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HomeMy WebLinkAboutTract Map 3929 Lot 200 Preliminary Soils -- ....~ ,t ,,-"t, i-i'; -.,.~ , co- - , . PRELIMINARY SOIL INVESTIGATION for Lot 200; TR 3929 APN: 921-192-002 February 18, 1999 Prepared for: Teri L. Safe 40895 Bucharest Lane Temecula, CA 92591 (909) 676-2366 Prepared by: Gunvant Thakkar, P.E. 45712 Classic Way Temecula, California 92592 (909) 676-7541 . \\Z ~9z..1 l4r Zeo RECEIVED MAY 31999 CITY OF TEMECUUI ENGINEERING DEPARTMEi" !J "1"".. . . GUNVANT THAKKAR, PROFESSIONAL ENGINEER 45712 Qlassic Way, Temecula, California 92592 (909)676-7541 February 18, 1999 Teri L. Safe 40895 Bucharest Lane Temecula, CA 92591 (909) 676-2366 Subject: Preliminary Soil'nvestigation Lot 200; TR 3929 APN: 921-192-002 Dear Teri: In accordance with your request and authorization, this report presents the results of our !Soils investigation of the subject property located at 30045 Del Rey Road, l'emequla, California (see Site Location Map Figure 1). The purpose of the study was to evaluate the existing soil condition on the subject property , relative to the proposed development. . 1. Site Descriotion The property is located at 30045 Del Rey Road, Temecula, Riverside County, California, and consists of approximately 0.62 acres, and is mostly ac~ssible. The property is covered with native vegetation. :2. Prooosed develooment . It is our understanding that the property is proposed to have a single residence with attached garage. The site is relatively flat. The highest point on the, property is the southeast portion and declines to approximately a 5 percent grade. Ther-efore, no grading will be required to create: a pad. It is our llnderstanding that one or two story buildings utilizing wood frame and/or masonry block construction, with slabs-on- grades and continuous footings are proposed. Building loads are Z- c . . ~j ... '. assumed to be typical for residential structures. It is also our understanding that sewage disposal will be accommodated by a subsurface sewage disposal system. 3. Field Studies The field ~tudies conducted during our evaluation of the property consisted of the following: a. review of available geotechnical data in our files pe~aining to the site. b. field reconnaissance by a soils engineer. c. labqratory testing of selected representative soil samples. d. preparation of this report presenting our findipgs, conclusions, and recommendations. 4. Subsurface Investioation Laboratory Testino , A total of two samples were taken in order to determine the conditions of the near-sLJrface natural material. The samples were logged, in-place moisture ar;1d density of the exposed materials were recorded, and representative bulk and relatively undisturbed samples were collected for laboratory testing. ~ 5. Laboratory ,Testino a. Soil Classification Soils, were classified visually according to the unified soils classification system. The soils classifications are shown on . Appendix A. b. ~Soils!Density The ~eld moisture content and dry unit weights were determined for -each lundisturbed sample of the soils encountered in the samples. The dry unit weight was determined in pound per cubic foot and the field moisture content was determined as a percentage of the dry .unit weight. The results of this test are shown on Appendix A. .3 :!, .i_ ~ . . .. 6. GenerallSite Gradino No;grading is being proposed for this site. 7. Ground Water No:groundwater or evidence of seepage was encountered within the sampleslat the time and location of the sample taking. However, other conditions may be there that would effect the entire proposed project and final plans and specifications. 8. Consolidation / Collaose Potential Considering the on-site low in-place densities, the susceptibility for consolidation / collapse under the proposed load is anticipated within the upper th~ee feet throughout the site. 9. Conclusion and Recommendation a. General 1. Based on our field exploration, laboratory testing, and our soil engineering analysis, it is our opinion that the project site is suited for the proposed development from a soils engineering viewpoint. The recommendation presented below should be incorporated in the design and construction considerations. 2. Soils engineering and compaction services should be provided during the footing excavation to aid the contractor in removing unsuitable soils. 