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HomeMy WebLinkAboutCDP 04-16; La Suvera; Addendum Geotechnical Report; 2001-09-121/607215539; September 12.2001 n CONSULTANTS 10/22/02 10:28AM;;fii£aL/,781;Page 2/6 Redeemer By The Sea C/o Kea Voemnan 1S] 7 South Pacific Stieet Ooeianside; CA 92054 References: Subject: Addendum Geoiecboical Repon Proposed aurch azul Residential Develonmeat Redeemer by the Sea Poinsettia Lane and Black Rail Road Carlsbad, CA CT 00-22 Investigation. Pioposed Church and November 20,2000. ••UOKM "Rough Grading Plans. Redeemer by the Sea" by Sowards anJ dated April 23,2001. . oy i»owanis and Brown. Dear Mr. Voortman: (F.n-c,«r.^Bml). EQ-10 (DayUsht On Lol} and EauaiSSSt^ 3 0 6 Q INDUSTRV ST SUITE 105 OCEANSIDE C A 9 2 0 s 4 TEL- 760.721.54M >AX: 760.^21.5559 o LU COPo4-i{t Q. 10/22/02 10:28AM;;fiifflL#781 ;Page 3/6 jlOltewyii; i| eoMiuii«.i>it In the area of Lots U & 12 and Street "A" Figure EG-6 applies. All unsuitable soil djould be removed down to bedrock or TeriBce Deposits and a minimum 1 S-foot wide key excavated jmor to placemeoi of fill. The fill should then be placed and benches excavated imo bedrock and the slope is being constructed. In the ^ofIx>ts 8-11 figure EG-10 applies. AU unsuitable soils are removed down to bedrocks retrace Deposits aminimum 1:1 projection fiom the edge ofthe pad. Fill is tl^gaced and benched into bedrocL Tbe resulting cut^ is handled in accordance with ilguies EG-)0 and EG-11. All other cut/BII transition lots are handled in accordance with Figure EG-11 Thecut poison ofthe lot is overevcavaied a minhnum ofthree feet and replaced as compacted fill (mhumum 90% relative conqjaction). -^f-*^ All ottw eoDclusions and recommeodatians contained in our geotechnical leoon of Novcmbcx 20.2000 apply to thc residenlial lots and arc stiUvaUd. I hope this addresses the concerns ofthe Cily of Carlsbad. Sincerely. , | J^^MSPA owlton RCE 55754 CEG 1045 ucii.. kjjr . Mv^ii j.v^M il'io 1 I. 1 /bU/21b53y; 10/22/02 10:28AM;Jfi|£ai_#781 jPage 4/6 TRANSITION LOT DETAIL CUT LOT (MATERiAL TYPE JHANSITIONJ NATURAL CRAOE COMPACTED FILL .UNWI TYPICAL BENCHING OVEREXCAVATE ANO RECOMPACT UNWEATHERED'BEDROCK OR APPROVED MATERUL CUT-FILL LOT (DAYUGHT TRANSITION) PAD GRADE NATURAL 6RA0E — COMPACTED RLL •^SSS-^S^^'OVEREXCAVATE ^•MiyiUM 5D\V- ANO RECOMPACT Tg^^WW^^/^^^^^^^^' MWIMUM» y UNWEATHERED 8E0ROQC OR APPROVED MATERIAL TYPICAL BENCHING NOTE: * DEEPER OVEREXCAVATION >4AY BE RECGMMENOEO BY THE SOILS ENGINEER ANO/OR.ENGJNeERlNO GEOLOGIST IN STEEP CUT-RLL TRANSITION AREAS. PLATE EG-11 FILL OVER NATURAL DETAIL PROPOSED GRADE TOE OF SLOPf AS SHOWN ON ORADING PLAN PROVIDE A 1:1 MIKIMUM PROJECTION FROM DESIOM TOE OP SLOPE TO TOE OP ICEY AS.SHOWM ON ASBUILT COMPACTED RLL MAINTAIN MINIMUM 15* WIDTH. SLOPE TO BENCH/BACKCUT ITI- Q I OJ NATURAL SLOPE TO BE RESTORED-wrrH COMPACTED FILL BACKCUT VARIES MINIMUM KEY WIDTH 2'X 3'MINIMUM KEY OEPTH 2'HINIHUM IN BEDROCK OR "APPROVED MATERIAL . BENCH WIDTH MAY VARY MIKIMUM mSL 1. WHERt THE NATURAL- SLOPE APPROACHES OR EKCEEOS THE DESION SLOPE RATIO. SPECIAL RECOMMENDATIONS WOULD BE PROVIDED BY THE SOILS ENQINEER, 2. THE NEED FOR AND DISPOSITION OF DRAINS WOULD BE OETERMINEO BY THE S0IL5 ENGINEER BASED UPON EXPOSED CONDITIONS. c c r c "1 J r O (VJ 01 tn Q CO fO o rvj a > -vl •9 TJ 0) tt Ul 0> DAYLIOHT CUT LOT DETAIL RfiCOMSTftOCt COMPACTED FILl. SLOPE AT 2:i OR FLATTER •IMAY INCREASE OR DECREASE PAD AREA). OVEREXCAVATE ANO RECOMPACT REPLACEMENT FILL NATURAL GRADE AVOID AND/OR CLEAN UP SPILLAGE OF MATERIALS ON THE NATURAL SLOPE . .xy^ ^ PROPOSED RNISH QRADE ^yj^>^'Jx^ ^'MINIMUM BLANKET FILL BEDROCK OR APPROVEO MATERIAL TVI>ICAL BENCHING - c r »< a c tr tr u IV; IV c IV; •D m .0 o NOTE: 1. SUBDRAIN ANO KEY WIDTH REQUIREMENTS WILL BE DETERMINED BASED ON EXPOSED SUBSURFACE CONDITIONS AND THICKNESS OF OVERBURDEN. 2.- PAD OVER EXCAVATION AHD RECOMPACTION SHOULD BE PERFORMED IF OETERMINEO NECESSARY DY THE SOILS ENGINEER AND/OR THE EMOlNEERlNfl OEOLOOIST. tc > r -0 03 n 0> v. 0> PRELIMINARY GEOTECHNICAL INVESTIGATION, PROPOSED CHURCH AND RESIDENTIAL DEVELOPIVIENT REDEEMER-BY-THE-SEA POINSETTIA LANE AND BLACK RAIL ROAD CARLSBAD, CALIFORNIA PRELIMINARY GEOTECHNICAL INVESTIGATION. PROPOSED CHURCH AND RESIDENTIAL DEVELOPMENT REDEEMER-BY-THE-SEA POINSETTIA LANE AND BLACK RAIL ROAD CARLSBAD. CALIFORNIA NOVEMBER 20. 2000 Prepared For: REDEEMER BY THE SEA c/o KEN VOERTMAN 1617 SOUTH PACIFIC STRRET OCEANSIDE. CA 92054 E o ; E C H C O N S V I I November 20. 2000 To: Redeemer by the Sea c/o Ken Voertman 1617 South Pacific Street Oceanside, CA 92054 Subject: Preliminary Geotechnical Investigation, Proposed Church and Residential Development. Redeemer by the Sea, Poinsettia Land and Black Rail Road, Carlsbad, CA. In accordance with your request and authorization, we have conducted a Geotechnical investigation at the subject site. The accompanying report presents a summary of our invest4gation and provides conclusions and-recommendations relative to site development. Please do not hesitate to contact this office if you have any questions regarding our report. We appreciate this opportunity to be of service. Respectfully submitted, Geopacifica Inc. James F. Knowiton R.C.E. 55754 C.E.G. 1075 3 0 6 0 INDUSTRY ST SUITE 105 OCEANSIDE C A 9 2 0 5 4 TEL: 760.721.5488 FAX: 760.721.5539 TABLE OF CONTENTS Section 1.0 INTRODUCTION 2.0 SITE DESCRIPTION AND PROPOSED DEVELOPMENT 2.1 Site Description 2.2 Proposed Deveiopment 3.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING 4.0 GEOTECHNICAL CONDITIONS 4.1 Regional Geology 4.2 Site Geology 4.3 Geologic Structure 4.4 Surface and Ground Water 5.0 FAULTING AND SEISMICITY 5.1 Faulting 5.2 Seismicity 5.2.1 Lurching and Shallow Ground Rupture 5.2.2 Liquefaction and Dynamic Settlement 6.0 CONCLUSIONS 7.0 RECOMMENDATIONS 7.1 Earthwork 7.1.1 Treatment of Existing Soils 7.1.2 Excavations 7 1.3 Trench Excavation and Backfill 7.1.4 Fill Placement and Compaction 7.1.5 Expansive Soils 7.1.6 Slope Stability 7.1.7 Structural Slope Stability 7.2 Surface Drainage 7.3 Foundation and Slab Design Considerations 7.3.1 Foundations 7.3.2 Floor Slabs 7.3.3 Mat Foundation TABLE OF CONTENTS (Continued) Section 7.3.4 Settlement 7.3.5 Lateral Earth Pressures and Resistance 7.4 Lateral Earth Pressures and Resistance 7.5 Retaining Wall Drainage and Backfill 7.6 Construciion Observation Figures Figure 1 - Site Location Map Figure 2 - Regional Seismicity and Index Map Figure 3 - Boring Location Map Rear of text Tables Table 1 - Seismic Parameters for Active and Potentially Active Faults Appendices Appendix A - References Appendix B - Boring Logs Appendix C - Laboratory Testing Procedures and Test Results Appendix D- General Earthwork and Grading Specifications 1.0 INTRODUCTION This report presents the results of our geotechnical/foundation investigation at the subject site. The purpose of the investigation was to identify and evaluate the Geotechnical conditions present on the site and to provide conclusions and recommendations regarding the proposed development. Our scope of services of the investigation included; • Review of available pertinent published and unpublished geologic literature and maps (Appendix A) • Aerial photographic analysis to assess the general geology of the site (Appendix A). • Fieid reconnaissance of the existing onsite Geotechnical conditions. • Subsurface exploration consisting of the excavation, logging and sampling of nine small diameter borings. The logs of the borings are presented in Appendix 8. • Laboratory testing of representative, undisturbed and bulk soil samples obtained from our subsurface exploration program (Appendix C) • Geotechnical analysis of field data and laboratory test results. • Preparaiion of this report presenting our findings, conclusions and recommendations with respect to the proposed development. 2.0 SITE DESCRIPTION AND PROPOSED DEVELOPMENT 2.1 Site Description The irregularly shaped subject site is bounded by vacant land to the North and East and the proposed extension of Poinsettia Lane south and Black Rail Road to the west in Carlsbad. California (Figure 1). The site is cun-ently vacant, but has been previously farmed with same grading. Although not encountered during our investigation, it is possible that buried agricultural fills and debris may be encountered during site development due to the priors use. but was not encountered over most of the site. 2.2 Proposed Development We understand the proposed Redeemer by the Sea Church and proposed Residential development will include construction of 12 residential pads, several church buildings with parking on the northern portion of the site. Structural informaiion was not available at the time of this report. However, building loads are assumed typical for these types of structures. Site grading to create the underground parking will include cuts up to depths of approximately +- 15 feet It is anticipated that the proposed cut and fill will encompass the entire site ' - ^"•"J^D^''' .