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Home My WebLink AboutCT 04-20; MATCHPLAY AT LA COSTA; GEOTECHNICAL INVESTIGATION; 2004-08-05Ff r I- I I I I- I I I- I I I I; I I- I I I- GEOTECHNICAL INVESTIGATION PROPOSED CONDONUNTITItlDEVELOPMENT LOT 41, NAVARRA DRIVE CARLSBAD, CALIFORNIA -_JOB NO. 04-01-07 AUGUST 5, '2004 RECEIVED MAY 1 3 2005 ENGtNEERlNG DEPAR.TMENT WESTERN SOIL AND FCUNDATIDN ENGIINEERI~N'C3 INC. .. r.,. WESTERN SOIL AND FOUNDATION ENGINEERING, INC: 423 HALE AVENUE PHONE: (760) 746-3553 FAX: (760) 746-4912 ESCONDIDC;:>. CALIFORNIA 92029 February 9,2005 Mr. Anthony J. Frost, Managing Partner Commercial Development Michael Crews Development P.O. Box 300429 Escondido, CA 92033 Project: Job No. 04-01-07 Proposed Condominium Development Lot 41 , Navarra Drive Carlsbad, California SUbject: Addendum No. 1 to our Report of Geotechnical Investigation dated August 5, 2004 Dear Mr. Frost: At the request of Mr. Steve Bundy, BRA, hlC., we are provi4ing this addendum to 'our referenced report. The purpose of this addendum is to clarify our recommendations for grading as they relate to comment no. 1 presented in a memorandum by Mr. Clyde Wickham. at the City of Carlsbad. It is our understanding that a significant quantity of soil material will be exported from the project site. Mr. Bundy has indicated that approximately 2,250 cubic yards of material would be ' removed during the rough grading alone. By the time foundation excavations, underground utilities and finish grading are performed, the total export could approach 3,000 cubic yards. We anticipate that any debris, 'organic' matter and oversized debris would logically be removed during the exporting proce'ss so that the more expansive-appearing soils (clays and silts) could be "selected" for export and the sandier materials "selected" to remain on-site. ~ ({:;)~ ~ ,e~ ~~ ~ ~ ~ -----~ t. '. Addendum' 1: Navarra Drive· Condos February 9, 2005 Our Job No. 04-01-01 Page 2 Therefore, the only remedial grading would be the building envelopes which are fiye-feet in depth below foundations and the four-foot removal depth below sub grade in driveway areas .. . If you have any questions after reviewing these recommendations, please do not hesitate to contact this office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Vincent W. Gaby, CEG 1755, Expires 7/31/05 Engineering Geologist Distribution: (l) Addressee (2) Steve Bundy, BRA, Inc. (1) Steve Bundy, BRA, Inc. via fax: (760) 931-7780 VWG:DEZllang WESTERN SOIL AND FOUNDATION ENGINEERING, INC. I~r . I' I ! I: : I ' I: ' 11 .,; I'" I I I': '1'· I. 1/ 1-,' I: i: .- J 'I GEOTECHNICAL INVESTIGATION PROPOSED CONDO~DEVELOPMENT LOT 41, NAVARRA DRIVE CARLSBAD, CALIFORNIA . JOB NO. 04-01-07 AUGUST 5, 2004 ~. . WESTERN SOIL AND FOUNDATION ENGINEERING, INC. \ )- fJA fl ! I· I! If: I" . I': I I' " I": I' I.· IJ I, If I- I i i WESTERN SOIL AND FOUNDATION ENGINEERING, INC. PHONE: (760) 746-3553 FAX: (760) 746-4912 August 5, 2004 Mr. Anthony J. Frost, Managing Partner Commercial Development Michael Crews Development P.O. Box 300429 Escondido, CA 92033 Project: Job No. 04-01-07 Proposed Condominium Developme~t Lot 41, Navarra Drive Carlsbad, California Subject: Report of Geotechnical InvestigaTIon Dear Mr. Frost: 423 HALE AVEN U E ESCONDIDO, CALlFOR~IA 92029 In accordance with your request, we have completed a geotechnical investigation ofthe referenced property. Weare presenting to you, herewith, our findings and conclusions regarding current site conditions, as well as recommendations for future site development. The findings of this study indicate that the site is suitable for the proposed improvements if the recommendations provided in the attached report are incorporated into the design and construction of this project. It is our prqfessional opinion that no detrimental ge~logic .constraints exist that would preclude site development. . 11 ~ -;i:::; • I i.....J " I, I: I, I I., I,', I. 1" I,': I .. I., I ~; I··; l- I" I, I, I I, I Proposed Navarra Drive Condos August 5, .2004 Our Job No. 04-01-07 Page 2 If you have any questions after reviewing the findings and reconllnendations contained in the attached report, please do not hesitate to contact this office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, WESTERN SOJL AND FOUNDATION ENGINEERING, INC. Vincent W. Gaby, CEG 1755, Expires 7/31105 Engineering Geologist Dennis E. ZimmelTIlan, C 26676, GE 928, Expires 3/31106 Geotechnical Engineer Distribution: (5) Addressee vWG:DEZlkmg WESTERN SOIL AND FOUNDA TJON ENGINEERING, INC. t' I. I .. I, I, I, I, I." I, : I, I ... I, I·. I) I. I I. I GEOTECHNICAL INVESTIGATION PROPOSED CONDOMINIUM DEVELOPMENT LOT 41, NAVARRA DRIVE CARLSBAD,CALWO~ Prepared For: Mr. Anthony J. Frost, Managing Pa.rtD.er <;:ommercial Development Michael Crews Development P.O. Box 300429 Escondido, CA 92033 JOB NO. 04-01-07 AUGUST 5, 2004 WESTERN SOIL AND FOUNDATION ENGINEERING, INC. I~j f' I I .. I. I. I. I. I. \ I.: I I I: I I .. I' I I I TABLE OF CONTENTS Page Introduction and Project Description ............................................................................................. 1 Project Scope ........ : .................................................. : ..................................................................... 2 Findings .......................................................................................................................................... 3 . . Site Description ...................................................................................... : ........ ~ ................ : .. 3 Subsurface Conditions ....................................................................................................... 4 Terrace Deposits ............... ~ ............................................................... : ..... : .......................... 4 Colluvium .......................................................................................................................... 5 Rippability ........................................................ : .................................................................. 5 Groundwater ....... , ................................................................. : ............................................ 5 Geologic Hazards .......................................................................................................... ; ................ 6 Faults and Seismic Hazards ................................................................. : ...... : ...... : .............. :6 Seismicity of Major Faults ............................................. : ........... ~ ....................................... 8 Liquefaction ........................................................................................... : ........................... 8 Landslides and Slope Stability .................................................... : ...................................... 9 Recommendations and Conclusions .............................................................................................. 9 Site Preparation ................................................................................ : ................................. 9 . Existing Soil. .................................................................. : ....................................... 9 Expansive Soil .................................................. ~ .................................................. 11 Excavation and Shoring ....................................................................................... 12 Inlported Fill ........... ~ .................................................... , ................................. :: .... 12 Earthwork ........................................ , .................................................................... 12 Slopes ........................................... ~ .............................. , ............................ : ............ 13 Surface Drainage ....................................................................................... : .......... 13 Subdrains ......................... : ..................................................................................... 14 WESTERN SOIL AND FOUNDATION ENGINEERING, INC. f~ f' I' I,: ~ I.": I.: I' I I~., I', I. I. I:;· I-·~ I' I~ I 1-. I TABLE OF CONTENTS -Cont. Page Foundation Recommendations ......................................................................................... 15 Seismic Site Categorization ................................................................................. 15 Footings ..................................................................................................... ~ ......... :.1.6 Concrete Slabs-On-Grade ..................................................................................... 17 Slab-On-Grade Bedding ....................................................................................... 17 hnpenneable Membrane ...................................................................................... 18 Transition Areas .... , ......... : ........................................................ : ......................... ,.18 Lateral Resistance ................ : ................................................. : ............................. 