3. Ground water is not expected to be a factor in the development of the site. However, caving and sloughing may be anticipated to be a factor in all subsurface excavation and trenching. . 4.. At the time of preparation of this report, the proposed finished pad grades, location of any structures, type of structures and loadings were all of a preliminary planning nature. b. Demolition/Grubbing 1. Existing shrubs, and any miscellaneous construction materials and debris should be removed from the site. ~ ~,. i.l~. . . 2. Any previous foundation, cesspools, septic tanks, leach fields, or other subsurface structures, uncovered during the recommended removal should be observed by the soils engineer so that appropriate remedial recommendations can be provided. 3. Cavities or loose soils (including all trenches) remaining after demolition and site clearance should be cleaned out, inspected by the soils engineer. c. General Foundation Criteria The proposed structure may be supported on conventional spread, on continuous wall footings, provided that they are at least 12 inches wide, and 12 inches below the final approved grade with one # 4 rebar at the top and bottom or as designed by the structural engineer. FQotings may be designed for a maximum bearing pressure of 1500 psf. A friction coefficient for concrete on natural and compacted soils of 0.36 may be employed. The effects of seismic shaking can be mitigated through consideration of the parameters presented above and by design in accordance with the latest Uljliform Building Code and the Structural Engineers Association. The allowable bearing pressure may be increased by one-third w~en considering loadings of short duration such as wind or seismic forces. This foundation criteria is considered minimum and may be superseded by more restrictive requirements of the stnuctural engineers, architects, or governing agency. d. Concrete Slabs on Grade Sufficient fine grained materials exist within near surface earth m:;lterials to possibly create moisture 'problems. Therefore, we recommend that a moisture barrier be placed under any concrete slabs that might receive a moisture-sensitive floor covering. This mQisture barrier should consist of a 10-mil polyethylene vapor barrier sandwiched between a one inch layer of sand, top and bottom, to prevent puncture of the barrier and enhance curing of the concrete. Nominal reinfOrcement of the slabs with light six inch bYlsixinch, 10 gauge/10 gauge welded wire fabric is advisable. Slabs should be designed for any special loads, such as cOnstruction crane loads, if warranted. Large slabs should have :S . . " . . .. cr;:lck control joints on 10 foot centers and small slabs should have them on five foot centers. e. Expansive Soils Based on visual observations and field classifications, there does not appear to be any soils within the upper two feet of the surface w~ich appear highly expansive; however, if fill materials are imported to the site, it is recommended that expansion testing be performed upon the completion of grading to evaluate any expansion potentials. f. Lateral Loads Lateral loads in the near surface soils are: I Active 35 pounds per square foot per foot of soil depth (psflft) 64 psf/ft 250psf/ft - wood shoring 350psf/ft - concrete footings I At Rest : Passive Active means movement of the structure away from the soil. At rest, means the structure does not move relative to the soil (such as. a loading dock or building wall). Passive means the structure moves into the soil. The coefficient of friction between the bottom of It he footings and the native soil may be taken as 0.35. g. Trench Stability The near surface soil is a depth of 6 feet may not stand vertically for more than several hours when excavated as tension cracks or joints may be locally found in the soils associated with past seismic ac~ivity from nearby major faults. Trenches in excess of 5 feet in depth should have the sides laid back at 1: 1 or shored in acpordance with OSHA requirements. h. General Site Grubbing and Clearing 1. General . . All site grubbing and clearing should be performed in accordance with the standard grading and earthwork specifications outlined in Appendix C, or unless otherwise modified in the text of this report. (." , .:,;. . . . 2. Clearing and Grubbing The site should be clear of any vegetation and hauled off site. Any and all of the debris, and all the deleterious and oversized material should be carefully removed and also hauled off site. The soil should be over-excavated as described below. 