— "T" — n MCCLELLAN AIRPORT . NORTH Scale 1"=2000' Taken From: Thomas Guide, 2000 Edition I LOCATION MAP 1 GEOPACIFICA PROJECT NO FIGURE NO. 1 3.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING Our subsurface exploratory program consisted of the excavation of 9 small diameter borings drilled to a maximum depth of 30 feet in the proposed building areas. The approximate locations of the borings are shown on the Boring Location Map (Figure 3). The purpose of this program was to evaluate the physical characteristics of the onsite soils pertinent to the site development and check existing ground water levels. The borings were logged and sampled by a geologist from our firm. Bulk and relatively undisturbed samples of the soils were obtained for laboratory testing. Logs of the borings are presented in Appendix B. Logs of the borings are presented in Appendix B. Subsequent to logging and sampling, ail borings were backfilled. Laboratory testing was performed on representative samples to evaluate the moisiure. density, and strength characteristics of the subsurface soils. A discussion of the laboratory tests performed and a summary of the laboratory tests are presented in Appendix C. Moisture and density test results are provided on the boring logs (Appendix B). 4.0 GEOTECHNICAL CONDITIONS 4.1 Regional Geology Tbe subject site is situated in the coastal section of the Peninsular Range Province, a California geomorphic province with a long and active geologic history throughout southern California. Through the last 54 million years, the area known as the San Diego Embayment has undergone several episodes of marine inundation and subsequent marine regression. This has resulted in a thick sequence of marine and non-marine sediments deposited on rocks of the southern California batholith with relatively minor tectonic uplift of the area. 4.2 Site Geology Based on our subsurface exploration (Appendix B). aerial photographic analysis, and review of pertinent Geotechnical literature and maps (Appendix A), the subject site is underiain by Pleistocene terrace deposits which are. in turn, underlain by the Tertiary Santiago Formation. Minor undocumented fill soils were encountered mantling the terrace deposits and in small canyons on the site. The Pleistocene terrace deposits were observed to predominantly consist of red- brown, orange-brown, dry to moist, medium dense to dense, silty. fine-to- medium-grained sand. Based on laboratory testing and visual classification, the Pleistocene terrace deposits on the site generally have relatively high shear strength and a very low expansion potential. The Santiago Formation encountered during our investigation primarily consisted of yellow-brown lo olive-brown and green-gray, moist, dense to very dense silty to slightly clayey, sandy, silt stone and sandstone. Based on visual classification and our experience with similar materials, the typically has relatively high shear strengths and a low to medium expansion potential. Claystones may have a high expansion potential. Fill soils were encountered in Borings B-6 and B-7. These undocumented fill soils were approximately 1-2 feet thick and consisted of brown to red-brown, silty sand lhal contained abundant debris. These soils are not considered suitable for the support of structural loads or support of fill in their present condition. 4.3 Geologic Structure Observations made during our subsurface exploration and experience with similar units on nearby sites indicate that the Pleistocene terrace deposits and sandstone units of the Tertiary Santiago Formation are generally massive in this area with no significant geologic structure. Pertinent Geotechnical literature (Appendix A) indicates that the sedimentary soils are generally flat lying to gently dipping. No major folding of the sedimentary units is known or expecied to exist at the site. 4.4 Surface and Ground Water No surface water was evident at the time of our investigation. Ground waler was not encountered in our borings. Ground water is not anticipated to be a constraint to development. However, seasonal fluctuations in rainfall and irrigation, variations in ground surface and subsurface conditions may significantly affect ground water levels. We recommend that all below grade walls be appropriately waterproofed. 5.0 FAULTING AND SEISMICITY 5.1 Faulting The two principal seismic hazard considerations for developmental projects in southern Califomia are damage resulting from earthquake-induced shaking and surface rupture along active or potentially active fault traces. The criteria followed in this report, relative to fault activity, are those enacted by the State of California and utilized by the Califomia Division of Mines and Geology in the Alquist-Priolo Act. This act establishes special study zones for active or potentially active faults to assure that unwise urban development does not occur across the traces of active faults. The subject site does not lie within the Alquist-Priolo Special Studies Zone. An active fault Is a fault, which has had surface displacement within the iasl 10.000 to 11,000 years (Holocene Epoch) A fault which exhibits ground rupture within the last 2 million years (Quatemary Period), but does not exhibit direct evidence of offsetting Holocene sediments, is considered polenlially active Any fault shown to be older than the Quafernary period is considered inactive. A review of available geologic literature and aerial photographs pertaining lo the subject sile (Appendix A) indicates that there are no known active faults crossing the property. Nor was any indication of faulting during our subsurface investigation. Figure 2 indicates the location of the sile in relationship to known major faults in the southern California region. Included on Figure 2 are the approximate epicentral area and magnitude of earthquakes recorded durinq the oeriod of 1769 to 1973. H UU. The nearest significant active regional faults are the Elsinore Fault Zone located approximately 19 miles northeast of the site and the offshore extension of the Rose Canyon Fault Zone, located approximately 5 miles to the southwest according to maps prepared by the California Division of Mines and Geology 5.2 Seismicity The subject site can be considered to iie within a seismically active region as can all of southern California. Table 1 indicates potential seismic events that could be produced by maximum probable earthquakes. A maximum probable earthquake is the maximum expectable earthquake produce from a causative fault furring a 100-year interval. Site-specific seismic parameters included in Table 1 are the distances to the causative faults. Richter earthquake magnitudes expected peak/repeatable high ground accelerations (RHGA), and estimated period and duration of ground shaking. The effect of seismic shaking may be mitigated by adhering to the Uniform Building Code or state-of-the-art seismic design parameters of the Structural Engineers Association of California. A number of secondary effects are produced by seismic shaking. These include soil liquefaction, seismic settlement and lurching. 5.2.1 Lurching and Shallow Ground Rupture Soil lurching refers to the rolling motion on the surface by the passage of seismic surface waves causing permanent inelastic deformation of surficial soil. Effects of this nature are likely to be significant where the thickness of soft sediments varies appreciably under a structure. Damage to the proposed development should not be significant because of the relatively dense nature of the onsite soils. Breaking of the ground because of active faulting is not likely to occur on site due to the absence of active faults. Cracking due to shaking from TABLE I SEISMIC PARAMETERS FfJR ACTIVE AND POTtN I IAI.I.Y ACriVE FAUl I S REDEEMER UY rHESEA Potential Causative Fault Distance fro in Fault to Site (Miles) Maxinuini Credible Earthquake Richter Magnitude MAXIMUM PROHAULE EARTHQUAKE (Functional Basis EaitlKiuake^ Peak Bedrock/ Re|)eatable Horizontal Cj round Acceleration** (Gravity) Predominant Period al Site in Seconds Duration of Str(.ing Shaking at Sile in Seconds Jo;^.