19 Lateral Resistance Values .................................................................................... 19 Footing Observations ................................................................................. : ....... ~.19 Retaining Walls ............................................. : ................................................................... ~O Lateral Pressures ............................................................................... · ................... 20 Drainage and Waterproofing.: ............................................................. : ............... :20 Backfill ............................................................................................................... :.21 Field Explorations ......................................................................................................................... 22 Laboratory Testing ................................................................................................ ; ...................... 23 Plan Review ...................................................................... = ........................................................... 23 Limitations .................................................................................................................... : ... : .......... 23 WESTERN . . SOIL AND FOUNDATION ENGINEERING, INC. fo t l ' I 1'[, I f 1 ' I I I I' I, I, I I. I., I,. I' I- I I I Plate No.1 Plate No: 2 Plate No.3 through Plate No.7 Plate No.8 through Plate No.1 0 APPENDIX I APPENDIXil ATTACHMENTS WESTERN Site Plan (In back pocket) Unified Soil Classification Chart Exploratory Excavation Logs Laboratory Test Results , Specifications for Construction of Controlled Fills References SOIL AND FOUNDATION ENGINEERING, INC. J.~ , . L.J Il:!'" . . .::: . I I. I I. I. . 1,'· I·, I: I I I I GEOTECHNICAL INVESTIGATION PROPOSED CONDONU~DEVELOPMENT LOT 41, NAVARRA DRIVE CARLSBAD, CALIFORNIA Introduction and Project Description This report presents the results of our geotechnical investigation performed on the above referenced site. The purpose of this investigation was to evaluate the existing surface and subsurface .conditions from a geotechnical perspective and to provide recommendations for site preparation, grading, foundation design, floor slab support and retaining wall constructit?n. The proposed project will be the development of an eight-unit, mu1ti~level'condominium building with a below-grade parking facility. The structure will incorporate concrete masonry block retaining walls below grade and wood framing above grade. Foundations are anticipated to consist of continuous and pad spread footings with concrete slabs-on-grade. Based.on the preliminary grading plan provided by Michael Crews Development, maximum cuts will be on the order of 12 feet, while maximlJIll fills are expected to be less than 5 feet. Fill slopes greater than 3 feet are not proposed for this project. The earthwork will consist primarily of . excavation for the below-grade portion ofthe structure and backfill for the retaining walls . The recommendations included herein are based on our understanding of the proposed proj ect as presented on the preliminary drawings. We should be allowed the opportunity to revise our recommendations, if necessary, after the final construction drawings ~ave been prepared. The site configuration and the approximate locations of our subsurface explo~ations are shown on the enclosed Bite Plan, Plate No 1. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. f'" I, 1,' I, , ~ " I'- I,'; I. I",' I,,' I .. I:;, 1-;, I, " j I I, I, I Proposed Navarra Drive Condos August 5, 2004 Project Scope Our Job No. 04-01-07 Pag~2 This investigation consisted of a surface reconnaissance coupled with a subsurface exploration. , , Representative samples of soil material were obtained from ~e site and returned to our laboratory for observation and testing. The results of the field and laboratory data collected are presented in this report. Specifically, the intent of this investigation was to: a) Explore'the subsurface,conditions to the depths that could be influenced bythe'proposed construction; b) Evaluate, by laboratory tests, the pertinent static physicaJ. properties of the various soil and rock stratigraphic units which could influence the development of this project; c) Describe the s~te geology, including potential geologic hazards and their effect upon the current and future proposed development; d) Provide recommendations for site preparation and grading; e) Present recommendations for foundation design, including bearing capacity, estimated settlements, lateral pressures and expansion potential of the on-site soils; and f) Provide soil parameters for retaining wall design and construction. This report has been prepared for Michael Crews Development and their design consultants to be used in the evaluation of the referenced site. This report has not been prepared for u~e by other parties, and may not contain sufficient information for purposes of other parties or other uses. The information in this report represents professional opinions that have been developed using that ,!\::-" degree of care and skill ordinarily exercised, under similar circumstances, by reputable geotechnical consultants practicing in this or similar localities. No other warranty, express or implied, is'made as to the professional advice included in this report. WESTERN' SOIL AND FOUNDATION ENGINEERING, INC. f-=-....... LJ t I. I, I, ! I, I, I, I, I I I, I. I·, I. 1-. I I I Proposed Navarra Drive Condos . August 5, 2004 Findings Our Job No. 04-01-07 Page 3 Site Description: The subject site is located on the south side of Navarra Drive, west of Viejo Castilla Way, in the city of Carlsbad, California. The site vicinity can be found in the north half qf grid G-l, page 1147 of the Thomas Brothers Guide for San Diego County, 2004 edition. The site is nearly rectangular in configuration and encompasses approximately one-half acre. It is bounded to the west and east by residential property, and to the south by a golf course. Approximately 95 f~et front Navarra Drive along the north property line. The property is situated at the southern margin of a narrow alluvial valley associated with San Marcos Creek. The site terrain is 'gently inclined. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. I , , , ';=i w f'" I, I: : I;" I," I. I' I" I .. : I I I:, I", I', I, I I I Proposed Navarra Drive Condos AugustS; 2004 Our Job No. 04-01-07 Page, 4 Elevations across the property range from around 83 feet above mean sea level (msl) at the southeast property comer, to 66 feet msl at the northeast property comer. Drainage is by sheet flow in a northerly direction into the gutters of Navarra Drive and eventually into San Marcos Creek. No jrnprovements were observed on the property at the time of our investigation. Vegetation consisted of sparsely growing wild grasses and ornamental trees along the south and west boundaries. Subsurface Conditions: The subject site is underlain by Quaternary age sediments that have been mapped by Tan and Kennedy (1996) and Weber (1982) as non-marine terrace deposits. These formational materials are mantled by a thin layer of colluvium. Each of these ~tratigraphic units is described below from oldest to youngest. Terrace Deposits: In the vicinity of our exploratory excavations, the terrace deposits are characterized by an interbedded sequence of clayey to very sandy silt; slightly clayey to very silty, , ,very fme to medium grained sand; and minor pebble and cobble lenses. Thes~ sediments are thinly to massively bedded, horizontally stratified and poorly to moderately indurated. They vary in color from mottled orangish-brown to greenish-gray and mottled orange and gray. The results of laboratory tests performed on samples of the, terrace deposits indicate that they may ,expand when saturated (plate No.9), and that they may be subject to consolidation under heavier loading (plate No. 10). The terrace deposits occur at 112 to 712 feet below the existing ground surface and extend beyond the vertical limits of our investigation. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. f' I, Ir'; I .. 'I' " i I'! , , I,: I, I" I,,': I,,: I." I,.:· I! I~) I- I I ... , I Proposed Navarra Drive Condos August 5, 2004 Our Job No. 04-01-07 PageS Colluvium: The terrace deposits are mantled by a thin layer of co,1luvium. For ~e purposes of this study, colluvium inchl;des in-situ developed soil as well as slope wash and topsoil. At the locations , . ' explored, it consists of dark brown, clayey silt; orangish-brown, very silty, fine to medium grained sand; and orangish-gray to orangish-brown, sandy silt. Its ~ariable consistency appears to be related to the underlyirig formation unit upon which it has developed. The colluvium is poorly . consolidated, fractured and porous. It ranges from damp to very moist. In its present condition, the colluvium is not considered suitable for the support offoundations, pavements or new fill.' Thicker or poorer quality fill materials may be encou.iLtered at locations that were not explored. Rippability: The exploratory trenches were excavated with little to 'moderate difficUlty using a Cat 420D rubber-tire backhoe. The trench depths ranged from SY2 to 13Y2 feet. Based on our field observations, it is our professional opinion that the materials exposed in our . . exploratory excavations could be excavated to the depth investigated using conventiona,l earthmoving equipment. It is possible' but not likely that resistant sediments andlor cobble that require expansive . grout or pneuma,tic cbipping may be encountered at locations that were not explored. Grou:Q.dwater: Free groundwater was not observed in any of the exploratory excavations. It should be noted th~t for four of the previous five years, rainfall totals reported for San Diego County have been below average. Furthermore, the "precipitation year" July 2002 through June 2003 marginally reached average levels. Southern California is currently considered to be in a five-year ~ought. Fluctuations of subsurface water will be affected by variations in annual precipitatio:t;l and local irrigation. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. ':..,,-. f '· --'-"'I L...: t' I I. I, I, I. I. I,. I, I I., I. I'· I, I· I I I Proposed Navarra Drive Condos August 5, 2004 Our Job No. 04~01-07 Page 6 Moreover, it has been our experience that periodic events of seepage will occur in areas of significant "cut" or any "below-grade" structures. Often, this seepage accumulates at the stratigraphic contact between soil materials of differing penneability (bedrock overlain by colluvium). Therefore, consideration should be given to appropriate surface and subsurface drainage systems, such as underdrains and swales, as recommended further in this'report. Geologic Hazards ,Faults and Seismic Hazards: The numerous fault zones in southern California include active, potentially active, and inactive faults. Active faults are those which display evidence of movement within Holocene time (from the present to approximately 11 thousand years) .. Faults that-have. . ruptUred geologic units of Pleistocene age (11 thousand to 2 million years) but not Holocene age materials are considered potentially active. Inactive faults are those which exhibit movement that is older than 2 million years. According to available published infonnation, there ate no known active or potentially active faults which intercept the project site. The site is not located within an Alquist-Priolo Special Studies Zone: Therefore, the potential for ground rupture at this site is considered low. There are, however, several active faults located in close proximity? and movement associated with them could cause significant ground motion at the site. Nearby faults include the Rose Canyon fault zone, which lies approximately 8 miles offshore to the west, the Coronado Bank fault zOJ,le, located approximately 21 miles to the southwest ( offshore) and the Elsinore fault zone, which occurs 22 miles to the northeast. WESTERN . SOIL AND FOUNDATION ENGINEERING, INC. Its I' I I, I I" I: I. I' I·, I,. I, I· I I' I Proposed Navarraprive Condos August 5, 2004 Our Job No. 04-01-07 Page 7 Evidence suggesting movement along the Rose Canyon fault zone during the Holocene has . . been presented by Moore and Kennedy (1975). The State of California has zoned portions of the Rose Canyon fault zone as active under the Alquist-Priolo Senate Bill. This has come about as a result of faulted paleosols in Rose Canyon that are considered to be unquestionably of Holocene age (T. Rockwell, 1989). The Coronado Bank fault zone is a complex series ofleft-and-right stepping enechelon . faults. Marine geophysical studies performed by Kennedy and Welday (19.80) and others have provided evidence that Holocene sediments have been offset by several faui~s associated with the Coronado Ban1c fault zone. Therefore, this fault system should also be conside!ed active. The Elsinore fault zone, which occurs approximately 22 miles to the northeast, is considered active With an estimated average rec~ence interval of 60 years. The table below presents the maximum credible and maximum probable earthquake 'magnitUdes and estimated peak ground accelerations anticipated at the site. These accelerations are based on the assumption that the maximum probable earthquake occurs on. specific faults at the closest point on that particular fault to the site. The maximum credible earthquake is defined as the maximum earthquake that appears to be reasonably capable of occurring under the conditions ofthe presently known geologic . . framework. The probability of such an earthquake occurring during the lifetime of this proj ect js considered low. The maximum probable earthquake' is considered an event having a return period of 100 years. The severity of ground motio;p. is not ~ticipated to be any great~r at this location than in other areas of San Diego County. WESTERN SOIL AND FOUNDATION ENGINEERING,. INC. ,Ir~ .L t' I I', I, I, I,. ,I. I. I, I I, I~ I" I; I' .. , I I I Proposed Navarra Drive Condos August 5, 2004 Our 'Job No. 04~01-07 Page 8 Seismicity of Major Faults Maximum Credible Distance Magnitude Fault (Miles) (Richter) Coronado Banks 21 7.6 L(2) Elsinore 22 7.5 L(3) Rose Canyon· 8 7.0L(2) San Andreas 72 8.3 L(3) San Jacinto 46 7.8 L.(3) L = Local Magnitude (1) Seed and Idriss, 1982 (2) Slemmons, 1979 Maximuin Estimated Probable Bedrock. MagnitUde Acceleration (1) (Richter) (g) 6.7 0.17 6.6 0.16 5.9 0.26 8.0, 0.07 7.0 0.08 (3) Greensfelder, C.D.M.G. Map Sheet 23, 1994 The preceding table suggests that the Rose Canyon fault zone would have the predominant influence on the site. The postulated design earthquake and ground acceleration is presented in the table below. Design Earthquake Maximum Peak Fault Probable Ground * Sustained Zone Magnitude Acceleration Acceleration ' Source (Richter) (g) (g) Rose Canyon 5.9 0.26 0.17 *Sustained Acceleration considered 65% of peak ground acceleration Liquefaction: The potential for seismically induced liquefaction is greatest where shallow ground- water and poorly consolidated, well sorted, :fine grained sands and silts are present. Liquefaction potential decreases with increasing density, grain size, clay content and gravel content. Conversely" liquefaction potential increases as the ground acceleration and duration of seismic shaking increase. , WESTERN , ' SOIL AND FOUNDATION ENGINEERING, INC. I:~~ 'LJ a:; , .: I I. I, ,I, I, I, I. I, I I II I· I" I- I I I Proposed Navarra Drive Condos August 5, 2004 Our Job No. 04-01-07 Page 9 Groundwater was not observed within any of our exploratory excavations and the site is ~der1ain by moderately indurated sediments. Based on the lack of shallow groundwater, the potential for generalized liquefaction in the event of a strong to moderate earthquake on nearby faults is . considered low. Landslides and Slope Stability: No evidence indic.ating the presep.~e of deep-seated landslides was observed' on or in the immediate vicinity of the site. Adverse geologic structure such as shear zones, fractures or jointing did not occur Within the subsurface explor~tions. Horizontal stratigraphy was noted in each of the exploratory excav.ations. It i~ therefore our opinion that the potential for deep- seated slope failure is very low. Observation of any cut slopes or excavations during and after grading will be important to identify potential shallow slope failures and rock falls. It is anticipated that any incompetent soil materials encountered during the earthwork will be mitigated as recommended further in this report. Therefore, the potential for slope failure after completion of this project is considered low, Recommendations and Conclusions Site Preparation Existing Soil: The overburden soils (colluviuni and weathered terrace deposits) are not considere~l suitable for the support of foundations, slab-on-grade or fill material. To provide more uniforin support for proposed structural improvements, we recommend that any fill, colluvium, weathered terrace deposits or otherwise unsuitable material be completely removed to firm, competent, undisturbed natural ground. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. f 'b I : L-J ,'''1. I I:'; I, I, I, 'I, I,; I. I, I, I,'· I·, I~ ~I· ,I, I' I Proposed Navarra Drive Condos August 5, 2004 Our Job No. 04-01-07 Page 10 The horizontal limits of removal and recompaction shall include the entire areas of.proposed structures, pavement, hardscape, fill or any proposed fill slopes .. Whenever feasible, all soil removal and replacement should extend at least 5 feet beyond the footprint of any features as described above and shall be accomplished in accordance with the earthwork and foundation recommendations presented in this report. Based on the results of our field explorations, it appears that the depth of removal will be on the order of 4 to 19 feet. Thicker and/or less competent materials may be ~ncountered at locations that were not explored. The minimum depth of removal shall be 5 feet below ~he bottom of the deepest footing in buildin~ envelopes and 4 feet below finish sub grade in driveway pavement areas. The on-site soils minus any debris, oversized rock or organic 'material may be used as controlled fill. Some selective earthwork may be necessary to avoid placement of detrimentally expansive soils. AIl fill shall be compacted to at least 90% of its maximum dry density as detennined 'by ASTM D1557~00. The moisture content at the time of compaction should be within 2% of optimum for non-expansive soils and between 2% and 4% over optimum for the clayey materials. AIl debris, organic matter or oversized materials (greater than 6 inches in maximum d:ir.llension) encountered must be removed and legally disposed of at a licensed disposal site. Large rock may be. used as decorative landscape material if placed and secured properly. Nested boulders and/or boulder/rock piles should not remain permanently on the site. If groundwater is encountered during the removal and recompaction of the soil, or if difficulty· is experienced in achie,:ing the minimum of90% relative compaction (ASTM D15S7-00), then this office shall be consulted for further recommendations. WESTERN SOIL AND FOUNDATION ENGINEERING, IN.C. IlL II'Li Ifj' . i' I I., I. ' I.