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Home My WebLink AboutCT 76-17; Canon Park Unit 1 Lots 1-4; Soils Report; 1977-03-03BENTON ENGINEERING. INC. APPLIED SOli. MECHANICS - FO”ND*TtON* 6717 CONVO” COURT SAN DIIEO. CALIFORNIA *Zlll March 3, 1977 - PHILIP HENKINa .LNTON .“l.IDIYI EI”4L 1*01*a11 TcLIP*O*I (,I., sas.,ess La Costa Land Company 2 100 Costa De I Mar Road Carlsbod, California 92008 RECEIVED - Subject: Project No. 77-l-5D Report an Compacted Filled Ground MAR 'i 1977 Lots 1 to 4, inclusive, of Canon Park Unit No. 1 Carlsbod, California This is to report the results of tests and bbservations made in order to inspect the compaction of filled ground placed an certain areas of Lots 1 to 4, inclusive, of Canon Park Unit No. 1 in Co&bad, California, The fills were placed during the period between February 24 and March 2, 1977. The filled ground was placed under our inspection in accordance with the approved specifications. The grading plan used for the placement of filled ground was prepared by Rick Engineering;Company. The approximate locations at which the tests were. taken and the final test results are presented on page 3, under the “Table of Test Results.” The laboratory determinations of the maximum dry densities and optimum moisture contents of the major fill materials are presented on page 3, under the “Laboratory Test Results.” Some of the maximum dry densities shown in the “Table of Test - Results” were combinations of these. /‘he tests were taken on the dates indicated below: Test Number Date 1, 2, 3and4 February 24, 1977 5 and 6 February 25, 1977 7, 8 ond 9 March 1, 1977 10 March 2, 1977 The final results of tests and observations indicate that the compacted filled ground has been placed at 90 percent of the maximum dry density or greater. It has been determined that the fill materials, compacted to 90 percent of the maximum dry density, have a safe bearing value of at least loo0 pounds per square foot for one foot wide continuous footings founded at a depth of 8 inches below the lowest adjacent final compacted ground surface and placed five feet or more inside the top of compacted filled ground slopes. If footings are placed closer to the exposed Project No. 77-l-51) -2” March 3, 1977 Canon Park slopes than 5 feet inside the top of compacted filled ground slopes, these should be deepened one foot below a 1 l/2 horizontal to 1 vertical line projected outward and downward from a point 5 feet horizontally inside the top of compacted filled ground slopes. Tests indicate that the compacted filled ground is adequate to satisfactorily support the proposed one and two story wood frame dwellings without detrimental settlements. Expansive soil conditions exist in the upper three feet below finished grade. It is understood that the post-tension slab system, to be used for support of these houses, has been designed to minimize possible detrimental effects caused by the potentially expansive soil conditions. A plan showing the approximate areas and depths of filled ground placed under our inspection in accordance with the approved specifications will be submitted with our finol report on this project. Respectfully submitted, BENTON ENGINEERING, INC. R. C. Remer Reviewed by S, H. Shu, Civil Engineer R.C.E. No, 19913 - Distr: (2) Addressee (1) Addressee - Attn: Mr. Burt b n C . Kramer (2) City of C&bad Building Department (1) Rick Engineering Co. (1) Waodward Companies .ENTON ENalNEL~ING. INC. ..~ - ,~ - - - - - ,- - Project No. 77-l-50 Canon Park -3- TABLE OF TEST RESULTS Approx- imate Test Location No. Lot No. 1 1 2 1 3 2 4 4 5 3 6 4 7 3 8 4 9 2 10 4 * Indicates finished grade. Depth of Fill at Test in Feet 0.5 15.6 115.4 2.4* 15.3 114.4 2.0 14.5 113.4 1.0 16.8 107.6 3.0 12.6 110.9 5.0 9.2 120.9 6.0* 13.2 117.7 9.0 16.0 109.6 4.0* 14.2 113.7 12.0* 18.0 109.8 Field Moisture % dry wt Dry Density Ib/cu ft LABORATORY TEST RESULTS March 3, 1977 Maximum Dry Density Ib/cu ft 119.2 121.6 121.6 114.7 114.7 125.8 121.6 114.7 121.6 114.7 Percent Compaction 96.8 94.1 93.3 93.8 96.7 96.1 96.8 95.5 93.5 95.8 The maximum dry densities and optimum moisture contents of the major fill materials as deter- mined by the A.S.T.M. D 1.557-70 method, that uses 2.5 blows of a 10 pound rammer falling from a height of 18 inches an each of 5 layers in a 4 inch diameter l/30 cubic foot compaction cylinder, are presented as follows: ! Maximum Optimum Mois- Dry Density ture Content Soil Description Ib/cu ft % dry wt Gray with red brown and white silty clay 114.7 15.3 Light yellow brown fine sandy clay 121.6 11.5 Light yellow silty fine sand 123.6 10.5 Brown clayey fine to medium sand 128.0 9.2 RECEIVED Jx! 2 7 1977 - BENTON ENGINEERING. INC. APPLIED ScJlL MECHANICS - FO”ND*TtON* 6717 CONKJI COURT 6&N DIEGO. C*LIFORNIA s*t11 PHILIP HENKING BENTON P”l.IDIYI ClYlL .