^are:.""''"'' "'"'"'^"^ ''''' °" ""^ ^"-"^ ^"-'"'^e ofthe geologic conditions ofthe San Diego For design puiposes. the repeatable horizontal ground acceleration may be taken as 65 percent of the n.-,l- lor the site wuhm approximately 20 miles of the epicenter (after Ploessel and Slolson 1974) ^iv» X., . ^S-J^ 1949 MAJOR EARTHQUAKES AND RECENTLY ACTIVE FAULTS IN THE SOUTHERN CALIFORNiA REGION ACTIVE FAULTS Tolol length of fault zona that l>rBalia Holocens depoaa> or ttiot ha« had Miamic sctivlly. EXPLANATION^ Fault ••gmant with niriac* mplura during an hislorii aarthquaka. or wHh asalamfe fault craap. O Holocena volcanic activity (Amboy, Plagah, Carro Prialo and Salton Buttes) EARTHQUAKE LOCATIONS Approximale apicanlral araa of aarthquak as that occurrad 1769-1933. MagnHudas not raeordad bv Inatrumania prior lo 1906 wera ealimaiad from damaga raporta aaaignad an inlaneitv VH (Modiiiad Marcali scale) or greatar thia Is roughly aquivaleni to HichterM6.0. 31 moderata" earthquakes, seven major and ona great earthquake (1S57) wera reported In tha 164-yaar period 17B9-1933. Earthquake epicaniara since 1933, plotted from inprovad instruments. 29 moderaia * • and three major aaithquakae were recorded In lha 40-year period 1933-1973. Sea Lamar. MerilMd. Proctor paper herein lor addilianal sxpianalion ol map. hu Compiled by Riehw^J. Proctor niain/y horn pubfished and ufwublished data iJi»».r^^^ rv. - • . ol Water Reaourci Bdledn 116-2 (1964); ^Section, Iron, iXti^S^ftS ct^i^^Tl?^"'.^ "^^^W- C>lilon», t).p«m»nl aemanlary Safamoloo, (195«: .nd Ih. Ifalbnal A««. G~log,cal Se„mologKal Scc=-s„ d America: Irom CF. Bchier. Bamenlary SaBmology (195a>: and lha Itotbn^ AUM. p.6e. REGIONAL SEISMICITY INDEX MAP Project No. Project Name Redeemer-by-thp-^PS Date_n/20/00 Figure No. _2_ fr-i •>••'. 5.2.2 Liquefaction and Dynamic Settlement Liquefaction and dynamic settlement of soils can be caused by strong vibratory rnotion due to earthquakes. Both research and historical data indicate that loose, saturated, granular soils are susc:eptible to liquefaction and dynamic settlement while the stability of silty clays and clays is not adversely affected by vibratory motion. Liquefaction is typified by a total loss of shear strength in the affected soil layer, thereby causing the soil to flow as a liquid. This effect may be manifested by excessive settlements and sand boils at the ground surface. Settlement may also occur in loose and cohesion-less material as a result of rapid, seismically induced shaking. The onsite Pleistocene terrace soils and the Santiago Formation are not considered liquefiable due lo their density and the absence of a near-surface ground water table. 5.2.3 Seismic Shaking Parameters Based on the sile condilions, Chapter 16 of the Uniform Building Code (International Conference, of Building Officials, 1997) and Peterson and others (1996). the following seismic parameters are provided. Seismic zone (per Figure 16-2*) 4 Seismic Zone Factor (per Table 16-1*) 0.40 Soil Proflle Type (per Table 16-J*) So Seismic Coefficient Ca (per Table 16-Q*) 0 44 NA Seismic Coefficient Cv (per Table 16-R*) 0.64 Nv Near Source Factor NA(per Table 16-S*) 1.0 Near Source Factor Nv (per Table 16-T*) 1.0 Seismic Source Type (per Table 16-U*) B Distance to Seismic Source 5.7 mi. (9.2Km) Upper Bound Earthquake Mw 6.9 * Figure and Table references from Chapter 16 of the Uniform Building Code (1997). 6.0 CONCLUSIONS Based on the results of our Geotechnical investigation of the site, it is our opinion that the proposed development is feasible from a Geotechnical standpoint provided the following conclusions and recommendations are incorporated into the project plans and specifications. The following is a summary of the main Geotechnical faclors, which may affect deveiopment of the site. CP! •yf r-yrP'j • .1 Based on laboratory testing and visual classification, the onsite formational soils have relatively high shear strength characteristics and a low expansion potential, both of which are favorable for design of foundations and slabs. Loose fill soils encountered on the site are potentially compressible and are nol considered suitable for structural loads or support of fill in their present condition. It is anticipated lhat site grading will remove all of these undocumented fill soils. However, some undocumented fills may need lo be removed and recompacted. Active faults are not known lo exist on or in the immediate vicinity of the site. The maximum anticipated bedrock acceleration on the site is estimated to be approximately 0.49g based on a maximum probable earthquake of Richter Magnitude on the active Rose Canyon fault Ground water was not encountered. Ground water is not anticipated to have an impact on the proposed development based on the currently proposed grading. Excavation of the onsite soils should generally be feasible with conventional, heavy- duty earthwork equipment in good condition. Localized cemented zones may require the use of rock breakers or localized blasting. Based on the success of our drilling program, the extent of such cemented zones should be minimal. Oversize rock materials are unlikely to be generated froiri excavations in the onsite soils. These materials should be disposed of off site, if encountered 7.0 RECOMMENDATIONS 7.1 Earthwork We anticipate that earthwork at the site will consist of site preparation, excavation and backfill. We recommend that earthwork on site be performed in accordance with the following recommendations and the General Earthwork and Grading Specifications included in Appendix D. In case of conflict, the following recommendations shall supersede those in Appendix D. 7.1.1 Treatment of Existing Soils In areas to receive fill, the existing ground will need to be over-excavated 3 feet and recompacted. Some areas may need deeper removals. Areas of undocumented fill and in canyon, areas may require up to 4-8 feet of recompaction. 7.1.2 Excavations Excavation of the onsite soils may be accomplished with conventional heavy-duty grading equipmeni. Due to the locally friable nature of the sandy terrace deposits, temporary excavations such as utility trenches with vertical sides may not be stable. Temporary excavations deeper than 5 feet should be shored or laid back to 1:1 (horizontal to vertical) in undisturbed Santiago Formation and Terrace deposits. Shoring recommendations can be provided if needed when final plans are available. All excavations should be made in accordance with OSHA requirements. 7.1.3 Trench Excavation and Backfill Excavation of utility trenches and foundations in the onsite soils appears to be generally feasible with heavy-duty backhoe equipment. The onsite soils may be used as trench backfill provided they are screened of organic matter, debris, and rock fragments greater than 6 inches in maximum dimension. Trench backfill should be compacted in uniform lifts (not exceeding 8 inches in thickness) by mechanical means to at least 90 percent relative compaction (ASTM Test Method Dl 557-78). 7.1.4 Fill Placement and Compaction The onsite soils are generally suitable for use as compacted fill provided they are free of organic material and debris. All fill soils including retaining wall backflll should be brought to near-optimum moisture conditions and compacted in unifonn lifts to at least 90 percent relative compaction based on laboratory standard ASTM Test Method Dl 557-78. The optimum lift thickness required to produce a uniformly compacted fill will depend on the type and size of compaction equipmeni used. In general, fill should be placed in lifts not exceeding 8 inches in thickness. Placement and compaction of fill should be performed in general accordance with local grading ordinances, sound constmction practice, and the General Earthwork and Grading Specifications presented in Appendix D. Materials placed within 3 feet of finished grade should be comprised of low expansive soils and contain no rock fragments over 6 inches in maximum dimension. 7.1.5 Expansive Soils Soils encountered on site should have a very low to medium potential for expansion. Expansive soils are not expected to be a constraint to development. 7.1.6 Slope Stabili^y Our review of the project grading plan indicates that cut and fill slopes at inclinations of 2:1 (horizontal to vertical) or flatter with an approximate maximum heights of 15 feet respectively are proposed on site. The proposed slopes were analyzed for gross stabilily utilizing Janbu's analysis method for earth slopes. Slope heights were based on the Figure 3. The strength parameters assumed in our analyses are based on our laboratory test results (Appendix C). our experience with similar units and our professional judgement. 