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Home My WebLink AboutCT 75-04; La Costa Estates North Lot 1; Soils Report Preliminary; 1985-10-29SAN MARCOS ENGINEERING ClYlL LltOlNTC”,. SO,” d ce”N~*I,oM PRELIMINARY SOILS INVESTIGATION . REPORT AND FOUNDATION RECOMMENDATIONS PROJECT: PROPOSED RESIDENTIAL HOUSE LOCATION: LOT #1 CARLSBAD TRACT 75-4 LA COSTA ESTATES NORTH MAP 8302 CANDIL PLACE, CARLSBAD, CA, R,E, HUGHES RtE, HUGHES CONSTRUCTION CO, P,O, Box 1146 'VISTA, CA. 92083 . . 380 MULsE*I” oawc S”,ll . SAN Y*mcOs. CA 9ZOSP lc3ls.l 704.0111 SAN MARCOS ENGINEERING 3.90 ImLBEBBY D!lIM, SUITE B SAII HARUB, CA 92x9 (619) 744-0111 Civil EngIneera * Plannera * Land Developaent * Surveya l blla and Foundrtloa EngInewIng October 29, 1985 Mr. R. E. Hughes R. E. Hughes Construction Co. P. 0. Box 1146 Vista, Ca. 92083 Re: Lot No. 1 La Costa Estates North Hap 7637 Candil Place Carlabad, California Dear Mr. Hughes. As per your request, we have performed a preliminary soils investigation at the above referenced site and this report is presented as regards our opinion of the site soils engineering factors that may affect your pro3ect. Description of Site ------ ---- -- ---- The pro]ect site is located southwesterly of the cul de sac of Candil Place in Cerlsbad, California. The site is a graded pad uhich is vacant at the present time. Some rock outcrops can be,found at the site. The site la relatively clean of wild vegetation, being recently cleared. Plate 1 ahowa the Vicinity Hap. -- 1 SAN MARCOS ENGINEERING civil. soils and foundations Candil Place Pro)ect,Soils Report, Cont'd... DppSrLption of Prolect ---_ -- --- --- The pro]ect is for the construction of a single fainily residential house structure of frame construction with tile roof and stucco wall. No heavy loadings are expected at the pro]ect site. The house will be two stories. There will be minimum grading of the site to for-s a house pad. Puress Of &he Sell5 Inveeflsatinn The purpose of this soils investigation is to determine the physical characteristica of the existing site aoile and to make .a report and foundation recommendation. TEE Soils Inveatiqation Program ----- ----_-- ----- _-- --_ The soils investigation program consists of an ocular observation of the site surface and near surface soils and the conduction of a subsurface exploration drilling. The purpose of the observation of surface and near surface soils is to detect any obvious surface soils instability caused by erosion or tension cracking of the exieting soils or landslides. The subsurface soils exploration program aims to 2 SAN MARCOS ENGINEERING civil, soils and foundations Candil Place Prolect, Soils Report, Cont'd... determine the characteristics of the subsurface soils especially at the founding elevations. Finding= ---_-- The existing site soils appear to be stable. No obvious signs of soils cracks or failures were observed. No erosion problem was detected. . Subeurface Soila Two (2)) test pit excavations were performed at site at the approximate locations indicated in Plate 2. The test pit excavations were done manually and marked as T-l b T-2. The soils encountered at site were visually identified and classified in accordance with the Unified Soils Classification System as shown in Appendix E of this report. The soils encountered were described and the identification logged. The log of the aoils are shown in Platee 3 and 4. Bulk samples were brought to the lab for further identification, classification and testing. The pro]ect site generalized soils profile which can be inferred from the test pit excavation is described as about 6" to 18" of medium compact to compact Sandy Clay 3 SAN HARCOS ENGINEERING civil, soils and foundations Candil Place ProJect, Soils Report, Cont'd... with some trace of shale rock fragments and overlying deaintegreted to competent shale rock. The rock sppears to be rippeble with machines in the upper surfaces, and appeara to become harder with depth. If deep excavations are required for construction of structures planned at site, it may require rock blasting. The vertical and horizontal limits of rock could not be ascertained at this tine. To get this information, it will require a more detailed subsurface exploration. The existing Sandy Clay aoile are expansive in our estimation and experience of similar soils in the area. Laboratory Sgile Testing --------- -_---- A maximum dry density test wae made of the Sandy Clay soils and the result indicate the soil to have a maximum dry density of 117 pcf at an optimum moisture content of 12x co~c1usIo!! an4 Foundc!Llon Eennm!!!es&&lnse 1. It is our opinion that the existing soila can safely support the proposed structure planned for the site, however, the following recommendations should be observed during the design and 4 SAN HARCOS ENGINEERING civil, soils and foundations Candil Place Prolect, Soils Report. Cont'd... construction of the etructure. 