%*al*‘1” January 26, 1977 TLLe,*OYr. ,-?I., ses.IPs= Woodward Companies 4500 Campus Drive Newport Beach, California 92660 Subject: Project No. 77-l-6F Post-Tension Slob System For Proposed Residential Dwellings Corona La Costa Canon Park Subdivision Carlsbad, California Gentlemen: In accordance with your request, we have reviewed the plans for the proposed post-tension slab system prepared bv N .A.M. Engineering and transmitted to us with their letter dated Yanuary LU, 1977. Expansion tests conducted on representative samples of the clayey soils existing on this sub- division indicated that the expansion for most of these soils varied between 6.8 and 14.7 percent. These tests were performed on samples that were allowed to air dry for two days and then saturate under CI unit load of 150 pounds per square foot. Calculations based on the results of previous laboratory tests indicate that both the firm natural soils and fill soils, uniformly compacted to at least 90 percent of maximum dry density, have a safe bearing capacity of at least 1000 pounds per square foot for the exterior footings, embedded approximately 8 inches below the outside grade, and for the proposed interior bearing wall or column footings. It is recommended that the soils in the upper 6 inches below finished subgrade for the slab be compacted to at least 85 percent of maximum dry density. It is recommended that an adequate moisture vapor barrier be provided beneath the concrete slab under the house. The moisture vapor barrier may consist of o minimum of 4 inches of 3/4 inch gravel on top of the soil, covered with a 6 mil polyethylene layer that in turn is covered with 2 inches of sand immediately beneath the concrete slab. - - Project No. 77-l-6F Canon Park Subdivision -2- January 26, 1977 It is concluded from our review of the plans for the post-tension slab system and the information presented in the letter from N.A.M. Engineering, that the proposed system with an adequate moisture vapor barrier is adequate for the anticipated expansive soil conditions. Respectfully submitted, BENTON ENGINEERING, INC. BY &Fe& R .‘C . Remer R.C.E. No. 10332 Distr: (2) Addressee (2) N .A.M. Engineering Attn: Mr. Avinash R. Khedakar RCQ’PHB/dp - BENTON ENGWJEERING. INC, SW 1 2 1979 .- - - - - .- - - BENTON ENGINEERING. INC. L,PL,lD Nl,L *.C”IYIc. - .O”“DATIOY. I,.0 l”F,lN “0.0 ,“,LW HlYllNe .IWTO” m..,ma*, . C,.,L ~*w*~=” September 10, 1979 lho Waodward Companh 5100 Compw Drlvb Newport bath, Callfornlo 92660 sub~rctl Rolrct No. 79-9-MF bwpctlm of Lots 62 to 78, Inclusive, 88, (jlc y-Y-4-73 r’- Lots 133 to 138, inclu5lvo, Lots 176 to 179, lncluslvs, and RECEIVED Lots 188 to 209, Inclusive Canan Rwk Unit NM. 2 and 3, Car&d, Callfomla OCT ‘.! 4 197q Gontlrrnonr CITY OF CARLSBAD Building Department )n occwdanw wkh the request of the Building Department OF the City of Carl&ad, we have Inspoctod the soli condltlms existing m the subject lots. lhe loh WOW Inspected by a representative of our argonlzatim m September 7, 1979 and, l xcopt for a hw rroded alope areas, It ir cmcluded that the roll conditions exiatlng m these Ior5 are l ssentlally the some as presented In aur report m the grading of thir r&division submItted under.our Rdecr No. 77-l-5D, doted December 5, 1977. Erosion gullies or slumped am on sloper were observed to exist m the Following lots: l’wo smoil eroslm gullies m easterly rlope Cut mode on portion of Front slope Small ermim gully m east slope Small slump adjacent to manhole at northwest corner Small erorlm gullies m rear slope Small erosion gully and slump area m slope at rear of lot It II antlclpotul rhot nme of the above descrtbed cmdltims will be detrlmental to the cmstructlm d raIdonus m those lots. it Is recammended that the final grading of these lots shauld Include rIopIng tha fInal around surface away From the top of slopes and directing the drainage Into the tinoh and etarm dmlna. - Ro/ecl No. 7%9-16F -2- September 10, 1979 The Woodward Companies I The 1011s In the upper three feet below Finished grade m all of the subiect lots have been - clarified as “expansive” with respect to volumetric change with change in moisture content. Therefore, It II recommended that special design and precautions be taken In order to minlmlre paJble detrimental effects caused by the potentially expansive aoil conditlms. . Rmpctfully rubmltted, - RENTON QfGINEERING, INC. - - Dlttrlbutlars (1) Addreude (2) Addressee, 204 Turf View, Solana Reach, California 92075, Attentlm: Mr. David Schultz - - - .wdToN -uuIo. uy.