7.1.7 Surficial Siope Stability Our analysis of properiy compacted fill slopes indicates an adequate factor of safety against surficial failures assuming adequate protection against erosion. However, the outer 2 to 3 feet of fill slopes generally become less dense with time. All slopes should be constructed in accordance with the General Earthwork and Grading specifications (Appendix D) and City of Carlsbad grading ordinances. Berms should be provided at the tops of fill slopes, and brow ditches should be constructed at the tops of cut slopes. Drainage should be directed such that surface runoff on slope feces is minimized. Inadvertent oversteepening of cut and fill slopes should be avoided during fine grading and construction. If seepage is encountered in slopes, special drainage features may be recommended by the Geotechnical consultant. Erosion and/or surficial failure potential of fill slopes may be reduced if the following measures are implemented during design and construction of the slopes. 7.2 Surface Drainage Surface drainage should be controlled at all times. Positive surface drainage should be provided to direct surface water away from the structure, toward the street or suitable drainage facilities. 7.3 Foundation and Slab Design Considerations Foundations and slabs should be designed in accordance with structural considerations and the following recommendations. These recommendations assume the soils encountered within 4 feet of pad grade will have a very low to low potential for expansion. This should be evaluated as necessary during grading. Sub-grade soils should be thoroughly moistened prior to placement of concrete or moisture barriers. The following preliminary foundation design parameters are based on a proposed lowest finish floor elevation of approximately 327 feet above mean sea level. 7.3.1 Foundations - Church Any proposed multi-story structures (church buildings) may be supported by conventional, continuous perimeter, or isolated spread footings extending a minimum of 24 inches beneath the lowest adjacent finished grade Footings may be designed for a maximum allowable bearing pressure of 3,000 pounds per square foot if founded into competent, formational soils or compacted fill. The allowable pressures may be increased by one-third for loads of short duration such as wind or seismic forces. Continuous footings should have a minimum width of 24 inches and 36 inches for isolated spread footings. Footings should be reinforced in accordance with the recommendations of the structural engineer. 7.3.2 Foundations - Residential The following foundation construction recommendaiions are presented as a minimum criteria from a soils engineering standpoint. Our experience in the site vicinity indicates onsite soils will likely vary from low lo medium in expansion potential (expansion index 21 to 55), based upon which earth material is exposed-at-finished grades The following foundation construction recommendations are presented as a minimum criteria from a soils engineering standpoint. The onsite soils expansion potentials are generally in the low to medium (expansion index 21 lo 55) It is anticipated that the finish grade materials will have a low to medium expansion potential. However, recommendations for low and medium, are presented herein for your convenience. Recommendations by the project's design-structural engineer or architect, which may exceed the soils engineer's recommendations, should take precedence over the following minimum requirements. Final foundation design will be provided based on the expansion potential of the near surface soils encountered during grading. Low Expansion Potential (Expansion Index 21 to 50) 1. Conventional continuous footings should be founded at a minimum depth of 18 inches below the lowest adjacent ground surface for one-story structural loads and 24 inches below the lowest adjacent ground surface for two-story structural loads. Interior footings may be founded at a depth of 18 inches below the lowest adjacent ground surface. Footings for one-story structural loads should have a minimum width of 12 inches, and footings for two-story structural loads should have a minimum width of 15 inches. All footings should have one No. 4 reinforcing bar placed at the top and one No. 4 base of the grade beam should be at the same elevation as the bottom of adjoining footings. 3. Residential concrete slabs, where moisture condensation is undesirable, should be underiain with a vapor barrier consisting of a minimum of 6 mil polyvinyl chloride or equivalent membrane wilh all laps sealed. This membrane should be covered above and below with a minimum of 2 inches of sand (total of 4 inches) to aid in uniform curing of the concrete and lo protect the membrane from puncture. 4. Residential concrete slabs should be a minimum of 5 inches thick, and should be reinforced with No. 3 reinforcing bar al 18 inches on center in both directions. No. 3 reinforcing bar at 18 inches on center should be doweled between the exterior footing and 3 feet inio the slab. All slab reinforcement should be supported to ensure placement near the vertical midpoint of the concrete. "Hooking" the wire mesh is not considered an acceptable method of positioning the reinforcement. 5. Residential garage slabs should be reinforced as above and poured separately from the structural footings and quartered with expansion joints or saw cuts. A positive separation from the footings should be maintained with expansion joint material to permit relative movement. 6. Pre-saturation is recommended for these soil conditions. The moisture content of the. sut>-grade soils should tie equal lo or grealer than 120 percent of optimum moisture content to a depth of 18 inches below grade in the slab areas. Prior to placing visqueen or reinforcement, soil pr-saturation should be verified by this office within 72 hours of pouring slabs. 7.3.3 Floor Slabs Floor slabs should be at least 5 inches in thickness and have a minimum reinforcement consisting of No. 3 rebar spaced 18 inches on center in both directions. Reinforcement should be placed mid-height in the slab. Slabs should be underiain by a 2-inch layer of clean sand over a 6-mil Visqueen moisture barrier, over a 3-inch sand layer. The potential for slab cracking maybe reduced by careful control of water/cement ratios. The contractor should take appropriate curing precautions during the pouring of concrete in hot weather to minimize cracking of slabs. Cracking can be further controlled by providing saw cuts at column lines. We recommend that a sipsheet (or equivalent) be utilized if grouted tile, marble tile or other crack-sensitive floor covering is planned directly on concrete slabs. All slabs should be designed in accordance with structural considerations. 7.3.4 Settlement The recommended allowable bearing capacity (for isolated spread footings and for a mat foundation) is generally based on a maximum total and differential settlement of 1 inch and V* inch, respectively. Actual settlement can be estimated on the basis that settlement is roughly proportional to the net contact bearing pressure and only after column loadings, locations, and footing elevaiions have been designed. Since settlement is a function of footing size and contact bearing pressure, some differential settlement can be expected between adjacent columns or walls where a large differential loading condition exists. However, for most cases, differential settlements are considered unlikely lo exceed Yi inch. With increased footing depth/width ratios, differential settlements should be less. 7.3.5 Moisture Conditioning The building pads and footing excavations should be thoroughly moistened prior to placement of concrete or moisture barriers. 