~ I,: I. I, i,~.: I I, I,,: I~ I'J l I· I'. " Proposed Navarra Drive Condos August 5, 2004 Our Job No. 04-01-07 Page 11 Expansive Soil: Potentially expansive soils (Expansion Index of21 or greater) were observed in ' the subsurface explorations. These materials generally consisted of clayey silts and clayey, silty sands. The results o flab oratory testing (Plate No.9) indicate that these soils have expansion indices that range from 30 to 47 (low to near-medium expansion potential). The lower expansion index represented a blended sample of soils. These extended from 3 to 10 feet below the existing ground surface in the vicinity of trench T-2. The near-medium expansion potential reflected in-" situ soil conditions below a depth of9 feet in the southwest quarter ofllie site. Based on visual 'observation, more granular and possibly less expansive soils appeared to be present in trenches T-3 and T-5. It is our opinion that selective grading may be necessary to reduce the amount of detrimentally expansive materials used during the earthwork on this site. However, construction of the below-grade parking garage foundations onto the near-medium expansive soils may be unavoidable. Therefore, foundation recommendations addressing moderately expansive soils are presented further in this report. At other locations, the use of soii materials with an expansion index greater than 30 should be avoided. Expansive soils should not be used as wall backfill, within 4 feet of finish subgrade beneath concrete pavements, or Within 15 feet (horizontally) of the face of any constructed slope that is greater than 5 feet in height. WESTERN SOIL AND FOUNDATION ENGINEERING, INC., 1_·-: '-~ t' I, I .. I, I. I, ,I, I, I, , I. I. I. I· " I' I" I I I Proposed Navarra Drive Condos Ap.gust 5, 2004 Our Job No. 04-01-07 Page 12 Excavation and Shoring: Temporary cuts and slopes shall meet minimUm OSHA requirements. Maximum slope gradients shall be %: 1 (horizontal:vertical) for formational soils to a maximum height of 10 feet, including foundation excavations. Slopes greater than 10 feet high or steeper than %: 1 shall be supported by shoring designed by a Structural Engineer registered in the State of California. The toe of the temporary 'cut slopes may be cut vertical to a maximum height of 3'-6". As currently proposed, improvements may occur within 5 feet of existing on-site structures. Removal depths adjacent to existing off site structures should be evaluated during cop.struction by the Soil Engineer or Engineering' Geologist. Depending on the soil conditions encountered, shoring of the removal excavation may be required. Imported Fill: hnported fill, if required at this site, shall be approved by our office prior to importing. The Soils Engineer should be provided ample notification so that sampling and testing of potential soils may be performed prior to importing. Approximately 3 to 5 working days may be necessary to sample and evaluate potential import soils. Imported fill material shall have an Expansion Index of 20 or less with not more than 25 percent passing the No. 2.00 U.S. standard sieve. Earthwork: All earthwork performed on-site must be accomplished in accordance with the attached Specifications for Construction of Controlled Fills (Appendix 1). All special site preparation recommendations presented in the sections above will supersede those in the Specificati~ns for , Construction of Controlled Fills. WESTERN SOIL AND FOUNDATION ENGINEERINO, .INC. Ii~ t I. I' I. I. I I I I I I. I: I· I, I. I I .1 Proposed Navarra Drive Condos August 5, 2004 Our Job No. 04-01-07 Page 13 All embankments, structural fill, and utility trench backfill shall be compacted to no less than 90% ofits maximum dry density. The moisture content of the gfanular fill soils should be within 2% of optimum moisture content at the time of compaction. The moisture content of the clayey soil materials should be maintained between 2% and 4% over optimum moisture content. The maximum dry density o(each soil type shall be determined in accordance with test method. /? ASTM D1557-00. Prior to commencement of the demolitionlbrushing operation, a pre-grading meeting shall be held at the site. The Developer, Surveyor, Grading Contractor, and Soil Engilleer should attend. Our firm should be given at least 3 days notice of the meeting time and date. Slopes: Based on the information provided, permanent, un-retained slopes greater than three feet in vertical height are not proposed for this project. We 'should be informed as early as possible if slopes greater than three feet in vertical height will be incorporated into this development, so that we may provide appropriate recommenc;lations. Surface Drainage: Surface drainage shall be directed away from structures and pav~d. areas .. The . ponding of water or saturation of soils should not be allowed adj acent to any of the foundations. We recommend that planters be provided with drains and low flow irrigation systems. Gutter, roof drains and other drainage devices shall discharge water away from the structure into surface drains and storm sewers. Surface water must not be allowed to drain in an uncontrolled manner over the top of any slope or excavation. WESTERN SOIL AND FOUNDATION ENGINEERING, INC.· fo Ii" I It: 1.1 I, ' I, I~ I,. I. : I .. ' I.,' I . .' I.·: I: I ... I I·, I Proposed Navarra Drive Condos August 5, 2004 Our Job No. 04-01-07 Page 14 The exterior grades should be sloped to drain away from the structures to mininiize ponding of water adjacent to the foundations. Minimum site gradients of at least 2% in the landscaped areas and of.! % in the hardscaped areas are recommended in the areas surroundi:r;tg buildings. These gradients should extend at least 10 feet from the edge of the structure. To reduce the potential for erosion, the slopes shall be pjanted as soon as possible after grB;ding. Slope. erosion, including sloughing, rilling, and slumping of surface soils may be anticipated if the slopes are left unplanted for a long period of time, especially during rainy s~asons. Swales ot e~ berms are recommended at the top of all permanent slopes to prevent surface water runoff from overtopping the slopes. Animal burrows should be controlled or eliminated since they can serve to collect n0rmal sheet flow on slopes, resulting in rapid and destructive erosion. Erosion control and drainage devices must be installed in compliance with the requirements of the controlling agencies. Subdrains: A subdrain system shall be installed at the toe of slopes draining into the .property, within buttress or stability fills or where fill is proposed over canyons or drainage areas. The fmal determination for the location of the sub drains shall be made by the Soil Engineer or 'Engineering Geol~gist during the site grading. Based on our understanding ofthis project, it is not likely that subdrains will be necessary with the exception ofretaining wall back drains. However, we are providing these recommendations should future conditions or design requirements indicate a need for subdrains. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. F":7 . -- L-2 I, I, I. I, . I,.: I, ,1, I .. I,· I: I-- I I 1 Proposed Navarra Drive Condos August 5, 2004 Our Job No. 04-01-07 Page 15" . The sub drain shall consist of a trench at least 36 inches deep and 18 inches wide. Mirafi 140N or Am<?co 4547 non-woven geotextile fabric, or an approved equivalent, shall line the bottom and sides of the trench. Four inches of3/4-inch rock bedding shall be placed on the geotextile at the bottom ofthe trench. A perforated pipe with a diameter of at least 4 inches shall be placed in the trench with the perforations down. A 6-inch diameter pipe may be necessary where larger volumes of water are anticipated. The pipe shall be ABS schedule 40 (ASTM-D1785) or an approved equal. . The drainpipe shall have a mipimum 1 % gradient and shall be centered within the trench horizontally. A minimum of 3 cubic feet of 3/4-inch rock per linear foot of subdram shall be placed over and around the pipe within .the geotextile lined trench. The geotextile sha1llap at least 12 inches . over the top of the rock. The subdrain shall outlet away from any structures or slopes in an approved legal manner. Founda,tion Recommendations Seismic Site Ca~egorization: The following seismic site categorization parameters may be used for foundation design. These design parameters are based on the information provided i~ ~hapter 16 of . the 2001 California Building Code, California Code 6fRegulations, Title 24, Part 2, Volume 2. Soil Profile Type Near Source Factor Near Source Factor Seismic Soitrce Type Na Ny WESTERN' = Se = 1.0 = 1.0 = B· SOIL AND FOUNDATION ENGINEERING,. INC. -=b .