3. Site Preparation The site will require removal of loose natural soils and fill materials (if found), based on field observation and laboratory testing. On all buildings that may have columns extending into the native materials, no preparations of soil is necessary when in place densities indicate 85 percent relative compaction beneath the footings providing all foundations are in natural soils. 4. Summary All grubbing and clearing should, at a minimum, follow the "Standard Grading and Earthwork Specifications" as outlined in Appendix C, unless otherwise modified in the text of this report. The recommendations of this report are based on the assumptions that all footings will be founded in properly compacted fill soil or natural dense soil as approved by the soils engineer. All footing excavations should be inspected prior to the placement of concrete in order to verify that footings are founded on satisfactory soil and are free of loose and disturbed materials 5. Investigation Limits The materials encountered on the project site and utilized in the laboratory are believed representative of the total area; however, soils materials may vary in characteristics between test excavations. Since our investigation is based upon the site materials observed, selective laboratory testing, and engineering analysis, the conclusions and recommendations are professional opinions. It is possible that variations in soil conditions could exist beyond the points explored in this investigation. Also, changes in the ground water condition could occur sometime in the near future due to variations in l .. '- . . , temperature, regional rainfall, and other factors. Should conditions be encountered during grubbing and clearing that appear to be different than those indicated by this report, the soils engineer should be notified. These opinions have been derived in accordance with current standards of practice and no warranties are expressed or implied. We since~ely appreciate this opportunity to be of service. If you have any questions concenning this report, please contact us at 909/676-7541. Very truly yours, ~~~~ Gunvant Thakkai, P.E. RCE'52856 Exp. "~'~/3Y02 _ .....,-....'! ~ ... ~." . . Enclosures: Figure 1: Site location map Plate 1: Sample location map Appendix A: Sample logs Appendix B: Laboratory test data Appendix C: Standard grading and earthwork specs. q l... /~ --- , \ I I 1 - ~ Sl'o "v~h" (f) e.: {)o.o 111 -...:: rn -;::'\- I") <~ ~ fir>; ." .h t, < .... :JJ l.~ YI1., C) .l> ~IA lJ :0<[ ,is - - PASEO \ \ Ov JW - ~W -- ~~~ DATE: '2.18- ~~ . , SITE LOCATION PLAN \0 , . -> ; . . DEL ICE"! ICO,qD o .,.48 I , - - --.. . ~ ~ ~ . 00 2 ~ . , o. LEGEND . APPROXIMATE SAM. LOCATION - \\ DATE: : SAMF>LE LOCATION PLAN , '.J . . APPENDIX A Sample Logs \2.- . . 'r~/04. "\lmb.r, SAFE "3/0. I &It,..."on I -Z.() TttflOII tlo. ..[ lProl.Gt H.-"n. - ltqvl....._t .., It aBOTECt-lNICAl. DI!l!lCnIPTION . ~ ! I "I ! f J~ a ~ l"n~ trY . '. (iT Z -/2 ' '}9 i '1 t il III ! ..Gr Da'e - i II g j- ..mpI~ It)' '" . .- .., SRN i> r , DG. ilee , ..' , ~ ct .- i ~ ' I .- .........~ ~ _. . .. 0' . O' .- . . . ,- ., ...: ,- .- .- - .- - - i . - - I ~~.., Loa trend - .ca'.: \-"5' 0 f- . Test SymbolS . f- - ... B . .....\11 .~"'.'. , , ,,- R'n, I.""r. .' , . . , . '. , '- &C - S,.tfl4 c.". I ' , t I , . I '- Me. "nWf\wM CHftf;ICJ' . - - Os.. "'...... 51.. , ! - - se - 80'- r...........'-"'I - .... .~.. Ii' . e'.o....rv.. 11't'C1.. - .. ns - fttmol4M 5,1.... - - - .. - - ! - . . . I j . t r . , . r ...";.. .. 1'~ 'reRAA - . ~ .: ' GEOSCIENCES ''',.~ . " . f r.o.. 8Dc t<'fltlf ! - 11."..... ,...,... C"A ,,.HJ - .. I \?::> . . ; ProJect N.J'n. ~ ''-'toS04:' U",mb"r SAFE ''3 to, I :., III...'..... I -2'.0 Tt-'t No. ~ e:qvlpofteftl .,. t I~ aBOTECHNICAL P&.CnIPTIOH . !j, :s. J it ! a f I.oft"d '"' . "0 ST 'Z-12 "'J 9 il " a. J U III .. ..GT De,,, ---- i Ii i ;j i- ! 1-.01.-1 .., '" ~ , . , Yi,H 1) ;r- DG. L 7: /,;2. , '7 . - 9i .'-" .r , .' :, ~.. " (f) ., -. '" , , .. ~ . .. . .. " . . I: .. I :J '" I - t- ,0 , ,- I .~ .- .- GRAPHIC LOG trencl- _cat.: '"..5' - . >- . Test Symbol a I >- \ i- .. "'\fl aMft_'. I , , , . '. ~ A. ...... """'" . . ' . I I- eo. SMoe C.... I ,.. I I \ , --. I , '- MQ.. "'"&Il'I\tffft CNMU,. :.. - os.. 4...... SI.. I. - - se - a.... ."""......,u - ......n - e' . ed........" ..... .. ns - flIcmoJdM 1,1..., I i... - "'" .. - . - I . ..~. . \ I . . . , . , . . . il . , , . . 1'~ TERRA - ~ ~ . GEOSCIENCES ;1 ''',.~ . f r.o. 8IDiC ,(Ilt9 - ~I"."'" 