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Home My WebLink AboutCT 81-10; Carlsbad Research Center Phase I Lot 9; Compaction Report; 1987-04-01,- SAN DIEGO GEOTECHNICAL CONSULTANTS, INC. SOIL ENGINEERING 8 ENGINEERING GEOLOGY - April 1, 1987 - Cardon Meadows Developm 9339 Genessee Avenue, S San Diego, California 92121 No. 05-3205-003-00-10 Log No. 7-1328 - Attention: SUBJECT: References: - - - - - - - Gentlemen: Mr. Bob Schmidt COMPACTION REPORT Proposed Commercial Development Lot 9, Phase I, Carlsbad Research Center Carlsbad, California San Diego Soils Engineering, Inc., "As-Graded Geotechnical Report, Rough Grading Completed, Carlsbad Research Center, Phase I, Carlsbad, Tract No. 81-10, Carlsbad, California" dated June 7, 1984, Job No. SD1144-10 San Diego Geotechnical Consultants, Inc., "Foundation Investigation, Proposed Commercial Development, Lot 9, Phase I, Carlsbad Research Center, Carlsbad, California," dated July 18, 1986, Job No. 30038-00 Submitted herewith is the report of observation and tests performed during precise grading at the subject site. Field density test locations are shown on the Plot Plan, Plate 1, test results are tabulated on Table I. "Results of Compaction Tests." The development consists of construction of three concrete tilt-up buildings with panel heights of approximately 20 to 28 feet, and concrete slab on-grade. The purpose of the grading and compaction was to grade the building pads to precise grade. ENGINEERING DEPT. LIBRARY City of Carlsbad 2075 Las Palmas Drive CartsbaQ CA 92009-4859 6455 NANCY RIDGE DRIVE l SUITE 200 l SAN DIEGO, CALIFORNIA 92121 l (619) 587-0250 - - - 7 ,- - - - - - - - - - -~ Cardon Meadows Development April 1. 1987 Job No. 05-3205-003-00-10 Log No. 7-1323 Page 2 1.0 PREVIOUS GRADING .The site had been previously rough-graded during the mass- grading of the Carlsbad Research Center. The mass-grading was performed using the observation and testing services of San Diego Geotechnical Consultants, Inc. (see referenced As-Graded Geotechnical Report). 2.0 PREPARATION OF EXISTING GROUND The exposed subgrade soil in areas to receive fill was scarified 8 to 12-inches, brought to near optimum moisture conditions and compacted to at least 90 percent relative compaction. 3.0 SOILS TYPES The soils encountered during grading consisted of light gray-brown clayey silt. The soil types used as fill are tabulated in Table II, "Laboratory Test Results." 4.0 FILL PLACEMENT Fill soils were placed in 6 to 8 inch lifts, brought to near optimum moisture content and compacted to a minimum of 90 percent of the maximum density as determined by ASTM D1557-78 (Five Layer Method). Grading operations were started and completed during the period covered by this report, February 23 to March 30, 1987. Density tests were made in accordance with ASTM D1556-82 (Sand-Cone Method), and ASTM D2922-81 (Nuclear Method). Results of the density tests made during the recompaction of - - - - - - - - - - Cardon Meadows Development April 1, 1987 Job No. 05-3205-003-00-10 Log No. 7-1328 Page 3 the fill are tabulated in Table I. Results of the maximum density and optimum moisture determination of the various .'soils encountered are tabulated in Table II, "Laboratory Test Results". 5.0 CONCLUSIONS Based on the results of the observations and testing noted herein, it is our opinion that the grading and compaction was performed in general accordance with our recommendations and the requirements of the City of Carlsbad. The condition at the site were found to be consistent with those indicated in the referenced Foundation Investigation. Therefore, the recommendations contained in the referenced report are valid and should be fully complied with. Utility trench and/or wall backfill consisting of the on-site material types should be placed by mechanical compaction to a minimum of 90 percent of the laboratory maximum density. All foundation excavations should be observed by the San Diego Geotechnical Consultants, Inc., prior to placement of forms or reinforcement to determine that soil bearing conditions are as anticipated. ALL excavations should be trimmed neat, level, and square. All loose or sloughed material should be removed prior to the placement of concrete. Materials from footing excavations should not be spread in slab-on-grade areas unless compacted to a minimum relative compaction of 90 percent. - - - - - - - - - - - - Cardon Meadows Development April 1, 1987 6.0 LIMITATIONS OF INVESTIGATION Job No. 05-3205-003-00-10 Log No. 7-1328 Page 4 .Cur description of grading operations, as well as observations and testing services herein, have been limited to those grading operations performed between February 23, and March 30, 1987. No representations are made as to the quality or extent of materials not observed, or for any subsequent changes made to this site. Elevations and test locations noted in the attached Table I are estimated from field surveys done by others. Based upon our observations and testing, it is our opinion, as afore- mentioned, that the work performed has been accomplished in accordance with our recommendations as well as the require- ments of the regulating agencies. This report should be considered subject to review by the controlling authorities. Professional judgements represented in this report are based partly on our evaluations of the technical information gathered, our understanding of the proposed construction, and our general experience in the geotechnical field. Our engineering work and judgments rendered meet or exceed the standard of care of our profession at this time. No other warranty, expressed or implied, is made as to the conclusions and professional advice included in this report. - - - - - - - - - - - - - - - - - - - Cardon Meadows Development April 1, 1987 Job No. 05-3205-003-00-10 Log No. 7-1328 Page 5 The opportunity to be of service is appreciated. If you have any questions, please call. Very truly yours, SAN DIEGO GEOTECHNICAL CONSULTANTS, INC. Robert M. Pintner Staff Engineer RMP/AFB/pb Attachments: Plot Plan, Figure 1 Tables I and II Distribution: (6) Addressee - - - -. - ,- - - - - - - - - - - - - - ..~ - TABLE I RESULTS OF COMPACTION TESTS OS tY& 3205-003-00-10 NAME, Cardon Meads Canwrcial WV. t9ecs.T DATEZ&&~ 1987 MOISTURE UNIT DRY RELATIVE EST NO. DATE EpEyATT$,N CONT;NT DE&X;Y COMPACTION so’L 6) TYPE 1 3-2-87 289 21.8 97.5 89"" 1 See Test K3 2 3-2-87 289 21.2 93.6 85* 1 See Test /14 3 3-2-87 289 20.5 94.0 a6** 1 See Test %5 4 3-2-87 289 20.6 101.0 92 1 Retest of bl 5 3-2-87 289 19.8 200.7 -92 1 Retest of #2 6 3-2-87 289 22.1 200.2 91 1 Retest of W3 7 3-3-87 291 20.1 102.7 93 1 8 3-3-87 292 20.2 201.3 92 1 9 3-3-87 293 21.4 100.7 92 1 10 3-4-87 290 20.6 102.9 91 2 11 3-4-87 290 20.1 202.8 91 2 12 3-4-87 292 21.4 100.6 92 1 13 3-4-87 292 19.6 102.9 91 2 14 3-4-87 290 21.0 102.0 90 2 15 3-5-87 293 19.5 102.4 90 2 16 3-5-87 290 20.6 101.0 92 1 17 3-5-87 291 19.3 201.2 92 1 18 3-5-87 290 22.1 101.8 90 2 19 3-18-87 292 19.1 96.5 88** 1 See Test #24 20 3-18-87 292 17.5 97.7 89** 1 See Test #25 21 3-18-87 292 21.3 92.3 84** 1 See Test t26 22 3-18-87 295 19.2 95.8 87* 1 See Test #28 23 3-18-87 295 21.7 92.2 84** 1 See Test #29 24 3-30-87 292 18.8 99.4 91 1 Retest of it19 25 3-30-87 292 16.8 105.6 96 1 Retest of 820 26 3-30-87 292 18.7 101.8 93 1 Retest of W21 27 3-30-87 292 16.9 104.6 92 2 28 3-30-87 295 18.4 101.6 93 1 Retest of #22 29 3-30-87 295 17.3 102.8 94 1 Retest of #23 SEE PLAN FOR TEST LOCATIONS ‘SAND-CONE TEST, ALL OTHERS NUCLEAR DENSITY TESTS *TEST FAILED. SEE RETEST SAN DIEGO GEOTECHNICAL CONSULTANTS. INC - -_ - - - - - - .- _- - - .- - - - - - TABLE II LABORATORY TEST RESULTS 05-3205-003-00-10 OS NO.: Cardon Fadcws Comercial Dev. NAME: Lot 9. base 1 DATE:APril 1987 SOIL MAXIMUM OPTIMUM TYPE CLASSIFICATION DENSITY MOISTURE 1PCF) (%) 1 Light gray-brcm silty CLAY 109.8 15.1 2 Light gray-bmm clayey SILT 113.4 15.3 A :. SAN DIEGO GEOTECHNICAL CONSULTANTS. IN<