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Home My WebLink About; La Costa South Unit 2; Soils Report Final; 1970-02-24PHILIP HENKINa BENTON PRL(IIDINT ClYlL IZNGINIC” BENTON ENGINEERING. INC. APPLIED SOIL MECliAN,C* - FO”No*TIONS 6745 EL CAJON BOULEVARD *AN DIEGO. C&LIFDRNIA es?,,5 February 24, 1970 *AN DILGO: 11*3-56m L* MESA: 468.se54 Ranch0 Lo Costa, Inc. Route I, Box 2550 Encinitas, California 92024 - Subject: Project No. 69-lo-ID &d Rem&n - Compacted Fii’led Ground Lok 186 to 191, inclusive, ond Lots 195 to 205, inclusive - La Costa South Unit No. 2 * 0 - Gentlemen: This is to report the resul k of tests and observations mode in order to inspect the compaction of fllled ground placed on certain areas of Lok 186 to 191, inclusive, ard 195 to 205, Inclusive, of La Costa South Unit No. 2, San Diego County, California. The fills were placed during the period between October 2 and October 24, 1969, with some final cleanup In February, 1970. The approximate oreas ond depths of filled ground placed under our inspection in occwdance - with the approved specificotlons ore shown on the attached Drawirg No. 1, entitled “Location of Compacted Filled Ground.” The grodirg plan used for the placement of filled ground ~(1s prepared by Rick Ergineeriw Company and dated August 12, 1969. - The approximate locations at which the tesk were token and the final test resulk are presented on pages 3 and 4, under the “Table of Test Resulk.” The laboratory determination of the maximum dry demities and optimum moisture contenk of the major fill materials are presented on poge 5, under the “Laboratory Test Resulk.” Sane of the maximum dry densi ties shown in the “Table of Test Resulk” were combinations of these. The tests were taken during the weekly periods indicated below: Test Number Week Endig 1 October 4, 1969 2 to 31, inclusive October 11, 1969 32 to 54, inclusive October 18, 1969 55 to 70, inclusive October 25, 1969 71 February 20, 1970 SlOlO .I?.87 - - - - - Project No. 69-lo-1D La Costa South Unit No. 2 -2- February 24, 1970 The final resulk of tesk and observations indicate that the ccmpacted filled grwnd has been placed at 90 percent of the maximum dry demity or greater. it has been determined that the fill moterlols, compacted to 90 percent of the maximum dry denlty, hove a safe bearlrg value of at least 2090~pauds per square foot for one foot wide continuous footings founded at o minimum depth and pieced five feet or more imide the top of compacted filled ground slopes. If footigs ore pieced closer to the exposed slopes than 5 feet lmide the top of ccmpacted filled ground slopes, these should be deefmned one foot below a 1 l/2 horlrontal to 1 vertical line projected wtword and domward fra Q polnt 5 feet horizontally imlde the top of compacted filled ground slopes. Tesk indicate that the compacted filled ground is adequate to satisfactorily support the propceed one or two story wood frame dweliirgs without detrimental settlemenk. In our report of the original Investigation conducted at this subdivision, (Proiect No. 69-3-24BC doted May 22, 1969), w stated that sane “expansive” soils existed on the site and if they were oiiowad to remain In the upper 3 feet below finished gmde sane of the iok would require speclolly designed footirgs ard slobs. We further stated that these lok would be listed upon the completion of gradig . &.&be lok were found to hove critically expamive roll remoinirg in the upper 3 feet. - It is recommended that the following spsciai design precautlom be token for the hwses to be constructed in the subject subdivision. 1. Isolated interior piers shwld not be used. Continuous footings should be used throughout, and these should be placed ct a minimum depth of two feet below the lowest adjacent exterior final ground surface. 2. Reinforce and Interconnect c0ntinuousiy with steel bars all interior and exterior footigs with two @4 bars at 3 inches above the bottan of oil footlgs and two 14 bon placed 1 l/Z inches below the top of the stems of the footings. 3. Use raised wood floors that span betwen contlnuws footings, or reinforce all concrete slobs with 6 x 6 - lO/‘lO woven wire fabric and provide o minimum of 4 inches of clean sand beneoth all concrete slobs. Rovide a moisture barrier 2 inches below slobs under living areas. 