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HomeMy WebLinkAboutCT 82-16; THE VILLAS AT CALAVERA HILLS VILLAGE J; FIELD OBSERVATION AND RELATIVE COMPACTION TEST; 1984-06-06REPORT OF FIELD OBSERVATION AND ..........RELATIVE COMPACTION TESTS PROPOSED LAKE CALAVERA HILLS VILLAGE CARLSBAD, CALIFORNIA PREPARED FOR . . . . Pacific Scene, Inc. 3200 Harney Street San Diego, California 92110 PREPARED BY Southern California Soil & Testing, Inc. Post Office Box 20627 . 6280 Riverdale Street San Diego, California 92120 SOUTHERN CALIFORNIA SOIL AND TESTING, INC. 6280 RIVERDALE ST. SAN DIEGO, CALIF. 92120 • TELE 2804321 • P.O. BOX 20627 SAN DIEGO, CALIF. 92120 74-831 V E L I E WAY PALM DESERT, CALIF. 92260' TEL 346-1070 679 ENTERPRISE ST. ESCONDIDO, CALIF. 92025 T E L E 746-4544 June 6, 1984 Pacific Scene, Inc. .. SCS&T 14144 3200 Harney Street Report No. 13 San Diego, California 92110 SUBJECT: Report of Field Observation and Relative Compaction Tests, Proposed Lake Calavera Hills Village J, Carlsbad, California. REFERENCE: Updated Geotechnical Investigation,, Proposed Lake Calavera Hills Village J, by Southern Californi-a Soil .& Testing, Inc., dated May 6, 1983. Gentlemen: In accordance with your request, this report. has been prepared to present the results of the field observations and relative compaction tests per- formed at the subject site by Southern California Soil & Testing, Inc. These services, were performed between February 8 and May 24, 1984. SITE DESCRIPTION . . . The subject site is an irregularly shaped unit that. is located on the flank of a 'northerly facing hill that slopes gently to steeply to the north. Unit J is bounded on the' north by Unit 0, on the east by Unit K, on the south by Unit G, and on 'the west by Unit I. Elevations on the site 40 SOUTHERN CALIFORNIA 'SOIL. AND TESTING. INC. SCS&T 14144 June 6, 1984 Page 2 ranged approximately 150 feet to 300 feet. A desilting basin exists in the northwestern portion of the unit. PROPOSED CONSTRUCTION The developer intends to construct one and two-story, wood-frame, single- family, attached residences. Shallow foundations with conventional slab- on-grade floor systems are anticipated. AVALIABLE PLANS To assist in determining the locations and elevations of our field 'density tests and to define the general extent. of the site grading for this phase of work, we were provided with a grading plan prepared by Rick Engineering Company dated June 6, 1983. - SITE PREPARATION Prior to grading, the vegetation and deleterious matter was removed and disposed of legally off-site. Topsoils and alluvium in areas of the fill were removed to firm natural ground and are deplicted on the plans con- tained in the pocket of this report. The exposed natural ground was then scarified to twelve inches, moisture conditioned and recompacted to 'at least 90% of the maximum dry density. Subdrains were installed in the canyon bottoms and are also shown on the plans. In addition, where mud- stones were encountered within the top three feet of finish grade, under- cutting was performed and these areas are shown on our copy of the site plans located in our office. S ' The fill material which consisted of variety, of silty sands and clayey sands obtained from cuts made on the site was placed in six (6) to eight (8) inch layers, watered to near 'optimum moisture requirements and was compacted by means of a sheepsfoot roller and heavy construction equip- ment. • • • S SOUTHERN CALIFORNIA SOIL AND TESTING. INC. SCS&T 14144 June 6, 1984 Page 3 ... The mass grading was, performed by Cameron Brothers Construction Company, Inc. of San Diego, using the following equipment: 3 - D-9 Dozer 3 - D-8 Dozer 1 - 834 Compactor 1-5X5 1 - 631 Waterpull 3 - 651 Scrapers 3 - 641 Scrapers 1 - 126 Motorgrader 1 - 225 Excavator '41 FIELD OBSERVATION AND TESTING Observations and field density tests were performed by a representative of Southern California Soil & Testing, Inc. during' the mass grading opera- tions. The density tests were