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HomeMy WebLinkAboutCT 73-30; PROPOSED APARTMENT SITE, LA COSTA DE LA PLAYA; SOIL INVESTIGATION; 1973-05-221o.;;, •• l • SOU THE R N CAL I FOR N I A .. EST I N G L A a 0 RAT 0 R y-INC 0 R F' 0 RAT E O' 6280 RIVERDAL.E ST. SAN DIEGO, CAL.IF. 92120 • TEL.E 280-4321 • P.O. 80X 20627 SAN DIEGO, CALIF. 92120 73-038 HIGHWAY 111 PAL.M DESERT, CAL.IF. 92260. TELIC 346-1078 678 ENTERPRISE ST. ESCONDIDO, CALIF. 92025 TELE 487-2662 Mr. Bob Bryan 2079 Garnet street San Diego, California May 22, 1973 92109 SCT 312260 Report No. 1 SUBJECT: Soil Investigation, Proposed Apartment Site, La Casa De La Playa, 256 Juniper Street, Carlsbad, California. Dea.r Mr. Bryan: In accordance with your request, we have performed an investiga- tion of the soil conditions at the subject site. The results of the investigation provides the required information to design the footings for the proposed structures. We are transmitting herewith a report of this investigation. In general, we found the site to be suitable for development, pro- vided the recommendations contained in this report are followed.- If you have any questions after reviewing our report, please do not hesitate to contact this office. This opportunity to be of service is sincerely appreciated. Respectfully submitted, SOUTHERN CALIFORNIA TESTING LAB., INC. MRF: jle Charles H. Christian, R. C. E. cc: (5) Submitted (1) SCTL, Escondido ... '. " INSPECTION • TESTING " RIESEARCH • DEVELOPMENT 6280 R i v e r d a I eSt. gSa n Die g 0 I C a Ii for n i a 921 20 • Ph 0 n e 280 ~A 3 21 . ======================================================~==============- ALI. REI'ORTS ARE !!UrlMITTEO AS THE CONFIDI!:NTIAL I'ROPERTY OF CLIENT". AUTHORIZATION FOR PUI>LICATION OF OUR REPORTS, CONCLUSIONS, OR 'EXTRACT" FROM OR REGI\.RDING THEM IS RESERVED PENOING OUR WRITTEN APPROVAL AS I\. MUTUAL PROTECTION TO CLIENTS, THE PUBLIC AND OURSELVES. REPORT OF SOIL' INVESTIGATION PROPOSED APARTMENT SITE LA CASA DE LA PLAYA 256 JUNIPER STREET; CARLSBAD, CALIFORNIA PROJECT DESCRIPTION AND SCOPE This report presents the results of our soil·inve.stigation for the pro- posed apartment site, La Casa De La Playa, located at .256 Juniper Street, Carlsbad, California. It is our understanding that a two story apartment building is planned for the site. The site configuration and trench locations are shown on Plate No. 1 of this report. This soil. investigation was undertaken to determine the phySical charac- teristics of the prevailing soils and to provide information for site preparation and foundation design. FINDINGS AND RECOMMENDATIONS The site is relatively level with drainage in the easterly direction. The soil at the site is homogeneous, nonexpansive, brown silty s~nd. , . ... ---" .... ,., .. ~ .. _~ ....... -.... ,..; , .. e, SCT 312260 May 22, 1973 P~ge Two Conventional spread footings founded a minimum of 18 inches below the adjacent finish grade are recommended for support of the proposed struc- ture. Continuous footings should have a minimum width of 12 inches. Based on past experience with similar soils in the area of the subject site, it is our opinion that the footings for the proposed structure may be designed for an allowable soil bearing pressure of 1,400 psf. The above allowable stresses may be increased by one third for wind and/or seismic loading and should be decreased by one fourth for dead load only~ Anticipated total and/or differential settlement may be considered negligible provided the recommendations presented in this report are followed. Active and passive soil pressures for the destgn of earth retaining struc- tures will be furnished by this office upon request should this information be necessary. Earthwork and grading for the project 'should be accomplished in accordance with the attached Recommended Grading Specifications and Special Provisions. Structural backfill should be compacted to a minimum relative compaction of 90 percent as determined by A.S.T.M. l557-66T, Method C. ' It is recommended that the footing excavations be inspected by' a represen- tative of this office prior to pouring concrete in order to verify the subsurface soil conditions determined by the soil investigation. , , . . -: SCT 312260 May 22, 1973 P~ge Three A subsurface exploration was made at the location indicated on the attached Plate No.1 on May 18, 1973. This exploration consisted of a trench dug by means of a backhoe. In addition, visual examination was made of an existing excavation under a recently demolished single story woodfra~~ , building. These excavations were carefully logged. These logs are pre~ sented on the attached Plate No.2. The soils are described in accordance with the Unified Soil Classification System as illustrated on the attached simplified chart. In addition, a verbal textural description, the wet color, the apparent moisture, and the density or consistency are given on the logs. Soil den~ities for granular soils are given as either very ,loose, loose, medium dense, dense or very dense. The consistency of silts or clays are given as either very soft, soft, medium stif.f, stifL, very stiff or hard. , ." . " :- I j I . f 1 ! ,....,._...