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Home My WebLink AboutCT 83-05; AVIARA UNIT A PHASE 1; Preliminary Geotechnical Investigation; 1983-01-31m$$*!»PRELIMINARY 6EOTECHNICAL INVESTIGATION PROPOSED CONDOMINIUM PROJECT LA CORUNA PLACE LA COSTA, CALIFORNIA Pf® PP$I Sdfe^kpr^A'.lftS^-•:,-,,,,»"'! WiiiA '/'•PH'iM^fflrl "Bfem PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED CONDOMINIUM PROJECT LA CORUNA PLACE LA COSTA, CALIFORNIA PREPARED FOR: Community Resources Corporation 1335 Hotel Circle South, Suite 201 San Diego, California 92108 PREPARED BY: Southern California Soil and Testing, Inc. Post Office Box 20627 6280 Riverdale Street San Diego, California 92120 SOUTHERN CALIFORNIA SOIL AND TESTING, INC. BZBO RIVERDALE ST. SAN DIEGO, CALIT. 9212D • TELE ZSQ-4321 • P.O. BOX 2O&27 SAN DIEGO, CALIF. 9212D 74-B31 VELIE WAY PALM DESERT, CALIF. 9ZZ6O • TELE 346-1D78 6 7 B ENTERPRISE ST. EBCDNDIDO, CALIF. 9ZO25 • TELE 746-4544 January 31, 1983 Community Resources Corporation SCS&T 14044 1335 Hotel Circle South, Suite 201 Report No. 2-R San Diego, California 92108 ATTENTION: Mr. Marv Berman SUBJECT: Report of Preliminary Geotechnical Investigation for the Proposed Condominium Project, La Coruna Place, La Costa, California. Gentlemen: In accordance with your request and our proposal dated May 19, 1982, we have completed a preliminary geotechnical investigation for the proposed project. We are presenting herewith our findings and recommendations. The findings of this study indicate that the site is suitable for the proposed development provided that the recommendations presented in the attached report are complied with. If you have any questions after reviewing the findings and recommendations contained in this report, please do not hesitate to contact this office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, SOUTHERN J$LIFORNIA SOIL>« TESTING, INC. */(& ^7^ ( T- A tJ^^Y^ Charles H. Chr'istTan, R.C.E. #22330 Curtis R. Burdett, C.E.G. #1090 CHC:CRB:AFB:mw cc: (6) Submitted (1) SCS&T, Escondido SOUTHERN CALIFORNIA SOIL AND TESTING, INC TABLE OF CONTENTS PAGE Introduction and Project Description 1 Figure No. 1, Site Vicinity Map 2 Preject Scope 3 Findings 4 Site Description 4 General Geology and Subsurface Conditions ..4 Geologic Setting and Soil Description 4 Groundwater 4 Tectonic Setting 5 Geol ogi c Hazards 5 Recommendati ons and Concl usi ons 7 General 7 Site Preparation 7 Soi 1 P repa rat i on 7 Earthwork 7 Subdrai ns 8 Foundati ons 8 General 8 Figure No. 2, Subdrain Cross-Section 9 Beari ng Capacity 10 Sett 1 ement Character!stics 11 Earth Retaining Structures 11 General 11 Backf i 11 11 Allowable Soil Bearing Pressure 11 Pas si ve Pressure 11 Active Pressure 11 Factor of Safety 12 Slope Stabi 1 ity 13 Limitations 13 Review, Observation and Testing... 13 TABLE OF CONTENTS (continued) Uniformity of Conditions, Change in Scope Time Limitations , Professional Standard..., Client's Responsibility., Field Explorations Laboratory Testing , PAGE ...14 ...14 ...14 ...15 ...15 ...16 ...16 ATTACHMENTS Plate Plate Plate Plate Plate Plate Plate Plate Plate 1 2-3 4 5-6 7 8-9 9 10 11 Plot Plan Development Cross-Sectional Views Unified Soil Classification Chart Boring Logs Natural Dry Density and Moisture Content Direct Shear Test Results Expansion Test Results Grain Size Distribution Detail-Weakened Plane Joint APPENDIX Recommended Grading Specifications and Special Provisions PRELIMINARY GEOTECHNICAL INVESTIGATION PROPOSED CONDOMINIUM PROJECT LA CORUNA PLACE LA COSTA. CALIFORNIA INTRODUCTION AND PROJECT DESCRIPTION This report presents the results of our geotechnical investigation for the proposed condominium site which is located northwest of La Coruna Place in the La Costa area of San Diego County, California. The project site consists of Lot 180 of La Costa South, Unit Number 1. The site location is shown on the vicinity map provided as Figure Number 1. It is our understanding that the project is still in the early planning stages and that the condominium units may consist of two stories, and three stories, and three stories over parking, and will be of wood-frame construction. It is further our understanding that because of the planned hillside construction, retaining walls up to approximately 10 feet in height and cut slopes on the order of 21 feet in height are anticipated. To assist in our investigation, we were provided with undated site and section plans prepared by Community Contractors Corporation and a topo- graphic map prepared by E. F. Cook and Associates, LTD, dated May 4, 1982. The site configuration, approximate topography, and location of our subsur- face explorations are shown on Plate Number 1 of this report. Cross- sectional views of the proposed development are shown on Plate Numbers 2 and 3. -M f—i-te i SOUTHERN CALIFORNIA BOIL & TESTING, INC. • 8»0 RIVKFIDALK •TBKRT • AN DIKOO, CALIFORNIA »B1«O La Corina Place Condos Escondido, California SITE VICINITY MAP SMS JOB NO.14044 DATE 9-29-82 Figure No. I SCS&T 14044-R January 31, 1983 Page 3 PROJECT SCOPE This investigation consisted of: surface reconnaissance; subsurface explorations; obtaining representative disturbed and undisturbed samples, laboratory testing; analysis of the field and laboratory data; research of available geological literature pertaining to the site; and preparation of this report. Specifically, the intent of this study was to: a) Explore the subsurface conditions to the depths influenced by the proposed construction. b) Evaluate, by laboratory tests, the pertinent engineering proper- ties of the various strata which will influence the development, including their bearing capacities, expansive characteristics and settlement