taken according to A.S.T.M. Test 1556-74 and the results of those tests are shown on the attached plates. The locations and elevations of the in-situ tests were determined in accor- dance with their importance and the accuracy and proximity of the survey control provided by' 'other than Southern California' Soil & Testing, Inc. representatives. Unless otherwise noted, their locations and elevations were determined by pacing and hand level methods and should be considered accurate only to the degree implied by the method ,used. As used herein, the term "observation" implies only that we observed,the progress of work we agreed to be involv'ed with, and performed tests, on which, together, we based our opinion as to whether the work essentially complies with the job requirements, local grading ordinances' and the Uniform Building Code. LABORATORY TESTS ' Maximum dry density determinations were performed on representative sam- ples of the 'soils used in the compacted fills. according to A.S.T.M Test SOUTHERN CALIFORNIA SOIL AND TESTING. INC. SCS&T 14144 June 6, 1984 Page 4 I 1557-78, Method A. This method specifies that a four (4) inch diameter cylindrical mold of 1/30 cubic foot volume be used and that the soil tested be placed in five (5) equal layers with each layer compacted by twenty-five (25) blows of a 10 pound hammer with an 18 inch drop. The results of these tests, as presented on Plate Number 16 , were used in conjunction with the field density tests to determine the degree of rela- tive compaction of the compacted fill. The expansive potential of clayey soils was determined by UBC Test Method 2922. The results of these tests are presented on Plate Nuriiber 17 . Based on the expansion indexes being in the low to moderately expansive range, it is our opinion, that the foundation recommendations presented in the referenced report are valid for these on-site soil conditions.. CONCLUSIONS Based on field observations and the density test results, it 'is the opin- ion of Southern California Soil and Testing, Inc.: that the grading was performed basically in accordance with the recommendations contained in the referenced report, and the recommendations contained there-in do apply to the subject site. . This report covers only the work performed between February 8, and May 24, 1984. Additional testing will be required for utility trench backfill, for retaining wall backfill and for pavement subgrade and base. As limited by the scope of the services which we agreed to perform, our opinions presented herein are based on our .'observation's and the relative compaction test results. Our work was performed in accordance with the currently accepted 'standards of practice and in such a manner as to pro- vide a reasonable measure of the compliance of the mass grading operations with the job requirements. No warranty, express or implied is given or SOUTHERN CALIFORNIA SOIL AND TESTING. INC. SCS&T 14144 June 6, 1984 Page 5 intended with respect to the services which we have performed, and neither the performance of those services nor the submittal of this report should be construed as relieving the grading contractor of his primary responsi- bility to conform with the job requirements. If you should have any questions after reviewing this report, please do not hesitate to contact this office. This opportunity to be of professional service is sincerely appreciated. Respectfully submitted, SOUTHERN CALIFORNIA SOIL & TESTING, INC. - Robert R. Russell, R.C.E. #32142 RRR:RSH:mw° • cc: (5) Submitted (1) SCS&T, Escondido • .• • SOUTHERN CALIFORNIA SOIL AND TESTING. INC Vu V. V V V SITE BUENA V VISTA / LAGOON V V V V / \ V V AGUA V V V I V HEOIOH 0 V / - LAGOON V / V - Run 0Y APPp RI R V V (V V V V 0 A T V LAKE V V V I ( V SAN MARCOS V V V BATIQUITOS_____ k V LAGOON LA CST V V OLIVENHAtN RD. / V V VICINITY MAP NO SCALE \ V . V V -- 4 oSOUTHERN -CALIFORNIA PROPOSED LAKE CALAVERA HILLS V --lp SOIL & TESTING,iNC. BY SMS DATE: 7-10-84 - -. JOB NUMBER 14144 ' 'flate No 1