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HomeMy WebLinkAboutCT 75-02; Carlsbad Meadows Unit 1; Soils Report; 1976-09-22- *\. ~7-75-2 GEOCON ENGINEERS AND GEOLOGISTS . CONSULTANTS IN THE APPLIED EARTH SCIENCES INCORPORATED - File No. D-@64-SO2 Septembe?22, 1976 - - Mr. Amos Sommers Sornners Development Corporation Post Office Box 1754 Ranch0 Santa Fe, California' 92067 Subiect: Carlsbad Meadows Unit 1 Sierra Morena Boulevard Carlsbad, California - TESTING AND OBSERVATION SERVICES DURING GRADING OPERATIONS FINAL REPORT OF WORK FROM S/16/76 THROUGH g/7/76 Dear Mr. Sommers: In accordance with your authorization our firm has performed testing and observation services during grading operations on the subject project. These services included: a. engineering observation of the grading operations, including observation of the removal and/or processing of the loose topsoils, uncompacted fill, and alluvial materials encountered. b. the taking of field density tests in the fill placed and compacted within the subject site. c. geologic observation of the cut slopes during the grading operations. Site preparation, compaction, and testing were performed between August 16, 1976 and September 7, 1976 in accordance with recom- mendations set forth in a soil and geologic investigation prepared by Geocon, Inc. dated June 6, 1975. Areas of loose or saturated soils in canyon areas were removed until firm natural ground was reached. The then exposed ground surface which was to receive fill was properly benched, scarified, - moisture conditioned, and recompacted. In-place density tests performed by our firm indicated relative compactions of at least 90% were being obtained. Fill derived from on-site cutting - - n 6645 CONVOY COURT - SAN DIEGO, CALIFORNIA 92111 * PHONE (714) 292-5100 File No. D-0364-SO2 September 22, 1976 operations was then placed in compacted layers until final elevations were reached. In-place density tests performed by our firm again indicated relative compactions of at least 90% were being obtained. All tests were based on ASTM Compaction Test D1557-70. - Expansive fillspils were placed at depths of greater than-m3 fee~t below final grade. Where known expansive soil was encountered in cut sections, it was over-excavated in accordance x with the project specifications. Footings for single or.,zwo-story residential structures placed on non-expansive undisturbed soil or non-expansive properly compacted fill soils, may be designed for a bearing capacity of 2000 psf at a depth of 12 inches below rough lot grade. Should expa,nsive clay soils be encountered within two feet of finish grade on any lot, specially designed footings will be required, and this firm should,be notified so that supplemental recommendations may bemade. -'We recommend that footing inspec- tions be made by our firm prior to the placement of concrete. In suumary, the subject project has been satisfactorily graded with respect to compliance with the grading recommendations contained in the project specifications, the specifications of the FHA, the San Diego County Grading Ordinance, and UBC Chap- ter 70. Potential geologic hazards and expansive soil hazards have been mitigated in accordance with the requirements of the project specifications and ordinances. Structures that will not tolerate differential settlement should not be located within five feet of the top of fill slopes unless properly designed to reflect this condition. Footings located closer than five feet from the top of slope should be deepened such that the bottom edge of the footing is at least five feet horizontally inside the face of slope. This report covers only work performed on the subject dates. Any subsequent grading should be performed only withy our testing and observation services. - The services provided on the site during the subject period were in accordance with local acceptable standards for this period. - - -2- GE!OCON INCOIPOP.ATE” - - - - .- - - .- - - - - File No. D-0364-SO2 September 22, 1976 The conclusions and opinions from our services apply only to our work with respect to grading, and represent conditions at the date of the conclusion of our services. The site should be properly drained and maintained to prevent damages by uncon- trolled water. Tables I and II present a summary of laboratory and field tests utilized by our firm. A site plan is also included. Very truly yours, GEOCON, INCORPORATED MWH:JEL:jp copies: (6) addressee -3- GEDCOW lNCDlP -- - .