7.4 Lateral Earth Pressures and Resistance Embedded structural walls should be designed for lateral earth pressures exerted on them. The magnitude of these pressures depends on the amount of deformation that the walls can yield under load. If the wall can yield enough to mobilize the full shear strength of the soil, it may be designed for 'active" pressure. If the wall cannot yield under the applied load, the shear strength of the soil cannot be mobilized and the earth pressure will be higher. Such walls should be designed for "at rest" conditions. If a structure moves toward the soils, the resulting resistance developed by the soil is the "passive" resistance. The recommended equivalent fluid pressure for each case for walls founded above the static ground water table is provided below: Equivalent Fluid Pressure Cantilever wall (yielding) 35 pcf Restrained wall (non-yielding) 50 pcf Passive resistance 350 pcf As an alternate to the above triangular pressure distribution for cantilever walls, the walls may be designed for a rectangular distribution of 25H psf where H is the retained earth height (in feet). The above pressures assume non-expansive, level backfill and free-drainage conditions. Non-expansive backfill should extend horizontally at least 0.5H from the back of the wall where H is the wall height. Retaining walls should be provided with appropriate drainage as shown in Appendix D. Wall footings should be designed in accordance with the previous building foundation recommendations as stated in Section 7.3, and reinforced in accordance with structural considerations. The soil resistance against lateral loading consists of friction of adhesion ai the base of foundations and passive resistance against the embedded portion of the structure. Concrete foundations designed using a coefficient of friction of 0.35 (total frictional resistance equals coefficient of friction times the dead load). In lateral resistance applications, a passive resistance of 350 psf per foot of depth with a maximum value of 3.500 psf can be used for design. The allowable lateral resistance can be taken as the sum of the frictional resistance and the passive resistance provided the passive resistance does not exceed two-thirds of the total allowable lateral resistance. The coefficient of friction and passive resistance values can be increased by one-third when considering loads of short duraiion such as wind or seismic loading. Surface drainage should be controlled at all times. The subject structures should have appropriate drainage systems to collect roof runoff. Positive surface drainage should be provided to direct surface water away from the structures toward the street or suitable drainage facilities. Positive drainage may be accomplished by providing a minimum 2 percent gradient from the structures. Planters should not be designed below grade adjacent to structures unless provisions for drainage such as catch basins and pipe drains are made. In general, ponding of water should be avoided adjacent to the structures. 7.5 Retaining Wall Drainage and Backfill Retaining walls should be provided with appropriate drainage as indicated in the typical detail in Appendix D. For the underground parking structure, walls should be designed with consideration of hydrostatic pressure of be provided with drainage as indicated in Appendix D in conjunction with a sump and pump system. Walls should be provided with appropriate waterproofing in accordance with the recommendations of the design civil engineer or architect Retaining wall backfill should be compacted to al least 90 percent of the soil's maximum dry density based on ASTM Test Method Dl 557-78. Backfill should be mechanically compacted in lifts not exceeding 8 inches in thickness. 7.6 Construction Observation The recommendations provided in this report are based on preliminary structural design information for the proposed facilities and subsurface conditions disclosed by widely spaced borings. The interpolated subsurface conditions should be reinforcing bar placed at the bottom of the footing. Isolated interior or exterior piers and columns should be founded al a minimum depth of 24 inches below the lowest adjacent ground surface. 2. A grade beam, reinforced as above, and at least 12 inches square, should be provided across the garage entrances. The base of the reinforced grade beam should be at the same elevation as the adjoining footings. 3. Residential concrete slabs, where moisture condensation is undesirable, should be underiain with a vapor barrier consisting of a minimum of 6 mil polyvinyl chloride or equivalent membrane with all laps sealed. This membrane should be covered above and below with a minimum of 2 inches of sand (total of 4 inches) to aid in uniform curing of the concrele and to protecl the membrane form puncture 4. Residenlial concrete slabs should be a minimum of 5 inches thick, and should be reinforced with No. 3 reinforcing bar al 18 inches on center in both directions. All slab reinforcement should be supported to ensure placement near the vertical midpoint of the concrete. "Hooking" the wire mesh is not considered an acceptable method of positioning the reinforcement. 5. Residential garage slabs should be reinforced as above and . poured separately from the structural footings and quartered with expansion joints or saw cuts. A positive separation from the footings should be maintained with expansion joint material to permit relative movemeint. 6. Pre-saturation is not required for these soil conditions. The moisture content of the sutj-grade soils should be equal to or greater than optimum moisture in the slab areas. Prior to placing visqueen or reinforcement, soil moisture content should be verified by this office within 72 hours of pouring slabs. Medium Expansion Potential (Expansion Index 51 to 90) 1. Exterior and interior footings should be founded at a minimum depth of 18 inches for one-story floor loads, and 30 inches below the lowest adjacent ground surface for two-story floor loads. All footings should be reinforced with two No. 4 reinforcing bars, one placed near the top and one placed near the bottom of the footing. Footing widths should be as indicated in the Uniform Building Code (International Conference of Building Officials, 1997). 2. A grade beam, reinforced as above, and al least 12 inches wide should be provided across large (e.g. doon^rays) entrances. The checked in the field during construction by representatives of Geopacifica Inc. Final project drawings should be reviewed by the Geotechnical engineer prior to beginning construction. Construction observation of all onsite excavations and field density tests of all compacted fill should be performed by the Geotechnical consultant to document construction is performed in accordance with the recommendations of this report. APPENDIXA REFERENCES Abbott, P L., ed.. 1985. On Ihe Manner of Deposition of the Eocene Strata in Northem San Diego Counfy; San Diego Association of Geologists Field Trip Guidebook. April 13. Albee. A.L., and Smith, J.L.. 1996, Earthquake Characteristics and Fault Activity Southern California iTLLung. R., and Proctor. R., Eds., Engineering Geology in Southern California. Association of Engineering Geologists, Speciai Publication dated October. Barrows. A G . 1974. A Review of fhe Geology and Earthquake History of the Newport-Inglewood Sfructural Zone. Southern California, California Division of Mines and Geoloqv Special Reporl 114. Bolt. B.A.. 1973, Durafion of Sfrong Ground Motion, Proc. Fifth World Conference on Earthquake Engineering. Rome. Paper N0.292, pp. 1304-1313. dafed June. Bonilla, M.J., 1970. Surface Faulfing and Related Effects. in_Wiegel, R.. Ed., Earthquake Engineering, New Jersey, Prentice-Hall. Inc.. pp"47-74 Eisenberg, L.I.. 1983, Pleistocene Terraces and Eocene Geology. Encinitas and Rancho Santa Fe Quadrangles. San Diego Couniy, California, San Diego Sfate University Master's Thesis (Unpublished) p. 386 1985. Pleistocerie Faults and Marine Terraces, Northern San Diego County in.Abbon P L.. Editor, On the Manner of Deposition of fhe Eocene Strata in Northern San Diego County. San Diego Association of Geologists. Field Trip Guidebook DD 86-91. ' Greensfelder, R.W., 1974, Maximum Credible Rock Acceleration From Earthquakes in California California Division of Mines and Geology, Map Sheef 23. Hannan, D.L., 1975, Faulting in the Dceanside, Carlsbad, and Vista Areas, Northern San Diego County. California in Ross, A. and Dowlen, R.J., eds.. Studies on the Geology of Camp Pendlelon and Western San Diego County. California. San Diego Association of Geologists Field Trip Guidebook, pp. 56-60. Hart, 1985, Fault-Rupture Hazard Zones In California. Alquist-Priolo Special Studies Zones Act of 1972 With Index to Special Study Zones Maps: Department of Consen/ation, Division of Mines and Geology, Special Publication 42. Jennings, C.W., 1975, Fault Map of Califomia, Scale 1:750,000. California Division of Mines and Geology, Geologic Map NO. 1. Lamar, D.L., Merifield, P.M., and Proctor, R.J., 1973, Earthquake Recurrence Inten/als on Major Faults in Southern Califomia, in Moran, D.E.. Slosson, J.E., Stone. R.O and Yelverton. C.A.. Eds.. 1973, Geology, Seismicity, and Environmental Impact Association of Engineering Geologists, Special Publicafion. c-£r.i-yrLF]f:A REFERENCES (Continued) Ploessel. M R., and Slosson. J.E.. 1974, Repeatable High Ground Accelerations From Earthquakes-Important Design Criteria, Califomia Geology. V. 27. NO.9. Schnabel, R.. and Seed, H.B.. 1973, Accelerations in Rock From Earthquakes in the Westem United States, Bulletin of the Seismological Society of America V 63 NO 2 pp. 501-516. Seed. H.B., and Idriss, I.M., 1982. Ground Motions and Soil Liquefaction During Earthquakes, Monogram Series. Earthquake Engineering Research Institute, Berkeley, California. Seed, H.B., and Idriss, L.M.. and Kiefer, R W., 1969. Characterisfics of Rock Motions During Earthquakes. Journal of Soil Mechanics and Foundations Division ASCE V 95 NO. SM5, Proc. Paper 6783. pp. 1199-1218. Weber, F. Harold Jr., 1982, Recent Slope Failures. Ancient Landslides and Related Geology of fhe North-Central Coastal Area, San Diego County, California. California Division of Mines and Geology, Open File Repori 82-12, L.A. Wilson. KL.. 1972, Eocene and Related Geology of a Portion of the San Luis Rey and Encinitas Quadrangles, San Diego, California. MAPS California Division of Mines and Geology. 1975, Fault Map of California, Scale 1"=750.000" U.S. Geological Survey. 1975, San Luis Rey, 7.5 Minute Series, Scale 1'=2000". U.S. Geological Survey, 1968, Encinitas, 7.5 Minute Series, Scale 1"=2000'. AERIAL PHOTOGRAPHS Date Source Flight Photo Nos. Scale 1953 USDA AXN-9M 192 and 193 r=2000' — 0 DRILLING COMPANY: Scotts Drilling RIG: Auger DATE BORING DIAMETER: 6" DRIVE WEIGHT: 1401 bs. 10- 15- 20- 25- 30- DROP: 30" Ul _J Q. 2 < CO Ul > E • O O u. CO o -J o 26 48 56 58 70 68 75 03 Z Ul a sl 108. 110.5 112.5 I- Ul o O 2 O 14.0 16.5 12.0 CO CO dtO ELEVATION: 355 BORING NO. 1 SOIL DESCRIPTION Terrace Deposits: Light Brown silty sand. Slightly moist, nedium dense to dense 014' darker brown Santiaqo Formation: Light Green Sandstone,moist hu / Total Depth 30' No Water No Caving BORING LOG GEOPACIFICA PROJECT NO. FIGURE NO. B-1 DRILLING COMPANY: Scotts Drilling R'G: Auger DATE: 10/30/00 BORING DIAMETER: 6" DRIVE WEIGHT: 1401 bs DROP: UJ Ul u. 0. Ul a IO UJ _l a < CO tu > c o O o u. m 5 o CO z UJ o sl 40 114.0 11.0 55 15 20 25- 30- 65 30" ELEVATION: 325 BORING NO. 2 SOIL DESCRIPTION Terrace Deposits: Light to Medium brown silty Sand, moist, dense Santiaqo Fonnation: Light green to yellow-brown silty to clayey sandstone, moist, very dense Total Depth 16' No Water No Caving BORING LOG GEOPACIFICA PROJECT NO. FIGURE NO. B-2 — 0 DRILLING COMPANY: Scotts Drilling BORING DIAMETER: 6" DRIVE WEIGHT: 1401bs RIG: Auger PATE: 10/jfvnn 15- 20- 25- LU DROP: 30" ELEVATION: 350 70 CO in 03 2z =fBi OO 0-3 BORING NO. 3 SOIL DESCRIPTION Terrace Deposits: Light Brown to Brown Silty Sand, and mediun sand, moist, dense to hard 115.2 9.6 113.5 10.0 Santiaqo Formation! Light yellow-brown clayey sandstone, moist, dense to hard Total Depth 30' No Water No Cavi ng BORING LOG GEOPACIFICA PROJECT NO. FIGURE NO. B-3 DRILLING COMPANY: Scotts Drilling RIG: Auqer BORING DIAMETER: 6" DRIVE WEIGHT: DATE: lO/3Jin)n 20 • LU 1401bs UJ 28 42 58 56 60 70 DROP: 30" to z UJ o sl H UI O O 2 O CO < • -I 03 lod I- w o =) CO C 107.8 9.0 ELEVATION: 334 BORING NO. 4 SOIL DESCRIPTION Terrace Deposits: Brown Silty Sand, Moist verv dense ' Santiaqo Formation: Light Green to yellow-brown siltstone, moist, very dense Total Depth 30' No Water No Cavi ng BORING LOG GEOPACIFICA PROJECT NO. FIGURE NO. B-4 DRILLING COMPANY: Scotts Drilling RIG: Auger DATE: 10/30/00 BORING DIAMETE.R: ^" — 0 I- lU UJ I »-a IU a a. 2 < CO a < ffl 10 15 DRIVE WEIGHT: 1401bs DROP: 30" ELEVATION: 344 ^ O 2 O < u. CO oc _l o o m z Ul o ^. UJ %^ O o 2 o CO CO < CO - w CO BORING NO. SOIL DESCRIPTION Terrace Deposits: Light Brown Silty Sand Moist, dense 38 45 60 20- 25- 30- Total Depth 16' No Water No caving BORING LOG GEOPACIFICA PROJECT NO. FIGURE NO. B-5 DRILLING COMPANY: Scotts Drilling RIG: Auger DATE: 12/4/00 I BORING DIAMETER: 6" DRIVE WEIGHT: 1401 bS DROP: 30" IU -I a. 2 < CO UJ > E o o o u. CO 5 O -I o 36 > CO z IU o sl 5z ^ z O o 2 o ELEVATION: ^26 to to < -I o CO I d zd CO CO 8 BORING NO. SOIL DESCRIPTION Fill: Dark Brown silty sand,moist, loose Terrace Deposits: Light Brown to brnwn rlaypy sand, moist, dense 60 15-i 20- 25- 30- 60 Santiago Fonnation: Light green and yellow slity to clayey sandstone, moist, very dense Total Depth 16' No Water No Caving BORING LOG GEOPACIFICA PROJECT NO. FIGURE NO. B-6 DRILLING CONWANY: ScOtts Dri 1 lino RIG: Auger PATE: 12/04/nn BORING DIAMETER: 6" DRIVE WEIGHT: 1401 bs DROP: 30" ELEVATION: 225 I- lU UJ u. I f- UJ o Ui UJ 1 -1 t-UJ 1 0. o a. 2 o < u. < CO CO CO Ul C3 > O < cc -i m o o 42 > CO z UJ Q > - It " 5z y- UJ O O 2 O CO CO < _l CO Ud =! tli (0 d BORING NO. SOIL DESCRIPTION Fill: Dark Brown silty sand, moist, 1 oose Terrace Deposits: Light brown to brown silty sand, moist, dense 10 IS 20- 25- 30- 66 56 Santiaqo Formation: Yellow-brown sandy claystone Moist, stiff yellow-brown sandy siltstone, moist,dense light green clayey sandstone, moist, den se Light reddish brown claystone, moist, hard Total Depth 16' No Water No Caving BORING LOG GEOPACIFICA PROJECT NO. FIGURE NO. B-7 10 15 21 DRIVE WEIGHT: 1401 bs DROP: 30" > ra z UJ o > = CO UJ (C AS Z _i 03* IISTI NTE u S.C. O O 5 2 O CO >>MI> 39 DATE: 12/04/00 ELEVATION: 345 BORING NO. 8 SOIL DESCRIPTION Terrace Deposits: Light Brown silty Sand, moist Medium dense """'^L. 20 • 25- 30- Total Depth 1] No Water No caving GEOPACIFICA BORING LOG PROJECT NO. FIGURE NO. B-8 DRILLING COKff'ANY: ScottS Drill inc RIG: Auger PATE: 12/5/nn BORING DIAMETER: 6" DRIVE WEIGHT: 1401 bs DROP: 30" 10 • 15 20- 25- 30- Ul _i a. 2 < CO UJ > IT O o o u. M o _l o 45 45 65 71 67 74 CO z UJ o >. ~ si CO Ul o: t- z -I CO ISTI NTE IL C S.C. O O O 3 2 O 03 d ELEVATION: 377 BORING NO. SOIL DESCRIPTION Terrace Deposits: Brown silty sand, moist, dense light brown silty sand with gravel, moist, hard 013' brown Total Depth 30' No Water No Caving 1 BORING LOG 1 GEOPACIFICA PROJECT NO. FIGURE NO. B-9 APPENDIX C Laboratory Testinq Procedures and Test Results Moisture and Density Tests: Moisture content and dry density determinations were performed on relatively undisturbed samples obtained from the test borings and/or trenches. The results of fhese tests are presented in fhe boring and/or trench logs. Where applicable, only moisture content was determined from "undisturbed" or disturbed samples. Direct Shear Tests: Direct shear tests were performed on selected remolded and/or undisturbed samples which were soaked for a minimum of 24 hours under a surcharge equal fo the applied normal force during testing. After transfer of the sample to the shear box. and reloading the sampfe. pore pressures set up in fhe sample due fo the transfer were allowed fo dissipate for a period of approximately 1 hour prior lo application of shearing force. The samples were tested under various normal loads, a mofor-driven, strain-controlled, direct-shear machine fhe motor was stopped and the sample was allowed to "relax" for approximately 15 minutes The "relaxed" and "peak" shear values were recorded. If is anficipated that, in a majority of samples tested the 15 minutes relaxing of the sampfe Is sufficient to allow dissipation of pore pressures set up in the samples due to application pf shearing force. The refaxed values are therefore judged to be a good estimatkjn of effective strength parameters. The test resufts were plotted on the "Direct Shear Summary". Soluble Sulfates: The soluble sulfate contents of selected samples were determined by the California Materials Method NO. 417. E.XP.AMSION INDEX TEST SAMPLE SOIL TYPE EXPANSION LOCATION INDEX EXP.ANSION POTENTIAL B-l;^r SM 15 \'TRY LOW B-2(a>4' SM 18 VERY LOW B-3/rwS' SM 5 VERY LOW MA.XIMUM DENSITY TESTS SAMPLE SAMPLE M.AXUVIUM LOCATION DESCRIPTION DRY DENSITY OPTIMUM .MOISTURE CONTENT B-I<2:1' SILri'SAND 122.3 n.o B-:-iM' SILTY SAND 116.0 .1-0 PH AND MINIMYM RESISTIVITY TESTS SAMPLE LOCATION PH MINIMUM RESISTIVITY B-ifojr 7.5 7,000 B-3(55S' 6.9 SOLUBLE SULFATES 2.500 SAMPLE LOCATION SULFATE CONTENT (%) POTENTIAL DRYER OF SULFATE ATTACK B-](a)V <0.015 NEGLIGIBLE B-2ia3' <0.015 NEGLIGIBLE LABORATORY TEST RESULTS GEOPACIFICA PROJECT NO. FIGURE NO. DIRECT SHEAB TEST SAMPLE LOCATION FRICTION ANGLE COHESION fPSF) B-l(%10' B---m' B-4@10' 38 36 34 200 250 200 LABORATORY TEST RESULTS GEOPACIFICA PROJECT NO. FIGURE NO. APPENDIX D General Earthwork and Grading Specifications 1.0 General Intent These specifications are presented as general procedures and recommendations for grading and earthwork to be utilized in conjunction with the approved grading plans. These general earthwork and grading specifications are a part of the recommendations contained in the Geotechnical report and shall be superseded by the recommendations in the Geotechnical report in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations, which could supersede these specifications, or the recommendations of the Geotechnical report. It shall be the responsibility of the contractor to read and understand these specifications as well as the Geotechnical report and approved grading plans. 