1....... C"f' ')o'~J - V\ ", . " . APPENDIX B Laboratory Test Data . \'5 140 10 II 2' BORING /TRENCH No. 1 SAMPLE No. DEPTH ft. , SOIL C lASSlFlCATlON ~M I Sfl~E I PROJECT I , METl-IOO: ASTM 01557 00 ASTM 0698 0 PROCEDURE: Aoo sO C 0 PREPARATION: MOIST 00 ORYO RAMMER: MANUAL 00 .. MECHANICAL CIRCUU>.R 0 ." SECTOR 0 MECHANICAL ~ .\1 ,.>. , -' , SIEVE DATA: I , , RETAINED ON No.4 SIEVE 0.0 7- , , RETAINED ON 3/8 in. SIEVE 0.0 7- . RETAINED ON 3/4 in. SIEVE 0.0 7- , 0 , , . Ife.s , MAXIMUM DRY UNIT WEIGHT pef. , I . OPTIMUM MOISTURE 10.G 7- , , I 5 , , , , , , , I , , , I 0 I , I , , - ! \ I , ~ , , I ~,+ , , , ,. . , 5 . , . , , I I . . - - , - , -- - , , - . , . , , I 1- - - - . .. - - -- ; I . - I 0 , , I , - I - , , I - 95 I I ; I > I - I ~ I . . , , , , , 90 , o 5 10 15 20 25 30 35 135 130 125 12 11 11 10 , Location A . . Maximum Drv Density Test Results Soil. Descriotion Sandy DG Light brown Lowl moisture Maximum Dry Density (oct) 128.5 Optimum Moisture 10.5% \l .' . . . APPENDIX C Standard Grading and Earthwork Specifications \~ . . STANDARD GRADING AND EARTHWORK SPECIFICATIONS These specificati.ons present our recommendations for grading and earthwork. No deviation from these specifications should be permitted, unless where specifically!superseded in the geotechnical report of the project or by written communications isigned by the geotechnical consultant. Evaluation performed by the consultant during the course of grading may result in subsequent recommendations which could supersede these specifications or the recommendations of the geotechnical report. 1.0 General 1.1 The geotechnical consultant is the owners or developers , representative on the project. For the purpose of these specifications, observations by the geotechnical consultant include observations by the soils engineer, geotechnical engineer, . engineering geologist, and those performed by persons employed by, land responsible to the geotechnical consultant. 1.2. All ylearing, site preparations, or earthwork performed on the project shall be conducted and directed by the contractor under the supervision of the geotechnical consultant. 1.3 Th~ contractor should be responsible for the safety of the project and. the satisfactory completion of all grading. During grading, the contractor should remain accessible. 1.4 Prior to commencement of grading, the geotechnical consultant shall be employed for the purpose of providing field, laboratory, and office services for conformance with the recommendations of the geo.technical report and these specifications. It will be necessary that the geotechnical consultant provide adequate testing and observations so that he may determine that the work was accomplished as specified. It shall be the responsibility of the contractor to assist the geotechnical consultant and keep him apprised of work schedule and changes so that he may schedule his personnel accordingly. 1.5 It should be the sole responsibility of the contractor to provide ade~uate equipment and methods to accomplish the work in acc<:>rdance with applicable grading codes or agency ordinance, these specifications, and the lilPproved grading plans. If, in the opinion of the geotechnical consultant, unsatisfactory conditions, suc~ as questionable soil, poor moisture condition, inadequate compaction, adverse weather, etc. are resulting in a quality of work less. than required in these specifications, the geotechnical \q . . con~ultant will be empowered to reject the work and recommend that!construction be stopped until the conditions are rectified. 1.6 It is ,the contractor's responsibility to provide access to the geotechnical consultant for the testing and/or grading observation purposes. This may require excavation of the test pits and/or the reloyation of grading equipment. 1.7 A final report shall be issued by the geotechnical consultant attesting to the contractor's conformance with these specifications. 2.0 Site Preoaration . 2.1 All v~getation and deleterious material shall be disposed of off site. This. removal shall be observed by geotechnical consultant and con91uded prior to fill placement. 2.2 Soil,' alluvium, or bedrock materials determined by the geotechnical consultant as being unsuitable for placement in compacted fills shall be removed by the site or used in landscape areas as determined by the geotechnical consultant. Any material inco'rporated as a part of compacted fill must be approved by the geotechnical consultant prior to fill placement. 