potential. c) Define the general geology at the site including possible geo- logic hazards which could have an effect on the site development. d) Develop soil engineering criteria for site grading and provide design information regarding the stability of cut and fill slopes. e) Determine potential construction difficulties and provide recom- mendations concerning these problems. f) Recommend an appropriate foundation systems for the type of structures anticipated and develop soil engineering design cri- teria for these recommended foundation designs. -r-.r-.MiA SOIL AND TESTING. INC SCS&T 14044-R January 31, 1983 Page 4 FINDINGS SITE DESCRIPTION The project site is an irregulary shaped lot located adjacent to and south of La Costa Avenue. Land use on adjacent lots or in the immediate area consists of developed residential lots or undeveloped lots which are zoned for residential use. Elevations at the site range from approximately 120 feet to 210 feet (MSLD). Drainage is accomplished by sheetflow towards three gunite-lined interceptor ditches and then northeasterly in the ditches. The lot slopes moderately to steeply towards La Costa Avenue (northerly). An existing 2:1 cut slope is present along La Costa Avenue; the remainder of the site is largely in a natural condition. Vegetation consists of a moderate growth of iceplant on the cut slope and native grasses and shrubs on the undisturbed portions of the site. GENERAL GEOLOGY AND SUBSURFACE CONDITIONS GEOLOGIC SETTING & SOIL DESCRIPTION: The subject site is located in the Coastal Plains Physiographic Province of San Diego County and is underlain by sedimentary deposits of Eocene age and associated residual, colluvial, and alluvial soils. The formational materials at the site consist pre- dominantly of greenish brown claystones and siltstones and yellowish brown sandstones of the Santiago Formation. These lithologies are interfingered and interbedded; however, it appears that the claystone and siltstone are prevalent below approximate elevation 165 feet while the sandstone is predominant above this elevation. The surficial materials at the site consist of brown silty sand (topsoil) and dark brown, sandy, silty clay (alluvium). GROUNDUATER: No groundwater was encountered during our subsurface explo- ration and we do not anticipate any major groundwater related problems, n i I T H F R N CALIFORNIA SOIL AND TESTING. INC SCS&T 14044-R January 31, 1983 Page 5 either during or after construction. However, it should be recognized that minor groundwater seepage problems may occur after development of a site even where none were present before development. Those are usually minor phenomena and are often the result of an alteration of the perme- ability characteristics of the soil, an alteration in drainage patterns and an increase in irrigation water. Based on the permeability character- istics of the soil and the anticipated usage of the development, it is our opinion that any seepage problems which may occur will be minor in extent. It is further our opinion that these problems can be most effectively corrected on an individual basis if and when they develop. TECTONIC SETTING: A review of avalable geologic maps indicates the sub- ject site to be located approximately 6 miles east of the Rose Canyon Fault Zone. The Rose Canyon Fault Zone is a series of northwest trending faults of Quaternary age that is currently classified as potentially active rather than active according to the criteria of the California Division of Mines and Geology. It addition it should be recognized that much of Southern California is characterized by major, active fault zones that could possibly affect the subject site. The nearest of these are the Elsinore Fault Zone, located approximately 25 miles to the northeast; and the San Jacinto Fault Zone, located approximately 46 miles to the northeast. GEOLOGIC HAZARDS The subject site can be considered to be relatively free of geologic hazards. Potential hazards such as tsunamis, seiches, liquefaction, or seismic induced settlement should be considered negligible or nonexistent. One of the more likely major geologic hazard to affect the site is ground- shaking as a result of movement along one of the major active fault zones SCS&T 14044-R January 31, 1983 Page 6 mentioned previously. The maximum bedrock accelerations that would be attributed to a maximum probable earthquake occurring along the nearest portion of the fault zones that could affect the site are summarized in the following table. TABLE 1 Fault Zone Rose Canyon Elsinore San Jacinto Classification Potentially Active Active Active Distance 6 miles 25 miles 46 miles Maximum Probable Earthquake 6.0 magnitude 7.3 magnitude 7.8 magnitude Maximum Bedrock Acceleration 0.35 g. 0.20 g. 0.13 g. Based on the current fault zone classification, and the maximum bedrock accelerations capable of developing, it is recommended that the Elsinore Fault Zone be considered the design earthquake source for the subject development. Construction in accordance with the minimum standards of the Uniform Building Code and the governing agency should minimize potential damage due to seismic activity. Another potential geologic hazard which could possibly affect the site is slope stability problems associated with the clayier portions of the Santiago formation. No evidence of former landsliding were observed at the subject site proper but several landslides have been observed in the vicinity of the site. The likelihood of slope stability problems at the site can be satisfactorily mitigated if the recommendations presented in this report and proper slope maintenance techniques are followed. s a u T E R N CALIFORNIA SOIL AND TESTING.I N C