2.0 Earthwork Observation and Testing Prior to the commencement of grading, a qualified Geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the Geotechnical report and these specifications. It shall be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes, at least 24 hours in advance, so that he may schedule his personnel accordingly. No grading operations should be performed without the knowledge of the Geotechnical consultant. Tfie contractor shall not assume that the Geotechnical consultant is aware of all grading operations. It shall be the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes and agency ordinances, recommendations in the Geotechnical report and the approved grading plans not withstanding the testing and observation of the Geotechnical consultant If. in the opinion of the consultant, unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than recommended in the opinion of the consultant, unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than recommended in the Geotechnical report and the specifications, the consultant will be empowered to reject the work and recommend that constmction be stopped until the conditions are rectified. Maximum dry density tests used to evaluate the degree of compaction should be performed in general accordance with the latest version of the American Society for Testing and Materials test Method ASTM 01557. 3.0 Preparation of Areas to be Filled 3.1 Clearinq and Grubbinq: Sufficient brush, vegetation, roots, and all olher deleterious material should be removed or properiy disposed of in a method acceptable to the owner, design engineer, governing agencies, and the Geotechnical consultant. The Geotechnical consultant should evaluate the extent of these removals depending on specific site conditions. In general, no more than 1 percent (by volume) of the fill material should consist of these materials should not be allowed. 3.2 Processinq: The existing ground which has been evaluated by the Geotechnical consultant to be satisfactory for support of fill; should be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory should be over-excavated as specified in the following section. Scarification should continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform, flat, and free of uneven features which would inhibit uniform compaction. 3.3 : Over-excavation: Soft, dry. organic-rich, spongy, highly fractured^ or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be over- excavated down to competent ground, as evaluated by the Geotechnical consultant. For purposes of determining quantities of materials over- excavated, a licensed land surveyor/civil engineer should be utilized. 3.4 Moisture Conditioning: Over-excavated and processed soils should be watered, dried-back, blended, and/or mixed, as necessary to attain a uniform moisture content near optimum. 3.5 Recompaction: Over-excavated and processed soils which have been properiy mixed, screened of deleterious material, and moisture- conditioned should be recompacted to a minimum relative compaction of 90 percent or as othenwise recommended by the Geotechnical consultant. 3.6 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical), the ground should be stepped or benched: The lowest bench should be a minimum of 15 feet wide; at least 2 feet into competent material as evaluated by the Geotechnical consultant. Other benches should be excavated into competent material as evaluated by the Geotechnical consultant. Ground sloping flatter lhan 5:1 should be benched or otherwise over-excavated when recommended by the Geotechnical consultant 3.7 Evaluation of Fill Areas: All areas to receive fill, including processed areas, removal areas, and toe-of-fill benches, should be evaluated by the Geotechnical consultant prior to fill placement. 4.0 Fill Material 4.1 General: Material to be placed as fill should be sufficiently free of organic matter and other deleterious substances, and should be evaluated by the Geotechnical consultant prior to placement. Soils of poor gradation, expansion, or strength characteristics should be placed as recommended by the Geotechnical consultant or mixed with other soils to achieve satisfactory fill material. •4.2 Oversize: Oversize material, defined as rock.or other irreducible material with a maximum dimension greater than 6 inches, should not be buried or placed in fills, unless the location, materials, and disposal methods are specifically recommended by the Geotechnical consultant. Oversize disposafoperations should be such that nesting of oversize material does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize materials should not be placed within 10 feet vertically of finish grade, within 2 feet of future utilities or underground construction, or within 15 feel horizontally of slope faces, in accordance with the attached detail. 4.3 Import: If importing of fill material is required for grading, the import material should meet the requirements of Section 4.1. Sufficient time should be given to allow the Geotechnical consultant to observe (and test, if necessary) the proposed import materials. 5.0 Fill Placement and Compaction 5.1 Fill Lifts: Fill material should be placed in areas prepared and previously evaluated to receive fill, in near-horizontal layers approximately 6 inches in compacted thickness. Each layer should be spread evenly and thoroughly mixed to attain uniformity of material and moisture throughout. 5.2 Moisture Conditioning: Fill soils should be watered, dried-back, blended, and/or mixed, as necessary to attain a uniform moisture content near optimum. fZvrmiiFr.' 5.3 Compaction of Fill: After each layer has been evenly spread, moisture- conditioned, and mixed, it should be uniformly compacted to noi less than 90 percent of maximum dry density (unless otherwise specified). Compaction equipment should be adequately sized and be either specifically designed for soil compaction or of proven reliability, to efficiently achieve the specified degree and uniformity of compaction. 5.4 Fill Slopes: Compacting of slopes should be accomplished, in additional to normal compacting procedures, by back-rolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of the fill out to the slope face should be at least 90 percent. 5 5 Compaction Testinq: Field tests of the moisture content and degree of compaction of the fill soils should be performed by the Geotechnical consultant. The location and frequency of tests should be at the consultant's discretion based on field conditions encountered. In general, the tests should be taken al approximate intervals of 2 feet in vertical rise and/or 1.000 cubic yards of compacted fill soils. In addition, on slope faces, as a guideline approximately one test should be taken for each 5.000 square feet of slope face and/or each 10 feet of vertical height of the slope. 6.0 Sub-drain Installation Sub-drain systems if recommended should be installed in areas previously evaluated for suitability by the Geotechnical consultant, to conform to the approximate alignment and details shown on the plans or herein. The sub-drain location or materials should not be changed or modified unless recommended by the Geotechnical consultant. The consultant however, may recommend changes in sub-drain line or grade depending on conditions encountered. All sub-drains should be surveyed by a licensed land surveyor/civil engineer for line and grade affer installation. Sufficient time shall be allowed for the surveys, prior to commencements of filling over the sub-drains. 7.0 Excavation Excavations and cut slopes should be evaluated by a representative of the Geotechnical consultant (as necessary) during grading. If directed by the Geotechnical consultant, further excavation, over-excavation, and refilling of cut areas and/or remedial grading of cut slopes (i.e.. stability fills or slope buttresses) may be recommended. 