-,U ,. I I f,' ! . I." I. I. I I .. I' I I. I.; I·. I., I. I I. I Proposed Navarra Drive Condos August 5, 2004 . Our Job No. 04-01-07 Page 16 Footings: To provide more uniform support we recommend that proposed structures he entirely supported on firm, competent, formational sediments or entirely on properly compacted filL Footings shall be designed with the minimum dimensions and allowable dead plus live load soil bearing values given in the following table: Foundation Design Parameters Minimum Minimum Allowable Footing Depth Width Soil Bearing Building Height Type (inches} (inches) Value (E.s.f} Two -Story Continuous 18 15 . 1,500 Three-Story Continuous 24 18 2,000 Two-or Three-Story Square 24 24 2,500 The minimum depth given shall be below lowest adjacent finish subgrade. If foundations are proposed adjac.ent to the top of any slope, we recommend that the footings be deepened to provide a horizontal distance of 8 feet between the outer edge of the footing and the adjacent sl0pe faGe: The soil load bearing v~lues presented above may be increased by one-third, f?r ~hort-term . loads, including wind or seismic. The soil load bearing values of any imported ~oi1 should be determined after its selection but prior to its delivery on-site. All continuous footings shall be reinforced in accordance with recommendations provided by a Structural Engineer. Settlements under building loads are expected to be within tolerable limits for the proposed . . structure. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Fr' I, II ~ I." I, I.'; I., I." I,,: I", I." I ," .1, I: I~j I.~, ' I I" I Proposed Navarra DIjve Condos August 5, 2004 ' Our Job No. 04-01-07 Page 17 Concrete Slabs-Dn-Grade: If the soils are prepared as recommended in this report, concrete slabs- 'on-grade shall be supported entirely on properly compacted fill Or undIsturbed natural ground. No, cut/fill transitions should be allowed to occur beneath the structures. Due to the moderately expansive nature of the .on-site soils, concrete slabs-on-grade should have a minimum thickness of 5Yz inches. Reinforcement should consist of No. 4 rebar placed at 18 ' inches on center in both directions. A low-slump concrete (4-inch maximum slump) should be used to further minimize possible curling ofthe slabs. The concrete slabs should be allowed to cure properly'before placing vinyl or other moisture-sensitive floor covering. The flooring contractor should test the slab for moisture vapor transmission requirements. Construction and weakened plane joint spacing and placement shall be provided by the Structural Engineer. Slab-Dn-Grade Bedding: To provide protection against vapor or water transmission through the building and floor slabs, we recommend that the slabs-on-grade be underlain by a 6-inch layer of , Caltrans Class 2 penneable material or gravel. A suggested gradation for the grayel1ayer is as follows: Sieve Size Percent Passing 3/4" 90-100 No.4 0-10 No. 100 0-3 WESTERN SOIL AND FOUNDATION ENGINEERING, INC. f-~--', '-0 " I I:: I, ' I, I 1 I. ' I,,' I. I I) I, I: I I I I Proposed Navarra Drive Condos August 5, 2004 Our Job No. 04-01-07 Page .18 Impermeable Membrane: In areas where vinyl or other moisture-sensitive floor coverings are planned or where moisture may be detrimental to the structure's contents, we recommend that the 6-inch-thick gravel layer be overlain by a 10-mil-thick impenneable plastic membrane (Stego Wrap or approved equal) to provide additional protection against water vapor transmission through the slah. The vapor barrier should be installed in accordance with the manufacturers instructions. Laps, edges and penetrations shall be sealed with manufacturer's approved tape. To protect the membrane during later concrete work, to facilitate curirlg of the concrete, and to reduce slab curling, a2-inch-thick layer of clean sand shall be placed over the membrane. Transition Areas: Any proposed structures should not be allowed to straddle a cut-fill transition line. Footings and floor slabs should be entirely supported on cut or entirely on fill. The tendency of cut and fill soils to compress differently can frequently result in differential settlement, cracking to portions of the structure and in severe cases structural damage. To reduce the potential for damage due to differential settlement in transition areas, we . recommend that cut areas be over-excavated to a depth of at least 2 feet below the bottom of the deepest footing and replaced with non-expansive soil material compacted to at least 90% of its maximum dry density (ASTM D1557-00). The compacted fill should extend at least 5 feet beyond the building floor plan. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. f \::;; tJ ~r' .=- I- I_- I I I- I I I Proposed Navarra Drive Condos August 5,2004 Our Job No. 04-01-07 Page 19 Lateral Resist~nce: Resistance to lateral loads may be provided-by friction at the base of the footings and floor slabs and by the passive resistance of the supporting soils. Allowable values of frictional and passive resistance are presented for the fill soils in the table below. The frictional resistance and the passive resistance of the materials may be combined without reduction in determining the tqtal lateral resistance. -_Lateral Resistance Values Soil Type Competent, Undisturbed Fonnation Compacted Fill Coefficient of Friction 0.35 0.25 Allowable Passive Pressure (ps£,ft of depth) 350 250 Footing Observations: Prior to the placement of reinforcing steel and concrete all foundation -. excavations should be observed by the Soil Engineer, Engineering Geologist or their reptesentiltive. Footing excavations shall be cleaned of any loosened soil and debris before placing steel or concrete. Footing excavations should be observed and probed for soft areas. Any soft or disturbed soils shall be over~excavated prior to placement of steel and concrete. Over-excavation of soils should not be perfonned-in-locations that were undercut for transition areas. This would compromise the thickness_ of the soil supporting the footings. In undercut transition areas loose soils should be recompacted. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. 11: t' I. I. I I. I. I. I .. I I I I, I· I; I I I I Proposed Navarra Drive Condos August 5, 2004 Retaining Walls Our Job No. 04-01-07 . Page20 Lateral Pressures: It is our understanding that retaining walls will be used for the below-grade parking of the proposed structure. Our analysis anticipated that retaining walls up to 12 feet in height would be constructed. These recommendations should be reviewed and updated if walls greater than 12 feet in height are to be installed. For the design of cantilevered retaining walls where the backfill is well drained, the equivalent fluid pressures for both active and at-rest conditions are presented below. Backfill Inclination Level 2:1 slope Active Pressure (p.e.f.) 40 53 At-rest Pressure (p.e.f.) 55 68 It is expected that the proposed retaining walls may be constructed within five feet of . . . property lines. It is possible that existing and/or future structures on adjacent properties will '. surcharge these proposed retaining walls. The Structural Engineer should consider this when designing the proposed retaining walls. . Drainage and Waterproofing: If the backfill is placed and compacted as recommended herein and good surface drainage is provided, the infiltration of water into the wall backfill may be reduced. Adequate drainage of adjacent planters should likewise be provided to reduce water infiltration into wall backfills. To limit the entrapment of water in the backfill behind the proposed wails, backdrains or other drainage measures should be installed. . WESTERN SOIL AND FOUNDATION ENGINEERING, INC. f"-: w ,t' I. I, I,' I, I, I, I, I, I, I I: I, I) I I I I Proposed Navarra Drive Condos August 5, 2004 Our Job No. 04-01-07 Page 21 Drainage should consist of vertical gravel drains about 18 inches wide connected to a 4-inch- diameter perforated pipe. The pipe shall be ABS schedule 40 (ASTM-D1527) or SDR 23.5 (ASTM-D2751) or approved equal. The perforated pipe should be placed with the perforations down and should be surrounded by at least 1 ~ feet of ~lter gravel or unifonnly graded gravel or Caltrans Class 2 permeable material wrapped in geosynthetic filter fabric, such as Mira£. 