptor swales, or other devices of a permanent nature on or adjacent to the property. MedaU, Aragon, Worswjck & Assoc., Inc. TOE SHOWN ON - - - - GRADING PLAN 7 ---1 ) 4 Typical PROJECTED I l/2I - - Of c •_ - - - NATURAL SLOPE 10' Typical BEDROCK OR FIRM -- FORMATION MATERIAL 2 I Minimum 15 Minimum PLATE GS-I -. .-.- - -,-- -S.---- •--- -.--------.- - - p--'--- . -___ _ •_ - - 1! 1117 111 P ± I 1 7 TYPICAL FILL OVER CUT SLOPE REMOVE ALL TOPSOIL, FILL - - COLLUVIUM AND CREEP MATERIAL FROM TRANSITION - - -. - - Of — — 000v - : Typico — -logs - --- -- 1-- - - - - - - - - - - .- io 'c.: •.-. -- ,l - CL - - - - - - - CUT SLOPE -- 15, Minimum - BEDROCK OR FIRM '.•-.' -'- FORMATION MATERIAL a, 1. 0 0