2.3 After the ground surface to receive fill has been cleared, it shall be scar.ified, disked, or bladed by the contractor until it is uniform and freelfrom roots, hollows, hummocks, or other uneven features which may prevent uniform compaction. Thelscarified ground surface shall then be brought to optimum moisture, mixed as required, and compacted as specified. If the scarified zone is greater than 12 inches in depth, the excess shall be removed and placed in lifts restricted to 6 inches. Prior to placing fill, the ground surface to receive fill shall be observed, tested, and approved by the geotechnical consultant. 2.4 Any lunderground structures or cavities, such as cesspools, cisterns, mining shaft, tunnels, septic tanks, wells, pipelines, or others, are to be removed or treated in the manner prescribed by the geotechnical consultant. 2.5 In cut fill transition lots and where cut lots are partially in soil, colluvium, or unweathered bedrock materials, in order to provide uniform bearing conditions, the bedrock portion of the lot, extending 2,0 ; . . , . . . ; a n;linimum of 5 feet outside of building line, shall be over- excavated a minimum of 3 feet and replaced with compacted fill. 3.0 Comoacted Fills 3.1 Materials to be placed as fill shall be free of organic matter and other deleterious substances, and shall be approved by the geqtechnical consultant. The soils of poor gradation, expansion, or str~ngth characteristic shall be placed in areas designated by the geqtechnical consultant or shall be mixed with other soils to serve as ~atisfactory fill materials, as directed by the geotechnical consultant. 3.2 Rock fragments less than 6 inches in diameter may be utilized in the:fill, provided: a. They are not placed in concentrated pockets. b. There is sufficient percentage of fine grained materials to surround the rocks. c. The distribution of rocks is supervised by the geotechnical consultant. 3.3 Roqks greater than 6 inches in diameter shall be taken off site or placed in accordance with the recommendation of the geotechnical con!,ultant in areas designated as suitable for rock disposal. 3.4 Materials that is spongy, subject to decay, or otherwise unsuitable, should not be used in the compacted fill. 3.5 Re~resentative samples of materials to be utilized as compacted fill shal' be analyzed by the laboratory of the geotechnical consultant to determine their physical properties. If any material other than thatipreviously tested is encountered during grading, the appropriate analysis of this material shall be conducted by the geotechnical consultant as soon as possible. 3.6 Mat~rials used in the compacting process shall be evenly spread, watered, processed, and compacted in thin lifts not to exceed 6 inch.es in thickness, to obtain a uniformly dense layer. The fill shall be placed and compacted on ;:I horizontal plane unless otherwise approved by the geotechnical consultant. 2-\ ,~ , ,.. . . ~ 3.7 If the moisture content or relative compaction varies from that required by the geotechnical consultant, the contractor shall rework thel fill until it is approved by the geotechnical consultant. 3.8 Each layer shall be compacted to 90 percent of the maximum density, in compliance with the testing method specified by the controlling government agency or ASTM 1557-78, whichever applies. If c9mpaction to a lesser percentage is authorized by the controlling governmental agency because of specific land use of expansive soil condition, the area to receive fill compacted to less tha(l 90 percent shall either be delineated on the grading plan or app,ropriate reference made to the area in the geotechnical report. 3.9 All fill shall be keyed and benched through all topsoil, colluvium, alluyium, or creep materials, into sound bedrock or firm materials where the slop receiving fill exceed a ratio of 5 horizontal to 1 vertjcal, in accordance with the recommendations of the geotechnical consultant. 3.10 The, key for side hill fills shall be a minimum width of 15 feet within bedrock or firm materials, unless otherwise specified in the soils report. 3.11 Sub, drainage devices shall be constructed in compliance with the ordinance of the controlling government agency or with the recommendations of the geotechnical consultant. 