-~l, ... -.-.-----------------------------~~ ,,:':l r---------~--4 --~ i r£EIVC/-I LDCATIOA/ SOUTHERN CALIFORNIA TESTING LABORATORY, INC. 6280 RIVERDALE STREET SAN DIEGO. CALJFORNIA 92120 PLOT PLAN Proposed Apartment Site La Casa De La Playa • Juniper s-treet Carlsbad, California BY MSC DATE 5/22/73 JOB NO •. 312260 PLATE NO. 1 . -.. 1.' ~. , , , ( I , e ·e. .-, TRENCH NUMBER 1 0 CLASS DESCRIPTION .. · SM Brown, Dry, Loose;to Medium Dense, -· SILTY SAND -' · · SM Brown, Humid, Dense·to Very Dense, r . SILTY SAND . : · · 5-· . .. · , -, · , '. · -· -, · . · · j · -, · , 10 0, CLASS . . '.. . - · . · · -, , -' ... - SM TRENCH NUMBER 2 DESCRIPTION Brown, Humid, Dense to Very Dense,· SILTY SAND · . 5~~~--~------------------------------- ~: Sample Location SOUTHERN CALIFORNIA TESTING LABORATORY, INC. 6280 RIVERDALE STREET SAN DIEGO. CALIFORNIA 92120 TRENCH LOGS Proposed Apartment Site Casa De La Playa Juniper Street Oceanside, California BY MRF DATE - .. 5/22/7.'J· JOB NO. 312260 PLATE NO. 2 ,. ! t . l . '~PPENPIX A, PAGE I JOB NO. ___ 3~J~2~~~~_ DATE ~ 5/ii/73 ----~~--~~~ RECOMMENDED GRADING SPECIFICATIONS GENERAL PROVISIONS GENERAL INTENT: The intent of these specifications is to establish procedures for clearing" compacting natural ground, preparing areas to be filled and ~lacing and co~­ pacting fill soil to the lines and grades shown on the accepted plans. The recommendations contained in the preliminary soil investigat~on report and/or the attached special provisions are a part of the recommended grading speci- fications and shali supersede the provisions contained hereinaft,er in the case of conflict. INSPECTION AND TESTING: A qualified soil engineer shall,be employed to inspect ahd test the earthwork in accordance with these specifications. It will be'necessary that the $oil engineer or his represerltativ~'~r6vide adequate inspe~tion so that ~e may certify' .that the work was or was not accomplished as specified. It shall be the responsibility of the contractor to assist the soil engineer and to keeI? him appraised of work schedules, changes and new information and d<;lta so that he may make these certifications. If, in the opinion of the soil engineer, substandard conditions are encount- ered, such as questionable soil, poor moisture control, inadequa'te c'ompaction" adverse weather, etc. > he will be empol'lered to either stop construction ,until .the conditions are remedied, or corrected or recommend rej ection' of the work. Soil tests used to determine the degree of compaction will De performed in accordance with the following American Society for Testing and Materials test methods: . , Maximum Density and Optimum !v10isture Content -A.S.~.M. D-1557-70. :.'. Density of Soil In-Place -A.S.T.M. D-1556~64. --. , ~ . -., . ~ APFEND1X A, PAGE 2 , . JOB NO.' 312 2-. DATE_--=5~/-=·2=2~/7-,-,3",--__ -PREPARATION OF AREAS TO RECEIVE FILL: _ Al~ vegetatioh, brush and debris shall be removed, piled and burned or other-- wise disposed of. After clearing, the natural ground shall be scarified to a depth of 6", brought to t~e proper moisture content, compa6ted and tested for the minimum density specified in the special provisions or the recommendations contained in the preliminary soil investigation report. •... .. " t . When the slope' .. of the natur.al, ground receiving fill' exceeds 20% (5 ,horizontal to 1 vertical), the 9riginal ground shall be stepped or benched .. Benc~es shall be cut to ~ firm 'competent soil condition. The lower bench shall be at least 10 feet wide and all other benches at least 6 feet wide. The horizontal por- tion of each bench shall be compacted prior to receiving fill as specified hereinbefore for compacted natural ground. Ground slopes flatter than 29% shall be benched when considered necessary by the soil engineer. : FILL IYIATERIAL: Materials placed in the fill shall be approved by the soil engineer and shall be free of vegetable matter and other deleterious substances. Granular soil shall contain sufficient fine material to fill the voids. The definition and disposition of oversized rocks, expansive and/or detrimental soils are covered ~ in the special provisions .. Expansive soils, soils of poor gradation or -strength characteristics may be thoroughly mixed with other 60ils to provide -satisfactory fill material, but only with the explic,i t consent of the soil _ engineer. ~ ". : .. ' ~ PLACING AND COMPACTION OF FILL: . ~.