SCS&T 14044-R January 31, 1983 Page 7 RECOMMENDATIONS AND CONCLUSIONS GENERAL Based on the findings of this study, it is our opinion that with respect to geotechnical aspects, the subject site is suitable for the proposed development provided the recommendations contained in this report are fully complied with. SITE PREPARATION SOIL PREPARATION: It is our understanding that it is planned to construct cut and fill building pads for the proposed development. In areas which are to receive structural loads or fill, we recommend that all loose topsoils be removed to firm natural ground, where firm natural ground is defined as soil having an in-situ density of at least 85% of its maximum dry density as defined by A.S.T.M. Test Method 1557-78. The desired grade should then be obtained by placing fill compacted to at least 90% relative compaction. Fills should be properly keyed into the existing hillside in accordance with good grading practive and the "Recommended Grading Speci- fications" appended to this report. EARTHWORK: All earthwork and grading contemplated for site preparation should be accomplished in accordance with the attached Recommended Grading Specifications and Special Provisions. All special site preparation recommendations presented in the sections above will supersede those in the standard Recommended Grading Specifications. All embankments, struct- ural fill and fill should be compacted to a minimum of 90%. Utility trench backfill within 5 feet of the proposed structures and beneath asphalt pavements should be compacted to a minimum of 90% of its maximum dry density. The maximum dry density of each soil type should be deter- mined in accordance with A.S.T.M. Test Method 1557-78, Method A or C. SCS&T 14044-R January 31, 1983 Page 8 SUBDRAINS We recommend that subdrains be installed behind the proposed retaining walls. The drains should have a fall of at least 0.5% away from the center, and should exit to daylight at each end. A typical section for the subdrain is shown on the following Figure Number 2. FOUNDATIONS GENERAL: It is anticipated that the proposed structures will be founded on a transition between cut and fill soils. Further, some of the on-site soils were found to have a high potential for expansion when undergoing an increase in moisture content. In consideration of these factors, we recommend that footings be founded at least 24 inches below lowest adja- cent finish grade and have a width of at least 15 inches. Continuous footings should be reinforced with at least four #4 bars (two at the top and two at the bottom of the footings). In addition, we recommend the following in order to minimize the effects of the expansive soil conditions. a) Interior slabs should be a minimum of 5 inches in thickness, should be underlain by a 4 inch blanket of clean washed sand, pea gravel or crushed rock, and should be reinforced with at least 6"x6"-10/10 welded wire mesh. Interior slabs should be complet- ely surrounded with a continuous footing. b) Exterior slabs should be a minimum of 5 inches thick. Walks or slabs three feet or less in width need not be reinforced. Those exceeding three feet in width should be reinforced with 6"x6"- 10/10 welded wire mesh and provided with weakened plane joints as recommended hereinafter. SOUTHERN CALIFORNIA SOIL AND TESTING. INC Page 9 SOUTHERN CALIFORNIA BOIL & TESTING , INC. •••O RIVKROALE STRKCT • AN OIBOO, CALIFORNIA BBIBO La Con'na Place Condos Escondido, California BY JOB NC AFB * 14044 DATE 9-29-82 Figure No. 2 SCS&T 14044-R January 31, 1983 Page 10 c) Weakened plane joints for exterior slabs should be provided for any slab greater than five feet in width. Any slabs between five and ten feet should be provided with longitudinal weakened plane joints at the center line. Slabs exceeding ten feet in width should be provided with a weakened plane joint located three feet inside the exterior perimeter as indicated on attached Plate Number 11. Both traverse and longitudinal weakened plane joints should be constructed as detailed. d) Clayey soils should not be allowed to dry before placing con- crete. They should be watered if necessary so that the soils are kept in a very moist condition or at a moisture content exceeding three percent above optimum moisture content. e) Surface drainage should be directed away from the proposed found- ation. Planters should be constructed so that water is not allowed to seep beneath foundations or slabs. Over-irrigation of areas adjacent to foundations and slabs should be avoided. f) Prior to placing concrete, the foundation excavations should be observed by a representative of this office to determine that the above recommendations have been followed. BEARING CAPACITY: The maximum allowable bearing capacity for footings of the minimum recommended dimensions is 3.0 kips per square foot. These stresses may be increased by one-third for wind and/or seismic loading and should be decreased by one-fourth for dead load only. Adjacent footings founded at different bearing levels should be located so that the slope from bearing level to bearing level is flatter than one horizontal to one vertical. AND TESTING. INC SCS&T 14044-R January 31, 1983 Page 11 SETTLEMENT CHARACTERISTICS: The anticipated total and/or differential settlements for the proposed structure may be considered to be within tolerable limits provided the recommendations presented in this report are followed. EARTH RETAINING STRUCTURES GENERAL: It is our understanding that the retaining structures planned for this project will be of masonry construction and that they will have a maximum height on the order of 10 feet. BACKFILL: All backfill soils should be compacted to at least 90% relative compaction. Expansive or clayey soils should not be used for backfill material within a distance of 5 feet from the back of the wall. The retaining structure should not be backfilled until the materials in the wall have reached an adequate strength. ALLOWABLE SOIL BEARING PRESSURE: The foundation for the proposed retain- ing structures should consist of spread footings founded in the firm native soils or compacted fill. Firm natural ground is defined as soil having an in-situ density of at least 85% of its maximum dry density. Footings may be designed for an allowable bearing pressure of 3.0 ksf. PASSIVE PRESSURE: The passive pressure for prevailing soil conditions may be considered to be 300 pounds per square foot per foot of depth. This pressure may be increased one-third for seismic loading. The coefficient of friction for concrete to soil may be assumed to be 0.3 for the resist- ance to lateral movement. When combining fractional and passive resist- ance, the latter should be reduced by one-third. ACTIVE PRESSURE: The active soil pressure for the design of earth retain- ing structures is as follows: cniifHFRN CALIFORNIA SOIL AND TESTING. INC. SCS&T 14044-R January 31, 1983 Page 12 A) Unrestrained Halls Level Backfill: 2:1 Sloping Backfill: EQUIVALENT FLUID PRESSURE 45 pcf 60 pcf B) Restrained Halls I 29H I Level Backfill /in J u 1 H 2:1 Sloping Backfill These pressures do not consider any surcharge loading (other than the sloping backfill). If any surcharge loadings are anticipated this office should be contacted for the necessary change in soil pressure. All earth retaining structures should have adequate weep holes or a subdrain system to prevent the buildup of hydrostatic pressure behind the wall. FACTOR OF SAFETY: The above values, with the exception of the allowable soil bearing pressure, do not include a factor of safety. Appropriate factors of safety should be incorporated into the design of all earth retaining structures to reduce the possibility of over turning and slid- ing. SHUT F R N C A L F D R N I A SOIL AND TESTING.I N C SCS&T 14044-R January 31, 1983 Page 13 SLOPE STABILITY The proposed slope configurations for the project were analyzed for deep- seated rotational failures using a computer program incorporating the Simplified Bishop Method. The proposed slope configuration and assumed soil strength parameters, are shown on the attached Plate Numbers 2 and 3. It is our opinion that the cut and fill slopes as shown on the proposed plans should be stable with relation to deep-seated failures with a factor of safety of at least 1.5. In the event that slope heights or slope ratios are changed, our office should be contacted for evaluation of slope stability. All grading plans should be reviewed by our office. It is recommended that footings not be founded nearer than 5 feet measured horizontally inward from the face of the slopes. Slopes should be planted with erosion resisting plants, preferably deep-rooted varieties adapted to semi-arid climates. Drainage should be directed away from the tops of all slopes. LIMITATIONS REVIEW, OBSERVATION AND TESTING The recommendations presented in this report are contingent upon our review of final plans and specifications. The soil engineer and engineer- ing geologist should review and verify the compliance of the final grading plan with this report and with Chapter 70 of the Uniform Building Code. It is recommended that Southern California Soil & Testing, Inc. be retain- ed to provide continuous soil engineering services during the earthwork operations. This is to observe compliance with the design concepts, SOUTHERN CALIFORNIA SOIL AND TESTING. INC SCS&T 14044-R January 31, 1983 Page 14 specifications or recommendations and to allow design changes in the event that subsurface conditions differ from those anticipated prior to start of construction. UNIFORMITY OF CONDITIONS The recommendations and opinions expressed in this report reflect our best estimate of the project requirements based on an evaluation of the subsur- face soil conditions encountered at the subsurface exploration locations and the assumption that the soil conditions do not deviate appreciably from those encountered. It should be recognized that the performance of the foundations and/or cut and fill slopes may be influenced by undis- closed or unforeseen variations in the soil conditions that may occur in the intermediate and unexplored areas. Any unusual conditions not covered in this report that may be encountered during site development should be brought to the attention of the soils engineer so that he may make modifi- cations if necessary. CHANGE IN SCOPE This office should be advised of any changes in the project scope or proposed site grading so that it may be determined if the recommendations contained herein are appropriate. This should be verified in writing or modified by a written addendum. TIME LIMITATIONS The findings of this report are valid as of this date. Changes in the condition of a property can, however, occur with the passage of time, whether they be due to natural processes or the work of man on this or adjacent properties. In addition, changes in the State-of-the-Art and/or Government Codes may occur. Due to such changes, the findings of this SOUTHERN CALIFORNIA BOIL AND TESTING. INC SCS&T 14044-R January 31, 1983 Page 15 report may be invalidated wholly or in part by changes beyond our control. Therefore, this report should not be relied upon after a period of two years without a review by us verifying the suitability of the conclusions and recommendations. PROFESSIONAL STANDARD In the performance of our professional services, we comply with that level of care and skill ordinarily