140N or approved equivalent. Care should ~e taken to select a filter fabric compatible with the backfill materials as clogging ofthe filter material may occur. " . The drainpipe should be located near the base of the wall and should discharge into a storm drain or onto a surface draining away from the structure. As an alternative to 'the vertical gravel drains, a drainage geocomposite such as Miradrain, or an approved equivalent, may be used with a 4 inch-diameter perforated pipe collector dniin. Backfill: The exterior grades should be sloped to drain away from the structures to minimize ponding of water adjacent to the foundations and retaining walls. Compaction of the backfill as recommended " herein will be necessary to r~duce settlement of the backfill and associated settlement of the overlying walks, paving, and utilities. All backfill should be compacted to at least 90% of the maximum dry density (ASTM D1557-00). WESTERN SOIL AND FOUNDATION "ENGINEERING, INC. f ·, '-b J : '-' r·l . I. I> I I. I. I. I.: Ii I.: I, I: I· I.: I. I. I. I Proposed NCj.varra Drive Condos August 5, 2004 Our Job No. 04-01-07 Page 22 Some settlement of the backfill sho.uld be anticipated, and any-utilities supported. therein should be designed to accept differential settlement, particularly at the points of entry to buildings. Also, provisions should be made for some settlement of concrete walks on-grade supported on fill. Field Explorations Subsurface conditions were explored by excavating five (5) backhoe trenches on July 9, 2004. The exploratory trenches were approximately 2 feet wide and 15 feet 19n9, and were advanced to depths of 512 to 13Y2 feet. No caving or groundwater seypage occurred in the excavation walls. The·locations of the exploratory excavations are depicted on the Site Plan, Plate No.1, in the back of this report. The surface reconnaissance and subsurface exploration were conducted by our geology and ·soil engineering p~rsonnel. The soils are described in accordance with the Unified Soil Classification System as illustrated on the attached simplified chart (piate No.2). In addition, a verbal texturai description, the wet color, the apparent moisture and the density or consistency are p~es.ented. The . density of granular material is given as either very loose, loose, medium de~e, de~e or very denSe. The consistency of silts or clays is given as either very soft, soft, medium stiff, stiff, very stiff or hard. The sampling and logging of our exploratory excavations were performed using standard geotechnical methods. The logs are presented on Plate No.3 through Plate No.7. Samples of typical and representative soils were obtained and returned to our laboratory. for observation and testing. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. r-s t, I, I, I, I, I,. I.' I., I,: I I. I: I· I, I- I I I Proposed Navarra Drive Condos August 5,2004 Our Job No. 04-01-07 . Page 23 Laboratory Testing Laboratory tests were performed in accordance with the American Society for Testing and Materials (ASTM) test-methods or suggested procedures. Test results are shown on Plate No.8 through Plate No. 10. Plan Review Western Soil and Foundation Engineering, Inc. should review the fmal grading and building plans for this project Limitations The recommendations and opinions expressed in this report reflect our best estimate of the project requirements based on an evaluation of the subsurface 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, pavlements and'constructed slopes maybe influenced by undisclosed or unforeseen variations in the soil conditions t4at.may occur , in the intermediate and unexplored areas. Any unusual conditions not covered in this report that are encountered during site development should be brought to the attention of the geotechnical consultant so that modifications can be made, if necessary. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. f~ , '-' f' I, I. I, I, I, I. I, I I I, I;' I" I., I: I I I Proposed Navarra Drive Condos August 5, 2004 Our Job No. 04-01-07 Page 24 It is recommended that Western Soil and Foundation Engineering, Inc. be retained to provide continuous geotechnical engine~ring services during the earthwork operations. This is to observe compliance with the design concepts, specifications or recommendations ~d to allow design changes in the event that subsurface conditions differ from those anticipated prior to start of construction. Western Soil and Foundation Engineering, Inc. and/or our consultants, will not be held. responsible· for earthwork of any kind perfOlIDed without our observation, inspection and testing. This office should be advised of any changes in the project scope so that it may be detennined if the recommendations contained herein are appropriate. This should be verified in writing or modified by a written addendum. The fmdings 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 ~d/or Government Codes may occur. Due to such changes, the findings of the report may be inyalidated wholly or in part by changes beyond our control. Therefore, this report should not be relied upon after a period of one year without a review by us verifying the suitability of the conclusions and recomnlendatio1).s. We will be responsible for our data, interpretations, and recommendations, but shall not be responsible for the interpretations by others ~fthe infonnation 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 perfonned or to be perfonned by:us, or by our prop'osal for consulting or other servjces, or by our furnishing of oral or written reports o,! findings. WESTERN SOIL AND FOUNDATION ENGINEERING/.INC .. ,i. , . -.::::: U t·, I I.';' I. I. I. I I I: I I, I: I· I! I. I I I Proposed Navarra Drive Condos Augu,sf 5,2004 Our Job No. 04-01-07 Page 25 It is the responsibility. of the Client or the Client's representative to ensure that the information and recommendations contained herein are brought to the attention of the engineer and . . architect for the project and incorporated 'into the project's plans and specifications. It is further the responsibility of the Client to take the necessary measures to ensure that the contractor and sub- contractors carry out such recommendations during construction. Respectfully submitted, WESTERN SOIL AND FOUNDATION ENGINEERING, INC. Vincent W. Gaby, CEG 1755, Expires 7/31/05 Engineering Geologist . Dennis E. Zimmerman, C 26676, GE 928, Expires 3/31106 Geotechnical Engineer VWG:DEZllang . WESTERN SOIL AND FOUNDATION ENGINEERING, INC. (, -:=j <-.J ,. I I.' I, . I, I. I. I, I:' I I' I:' I· I I- I I I' ATTACHMENTS WESTERN . .' SOIL AND FOUNDATION ENGINEERING, iNC. fj I' I I,' I' I, I I' I, t: I I. I: I, I, I.· I I' I SITE PLAN (Plate No.1) WESTERN SOIL AND FOUNDATION ENGINEERING, INC. I , , 1.:::) W' I I,' I. I., I" I I, I,'; I~, I,: I~, I, I I I. SUBSURFACE EXPLORATION LEGEND UNIFIED SOIL CLASSIFICATION CHART Soil Description COARSE GRAINED: More than half of material is larger than No. 200 sieve size. Gravels: More than half of coarse fraction is larger than No.4 sieve size but smaller than 3". CLEAN GRAVELS GRAVEL WlFlNES Sands: More than half of coarse fraction is smaller than No.4 sieve size. CLEAN SANDS SANDS WIFlNE8 Group Symbol Typical Names GW Well graded gravels, gravel sand mixtures, little or no fines. GP Poorly graded gravels, gravel sand mixtures, little or no fmes. GM Silty gravels, poorly graded gravel-sand-silt mixtures. GC Clayey gravels, poorly graded gravel-sand, clay mixtures. 8W Well graded sand, gravelly sands, little or no fines. SP Poorly graded sands, gravelly sands, little or no fines. 8M Silty sands, peorly graded sand and silt mixtures. SC Clayey sands, poorly graded sand and clay mixtures. II. FINE GRAINED: More than half of material is smaller than No.,200 sieve size. Silts & Clays: Liquid limit less than 50 Silts' & Clays: Liquid limit greater than 50 HIGHLY ORGANIC SOILS ML Inorganic silts and very fine sands, rock flour, sandy silt or ~layey-silt-sand mixtures with slight plasticity. CL Inorganic clays of low to ;medium plasticity;gravelly clays, sandy clays, silty clays, lean clays. OL Organic silty and organic silty clays of low plasticity. MH Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts. CH Inorganic clays of high plasticity, fat. OH Organic clays of medium to high plasticity. PT Peat and other highly organic soils. Plate No.2 WESTERN SOIL AND FOUNDATION ENGINEERING, INC. f " -....., . 'I to' I I I I' I" I', I! I; I ,I .. I" 'I, Ii I' I I I -W z I-0 a.. W >-j:: W I-..J<C LI.. -W _(J 0-:r ..J en!:!: l-n. en a.. :iE en w <, < C en -' (.) --" -f 1;0" -, ML·' .... :-- 1-' To '.' '1. MHr. ..t....:.:! .-:. -;j~,,,:" .. .~,.... . 2-~ , " " ...:.......r.7 -~ , .. .. --. .. ---:-... -r-_.-r"'o 3-.J~ -.~ ;"'M~; -'-;;--~ .. -'r" -4-.-.-~,. _ J-. ...,... '--. -:.:::....: ....;0' -!-.:---" --:----- 5-C :MH": ,--....-. -------~= 6--r-2- ---~ -/=- 7--~~-~" -------8---------~---'-'-.. ~ :.:, 9-I':.· ... ~"". ::"'--:':7 l! . . . -.--:~SM :7 10- ::;. To ;:: ';"!ML':':' B · .... -;0-. ,--A' ·If"::: --· " ....... 11-:-:...:.~. .... " ...... -:-.. ":"'~ . .. ~...,...... -:t.!~_:_:· i.--~--' ---. 12-.----. ::-. =-: .. -;-:. -C ·"--:-,7..,=.: :.. .. :....,.-=.. 13-• )o.l, .... ", - 14-, JOB NUMBER 04-01·07 TRENCH NO. T-1 >-~ ~ --I-w 1-0 w~ I-w Z w ELEVATION ±79 Zo::: zz en ..... 0::->Q w w::J wW :;,1-, 0::1-0:1-Z 11. I-z -l-Ll.. WO ~O - SAMPLING <en <22 CCI.. (J)'w :r n.-a.. en -I-~ I->-..... oz METHOD CAT 4200 BACKHOE a.. 0 a..z ~== a.. <:iE <0 a:: ' :leO W DESCRIPTION 'U C 0, 0 C (.) COLLUVIUM -Dark Brown, Sandy, Clayey, Moist Medium -Silt, Fractured To Stiff -1 Very To Grades To ~oist Stiff - Very Clayey Silt -2' : -1 , TERRACE DEPOSITS -Mottled Orangish-Brown Soft Very and Greenish-Gray, Moist -3 Slightly Clayey, Sandy Silt - -4 Grades To - 105.8 16.3 -5 Dark Brown with Greenish-Gray Very Medium Mottling, Clayey Siltstone Moist Stiff - Poorly Cemented -6 -Minor Random Slickensides from Desiccation Shrink/Swell -7 - -8 - HORIZONTAL BEDDING Mottled Orang ish-Brown and Gray, Moist Medium -9 Very Silty, Very Fine Grained To Dense Sandstone, Poorly Cemented, - with Interbedded, Slightly Clayey, Very To -10 Sandy Silt Moist Stiff - -11 - SAMPLE LEGEND B = Bulk Sample -12 . C = Chunk Sample 107.8 14.6 - -13 BOTTOM OF TRENCH @ 13 FEET - -14 NAVARRA DRIVE CONDOMINIUMS DATE LOGGED LOGGED BY MICHAEL CREWS DEVELOPMENT 07-09-04 VWG SUBSURFACE EXPLORATORY LOG' Plate No.3 t I. I, . .., I I', I.; I. I: I: I, I·, I: I I I I -w z 0 l-e. W >-i= W I-et IJ.. :::!o -W 0-.::C ...J en!::!: l-e. :! en e. en W et :3 C en (.) "..., ' •• ':-01 <:t:." ••• -... SMa; :;: To .. : -... 