~: ::":;: ~ '. . ; .. :;.~.-: c • .. . . Approved fill material shall be placed in areas prepared to receive fill in ( ,layers not to exc'eed 6 inches in compacted thicknes·s. Each layer shall. have .. a uniform moisture content in the range that will allow the compaction effort .' .' '~. . ',' '. , . ., . ~ .... , . . .. -AP.PEND~X A, PAGE 3 JOB NO. ~" 3122. DATE __ ---'S/'-.2_2..;./_1_.3. ....... ____ .,..... -to be efficiently applied to achieve the specified degree of compaction. _ Each layer shall be uniformly compacted.to a minimum specified density " -with adequately sized equipment, either specifically designed for soil compaction or of proven reliability. The minimum degree of compaction to be achieved is specified in either the special provisions or the re- -commendations 'contained in the preliminary soil invest'igation report •. :-:Field tests and inspections to check the degree of compaction of the 'fill .. will be taken by the soil engineer or his representative. The location ~andfrequency of the tests shall be at the soil engineer's discretion. In ; general, the density tests will be made at an interval not exceeding 2 feet ~~n vertical rise and/or 500 cubic yards of embankment. :: SEASON LIMITS: Jill shall not be placed during unfavorable weather conditions. When 'work -is interrupted by heavy rain, filling operations shall not be resumed until ::the.:..proper moisture content and density of the fill, has been acbiev'ed. Dam- .~ge resulting from weather shall be repaired before acceptance of work. ~NFORESEEN CONDITIONS: ~n the event that conditions are encountered during the site preparation =and construction that were not encountered during ,the preliminary soil in- 7Vestigation, Southern California Testing Laboratory, Inc. assumes no respon- ::sibil'ity for conditions encountered which differ from those conditions found 3and described in the preliminary soil investigation report. :-;.... • ;A • .,,: ';'.: • • • '» • , • "0 .- '. ' '.-. .. ' , -.' " , ,. ,,' ! .~ • -........ , . ~ : '" . --: " • > ~ • ; .... ~ . , . .... . " . . '--}: .. , .' ~'. ' .. ,:" " -. '. ~.. . '. _0_, . . . . :... ", 0.·_:.-._ ...... _, .-__ , .............. -, ........ _. . ! -~.-, -; • ~ ..... -' • ..:c:-'.:..'.." -'-.. ----'..---""''''''-~~ • RECOMMENDED GRADING SPECIFICA~IONS SPECIAL PROVISIONS The minimum des:r..ee"of compaction to be obtained in compacting natural ground and'in the compacted fill shall be 90 percent. Q.e.tr.imental.ly ex~ns.ive soils is defined as soil which will swell more than 3 percent against a pressure of 150 pounds per square foot from a condition of 90 percent density and optimum moisture content to saturation. oversized ... f,ill material is defined as rocks or lumps over six inches in diameter. At least 40 percent of the fill soil shall pass through a No.4 u.S. Standard Sieve. , , ' . " , " ,,' . ~­, ,,- " ' .. : '-"", >, , :~ . . l' -,-;- ,; • UNIFIED SOIL CLASSIFICATION CHART SOIL DESCRIPTION GROUP SYMBOL 1. COARSE GRAINED, More than half of material is larger than No. 200 sieve size. GRAVEL~ CLEAN GRAVELS GW More than half of coarse fraction is larger than No. 4 GP sieve size but smaller than 3". GRAVELS WITH FINES GM (Appreciable amount of fines) GC §ANDS CLEAN SANDS SW More than half of coarse fraction is SP smaller than No. 4 sieve size. SANDS WITH FINES SM (Appreciable amount of fines) SC 11. FINE GRAINED, More than half of material is smaller than No. 200 sieve size. SILTS AND CLAYS Liquid Limit less than 50 SILTS AND CLAYS Liquid Limit greater than 50 HIGHLY ORGANIC SOILS ML CL OL MH CH OR PT TYPICAL NAMES Well graded gravels, gravel- sa'nd mixtures, li tt"le or no fines. Poorly graded gravels, gravel· sand mixtures, little or no fines. Silty gravels, poorly graded gravel-sand-silt mixtures. Clayey gravels, poorly graded gravel-sand, clay mixtures. well graded sand, gravellY sands, little or no fines. Poorly graded sands,gravelly sands, little or no fines. Silty sands, poorly graded sand and silt mixtures. Clayey sands, poorly graded sand' and clay ~ixtures. Inorganic silts and very ~~. fine sands, rock flour, sandy silt or clayey-silt-sand mixtures with slight plast- icity Inorganic clays of low to, medium plasticity/gravelly clays, sandy clays,silty Clays, lean clays. Organic silts and. organic silty clays of low plasticity Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, 'elastic silts. Inorganic clays of high 'plasticity, fat clays. Organic claYS or medium to high plasticity. Peat and other highly organic soils ... SOUTHERN CALIFORNIA TESTING LABoRATORY