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Home My WebLink AboutCT 2017-0004; SIX ON MADISON CONDOMINIUMS; FINAL SOILS REPORT; 2021-12-20ALLIED EARTH TECHNOLOGY =ROBERT CHAN. P.E. 7915 SILVERTON AVENUE. SUITE 317 SAi' DIEGO. CALIFORNIA 92126 PH. (858) 586-1665 ( 6 19) -14 7--17-17 FAX ( 858} 586-1650 FINAL REPORT OF GEOTECHNICAL OBSERVATION AND SOIL TESTING PROPOSED SIX-UNIT CONDOMINIUM BUILDING SITE 3095 MADISON STREET CARLSBAD, CALIFORNIA FOR OAK AND MADISON LLC PROJECT NO. 18-1106E5 DECEMBER 20, 2021 ALLIED EARTH TECHNOLOGY 7915 SILVERTON AVENUE. SUITE 317 SAN DIEGO. CALIFORNIA 92126 PH. (858) 586-I 665 FAX (858) 586-1650 ( 6 I 9) 44 7-4 7 4 7 ROBERT CHAN. P.E. December 20, 2021 Oak & Madison LLC 7851 Mission Center Court San Diego, CA. 92108 Attn: Subject: Mr. Mehran Saberi Project No. 18-1106E5 Final Report of Geotechnical Observation and Soil Testing Proposed Six-Unit Condominium Building Site 3095 Madison Street Carlsbad, California Dear Mr. Saberi : This report presents the results of our geotechnical observation and testing of fill soils placed during the grading for the proposed six unit condominium building site on subject property, more specifically referred to as being Lot Nos. 31 and 32 , in Block No. 39 and adjacent street closure, according to Map thereof No. 775 (APN 203-305-10-00), in the City of Carlsbad, State of California .. Rough Grading _Prior to commencement of grading, the site was cleared and grubbed, and all debris hauled away and disposed of offsite. Grading began in early April, 2020, with the installation of temporary shoring along the west property line adjacent to the alley. After the temporary shoring was in place, excavation for the carlift was accomplished. Temporary excavations with vertical excavations up to 5 feet, and I : I (horizontal : vertical) above were accomplished along the north and south sides. A temporary access ramp was graded along the east side. The excavated soils were removed and exported from the site. Groundwater was encountered along the base of the carlift excavation. The groundwater level was lowered to permit the subgrade soils to dry out, and in-situ density tests were then performed along the base of the carlift. Project No. 18-1106E5 Oak & Madison, LLC 3095 Madison Avenue 12/20/21 Page2 The upper soils on the main level of the proposed structure within 5 feet outside the foundation lines were removed to a depth of 3 feet. The bottom of the over-excavation was inspected by our firm, scarified and uniformly recompacted. Inspection of Foundation Trench Excavations The foundation for the carlift consisted of an 18 inch concrete mat, with a base layer, consisting of¾ to 1 inch gravel beneath the mat foundation. The foundation of the main level consisted of continuous and isolated pier footings. All foundation excavations wee inspected by our firm, and the results of our inspection indicate that all foundation excavations inspected were into competent natural or compacted fill soils. Backfill Behind Carlift Retaining Walls Backfilling commenced after the basement retaining walls are constructed and the subdrains installed. Backfilling was accomplished with a tractor-mounted sheeps-foot roller in lifts on the order of 6 to 8 inches until finished grade is achieved .. The soils encountered on the site possess low expansion potential (Expansion Index = 26). The in-situ densities of the fill and backfill soils placed were tested in accordance with