1-··'GM".=. !2?~ . • :--0"::'::" ".-:-; : ... ~~ --: ...... :--. :=:~..:.. 2--.. -~ --. '- -I-':"ML:: """:a_ ...... '------3-.:......: ..:....:... ............. -:-.--:-~:::;-::~ -"-........... ---............. . -- 4---"-~-"-. ... . ,. ---," .. -SM/SW . _. -' 5-~ ':-: .,,:. --r' ... 4' ... 1.-,. .. .f 4'J .. ". -c,aoo : :4t~ •• : .. -..... 6-.. '. " ......... : B " ... '.; ..... :," -" ! j •••• .. : !" :." --: 7-,,"''' --::-":"'ML:': :.... .. _!....! -~~~ .. ~ ..... ., . 8-.... :-:~: :., '" ~-----~ -J---e,.. :.:. :... ',..:..;. J.:..-~-....!..'. 9--".-.. .. :.-.~ ~ •• _ s-..:.. ---..,; -;.: :.:..:-,...:.. ._-." ............. 10-f------.. ....:~ .. .. ~ .. -.. ---......... ,. .. -:"""" .--:" -'!;-... ":"" :*"7 --.::..:. .. !:. !-:... 11-oDaCb f,_C .. . . -SM/SW .. ", ". " .. ,.' 12-'. -=-,'. ~ ,",; :':.:: .. '.~ '''~ C .. _I""." --.. ~".::;:;: " .. '."-=-" 13-' .. "', ~ .. 41!: .... '1"'. -' .. . . , " ...... • .... ,. I, . , .. ,... ... - 14- JOB NUMBER 04-01-07 TRENCH NO. T-2 >-'#. ~ --I-w 1-(.) w~ J-w Z w ELEVATION ± 78 Zo::: ZZ Ci5_ 0:::-.>Q W W::J WW Zu.. ::JI--I-!:!:.. 0:::1-0:::1-I-z S~ wo SAMPLING eten etfQ o ll.. en w :c e.-e.en -l-I- METHOD CAT 4200 BACKHOE e.0 >-_ .. OZ WO-e.z e. et~ eto 0::: ~O 0::::= w DESCRIPTION (.) c 0 0 C (.) COLLUVIUM -Pale Orangish-Brown, Very Silty, Damp Loose -Fine to Medium Grained Sand with Cobble -1 - TERRACE DEPOSITS -Mottled Orang ish-Gray, Moist Medium Sandy Silt Stiff -2 Very Porous - -3 Grades To - -4 Orangish.Gray, Slightly Silty, Fine Moist Medium to Medium Grained Sand Dense - -5 -~ COBBLE LENSE -6 Grades To - Mottled Greenish-Gray and Very Medium -7 Orangish-Brown, Very Moist Stiff Sandy Silt - -8 - -9 - -10 - -11 ~ COBBLE LENSE Very Medium Orang ish-Brown, Slig htly' Silty, Moist Dense - Fine Grained Sandstone To -12 Dense - 107.7 17.7 -13 " - BOTTOM OF TRENCH @ 13% FEET -14 I. NAVARRA DRIVE CONDOMINIUMS DATE LOGGED LOG(;ED BY "I MICHAEL C~EWS DEVELOPMENT 07-09-04 NSBNWG SUBSURFACE EXPLORATORY LOG Plate No.4 'f4 ~. .~ 1 I , I· I~'~ I" I' 'i I'. I, :1: I" I· I, I.·· I:: I·. I. I I -W z 0 l-e.. W ~ W >-I-Ll.. ::!o -W :I: -I 0- l-e.. (I)!:!: e.. :s (I) w « (I) < 0 (I) ..J 0 -.1"-:. ,'.. .. ,. -ZML7. ~-_ .... 1- . __ ..... :;....-~-. !-:..:. .:.:-, ~; ........... -" . -:-~ ... • .:.:. -..!.. 2-?L ML':'I, wI.!._...:t ._1..1'" -!.; .. ,.~ '-;.t.. I_~' :...: • 100 -. .. ' 3-, .. -'-,,,t ..... _ .' ._,-. -' ...: -:::.. SM .:: 4-;~-"-" .. '. -'".,. ft~ - 5--..... ..,.:... .. .' ........ ,;.:., -: ~:: :::::: ... -... ~ 6-0',",0 ...... :, .. ' ........ :":', :: ... ·f -ooo~ ,.-_7 ... • " 7-~." r-•• f.:) .. Cbc:>, ~:.:,~ -• .:.,.;'"lfl? ' •. --1. 8-~6'" . oGM~' ",,!-f" I' • -:~7t~:. 9-lDifDCO :',..:.r: .. ~: .. oc::f>ciJ ,'. .. " " -,-' o;;.;~ 10-•••••• 7-; .... ', - 11- - 12- - 13- - 14- JOB NUMBER 04-01-07 TRENCH NO, T-3 >-~ >---I-w 1-0 w~ w Z I-I-W ELEVATION ±74 Zo:: ZZ c;;_ 0::->Q w w::J ww ::JI-0::1-ZLI.. -l-LL. 0::1-WO I-z 1-0 - SAMPLING «(I) <~ (l)w :5« ::c e..-e..(I) O!l. -l-I- METHOD CAT 4200 BACKHOE e..0 e..Z >--, OZ we.. e.. «:5 <0 0:: ::EO o:::!! w DESCRIPTION 0 0 0 a 0 0 COLLUVIUM -Mottled Orangish'C;;ray, Sandy Silt, Porous Damp Soft - -1 - TERRACE DEPOSITS -Pale Gray with Orange Moist Medium Mottling, Very Sandy Silt Stiff -2 -Grades To -3 Pale Brown with Orange Mottling, - Very Silty, Fine Grained Sand, Slightly Porous Very Medium -4 Moist Dense - -5 - -6 - COBBLE LENSES -7 Interlayered with Very Stiff Greenish-Gray, Silt and Orangish· Moist To - To Medium Brown, Silty, Fine to Medium Moist Dense -8 Grained Sandstone - -9 - -10 BOTTOM OF TRENCH @ 10 FEET - -11 - -12 - -13 - -14 NAVARRA DRIVE CONDOMINIUMS DATE LOGGED LOGGED BY MICHAEL CREWS DEVELOPMENT 07·09·04 NSBNWG SUBSURFACE EXPLORATORY LOG Plate No.5 13 t' I I, I, ii, I., I. I; I i. . : " , I' , , I , -, 'I: • I I~ I. I: 'II I I' p W W 11. -:t: l-e. w c 1- W 0.. ~ W ...J c.. :E ~ z o i= ...J< _0 0-en!:!: CI) CI) :3 o ....... ~ .. ~ML~· . -' ~ .. -:~ TRENCH NO. T·4 ELEVATION ± 70 SAMPLING METHOD CAT 4200 BACKHOE DESCRIPTION COLLUVIUM -Pale Orangish·Brown, Very Sandy Silt I-W Zo::: W:::l 0:::1-<en c..- 0..0 <::B Damp >-1-0 zZ WW 0::1-<era c..en c..z '<0 o Soft To Medium Stiff ~ CI) ...... Zu.. w(,,') cc.. )-o-n:: c W~ 0::-::::JI- I-Z en W -I-Oz :EO o p W W 11. -:I: l-e. W c -1 ~%:~ _r-~=_~.~ .. ~.~~~ __ -=--~-----------------r~~-1~~--+---~--~~~~-:.:-:... TERRACE DEPOSITS -Mottled Orange and Gray, Very Medium 2- 3- 4- 5- 6- 7- 8- 9- 10- 11- 12- 13- 14- JOB NUMBER 04·01·07 Very Sandy Silt Moist Stiff Moderately Porous Grades To Mottled Orangish-Gray, Very Silty, Fine Grained Sand NAVARRA DRIVE CONDOMINIUMS MICHAEL CREWS DEVELOPMENT Moist Medium Dense 100.8 DATE LOGGED 07·09-04 SUBSURFACE EXPLORATORY LOG -2, -3 -4 9.9 -5 -6 -7 , --8 -9 -10 -11 -12 -13 -14 LOGGED BY NSBNWG Plate No.6 F~ t._~.! t I, I, I, I, I. " , ~ , I, I., I.: I" I I; I· I: I .. I. I I -W Z I-0 W e.. i= ~ W ...J< u. -W _0 0-:J: ...J en!:!: l-e.. :E (J) c.. (J) W < <c c en -I U ---SM ------1-~o_ .. :.. ... 00:. -j!)' '.-;-, p.. • • ... '*7P .. 2--<!)'-, &:_0- -• GM· =-0 3-~ #.~ ..'. ~, ... * • oot:>~ -----to T".':""~' 4-~ML':'':' 00 .-" ---------. -~,/,. ' .... 0°0' . ,,.." 5-,-_. :~·,·O. :': .-:...,.-----:;:;~'g ~ 6-• '.' .t •• C . " ., · .. ' .. ·dp~"I&· .t., '.,:.: .. - 7- - 8- - 9- - 10- - 11- - 12- - 13- - 14- JOB NUMBER 04-01-07 TRENCH NO. T-5 >-~ ~ -;:::- I-w I-U w~ w Z W ELEVATION ± 68 Zo::: ZZ en ....... 0::->0 W w::> WW Zu.. :::II-. i= i= u.. 0::1-a::: I-I-z -wo <cO ! : SAMPLING <en <c!l2 co. (J)w :J: 0.-o.en -I--I<C I- METHOD CAT 4200 BACKHOE 0.0 >--Oz wo. o.z 0. <,:E <0 0::: :EO 0:::!E w DESCRIPTION u c (J 0 c (.) COLLUVIUM -Dark Grayish-Brown, Silty, Fine to Dry Loose -Coarse Grained Sand and Cobble -1 TERRACE DEPOSITS -Dark Grayish-Orange, Moist Medium Slightly Silty, Coarse Grained Sand - with Pebbles and Cobbles, Dense -2 Horizontally Bedded - -3 -Thinly Interbedded with Pebble and Cobble Lenses, and Very Stiff -4 Greenish-Gray, Sandy Silt Moist - -5 - 103.7 14.3 -6 - BOTTOM OF TRENCH @ 6% FEET -7 - -8 - -9 - -10' - -11 - "":12 - -13 - -14 NAVARRA DRIVE CONDOMINIUMS DATE LOGGED LOGGED BY MICHAEL CREWS DEVELOPMENT 07-09-04 NSB SUBSURFACE EXPLORATORY LOG Plate No.7 f-J t" I I: I~ I. I. ; I. I, • J I I I. I:· I. '. , I: '. J I, I I I. Sample Location LABORATORY TEST RESULTS , Maximum Density/Optimum Moisture Description Maximum Dry Density (pc£) T-~ @ 3' to 10' Pale Brown, Silty, Fine to Medium Grained Sand 125.5 Direct Shear Angle of Apparent Internal Sample, Cohesion Friction Location (psi) (degrees) . *T-l @ 12' 75-32 **T-2 @ 3' to 10' 35.0 ' 25 * Sample at in-place density and moisture. ** Sample remolded to 90 percent ofmaximiun dry density and 3 percent over optimum moisture conterit. (All samples satmated during testing.) Plate No.8 WESTERN SOIL AND FOUNDATION ENGINEERING, INC. OP#mum Moisture Content' (percent) 10.5 , ._, .... ..~ F~ t··, I I. ~ I I, I I. I. , I. : I. I. I; I· I, I. I I I LABORATORY TEST RESULTS -Cont. Expansion Index Sample Initial Final Expansion Expansion Moisture Moisture Location Content (%) Content (%) Index Potential T-l @9Wto 12' 11.i 22.7 47 Low* T-2 @3'to 10' 8.2 19.3 30 Low* * Low expansion potential ranges fonn 21 to 50.' In-Situ Moisture and Density Dry Moisture . Sample . Density Content Location (pc£) (%) T-1 @'5' 105.8 16.3 T-1 @ 12' 107.8 14.6 T-2 @ 13' 107.7 17.7 T-4@5W 100.8 9.9 T-5 @6' 103.7 14.3 Plate No.9 WESTERN SOIL AND FOUNDATION ENGINEERING, INC.' f~:::; u t-' I I. I I, I. : I, - I,: I_! I, ' I, 1,- 1-. I: ._ J I .. I I_- I -- CONSOLIDATION CURVES Load in KIPS Per Square Foot 0.2 0.4 0.6 0.81.0 2 4 6-8 10 _16 0 ~ . 1 ~ .- """"c; en 2 h., ..... en ro..... CJ.) s:=-" -=:s::: ' ..... <:,;) :2 3 l I--'" CJ.) ~ -a... E co 4 en 0 " ........ " s:= CJ.) ~ 5 CJ.) Cl--~ I o~ REBOU D :z c:::> 6 ." ~ t:::::l ::::J c:::> en 7-:z c:::> c...::> 8 : 9 10 o Indicates percent consolidation at field moisture • Indicates percent consolidation afte.r saturation DATE: 07-29-04 NAVARRA DRIVE CONDOMINIUMS JOB NO. 04-01 ~07 BY: VWG T-2 @ 13 FEET Plate No.10 WESTERN SOIL AND FOUNDATION ENGINEERING, INC. f~ f; I ,I ~ I " I I: I. I~ I: I I, I: I, I>' I" I I I APPENDIX I WESTERN SOIL AND FOUNDATION ENGINEERING, INC. , ' I. ; 1 I. I I I, ' I: I I I: I, I; I. I I I SPECIFICATIONS FOR CONSTRUCTION OF CONTROLLED FILLS General Description: The construction of controlle4 fills shall consist of adequate geotechriical investigations, and clearing, removal of existing structures and 'foundations, preparation ofland to be filled, excavation of earth and rock from'cut area, compactIOn and control of the fill, and all other work necessary to complete the grading of the filled area to conform with the lines, grades, ,and slopes as shown on the accepted plans. Clearing And Preparation Of Areas To Be Filled: (1) All fill control projects shall have an investigation or a visual examination, depending upon the ' nature of the job, performed by a qualified soil engineer prior to grading. (2) All timber, trees, brush, vegetation, and other rubbish shall be removed, piled 'and burn~'d, or otherwise disposed ofto leave the prepared area with a finished appearance free from unsightly' debris. , ' (3) Any soft, swampy or otherwise unsuitable areas, shall be corrected by drafuage or removal of compressible material, or both, to the depths indicated on the pl~s or as directed by,th~ soil engmeer. {4) The natural ground which is determined to be satisfactory for the support of the :filled ground shall then be plowed or scarified to a 'depth of at least six inches (6") or deeper as specified by th~ soil engip,eer, and until the surface is free from ruts, hummocks, or other uneven features which would tend to ,prevent uniform compaction by the equipment to be used. (5) No fill shall be placed until the prepared native ground has been approved by the soil engineer. (6) Where fills are made on the hillsides 'with slopes greater than 5 (horizontal) to ,1 (vertical), honzontal benches shall be cut into firm undisturbed natural ground to provide lateral. and v.ertical stability. The initial bench at the toe of the fill ,shall be a least 10 feet in width on firm undisturbed natural ground at the elevation of the toe stake. The soil engineer shall q,eterm.in.e the width and frequency of all succeeding benches which will vary with the soil conditions and the steepness of slope. (7) (After the natUral ground has been prepared, it shall be brought to the proper moisture content and compacted to not less than 90% of maximum density, ASTM Di557-00. (8) Expansive soils may require special compaction specifications as directed in the report of geotechnical,inves~igation by the soil engineer. ' WESTERN SOIL AND FOUNDATION ENGINEERING, INC. I, I, I I I. I I I .. I. I I, I~ I, I, I, I I I· (9) The cut portions of building pads may require excavation and recompaction for density compatibility with the fill as directed by the soil engineer. Materials: The fill soils shall consist of select materials graded so that at least 40 percent of the material passes the No.4 sieve. The material may be obtained from the excavation, a borrow pit, or by mixing soils from one or more sources. The material used shall be free from vegetable matter, and other' deleterious substances, and shall not contain rocks or lumps greater than 6 inches in diameter. If . excessive vegetation, rocks, or soils with unacceptable physical characteristics are encountered, th~se materials shall be disposed of in waste areas designated on the plans or as directed by the soil engineer. If soils are encountered during the grading operation which were not reported in the report of geotechnical investigation, further testing will be required to ascertain their engineering properties. Any special treatment recommended in the preliminary or subsequent soil reports not covered herem shall becom~ an addendum to these specifications. No material of perishable, spongy, 'or otherwise unstable nature shall be used in the fills. Placing, Spreading And Compacting Fill Material: (I) . The selected fill material shall be placed in layers which shall not exceed six inches (6") when. compacted. Each layer shall be spread evenly and shall be thoroughly blade-mixed during the, spreading to insure uniformity of material and moisture in each layer. ' . . (2) When the moisture content of the fill material is below that specified by the soil engineer, water shall be added until the moisture content is near optimum as determined by the soil engineer to assure thorough bonding during the cO,mpacting process. (3) When the moisture content of-the fill material is above that specified by the soil engineer,. the ,fill material shall be aerated by blading and scarifying, or other satisfactory methods until the moisture content is near optimum as d.etennined by the soils engineer. , , (4) After each layer has been placed, mixed and spread evenly, it shall be thoroughly compacted to not less than the specified maximum density in accordance with ASTMDI557-00. Compaction sha1I be by means oftamping or sheepsfoot rollers, multiple-wheel pneumatic-tired rollers, or other types of rollers. Rollers shall be of such design that they will be able to compact the fill to the specified density. Rolling of each layer shall be continuous over its entire area'and the roller shall make sufficient passes to obtain the desired density. The entire area to be .filled shall be compacted to the specified density. WESTERN SOIL AND FOUNDATION ENGINEERING, INC. I I I I I I I I. I;· I·. I: I I I I (5). Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compacting operations shall be continued until the slopes are stable and until there is no appreci~ble amount ofloose soil on the slopes. Compacting of the slopes shall be accomplished by backrolling the slopes in increments of 3 to 5 feet in. elevation gain or by other methods producing sa~sfactory results. (6) Field density tests shall be made by the soil engineer for approximately each foot in elevation gain after compaction, but not to exceed two feet in vertical height between tests. The location of the tests in plan shall be spaced to give the best possible coverage and 'shall be taken no farther than 100 feet apart. Tests shall be taken on comer and terrace lot.s for each two feet in elevation again. The soil engineer may take additional tests as considered necessary to check on· the' unifonnity of compaction. Where sheepsfoot rollers are used, the tests shall be taken in the compacted material below the disturbed surface. No additional layers offill shall be spread until the field density tests indicate that the specified density has been obtained. (7) The fill operation shall be continued in six inch (6") compacted layers, as specified above;until the fill has been brought to the finished slopes and grades as shown on :the accepted plans. Supervision: Supervision by the soil engineer shall be made during the filling and compacting' operations so that helshe can certify that the fill was made in accordance with accepted specifications. The specifications and soil testing of sub grade, subbase, and base materials for roads, or other public property shall be done in accordance with specifications of the governing agency. Seasonal Limits: No fill material shall be placed, spread, or rolled during unfavorable weather. conditions. When the work is interrupted by heavy rain, grading shall not be resumed until field tests by the soil engineer indicate that the moisture content and density of the fill are as previously specified. In the event that, in the opinion of the engineer, soils unsatisfactory as foundation material are encountered, they shall not be incorporated in the grading, and disposition will be made at the . engineer's discretion. WESTERN SOIL AND FOUNDATION ENGINEERING, INC.' F'-' . :::; -.J f' I I. : I. ) I I I I, : I: I I I:· I· I, I .. ' 1 I I, APPENDIX II WESTERN SOIL AND FOUNDATION ENGINEERING, INC. I, I.,: I," I, I. I. I. , 1,1. I I, I~ I" I: I. I I I REFERENCES Greensfelder, RW., 1974, Maximum Credible Rock Accelerations from Earthquakes in California, California Division of Mines and Geology Map-Sheet 23 Kennedy, M. P., 1975 Geology of The San Diego Metropolitan Area, California, California Division of Mines and Geology, Bulletin 200 Kelmedy, M.P. and Welday, E.E., 1980, Recency and Character of Faulting Offshore Metropolitan San Diego, San Diego, California Division of Mines and Geology, Map Sheet 40. , '. Moore, G.W., and Kennedy, M.P., 1975, Quaternary Faults at San Diego Bay California, U.S. Geological Survey, Journal Research, Vo1. 3, pp. 589-595. Rockwell, T.K. 1989, Holocene Activity of the Rose Canyon Fault in S~ Diego Based, on.' Trenching Studies: Evjdence ofM6+ Surface Rupturing Earthquakes, in: The Seismic Risk in the San Diego Region: Special Focus on the Rose Canyon Fault System. Seed, H.B. and Idriss, IM., 1982, Ground Motions and Soil Liquefaction During Earthquakes, EERT Monograph Series , S1emmons, D.B., 1979, Evaluation of Geomorphic Features of Active Faults for Engineering , Design and Siting Studies, Association of Engineering Geologists Short Course Tan, S. and Kennedy, M.P., 1996, Ge~logic Maps of the Northwestern Part of San Diego'County, California: California Division of Mines and Geology, Open-File Report 96-02. Weber, Harold F. Jr., 1982, Recent Slope Failures, Ancient Landslides, and Related Geology of , The North-Central Coastal Area, San Diego County, California: California Division of Mines and Geology, Report 82-12. Wilson, Kenneth L., 1972, Eocene and Related Geology' of a Portion of the, San Luis Rey and Encinitas Quadrangles San Diego County, California: Masters Thesis, U.C. Riverside. WESTERN SOIL.AND FOUNDATION ENGINEERING, INC. 98062 NAVARRA ". . " A' 8°1 __ _ -----~= COllUVium ----.. -..,;.;._ Qt , PLATE NO.1 N 1 .. = 20 I QT A' 80 '10 GEOLOGIC CRO:SS SEOTION 50~-----------------------."-_--. -"~ .. --.--------------------------~SO SbALE: 1.11 =" 2(1) "h.:HORIZ. "1 " = 10 • VERT. ~ I APPROXIMATE LOCATION OF EXPLORATORY TRENCHES .. : Qt . TERRACE DEP'OSITS . .,.. NAVARRA JOB NO. 0.4-01-07 (8/04)" \l\tESTERN SOIL AND FOUNDATION ENGINEERING INC.