2. The site should be cleared of all weeds, trash, vegetation and other deleterious materiala within the limits of construction prior to grading operations. The Earthwork Specifications found in Appendix A of this report forms part of this recommendation. 3. We recommend the proposed structure to be founded with atandard s0il bearing footings with an allowable soil bearing pressure of 1800 paf. The bottom of the footings should be founded to at least 24" below existing aground surface or ad JaCent finish grade. Perimeter wall footings should be at least 18" wihe and continuously reinforced with at least l-#S bar placed 3" above the bottom of the footing and l-#5 bar placed 2" below the stem of the footing or floor slab. Isolated footinge should be at least 24" square and reinforced with 2-#5 bars placed each way. 4. Slabs on grade should have a minimum thickness of 4" I and reinforced with welded wire mesh placed at midheight of ths slab. The slab should be underlain by at least 4" of sand placed over the 5 SAN MARCOS ENGINEERING civil, soils and foundations Candil Place Project, Soil8 Report, Cont'd... .- prepared subgrade. The subgrade should be vetted to at leaet 4X above the optimum moieture content of the soils prior to placing the sand over it. 5. In areas where rock are found to be at ehallow depth, it ia recommended that the diaintegrated rock be removed. Footings ehould be at least 12" into good competent rock. 6. Footinga placed in fill areae should be positioned aa indicated below: !I Fill I-/< Slope) L /fLL 5' 'n: in. 7. Cut and fill elopes should be no greater that 2:l horizontal to vertical ratio. 8. The San Diego county Standard Drawings and Specifications for design of retaining walls maybe used in the construction of retaining walls for this pro]ect. 6 SAN MARCOS ENGkNEERING civil, soils and foundations Cendil Place Project, Soil8 Report, Cont'd... 9. Blasting of near surface rocks maybe necessary to achieve the designed pad. The limits of the rock are unknown at thie time. 10. Recommend that this firm be informed when the footing trenches are excavated so a soils engineer can inspect the founding soils to make sure that they are adequate for the purpose intended. 11. All eurface water runoff should be directed away from the foundation system positively. SAN MARCOS ENGINEERING civil, soils and foundations Cendil Place ProIect, Soils Report, Cont'd... Limitation of Report ---------- -- -- --- The soils engineer hae prepared this report for the exclusive use of the client and his authorfzed agents. This report has been prepared in accordance with generally accepted soil and foundation engineering practices. No other warranties either expreaeed or implied are made aa to the profeaaional advice provided under the terms of this agreement, and included in the report. If you have any queatione about thie report, please call. Very truly yours, SAN MARCOS ENGINEERING Distribution: (4) Addressee 8 .’ . SAN MARCOS ENGINEERING ,-- N NO SC 1 ‘.--, I / ‘c. ~,‘=-. .I !., t PLATE 1, VICINITY MAP PROJECT: HUGHES RESIDENCE CANDIL PLACE CARLSBAD, CA. TH E ..- .---L- ,I-h-----L--r -.--- REFERENCE: THOMAS BROS, MAP PAGE 20 C-5 3eo HUC.L-m” OIIVC ,“,I*. SAM Y_--^- -. _..~. .,-- ” - ..-. -_. , , ___---. -_ TV&“IJ’~~~W PLATE 2, SITE 8 BORING LOCATION PLAN _--. OW 00’ --: PROJECT: HUGHES RESIDENCE I LOT 1 MAP 7637 /- ?EL ,VT 70 SAN L’!E6D GAS 8 Ef EC,?RC CO CANDI L PLACE, CARLSBAD, CA, ‘WSES REC 4-22-5-4, AS DK’52G29, SK 52/2, =C 5-/Z-P, RS aX”62394, 5K 5235, 23 /39, OR ,“” ' LEGEND: ?/@fT TO 7ii?!M CR Z-5 ANY L?EES WiTHM ; ” a INDICATES APPROXIMATE LOCATIOC F/Of OF MS3fE’fT RIGHT OF WAY liM/T5Ts, I,’ OF TEST PIT EXCAVATION l-hi. I. no, . l “rx\cI ,,I ,hc l,?d. bUl i. iO”,>~l..d Ial, inrurm~tion ““I\. n.ar i5 it . p,,, ,A ,hr ru,wrt nr p.,,,r\ ,u r!,kb ;I m.\ h+ ttt!*,hrd. PLATE 3, BORING LOG SAN MARCOS ENGINEERING ClllL L*O1.a*... SOIC. . roIlr.o.l~all Wing No. 7=/ 360 “UL,I.n-. o-l”*. ,r,.. . ..” “r.CD.. c* .a=.. idlO> 7...0111 Skeet No.e+Of& Ua!srial h Remarks PLATE 4, BORING LOG SAN MARCOS ENGINEERING Cl”% L*al.a‘.*. 30%. . ,OU?.D.I\O.a ,a0 -4”L.r-m O.,“C. v*,-e. Boring No.= ,.* “LICO,. c. .a.=.. IalP, 74.-o,,, Skeet No.+Ot& WdrJrial h Renarkr SAN MARCOS ENGINEERING C,“lL L*o,rms.s. 101L. . rourro.7loP4 _- Project: PLATE 5. f”l&fm TlRY IlFNSlTY ;Lloisture vs. Dry Density Curve Soil Type: I /) . /* f%J cr/a!&f.c J&~~~~~ @ . LOCa&ll ~ 2 6?p z37 I 140 130 120 110 100 90 MOISTURE CONTENT, % Remarks: