The URL can be used to link to this page

Home My WebLink AboutCT 01-16; CASA LAGUNA; REPORT OF CERTIFICATION OF COMPACTED FILL GROUND; 2002-12-12 RECEPJ NORTH Comm COMPACTION ENGINEERING, INC. December 12, 2002 Project No. CE-6687 The Merit Group, Inc. 2171 El Camino Real Ste 202 Oceanside, CA 92054 Subject: Report of Certification of Compacted Fill Ground Casa Laguna Condominiums, Units 1 thni 12 670 Laguna Drive Carlsbad, California Dear Mr. Buckmaster: In response to your request, the following report has been prepared to indicate results of soil testing, observations, and inspection of earthwork construction at the subject site. Testing and inspection services were performed from November 25, 2002 through December 10, 2002. Briefly, our findings reveal filled ground has been compacted to a minimum of ninety percent (90%). Therefore, we recommend construction continue as scheduled. Our firm was retained to observe grading operations with regard to current standard practices and to determine the degree of compaction of placed fill. Grading plans were prepared by Erick L. Ricci and were dated November 27, 2002. Grading operations were performed by Mike Sage of Escondido, California. Reference is made to a previously submitted soils reports: "Geotechnical Report" by AGRA Earth and Environmental dated August 24, 2000 "Update Soils Investigation/Inspection" prepared by NOrth County Conipaction Engineering, Inc. dated August 7, 2002 P.O. SOX 302002 ESCONPIOO, CA 92030 (760) 480-1116 FAX (760) 741-6568 NORTH COUNTY COMPACTION ENGINEERING, INC. Project No. CE-6687 Page Approximate locations and depth of filled ground and extent of earthwork construction covered in this report are indicated on the attached Plate No.:One entitled, "Test Location Sketch". Grading operations were performed in order to remove and recompact compressible top soils (old fill/plowed ground) and to construct a level building pad(s) to accommodate the proposed condominium development Should the finished pad(s) be altered in any way, we should be contacted to provide additional recommendations. . . The site was graded in accordance with recommendations set, forth in the previously referenced soils reports: . . The site was graded toapproximately conform to project plans. Actual pad size and elevation may differ. Finish grade operations are to be completed at a later date LABORATORY TESTING Representative soils samples were collected and returned to .the laboratory for testing. The following tests were performed and are tabulated on the attached Plate No; Three. 1: Optimum Moisture/Maximum Density (ASTM D-1557) . . 2. Expansion Potential Test (FHA Standard) SOIL CONDITIONS Native soils encountered were silty-sands, clayey-sands and sandy-clays Fill soils were imported and generated from on-site excavation. The building site contained a transition from cut to fill. However, cut areas located within the building area were over excavated a minimum of 3 feet and brought to grade with compacted soil Over excavation was carried a minimum of 5 feet beyond the exterior building penmeter. Hence, no consideration need be given this characteristic. • . Imported soils were classified as being. low to very low in expansion potential. On-site highly expansive soils were placed a minimum of 3 feet below finish grade and/or blended with non- expansive soils to reduce the expansion potential of foundation bearing soils: Soils within the proposed foundation bearing zone were found to have an expansion index of 24 and are. classified as being "low" in expansion potential COMPACTION . NORTH COUNTY ENGINEERING, INC. Project No. CE-6687 Page Fill soils were placed, watered, and compacted in 6 inch lifts. During earthwork construction, areas where fill was placed were scarified, watered, and compacted toa minimum of ninety percent (90016). To determine the degree of compaction, field density tests were performed in accordance with ASTM D-1556 or D-2922 at the approximate horizontal locations designated on the attached Plate No. One entitled, "Test Location Sketch". A tabulation of test results and their vertical locations are presented on the attached Plate No Two entitled "Tabulation of Test Results". During grading operations, all.fihl soils found to have arelative compaction-of less the ninety percent (90%), were reworked until proper compaction was achieved. / RECOMMENDATIONS AND CONCLUSIONS . Continuous inspection was not requested to verify fill soils are placed in accordance with current standard practices regarding grading operations and earthwork construction. Therefore, as economically feasible as possible, part-time inspection was provided. Hence, the following recommendations are based on the assumption that all areas tested are representative of the entire project. Compacted fill and natural ground within the defined building areas have adequate strength to safely support the proposed loads.. Slopes may be considered stable with relation to deep seated failure provided they are properly maintained. Slopes should be planted with light groundcover (no gorilla ice plant) indigenous to the area Drainage should be diverted away from the slopes to prevent water flowing on the face of slope. This will reduce the probability of failure as a result of erosion. In our opinion, soil liquefaction at the site is unlikely to occur due to the following on-site soils conditions: A); Groundwater was not encountered at the time of grading. B). Loose compressible topsoils were removed to firm native grOund and recompacted to a minimum of ninety percent (90%) of maximum dry density. Q. The dense nature of the formation underlying the site. D). On-site soils possess relatively high cohesioncharacteristics. NORTH COUNTY COMPACTION : ENGINEERING, INC. Project No. CE-6687 Page 4 Continuous footings having a minimum width of 12 inches and founded a minimum of 18 inches below lowest adjacent grade, will have an estimated allowable bearing value, of 2000 pounds per square foot. Footings located on or adjacent to slopes should be founded at a depth such that the horizontal distance from the bottom outside face of footing to the face of. the slope is amiñimum of 8 feet. Plumbing trenches should be backfihled with a non-expansive soil having a swell of less than two percent (2%) and .a minimum sand equivalent of 30. Backfill soils should be inspected and compacted to a minimum of ninety percent (90%). Unless requested, recommendations for future improvements (additions pools, recreation slabs, additional grading, etc.) Were not included in this report. Prior to construction, we should be contacted to update conditions and provide additional recommendations. ., Completion of grading operations was left at rough grade; Therefore, we recommend a landscape architect be contacted to provide finish grade and drainage recommendations. Drainage recommendations should include.a two percent (2%) minimum fall away from all foundatiOn zones. POST-TENSION SLAB AND FOUNDATION It is our understanding foundation will consist of post-tension slab system. Therefore, the post tension design criteria presented in the soils report by AGRA is as. follows and should be incorporated, into the proposed foundation systems.. The design should be performed by a licensed structural engineer engaged in this type of design and who has a minimum of 5 hears experience. • . • , . 1): Continuous footings having a minimum width of 12 inches and founded a minimum of 18 inches below lowest adjacent grade will have an allowable bearing pressure of 2000 pounds per square foot. •, ' NORTH COUNTY COMPACTION ENGINEERING, INC. Project No. CE-6687 Page 5 On site soils were found to have an expansion index of 24. Em Center Lift = 5.5' (Edge moisture variation distance) Em Edge Lift = 2.5' (Edge moisture variation distance) Ym Center Lift = 3.0" (Max. differential soil movement) Ym Edge Lift = 1.0" (Max. Differential soil movement) 4) Clayey soils should not be allowed to dry prior to placing concrete. They should.be kept in a very moist condition or at a moisture content exceeding optimum moisture content by a minimum of three percent (3%). ° Prior to pouring of concrete, North County COMPACTION ENGINEERING, INC. should be contacted to inspect foundation recommendations for. compliance to those set forth. During placement of concrete North County COMPACTION ENGINEERING, INC. and/or a qualified concrete inspector should be present to document construction of foundations.