~~ - - - - .- - - - - - File No. D-0364-SO2 September 22, 1976 s* 34 &j “r” I s-l@ l 19 sz..? 2 3 ; f5l 154. ’ 55. SCALE:/“=/50 l LOCATION OF FELD DENSl/TY TEST SITE PLAN & LOCATION OF FIELD DENSITY TESTS CARLSBAD MEADOWS UNIT 1 Sierra Morena Boulevard Carlsbad, CA 3GURE NO- 1 PAGE NE GEOCON , INCORPORATED - .i - .- -. - - - - .~ - - - - - - - File No. D-0364-SO2 September 22, 1976 TABLE I Summary of Laboratory Compaction Test Results Soil Source & Description ;ype Max. DrzfDensity Optim~d~i.s~ure P 0 Y - 1 Yellow Silty Clayey SAND 117.2 13.4 2 Dark brown Sandy CLAY '118.5 12.5 3 Dark brown Silty Clayey SAND 119.8 11.5 4 Light brown, medium-grained 123.8 12.8 SAND TABLE II Summary of Field Density Test Results Zest L. ..O. 1 2 3 4 5 6 7 8 9 10 11 12 Date 1976 8118 II 1‘ 8/19 11 II II 11 8120 II II II Location & Elevation Dry Dens, Moisture Rel. Comp. Soil Type pcf % dry wt. % of max. & Remarks Lot 26 70 108.3 18.3, 91.1 2 Lot 33 72 111.3 15.1 93.2 4 Lot 24 72 109.3 17.4 92.1 2 Lot 31 77 111.3 16.2 93:9 2 Lot 20 72 117.3 14.7 94.7 4 Lot 30 80 112.1 15.7 90.5 4 Lot 20 76 109.6 17.1 92.4 2 Lot 23 80 109.6 18.9. 92.4 2 Lot 32 82 106.7 13.4 90.0 2 Lot 28 83 105.6 11.7 90.1 1 Lot 33 78 108.9 14.0 91.8 ,2 Lot 31 84 .110.2 13.2 92.9 2 GZSOCON INCOIPOIATE” File No. D-0364-SO2 September 21, 1976 Test Date L 1976 13 8120 14 " 15 " 16 " 17 " 18 " 19 8124 20 " 21 " 22 8/25 23 " 24 " 25 8/26 26 " 27 " 28 " 29 " 30 " 31 8127 32 " 33 " 34 " 35 " 36 " 37 " 38 8128 39 " TABLE II (Continued) Location & Elevation Lot 25 78 Lot 20 81 Lot 27 84 Lot 27 88 Lot 24 80 Lot 24 86 Lot 10 86 Lot 13 88 Lot 23 87 Lot 28 90 Lot 29 95 Lot 22 89 Lot 38/offsite 82 Lot 40/offsite 85 Lot 32 95 Lot 30 93 Lot 26, 93 Sierra Morena 94 Opp. Lot 27 Lot 12 91 Retest #31 91 Lot 15 94 Lot 11 95 Lot 14 99 Lot 8 94 Lot 34 97 Lot 37/offsite 91 Lot 17 100 Dry Dens. Moisture p c.f. . % dry wt. 113.9 14.3 106.4 11.7 112.1 14.2 117.2 12.5 112.2 13.6 120.7 14.8 112.8 13.0 114.9 13.2 117.3 14.7 118.7 13.9 119.6 13.2 114.2 14.2 106.9 9.2 108.1 11.2 108.2 11.6 116.8 12.0 118.2 14.0 117.7 13.9 Rel. Comp. % of max. Soil Type & Remarks 96.1 2 90.8 1 94.5 2 94.7 4 90.6 4 97.5 4 95.2 2 92.8 4 94.7 4 95.9 4 96.6 5 92.2 4 90.2 2 91.2 2 91.3 2 94.3 4 95.4 4 95.0 4 110.0 12.0 88.0 4* 111.8 13.6 90.3 4 114.7 14.4 96.7 2 110.0 12.2 92.8' 2 117.2 11.7 94.7 4 115.6 12.6 93.6 4 112.3 12.2 94.7 2 112.3 93.6 94.7 2 114.7 14.1 96.8 2 *Indicates Test Failure GEDCON ,nCOP.POF.lTrn - ‘. . File No. D-0364-SO2 September 22, 1976 - .- Test Date so. Eu6 40 B/28 41 " - 42 9/l 43 " - 44 " 45 " - 46 Y' 47 " 48 " 49 " 50 " - 51 " 52 " - 53 " 54 " - 55 " 56 " 57 " - 58 " 59 9/2 60 " " - 61 62 917 63 " - 64 " 65 " - 66 " 67 " - 68 " - TABLE II (Continued) Location & Elevation Lot 21 90 Lot 39loffsite 92 Lot 19 FG Lot 18 I' Lot 17 11 Lot 16 ,I Lot 15 11 Lot 14 11 Lot 13 I’ Lot 12 I, Lot 11 11 Lot 10 ,I Lot 9 I, Lot 8 1, Lot 7 11 Lot 6 1, Lot 5 11 Lot 4 1, Lot 3 ‘I Lot 25/storm +3 drain backfill 11 I, i-7 1, 11 +11 Lot 34 FG Lot 33 FG Lot 32 FG Lot 31 FG Lot 30 FG Lot 29 FG Lot 28 FG Dry Dens. p.c.f. 117.7 105.1 116.0 120.8 118.9 121.6 115.7 118.9 116.0 120.7 122.2 112.8 117.0 119.2 119.4 118.2 116.6 ,114.g 116.5 116.5 EF” 0 wt. 13.9 12.3 8.1 10.2 10.2 12.0 8.4 9.6 8.1 10.5 14.0 8.4 9.9 10.5 10.2 9.6 8.1 7.8 8.7 8.1 Rel. Comp. % of max. Soil Type & Remarks 95.1 90.0 93.7 97.6 96.0 98.2 93.5 96.0 93.7 97.5 98.7 91.1 94.5 96.3 96.4 95.5 94.2 92.8 94;l 94.1 115.8 7.7 93.5 115.7 14.5 93.4 117.6 10.5. 95.0 115.5 7.8 93.3 114.1 7.8 92.2 117.0 8.1 .94.5 117.2 10.2 94.7 116.0 7.5 93.7 115.4 7.8 93.2 4 1 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 9MGE i’ - - - - - .- - - - - - File No. D-0364-SO2 September 22, 1976 Test & 69 70 71 72 73 74 75 76 77 78 Date 1976 917 11 11 11 11 11 11 11 11 11 TABLE 11; (Continued) Location & Elevation Lot 27 FG Lot 26 FG Lot 25 FG Lot 24 FG Lot 23 FG Lot 22 FG Lot 21 FG Lot 20 FG Lot 2 FG Lot 1 FG Dry Dens. p.c.f. 113.5 113.5 112.3 115.4 120.4 113.4 117.2 115.9 117.1 113.9 Moisture % dry wt. Rel. Comp. % of max. 7.5 91.7 4 7.5 91.7 4 7.3 90.7 4 8.1 93.2 4 10.5 97*3 4 7.8 91.6 4 7.8 94.7 4 7.5 93.6 4 7.5 94.6 4 7.3 92.0 4 Soil Type & Remarks GEOCON ,NCO”FOR*TI”