3.12 The, contractor will be required to obtain a relative compaction of 90 perqent out of the finished slope face of fill slopes, buttresses, and sta~i1ization fills. This may be achieved by either overbuilding the slope and cutting back to the compacted core, by direct compaction of the slope and cutting back to compacted core, by direct compaction of the slope face with suitable equipment, or by any oth~r procedure which produces the required compaction approved by t~e geotechnical consultant. 3.13 All fi.1I slopes should be planted or protected from erosion by other met~ods specified in the geotechnical report. 3.14 FilI-over-cut slope shall be properly keyed through topsoils, colluvium, or creep materials into rock or firm materials, and the transition shall be stripped of all soils prior to placing fill. t.-z.. ~ . I' -. ,. ~ . . 4.0 Cut Slooe 4.1 The geotechnical consultant shall inspect all cut slopes or vertical intervals not exceeding 10 feet. 4.2 If l:Iny conditions not anticipated in the geotechnical report, such as perched water, seepage, lenticular, or confined strata of potentially adverse nature, unfavorably-inclined bedding, joints, or fault planes encountered during grading, these conditions shall be analyzed by the engineering geologist, and recommendations shall be made to mi~igate this problem. 4.3 Cu.t slopes that face in the same direction as prevailing drainage shall be protected from slope wash by a non-erodible interceptor swell placed at the top of the slope. 4.4 Unless otherwise specified in the geotechnical report, no cut slopes shall be excavated higher or steeper than that allowed by the ordinance of controlling governmental agencies. 4.5 Drainage terraces shall be constructed in compliance with the ordinances of controlling governmental agencies, or with the recommendations of the geotechnical consultant or engineer geologist. 5.0 Trench Backfills 5.1 Trench excavations for utility pipes shall be backfilled under the supervision of the geotechnical consultant. 5.2 After the utility pipe has been laid, the space under and around the pipe shall be backfilled with clean sand or approved granular soil to a gepth of at least 1 foot over the top of the pipe. The sand backfill shall be uniformly jetted into place before the controlled backfill is pl~ced over the sand. 5.3 The onsite materials, or other soils approved by the geotechnical cqnsultant, shall be water and mix as necessary prior to placement in I lifts over the sand backfill. 5.4 The controlled backfill shall be compacted to at least 90 percent of the maximum laboratory den$ity as determined by ASTM D1557-78 or, the controlling governmental agency. tP ~- ..~, " . . -. ~ ;; 5.5 Fill,density test and inspection of the backfill procedures shall be made by the geotechnical consultant during backfilling to see that proper moisture content and uniform compaction is being maintained. The contractor shall provide test holes and exploratory pit$ as required by the geotechnical consultant to enable sampling and testing. 6.0 Gradino Control 6.1 Inspections of the fill placement shall be provided by the geotechnical consultant during the progress of grading. 6.2 In general, density tests should be made at intervals not exceeding 2 fElet of fill height or every 500 cubic yards of fill placed. This criterion will vary, depending on the soil condition and size of the job~ In any event, an adequate number of fill density tests shall be mape to verify that the compaction is being achieved. 6.3 Deljlsity tests should also be made on the surface material to receive fills as required by the geotechnical consultant. 6.4 All ~Ieanup, processed ground to receive fill, key excavations, sub.drains, and rock disposals should be inspected and approved by the geotechnical consultant prior to placing any fill. It shall be the,contractors responsibility to notify the geotechnical consultant when such areas are ready for inspection. 7.0 Construction' Consideration 7.1 Ero~ion control measures, when necessary, shall be provided by the :contractor during grading and prior to the completion and con,struction of permanent drainage control. 7.2 Upon completion of grading and termin.ation of inspectors by the . geo.technical consultant, no further filling or excavating, including that necessary for footings, foundations, large tree wells, retaining . walls, or other features shall be performed without the approval of the geotechnical consultant. 7.3 Care shall be taken by the contractor during final grading to preserve any berms, drainage terraces, interceptor swells, or other devices of permanent nature on or adjacent to the property. ~A..