8.0 Quantity Determination For purposes of determining quantities of materials excavated during grading and/or determining the limits of over-excavation, a licensed land surveyor/civil engineer should be utilized. CANYON SUBDRAIN \ PROPOSED GRADING COMPACTED FILL BEDROCK • '^^'^^^>^/y^--//Ayy^v/yi//r BENCH: VERTICAL 4' MIN HORIZONTAL 6' MIN DOZER TRENCH CANYON SUBDRAIN DRAINS ALONG CANYON WALLS AS RECOMMENDED BY THE GEOTECHNICAL CONSULTANT. INSTALL AS NEEDED PER BUTTRESS BACKDRAIN DETAIL. GEOFABRIC ALTERNATIVE DOZER TRENCH ALTERNATE FOR FILLS OF 50' FILT 9 CU. FT./FT ER MATERIAL S" MIN BACKHOE TRENCH 6" MIN 1" OR 1 1/2" OPEN GRADED ROCK. 9 C.F./L.F. NOMINAL 2 - 3" / / SEPARATION GEOFABRIC ALTERNATIVE / GEOFABRIC: 6" MIN MINIMUM 4% OPEN ^ AREA. EOS = 70 - 140 r MIN OVERLAP 24" MIN <^ f ,24" MIN -NOMINAL 2 ^ FILTER MATERIAL 9 CU. FT./FT. Notes: 1. Pipe should be 4" minimum diameter, 6" minimum for runs of 500', 8" minimum for runs of 1000" or greater. 2. Pipe should be Schedule 40 PVC for fills less lhan 100', Schedule 80 for fills to ISO". Upstream ends shoukl be capped. 3. Pipe should have 8 uniformly spaced 3/8" perforations per foot placed at 90° offset on underside of pipe. Rnal 20 foot of pipe should be nonperforated. 4. Filter material should be California Class II Permeable Material. 5. Appropriate gradient shouid be provided for drainage; 2% minimum is recommended. 6. For the Geofabric Altemathres and gradients of 4% or grealer, pipe may be omitted from the upper 500'. For runs of 500", 1000', and 1500' or greater, 4", 6", and 8" pipe, respeclively, should be provided. 7. Concrete cutoff well shall be installed at end of perforated pipe. STANDARD DETAIL NO. 1 GEOPACIFICA PROJECT NO. FIGURE NO. BENCH: VERTICAL 4' MIN HORIZONTAL 6' MIN BACKCUT NOT STEEPER THAN 1:1 "^2' MIN KEY DEPTH AT TOE, TIP KEY 1' NOMINAL OR 4% INTO SLOPE FILL OVER CUT SLOPE BENCH: VERTICAL 4' MIN HORIZONTAL 6' MIN BACKCUT NOT STEEPER THAN 1:1 Notes: 1. If overfilling and cutting back lo grade is adopted, 15' fill width may be reduced fo 12' minimum In no case should the fill width be less than 1/2 Ihe height of fill remaining. 2. Backdrain as recommended by Geotechnical Consultant per Buttress Backdrain Detail. STANDARD DETAIL NO. 2 GEOPACIFICA PROJECTNO. FIGURE NO. STABILIZATION FILL H ^ 9^A^ oe>XOMPACTED / FILL /r—^ 2' MIN-' • \ 2' MIN-' HIZ OR 15' MIN j {_ MN r 3' MIN CAP (2) BACKCUT 1:1 MAX MAINTAIN 15' MIN FILL WIDTH BENCH: VERTICAL 4' MIN HORIZONTAL 6' ,MIN BACKDRAIN SYSTEM IF RECOMMENDED BY GEOTECHNICAL CONSULTANT BUTTRESS FILL 3' MIN CAP (2) f^^BEDDING PLANES OR OTHER ADVERSE GEOLOGIC CONDITION Oh (5) BACKCUT 1:1 MAX MAINTAIN 15' MIN WIDTH -BENCH: VERTICAL 4' MIN HORIZONTAL 6' MIN BACKDRAIN SYSTEM PER STANDARD DETAILS Notes: 1. If overfilling and cutting back to grade is adopted, 15' may be reduced fo 12". In no case should the fill width be less than half the fill height remaining. 2. A 3' blanket fill shali be provided above stabilizafion and buttress fills. The thickness may be greater as recommended by the Geotechnical Consultant. 3. W = designed widlh of key. 4. Dt = designed depth of key at toe. 5. Dh = depth of key at heel; unless otherwise specified, Dh=Dt -»• 1 foof. STANDARD DETAIL NO. 3 GEOPACIFICA PROJECT NO. FIGURE NO. BUTTRESS. BACKDRAIN SYSTEM 1 HORIZONTAL SPACING OF OUTLETS SHOULD BE LIMITED TO ABOUT IOO*., 1' NOMINAL 15' NOMINAL INTERVAL* BLANKET FILL. 3' MIN -'SEE DETAILS BELOW 1—2' NOMINAL CONVENTIONAL BACKDRAIN k CALIFORNIA CLASS 2 PERMEABLE MATERIAL 3 CU- FT./FT ^FOR 20' ADDITIONAL UPPER DRAIN MAY BE OMITTED 3' NOMINAL 2' MIN 1. 2 3. 4. MIN GEOFABRIC ALTERNATIVE GEOFABRIC: MINIMUM 4% OPEN AREA EOS = 70-100, 1* MIN OVERLAP ^^^^^^ 3' NOMINAL A Notes: Pipe should be 4" diameler Scheduie 40 PVC. Gradients should be 4% or grealer. Cap all upstream ends. Trenches for outlet pipes should be backfilled with compacted nalhre soiL Backdrain pipe should have 8 uniformly spaced perforations per foot placed 90" offset on underside of pipe. Outlel pipe should be non- perforated. For the geofabric alternative the backdrain pipe may be omitted provided at least 20 feet (i.e. 10' each side of outlet) ol perforated pipe Is provided to lead into each oulleL At each outlet the geofabric should be appropriately overlapped (1*) at cuts in fabric or olherwise sealed or taped around the pipe. Ll 2' MIN 2" NOMINAL CLEAN, OPEN GRADED ROCK, PEA GRAVEL 1/2. 3/4. OR 1". 3 CU. FT./FT. STANDARD DETAIL NO. 4 GEOPACIFICA PROJECT NO. FIGURE NO. FUTURE CANYON FILL VIEW ALONG CANYON PROPOSED FUTURE GRADE CURRENT LIMIT OF ENGINEERED FILL \^ TPMPORARY Tn rnnv'"«= QRAINAGE ENGINEERED FILL ^'/AA/ ri^/y^'/^^y BEDROCK FUTURE REMOVAL OF UNSUITABLE MATERIAL 5^^^ ..... OF SUBORAia ENSIQN." '^'uBDBAlN-X-"^^-^ '^SURVEY END OF SUBD RAIN VIEW OF CANYON SIDEWALL PROPOSED FUTURE GRADE FUTURE LIMIT OF ENGINEERED FILL FUTURE LIMIT OF ENGINEERED FILL FUTURE BENCHING K BEDROCK 1 STANDARD DETAIL NO. 5 1^ GEOPACIFICA PROJECT NO. RGURE NO. TRANSITION. LOT OVEREXCAVATION CUT LOT PER GRADING PLAN 'BENCH: VERTICAL 4' MIN HORIZONTAL 6' MIN 6" MIN SCARIFICATIOr IN PLACE AND RECOMPACTION OVEREXCAVATE AND REPLACE AS ENGINEERED FILL CUT-FILL LOT PER GRADING PLAN BENCH: VERTICAL 4' MIN HORIZONTAL 6' MIN 6' MIN SCARIFICATION IN PLACE AND RECOMPACTION OVEREXCAVATE AND REPLACE AS ENGINEERED FILL Notes: 1. Topsoil, colluvium, weathered bedrock and otherwise unsuitable materiais should be removed to firm natural ground as identified by the Geotechnical Consultant. 2. The minimum depth of overexcavation should be consklered subject to review by the Geotechnkal Consultant. Steeper transitions may require deeper overexcavation. 3- The lateral extent of overexcavation shoukl be 5* minimum but may include Ihe entire lot as recommended by the Geotechnical Consultant 4. The contractor should notify the Geoiechnicai Consultant in advance of achieving final grades (Le. wrthin 5") in order to evaluate overexcavatkjn recommendations. Addrtional staking may be requested to aid in the evaluation of overexcavations. STANDARD DETAIL NO. 6 GEOPACIFICA PROJECT NO. FIGURE NO. WINDROW SECTION FILL SURFACE DURING GRADING DOZER V-DITCH OR FILL THOROUGHLY COMPACTED TO A SMOOTH UNYIELDING CONDITION (E.G. BY WHEEL ROLLING} WINDROW PROFILE FILL SURFACE DURING GRADING — CLEAN GRANULAR MATERIAL (SE > 30) SHOULD BE THOROUGHLY FLOODED TO FILL VOIDS AROUND ROCK COMPACTED FILL ROCK SHOULD BE PLACED END TO END. ROCK SHOULD NOT BE NESTED Notes: 1. Following placement of rock, flooding of granular material and placement of compacted fill adjacent to windrow, each windrow should be thoroughly compacted from the suriace. 2. The contractor should provide plans to the Geotechnical Consultant prepared by surveys documenting the location of buried rock. 3. Disposal in streets may be subject to more restrictive requirements by the governing authorHies. STANDARD DETAIL NO. 7 GEOPACIFICA PROJECT NO. FIGURE NO. MINOR SLOPE REPAIR MAINTAIN 5' MIN FILL WIDTH OUTLET PIPE ORIGINAL SLOPE SURFACE TO BE RECONSTRUCTED SLUMP DEBRIS TO BE REMOVED EARTH BERM 2%. BENCH: VERTICAL 2' MIN HORIZONTAL 4' MIN BACKDRAIN SYSTEM (SEE DETAILS BELOW). VERTICAL SPACING 8' NOMINAL. OUTLET WITH NON- PERFORATED" PIPE AT-50' MAX SPACING. PLAN FIRST LEVEL OF DRAINS TO OUTLET 1-2' ABOVE TOE OF SLOPE. EXCAVATE KEY INTO FIRM UNDERLYING UNAFFECTED MATERIAL SLUMP FAILURE SURFACE OR BASE OF EROSION CALIFORNIA CLASS 2 PERMEABLE MATERIAL, 2 CU. FT./FT. MIN ^ 4% ZZl *: •? GEOFABRIC: MIN 4% OPEN AREA EOS 70-100 -: 1' MIN OVERLAP OPEN GRADED ROCK 3/4 OR 1". 1 CU.FT./FT. MIN 4% ^^^^^ CONVENTIONAL DRAIN PLACE PIPE ON 4" MIN BED OF RECOMMENDED PERMEABLE MATERIAL 3" PERFORATED SCH 40 PVC (3/8" PERFORATIONS AT 90° PLACED DOWN) GRADED AT 4%. OUTLET PIPES NON-PERFORATED AND SPACED AT 50' MAX. GEOFABRIC ALTERNATIVE PLACE PIPE ON 2" NOMINAL BED OF RECOMMENDED OPEN GRADED ROCK CALIFORNIA CLASS 2 PERMEABLE MATERIAL, 1 CU.FT./FT. MIN 'DRAIN GUARD' PIPE 3" 'DRAIN GUARD' PIPE OR SIMILAR PLACED ON THIN BED OF SELECT NATIVE OR RECOMMENDED PERMEABLE MATERIAL. GRADE AT 4% TO OUTLET PIPES. NOTE: CAP ALL DRAIN PIPES AT UPSTREAM ENDS STANDARD DETAIL NO. 8 GEOPACIFICA PROJECT NO. FIGURE NO. LOT DRAINAGE YARD DRAINS AT 1% OR GREATER. 4" MIN PVC PIPE OR SIMILAR TO SUITABLE DISPOSAL AREA (E.G. CURB OUTLET) 5 (0 >. o •o 10 E E c E •o CM _t IB .a •° >. "O <• 3 ^ E 1^ - la ? o 5 « 2 » Bl - o » = a 3 cs - E ' 2 o S O 11. STANDARD DETAIL NO. 9 GEOPACIFICA PROJECT NO. FIGURE NO. 19 ' • •"iks:^ AI —-i^' - '.nr..-.:' .... ; r.'5-;ie<y-<«\i i > I I ! i < I : I ! \ I ! I \ 'jl ' I ! 1 ; I. p^m \ I \ 1 i J i ^ -> EXPLANATION I Qudf Qcol Qt Undocumented Fill Colluvium Terrace Deposits ' Approximate Contac "^^^^-^^^ , Approximate Locati ~ -'. S»i«r>A MHTOR* fm..0Mi I* g^tf-tf' )cation Map/Geology Map ICA FIGURE NO.