4. Separate garage slabs frun perimeter footlrgs by l/2 inch thickness of construc- tion felt or equivalent, to allow independent movement of garage slobs relative to perimeter footirgs. 5. Provide positive droinoge awuy from ail perimeter footiqs to o horizontal distonce of at least 6 feet wklde the house walls. The safe bearing value for footigs on ~tural~+~rciii&B?s~%~pwrs& per square foot. Respectfully submitted, BENTON ENGINEERING, INC. William G. Catlin, Civil Ergineer BENTON ENGINEERING. INC. - - - - - - - - - Project No. 69-lo-1D Roncho La Costo Swth Unit No. 2 -3- TABLE OF TEST RESULTS Test No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Approx- Depth imate of Fill Location ot Test Lot No. inFeet 199 204F' 200F 203 F 199 199 199 204 F 200 F 203 F 199 200 R * 202R 199 201 R 186 186 187 186 200 R 202 R 203 F 189 188 190 189 188 190 189 187 186 187 Novorro Dr. opp. 190 186 187 186 187 190 187 191 2.0 12.5 114.4 123.1 93.0 1.0 12.0 113.6 123.1 92.2 1.0 12.6 118.0 123.1 95.9 o-o.5 11.6 116.0 123.1 94.3 Natural Ground 4.0 11.9 113.5 123.1 92.3 6.0 13.9 113.3 122.8 92.3 8.0 15.2 113.8 122.5 92.9 3.0 13.2 117.2 122.8 95.6 3.0 14.3 115.2 122.8 93.8 1.0 14.6 111.8 122.5 91.3 10.0 10.3 120.1 126.3 95.1 2.0 10.2 110.4 122.5 90.2 2.0 10.0 116.0 123.0 94.3 12.0 12.6 124.5 129.6 96.1 2.0 11.5 120.2 129.6 92.8 2.0 12.7 118.2 129.6 91.3 4.0 12.3 119.2 129.6 92.0 2.0 10.9 116.2 126.5 91.9 8.0 10.8 117.2 126.5 92.7 6.0 9.8 125.7 129.6 97.0 6.0 9.0 126.1 129.6 97.3 3.0 13.9 117.8 122.5 96.1 2.0 8.4 116.0 126.5 91.7 4.0 9.5 119.5 129.6 92.3 3.0 8.3 111.1 123.5 90.1 6.0 8.3 122.8 129.6 94.9 8.0 8.4 111.8 123.1 90.7 7.0 15.7 112.1 123.1 91.0 10.0 14.2 113.2 122.5 92.5 6.0 6.6 111.7 122.8 91.0 12.0 7.1 111.1 122.5 90.7 8.0 a.7 109.8 119.0 92.3 1.0 13.9 119.9 129.6 92.6 14.0 8.2 115.8 123.5 93.7 10.0 7.5 116.5 123.5 94.4 16.0 8.2 123.4 129.6 95.2 12.0 8.7 119.2 125.4 95.2 11.0 18.7 108.5 119.9 90.5 14.0 14.2 112.5 123.1 91.3 1.0 13.3 104.8 114.6 91.5 * F= Front Lot R= Rear Lot Field DV Moisture Density %dry wt Ib/cu ft BENTON LNOINEERING. INC. fibruory24, 1970 Maximum DV Demity Ib/cu ft Percent Compaction Remarks - - - - - - - - - - - Project No. 69-lo-1D Ranch0 La Costa South Unit No. 2 -4- Test No. 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Approx- imote Location Lot No. 205 195 R l 196 F * 197 R 190 189 0 201 R 198 188 190 204F 189 Novarro Dr. opp. 190 l F = Front Lot R= f&or Lot TABLE OF TEST RESULTS(CONT.) Depth of Fill ot Test in Feet Maximum Field Moisture % dry wt Ib/cu it Dry Density Ib/cu ft Percent Compaction Remarks 1.0 11.7 112.3 123.1 91.2 1.4 ** 13.7 117.5 123.1 95.5 2.4+* 13.5 110.0 122.5 90.0 2.5** 14.5 110.7 122.5 90.5 12.0 11.2 117.5 126.3 93.1 18.0 10.4 126.1 129.6 97.3 ,- 14.0 13.3 116.3 126.3 92.2 15.0 14.3 122.7 129.6 94.7 18.0 12.9 125.9 129.6 97.2 20.0 11.9 125.8 129.6 97.1 - 6.0 9.2 125.1 129.6 96.5 2.0 13.8 113.9 119.7 95.3 16.0 15.3 110.4 122.5 90.0 5.0 14.7 111.3 123.1 90.4 24.0 13.0 116.5 126.0 92.5 - 18.0 13.2 109.2 116.8 93.6 19.0 il.7 111.7 123.5 90.5 4.4 ** 11.2 117.3 126.0 93.0 10.0 ** 8.6 114.9 122.5 93.8 9.0** 9.7 128.0 129.6 98.8 15.0** 11.9 125.7 129.6 97.0 6.0** 11.2 116.1 124.7 93.2 28.0 13.3 111.8 123.1 90.8- 22.0 12.7 111.1 123.1 90.2- 20.5 ** 7.5 121.5 129.6 93.7 22.5** 13.2 113.9 124.7 91.4 22.0** 11.2 120.5 129.6 93.0 24.0'* 11.8 121.3 129.6 93.6- 31.0** 10.0 121.3 129.6 93.6 c 9.0** 12.3 119.2 129.6 92.0 5.0** 17.8 110.9 115.6 95.8 l + Finished Grade BENTON ENGINEERING. INC. February24, 1970 - - - - - Proiect No. 69-lo- 1D Ranch0 La Costa Swth Unit No. 2 -5- February 24, 1970 LABORATORY TEST RESULTS The maximum dry demities and optimum moisture contenk of the major fill moterlals o deter- mined by the A.S.T.M. D 155758T method, that uses 25 blow of CI 10 pound hammer follirrg from a height of 18 inches on each of 5 loyen in a 4 inch diometer l/30 cubic foot ccmpoction cylinder, ore presented os follow: Soil Type Brown silty cloy Brown fine sandy cloy Brown gravelly clayey fine to coarse sand Brown gravelly slightly silty flne to coarse sand Olive gray silty cloy Maxlmum Optimum Mois- Dry Density ture Content Ib/cu ft % dry wt 123.1 10.9 122.5 11.4 129.6 8.9 123.5 8.0 110.6 15.7 - BENTON ENGINEERING. INC