exercised by members of our profession cur- rently practicing under similar conditions and in the same locality. The client recognizes that subsurface conditions may vary from those encoun- tered at the locations where our borings, surveys, and explorations are made, and that our data, interpretations, and recommendations are based solely on the information obtained by us. We will be responsible for those data, interpretations, and recommendations, but shall not be re- sponsible for the interpretations by others of the information developed. Our services consist of professional consultation and observation only, and no warranty of any kind whatsoever, express or implied, is made or intended in connection with the work performed or to be performed by us, or by our proposal for consulting or other services, or by our furnishing of oral or written reports or findings. CLIENT'S RESPONSIBILITY It is the responsibility of Community Resources Corporation, or their representative to ensure that the information and recommendations con- tained herein are brought to the attention of the engineer and architect for the project and incorporated into the project's plans and specifica- tions. It is further their responsibility to take the necessary measures to ensure that the contractor and his subcontractors carry out such recom- mendations during construction. OUTHERN CALIFORNIA SOIL AND TESTING. INC SCS&T 14044-R January 31, 1983 Page 16 FIELD EXPLORATIONS Two subsurface explorations were made at the locations indicated on the attached Plate Number 1 on June 18, 1982. These explorations consisted of borings made with a truck mounted bucket auger. In addition near surface samples were taken from hand dug pits at eleven locations on the existing slope at the site. The field work was conducted under the observation of our engineering geology personnel. The explorations were carefully logged when made. These logs are presen- ted on the following Plate Numbers 5 and 6. The soils are described in accordance with the Unified soils Classification System as illustrated on the atttached simplified chart on Plate 4. In addition, a verbal textural description, the wet color, the apparent moisture and the density or consistency are given on the Logs. Soil densities for granular soils are given as either very loose, loose, medium dense, dense or very dense. The consistency of silts or clays is given as either very soft, soft, medium stiff, stiff, very stiff, or hard. Disturbed and undisturbed samples of typical and representative soils were obtained and returned to the laboratory for testing. LABORATORY TESTING Laboratory tests were performed in accordance with the generally accepted American Society for Testing and Materials (A.S.T.M.) test methods or suggested procedures. A brief description of the tests performed is presented below: A i i r n o KI i A t; n i L AND TESTING. INC SCS&T 14044-R January 31, 1983 Page 17 a) MOISTURE-DENSITY: Field moisture content and dry density were determined for representative undisturbed samples obtained. This information was an aid to classification and permitted recogni- tion of variations in material consistency with depth. The dry unit weight is determined in pounds per cubic foot, and the field moisture content is determined as a percentage of the soil's dry weight. The results are summarized in the trench logs and Plate Number 7. b) CLASSIFICATION: Field classifications were verified in the laboratory by visual examination. The final soil classifi- cations are in accordance with the Unified Soil Classification system. c) DIRECT SHEAR TESTS: Consolidated drained shear tests were per- formed to determine the failure envelope based on yield shear strength. The shear box was designed to accomodate a sample having a diameter of 2.375 inches or 2.50 inches and a height of 1.0 inch. Samples were tested at different vertical loads and at saturated moisture content. The shear stress was applied at a constant rate of strain of approximately 0.006 inches per minute and 0.05 inches per minute as indicated on the attached data sheets. The results of these tests are presented on attached Plate Numbers 8 and 9. d) EXPANSION TEST: The expansive potential of clayey soils was determined in accordance with the following test procedure and the results of these tests appear on Plate Number 9. Allow the trimmed, undisturbed or remolded sample to air dry to a constant moisture content, at a temperature of 100 degrees F. Place the dried sample in the consolidometer and allow to compress under a load of 150 psf. Allow moisture to contact the sample and measure its expansion from an air dried to saturated condition. SOUTHERN CALIFORNIA SOIL AND TESTING. INC SCS&T 14044-R January 31, 1983 Page 18 e) GRAIN SIZE DISTRIBUTION: The grain size distribution was deter- mined for representative samples of the native soils in accor- dance with A.S.T.M. Standard Test D-422. The results of these tests are presented on Plate Number 10. f) PLASTICITY INDEX: The Plasticity Index (PI) which is defined as the liquid limit of a soil minus its plastic limit was determined for certain representative cohesive samples. The liquid limits and plastic limits were determined in accordance with A.S.T.M. Test Method 0433-66 and 0424-59 respectively. The results of these tests are presented on Plate Number 10. SOUTHERN CALIFORNIA BOIL AND TESTING. INC 1 $•'?!H' .1 CO 3 O CP CCL olo» t (/I FH m 0)Kif CO R o o <jj 00 r rr SUBSURFACE EXPLORATION L.EGEND UNIFIED SOIL CLASSIFICATION CHART SOIL DESCRIPTION 1.COARSE GRAINED, More than half of material is larger than No. 200 sieve size. GRAVELS CLEAN GRAVELS More than half of coarse fraction is larger than No. 4 sieve size but smaller than 3".GRAVELS WITH FINES (Appreciable amount of fines) SANDS More than half of coarse fraction is smaller than No. 4 sieve size. CLEAN SANDS SANDS WITH FINES (Appreciable amount of fines) 11. FINE GRAINED, More than half of material is smaller than No. 200 sieve size. SILTS AND CLAYS Liquid Limit less than SO SILTS AND CLAYS Liquid Limit greater than 50 HIGHLY ORGANIC SOILS GROUP SYMBOL GW GP GM GC SW SP SM sc ML CL OL MH CH OH PT TYPICAL NAMES Well graded qravels, gravel- sand mixtures, little or no fines. Poorly graded gravels, gravel •and mixtures, little or no fines. Silty gravels, poorly graded gravel-sand-silt mixtures. Clayey gravels, poorly graded gravel-sand, clay mixtures. Well graded sand,gravelly sands, little or no fines. Poorly graded sands,gravelly sands, little or no fines. Silty sands, poorly graded sand and silt mixtures. Clayey sands, poorly graded sand and clay mixtures. Inorganic silts and very fine sands, rock flour, sandy silt or clayey-silt-sand mixtures with slight plast- icity Inorganic clays of low to medium plasticity,gravelly clays, sandy clays,silty clays, lean clays. Organic silts and organic silty clays of low plasticity Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts. Inorganic clays of high plasticity, fat clays. Organic clays of medium to high plasticity. Peat and other highly organic soils. •^ - Water level at time of excavation or as indicated US CK B - Undisturbed, driven ring sample or tube sample - Undisturbed chunk sample - Bulk sample SOUTHERN CALIFORNIA BOIL & TESTING , INC. • ••O MIVinOALSj «TP>BT • AN oi«aa, CALIFORNIA siaiBo La Corina Place Condos Escondido, California BY AFB JOB NO.14044 DATE 9-29-82 Plate No. 4 ' - - 1 ~~ -A — .SAMPLE TYPEUS BG CK US US z0 I— 4 U SO'LCLASSIFML/ CL SC SM/ SC rr BORING NUMBER 1 ELEVATION ] 3(3 DESCRIPTION -SANDY, VERY SILTY, CLAY (ALLUVIUM) VERY CLAYEY SAND GRADES TO SILTY CLAYEY SAND BOTTOM COLORDRK-BRN GRN-BRN YEL-BRN APPARENTMOI^TI mrMOIST MOIST APPARENTCONSISTENCYon DE-NSITY^STIFF VERY DENSE PENETRATION |RESISTANCE *«*•IBLOWS/FT OF DRIVL f12 17 24 STANDARDPENETRATIONRESISTANCE(BLOVA/S/FT OF DRIVE )DRY DENSITYtPCF)108.0 MOISTURECONTENT (c<o)13.3 RELATIVECOMPACTION e°'o>t• • • • • - &f^ SOUTHERN CALIFORNIAr~r •» \ \^r SOIL & TESTING, INC. SUBSURFACE EXPLORATION LOB LOGGED BY CRB JOB NUMBER 14044 DATE DRILLED 6-18-82 Plate No. 5 _-—--_ .J»" " ' — 2- 4- — 6- j - o- 2~ i 4~ 6- p —0 in •U (SAMPLE TYPEUS CK CK US CK ' z 0 u SO'LCLASSIFIML/ CL r f BORIMB NUMBER 2 ELEVATION 154 DESCRIPTION VERY SANDY, VERY SILTY •CLAY BOTTOM COLORGRN-BRN GRN-BRN TO YEL-BRN APPARENTMOISTUREMOIST r * *APPARENTCONSISTENCYOR DE'NSITYVERY STIFF g PENETRATIONRESISTANCEt BLOXA/S/FT OF D9 13 UJ>STANDARDPENETRATIONRESISTANCEC BLOWS/FT OF OFDRY DENSITYtPCF)116.8 112.1 MO'STURECONTENT fov,)24.6 15.6 5 RELATIVECOMPACTION Cr™ • • - • - • - . - - - ^f\. SOUTHERN CALIFORNIA V lyT SOIL & TESTING, INC. SUBSURFACE EXPLORATION LOG LOGGED BY JOB NUMBER 14044 DATE DRILLED C 1 0 QO Plate No. 6 r r Natural Dry Density and Moisture Content Sample P3 P6 P9 P10 Description Sandstone Si Its tone Sandstone Si Its tone Density p.c.f. 132.8 112.3 136.8 119.3 MoistureContent•h 9.5 18.3 8.1 15.6 S\ SOUTHERN CALIFORNIA X§US SOIL & TESTING , INC. ^W 1 yT •••O MIVIPDALH »TB««T ^W<|^r BAN OIBOO, CALIFORNIA ••1BO La Corina Place Condos Escondido, California BY AFB JOB N°- 14044 DATE 9-29-82 Plate No. 7 4-5 to 20 NORMAL STRESS 4-0 SOUTHERN CALIFORNIA BOIL A TESTING , INC. • ••O HIVKROALK BTBKBT • AN OIBOO. CALIFORNIA •B1*D La Corina Place Condos Escondido, California BY DIRECT SHEAR TEST DATA AFB JOB NO. 14044 DATE 9-29-82 Plate No. 8 DIRECT SHEAR I c!$ i RESULTS SAMPLE BI @ e B2 0 10 P7 P4 PI 2 DESCRIPTION Undisturbed Ring Sample Undisturbed Ring Sample Undisturbed (ring cut from chunk) Undisturbed (ring cut from chunk) Remolded to Natural Density Angle of internal friction( °) 25.5 31 32 39 39 Cohesion intercept (psf) 300 250 200 2400 550 EXPANSION TEST RESULTS SAMPLE CONDITION INITIAL M.C.CVo) INITIAL DENS1TY(PCF) FINAL M.C. (•/.) NORMAL STRESS (PSF EXPANSION («/.) B2 9 2 Undisturbed Air Driprl 6.9 116.8 24.6 150.0 14.6 P6 Remolded Air Dried 5.0 129.7 19.2 150.0 15.8 SOUTHERN CALIFORNIA BOIL & TESTING LAB, INC. • 8BO RIVERDALB STREET SAN DIEOO, CALIFORNIA BB1BO La Corina Place Condos Escondido» California BY AFB DATE 9_29-82 » ' 4f^~ ^^ *a r 8 US Standard S/eves HydrometerVf «io »20 ««o *eo (Minutss)IT *<» «8 «<6 *30 «50 «IOO «200 125 3O*• A V, (\t 'CD rT -s 8 | ? o o o a? o> » r~ y _*_• •* ...J 1 jj ^T Tl••••f -f — ^ \ I 1 1 ' ' ci e} C1) 0 / / \ ) C} f i Ml « - / - — S V* f "*i i 'T°T \ '/or* irw_/ luaojsd O O O O O.. in •» i« CM - O ^/ 1 \ s <//J/ jff ... \ s tu ••'•'? jf^--'- i s 90 JA ".".".•:•:•:•„. "-•:-4i..,.,. 1 ;/r ..... ? i d XqrS. SOUTHERN CALIFORNIA >^W/ BOH. A TESTING , INC. GRAIN SIZE DISTRIBUTION i \~r / ••:•:•,. "*:»•: / r " — -- \ t- ._ > C O * *^ tn * * t— : -J nj •o » UJ 0 *> fg ;| in °>O UJ _J U <r rt tff « Q. m (0 5§ U) u o m o (0 [ GRAVEL_c Medium1 il U COBBLESI 1 o oiuj o 1 12 cO *J u oI 2•> u 0 > * UJ o 2 < *-- • "**-e o x> w ^ -. i- T M — — • X « •- t Sc => i ? ? MilS 2 | a. La Corina Place Condos Escondido, California " AFB JOB NO. DATE 9-29-82 r /Vy .. .' • ^ WEAKENED ' PI AMP ° •r l_MINt . • JOINTS ' ^>. ••'••" '•' •' ; 10' ^•:-:S >•**• • • • .' ''• >TRANSVERSEL/P A i/FMpnM CM i\U IN C.U PLANE JOINTS 6' ON CENTER (MAX,) 3' w W/2 ^ ;-K'. '. . • • ' _ 5'- lW/2 .V?^| '.'•'.' • • .- • -10' SLABS IN EXCESS OF 10 FEET IN WIDTH SLABS 5 TO 10 FEET IN WIDTH PLAN N.T.S, 1 - \ \-'-.'-: '••'••':/.'• .'u/4 [,' •'-..': \ ' * * " • * ^^^^Z^_ * O \. -o- .. . • o j • . • . • • o _ 1/8 TO 1/4 JOINT SEALER • ' • • • • . ' • '.'••.' '•'..'-.'•• .:• •.•".