- UNCERTAINTY AND LIMITATIONS In the event foundation excavation and steel placement inspection is required and/or requested,. an additional cost of $170.00 will be invoiced to perform the fieldinspection and prepare a "Final Conformance Letter". If foundations are constructed in more than one phase; $120.00 for each additional inspection will be invoiced. . . ., . . It is the responsibility of the owner and/or his representative to carry our recommendations set forth in this report. . . San Diego County is located in a high risk area with regard to earthquake Earthquake resistant projects are economically unfeasible. Therefore, damage as a result-of earthquake is probable and we assume no liability. We assume the on-site safety of our personnel only. We cannot assume liability of personnel. other than our own, It is the responsibility of the owner and contractor to insure construction operations are conducted in a safe manner and in conformance with regulations governed by CAL-OSHA and/or local agencies. . . . 11 NORTH COUNTY COMPACTION ENGINEERING, INC. SOIL TESTING CASA LACUNA CONDOMINIUMS APPROX. SCALE UNITS 1 - 1.2 1" = 15' LACUNA DRIVE CARLSBAD CALIFORNIA _P. PE _ 41 P. 11 PAI 'H cn 21 U-4 B) I' U-9 (1PC A) GARAGE i S 9 _L_ PAD42.8O./ P. 'L5 --\ o(pE— e; (TYPE A) pl PAD 42.50 P. P. 91 .30 F. I AD A / - .' --. P22O 2 42.10 GARAGE U 1 PE 8) I u—i 2 (PE—A) in - - - , S 29 'r LAI 20.0 0, TEST LOCATION SKETCH S PROJECT NO. CE- 6687 PLATE NO. ONE -II COMPACTION NORTH COUNTY ENGINEERING, INC. TABULATION OF TEST RESULTS Test # Date Horizontal Vertical Field Moisture Dry Density Soil Percent of I Location Location % Dry Wt. LB Cu. Ft. . Type Compaction 1 11/25/02 See 39.0 13.4 116.7 III 95.2 2 Plate 40.0 . . 10.4 115.5 LII 94.2 3 One 39.0 11.2 115.8 III 94.5 4 40.0 13.1 116.3 111 94.9 5 " 39.0 10.3 114.2 III 93.2 6 " 40.0 11.2 113.3 . 111 92.4 7 11/26/02 41.0 09.7 118.0 I 93.4 8 " . 41.5 08.6 118.9 1 94.1 9 41.0 08.9 120.2 1. 95.1 10 . 41.5 09.1 119.2 . 1 94.3 11 41.0 09.7 115.8 1 91.6 12 " 41.0 09.6 121.0 1 95.8 13 41.5, 08.9 117.7 L 93.1 14 11/26/02 36.0 - 15.3 115.1 II 97.5 15 38.0 16.4 . 111.9 11 94.8 16 " 40.0 09.5 120.6 IV 93.6 17 " 41.5 08.0 121.7 IV 94.4 18 11/27/02 . 39.0 08.6 115.3 1 91.2 19 41.0 09.2 122.8 .1 97.2 20 " " 39:0 09.4 118.8 111 96.9 21 " " 41.0 . 09.8 117.4 111 95.8 22 " " 39.0 09.9 . 116.1 111 94.7 23 41.0 10.3 116.5 III 95.1 24 " 39.0 10.3 117.4 111 95.8 25 " 41.0 09.1 118.1 111 96.4 26 12/05/02 39.0 08.7 . 121.3 V 91.3 27 '' 41.0 09.3 120.7 V 90.8 28 '' 41.0 10:3 119.9 V 90.2. 29 12/10/02 .42.2 RFG. 08.8 123.8 IV 96.1 30 " 42.2 RFG 08.6 127.4 IV 98.9 31 " 42.5 RFG 09.1 125:1 IV 97.1 32 " 42.6 RFG 07.3 . 121.8 - IV 94.5 '33 42.6 RFG 07.8 . 127.5 -V - 96.0 34 " " 43:7 RFG 08.3 125.2 V 94.2 35 ' " 42.8 RFG 09.2 124.8 V 93.9 36 " 42.6RFG 08.4 126.5 V 95.2 37 " 42.6 RFG 08.7 120.1 V 90.4 REMARKS: RFG = Rough Finish Grade PROJECT NO. CE-6687 PLATE NO. TWO NORTH COUNTY COMPACTION ENGINEERING, INC. TABULATION OF TEST RESULTS OPTIMUM MOISTURE/MAXIMUM DENSITY SOIL DESCRIPTION TYPE MAX. DRY. DENSITY OPT. MOISTURE - S (LB. CU. FT) (% DRY WT) Red Brown Silty-Sand I 126.3 10.1 (hey Brown SandClay II 118.0 14.0 - Dark Brown Silty-Sand Ill 122.5 10.5 Red Brown Silty-Sand (Import) -IV 128.8 09.5 Red Brown Silty-Sand (Import) V 132.8 08.4 EXPANSION POTENTIAL SAMPLE NO, I II 111 IV CONDITION Remold 90% Remold 90% Remold 90% Remold 90% INITIAL MOISTURE (%) 9.5 13.5 10.5 9.3. AIR.DRY MOISTURE (%) 3.1 9.1 4.4 1.6 FINAL MOISTURE (%) 16.6 32.2 20.4 12.4 DRY DENSITY PCF) . 113.7 .106.2 110.3 1159 LOAD(PSF) I 150 150 150 150 SWELL (%) 1.1 15.0 . 2.4 .4 . EXPANSION INDEX 11 15.0 24 4 DIRECT SHEAR •• •. SAMPLE NO. CONDITION S S Remold 90% Remold 90% ANGLE 'INTERNAL FRICTION COHESION INTERCEPT (PCF) • S. • S • ., PROJECT NO CE-6687 S S PLATE NO. THREE S S. •