•• -1-V9- '. \ ' • • ' "\ c. i• • \ o • o • . . . o . \ 18" 6"x6"-10/10 WWM CONTINUOUS \6"x6"-10/10 STRIP IN ADDITION TO CON- TINUOUS REINFORCEMENT DETAIL-WEAKENED PLANE JOINT N.T.S, SOUTHERN CALIFORNIA SOIL & TESTING LAB, INC. RIVEROALK BTRKET SAN DIEOO, CALIFORNIA BB1RQ La Corina Place Condos Escondido, California BY AFB JOB NO.14044 DATE 9-29-82 Plate No. II SCS&T 14U44 September 29, 1982 Appendix A, Page 1 PROPOSED CONDOMINIUM PROJECT, LA CORINA PLACE, LA COSTA, CALIFORNIA RECOMMENDED GRADING SPECIFICATIONS - GENERAL PROVISIONS GENERAL INTENT The intent of these specifications is to establish procedures for clear- ing, compacting natural ground, preparing areas to be filled, and placing and compacting fill soils to the lines and grades shown on the accepted plans. The recommendations contained in the preliminary soil investiga- tion report and/or the attached Special Provisions are a part of the Recommended Grading Specifications and shall supersede the provisions contained hereinafter in the case of conflict. These specifications shall only be used in conjunction with the soil report for which they are a part. No deviation from these specifications will be allowed, except where specified in the soil report or in other written communication signed by the Soil Engineer. OBSERVATION AND TESTING Southern California Soil & Testing, Inc. shall be retained as the Soil Engineer to observe and test the earthwork in accordance with these speci- fications. It will be necessary that the Soil Engineer or his representa- tive provide adequate observation so that he may provide an opinion that the work was or was not accomplished as specified. It shall be the re- sponsibility of the contractor to assist the soil engineer and to keep him apprised of work schedules, changes and new information and data so that he may provide these opinions. In the event that any unusual conditions not covered by the special provisions or preliminary soil report are encountered during the grading operations, the Soil Engineer shall be contacted for further recommendations. SCS&T 14U44 September 29, 1982 Appendix A, Page 2 If, in the opinion of the Soil Engineer, substandard conditions are en- countered, such as; questionable or unsuitable soil, unacceptable moisture content, inadequate compaction, adverse weather, etc., he will be empower- ed to either stop construction until the conditions are remedied or cor- rected or recommend rejection of this work. Test methods used to determine the degree of compaction should be per- formed in accordance with the following American Society for Testing and Materials test methods: Maximum Density & Optimum Moisture Content - A.S.T.M. D-1557-78. Density of Soil In-Place - A.S.T.M. D-1556-64 or A.S.T.M. D-2922. All densities shall be expressed in terms of Relative Compaction as deter- mined by the foregoing A.S.T.M. testing procedures. PREPARATION OF AREAS TO RECEIVE FILL All vegetation, brush and debris derived from clearing operations shall be removed, and legally disposed of. All areas disturbed by site grading should be left in a neat and finished apperance, free from unsightly debris. Any abandoned buried structures encountered during grading operations must be totally removed. All underground utilities to be abandoned beneath any proposed structure should be removed from within 10 feet of the structure and properly capped off. The resulting depressions from the above des- cribed procedures should be backfilled with acceptable soil that is com- pacted to the requirements of the Soil Engineer. This includes, but is not limited to, septic tanks, fuel tanks, sewer lines or leach lines, SOUTHERN CALIFORNIA SOIL AND TESTING. INC SCbiT 14U44 September 29, 1982 Appendix A, Page 3 storm drains and water lines. Any buried structures or utilities not to be abandoned should be investigated by the Soil Engineer to determine if any special recommendation will be necessary. All water wells which will be abandoned should be backfilled and capped in accordance to the requirements set forth in the Geotechnical Report. The top of the cap should be at least 4 feet below finish grade or 3 feet below the bottom of footing whichever is greater. The type of cap will depend on the diameter of the well and should be determined by the Soil Engineer and/or a qualified Structural Engineer. When the slope of the natural ground receiving fill exceeds 20% (5 hori- zontal units to 1 vertical unit), the original ground shall be stepped or benched. Benches shall be cut to a firm competent soil condition. The lower bench shall be at least 10 feet wide or 1 1/2 times the equipment width which ever is greater and shall be sloped back into the hillside at a gradient of not less than two (2) percent. All other benches should be at least 6 feet wide. The horizontal portion of each bench shall be compacted prior to receiving fill as specified hereinbefore for compacted natural ground. Ground slopes flatter than 20% shall be benched when considered necessary by the Soil Engineer. After clearing or benching, the natural ground in areas to be filled shall be scarified to a depth of 6 inches, brought to the proper moisture con- tent, compacted and tested for the minimum degree of compaction in the Special Provisions or the recommendation contained in the preliminary soil investigation report. All loose soils in excess of 6 inches thick should be removed to firm natural ground which is defined as natural soil which possesses an in-s1tu density of at least 85% of its maximum dry density. SOUTHERN CALIFORNIA SOIL AND TESTING. INC SCS&T 14U44 September 29, 1982 Appendix A, Page 4 FILL MATERIAL Materials placed In the fill shall be approved by the soil engineer and shall be free of vegetable matter and other deleterious substances. Gran- ular soil shall contain sufficient fine material to fill the voids. The definition and disposition of oversized rocks, expansive and/or detrimen- tal soils are covered in the soils report or Special Provisions. Expan- sive soils, soils of poor gradation, or soils with low strength character- istics may be thoroughly mixed with other soils to provide satisfactory fill material, but only with the explicit consent of the soil engineer. Any import material shall be approved by the Soil Engineer before being brought to the site. PLACING AND COMPACTION OF FILL Approved fill material shall be placed in areas prepared to receive fill in layers not to exceed 6 inches in compacted thickness. Each layer shall have a uniform moisture content in the range that will allow the compac- tion effort to be efficiently applied to achieve the specified degree of compaction. Each layer shall be uniformly compacted to the minimum speci- fied degree of compaction with equipment of adequate size to economically compact the layer. Compaction equipment should either be specifically designed for soil compaction or of proven reliability. The minimum degree of compaction to be achieved is specified in either the Special Provisions or the recommendations contained in the preliminary soil investigation report. When the structural fill material includes rocks, no rocks will be allowed to nest and all voids must be carefully filled with soil such that the minimum degree of compaction recommended in the Special Provisions is SOUTHERN CALITQRNIA SOIL AND TESTING. INC SCS&T 14044 September 29 1982 Appendix A Page 5 achieved. The maximum size and spacing of rock permitted in structural fills and in non-structural fills is discussed in the soil report, when applicable. Field observation and compaction tests to estimate the degree of compac- tion of the fill will be taken by the Soil Engineer or his representative. The location and frequency of the tests shall be at the Soil Engineer's discretion. When the compaction test indicates that a particular layer is less than the required degree of compaction, the layer shall be reworked to the satisfaction of the Soil Engineer and until the desired relative compaction has been obtained. Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction by sheepsfoot rollers shall be at vertical intervals of not greater than four feet. In addition, fill slopes at ratios of two horizontal to one vertical or flatter, should be track- rolled. Steeper fill slopes shall be over-built and cut-back to finish contours. Slope compaction operations shall result in all fill material six or more inches inward from the finished face of the slope having a relative compaction of at least 90% of maximum dry density or that speci- fied in the Special Provisions section of this specification. The compac- tion operation on the slopes shall be continued until the Soil Engineer is satisfied that the slopes will be stable in regards to surficial stabil- ity. 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 that day of such conditions by written communication from the Soil Engineer in the form of a daily field report. SOUTHERN CALIFORNIA SOIL AND TESTING. INC SCS&T 14044 September 29, 1982 Appendix A, Page 6 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. CUT SLOPES The Engineering Geologist shall inspect all cut slopes excavated in rock or lithified formational material during the grading operations at inter- vals determined at his discretion. 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 Soil Engi- neer to determine if mitigating measures are necessary. Unless otherwise specified in the soil and geological report, no cut slopes shall be excavated higher or steeper than that allowed by the ordinances of the controlling governmental agency. ENGINEERING OBSERVATION Field observation by the Soil Engineer or his representative shall be made during the filling and compacting operations so that he can express his opinion regarding the conformance of the grading with acceptable standards of practice. The presence of the Soil Engineer or his representative or the observation and testing shall not release the Grading Contractor from his duty to compact all fill material to the specified degree of compac- tion. SOUTHERN CALIFORNIA SOIL AND TESTING. INC SCS&T 14044 September 29, 1982 Appendix A, Page 7 SEASON LIMITS Fill shall not be placed during unfavorable weather conditions. When work is interrupted by heavy rain, filling operations shall not be resumed until the proper moisture content and density of the fill materials can be achieved. Damaged site conditions resulting from weather or acts of God shall be repaired before acceptance of work. RECOMMENDED GRADING SPECIFICATIONS-SPECIAL PROVISIONS The minimum degree of compaction to be obtained in compacting natural ground, in the compacted fill, and in the compacted backfill shall be at least 90 percent. Detrimentally expansive soil is defined as soil which will swell more than 3 percent against a pressure of 150 pounds per square foot from a condi- tion of 90 percent of maximum dry density and air dried moisture content to saturation. Oversized fill Material is defined as rocks or lumps over 6 inches in diameter. At least 40 percent of the fill soils shall pass through a No. 4 U.S. Standard Sieve. Transition Lots: Where transitions between cut and fill occur within the proposed building pad, the cut portion should be undercut a minimum of one foot below the base of the proposed footings and recompacted as structural backfill. SOUTHERN CALIFORNIA SOIL AND TESTING. INC LOCAT CASE NO. A P P LIC A N T_lCRC/L_AjCO_STA_._ VICINITY MAP