the applicable provisions of ASTM D2922. The depths of fill at which the tests were taken and the final test results are presented on pages T-1 and T-2, under, "Table of Test Results". The laboratory determinations of the maximum dry densities and optimum moisture contents of the fill soils are set forth on page L-1 under, "Laboratory Test Results". The approximate location of the compacted filled ground and field density tests are shown on Figure No. 1, entitled, "Approximate Location of Field Density Tests". The results of the tests and observations indicate that the fill soils and backfill soils placed on the site have been compacted to at least 90 percent of maximum dry density at near optimum moisture content. Test results indicate that these fill soils are adequate for their purpose of supporting the proposed condominium building. The geotechnical conditions encountered during grading did not differ substantially from those presented in our Geotechnical Investigation Report for subject property, and all recommendations presented therein have been substantially complied with. The grading performed have been in substantially conformance with the approved grading plans and our recommendations. Foundation and slab recommendations as presented in or Geotechnical Investigation Report and approved foundation plans should be followed. Project No. 18-1106E5 Oak & Madison LLC 3095 Madison Street LABORATORY TEST RESULTS 05/12/20 Page L-1 1. The maximum dry densities and optimum moisture contents of the fill and backfill soils placed were determined in accordance with A.S.T.M. D1557, Method A. The results of the tests are presented as follows : Soil Type 1 2 Soil Description Brown fine sand (SP) Brown fine to medium sand Maximum Dry Density (lbs/cu.ft.) 122.5 126.0 Optimum Moisture Content (% Dry Wt.) 11.5 9.5 Project No. 18-1106E5 Oak & Madison LLC 3095 Madison Street 12/20/21 TABLE OF TEST RES UL TS ====== Depth Plus of Fill Field Dry ¾" Maximum Date Test Soil at Test Moisture Density Rock Dry Density Percent of No. Type (Ft.) (% Dry Wt.) (lbs./cu.ft.) (%) (lbs./cu.ft.) Compaction Test + 3 12.1 110.8 0 122.5 90.4 03/27/20 2 + 3 13.2 112.0 0 122.5 91 .4 03/27/20 3 + 3 11.5 112.3 0 122.5 91.7 03/27/20 4 + 3 11.9 112.4 0 122.5 91.8 03/27/20 5 + 3 10.8 114.1 0 122.5 93.l 03/27/20 6 + 3 11.l 112. l 0 122.5 91.5 03/27/20 7 + 3 9.9 113.2 0 122.5 92.4 03/31/20 8 + 3 10.l 112.4 0 122.5 91.8 03/31/20 9 + 3 10.7 113.1 0 122.5 92.3 03/31/20 10 + 3 11.5 112.9 0 122.5 92.2 03/31/20 11 + 3 10.3 113.l 0 122.5 92.3 03/31 /20 12 + 3 11.0 112.8 0 122.5 92.1 03/31/20 13 + 3 12.8 111.9 0 122.5 91.3 04/02/20 14 + 3 11.1 110.8 0 122.5 90.4 04/02/20 15 1 + 3 12.5 113.l 0 122.5 96.4 04/02/20 16 + 3 13.l 112.1 0 122.5 91.5 04/02/20 17 + 3 10.9 112.2 0 122.5 91.6 04/02/20 18 + 3 12.8 110.9 0 122.5 90.5 04/02/20 Page T-1 Remarks Finished grade " " " " " " " " " " Project No. 18-1106E5 Oak & Madison LLC 3095 Madison Street 12/20/21 TABLE OF TEST RESULTS (Cont'nd) ======= Depth Plus of Fill Field Dry ¾" Maximwn Date Test Soil at Test Moisture Density Rock Dry Density Percent of No. Type (Ft.) (% Dry Wt.) (lbs./cu.ft.) (%) (lbs./cu.ft.) Compaction Test 19 2 + 3 9.3 120.6 0 126.0 94.6 07/02/20 20 2 + 3 10.3 121.5 0 126.0 96.4 07/02/20 21 2 +5 9.6 121.9 0 126.0 96.7 07/02/20 22 2 +7 8.2 119.3 0 126.0 94.6 07/03/20 23 2 +7 9.7 121.4 0 126.0 96.4 07/03/20 24 2 +7 9.4 121.3 0 126.0 96.2 07/03/20 25 2 +7 6.0 122.5 0 126.0 97.2 07/03/20 26 + 3 10. l 112.4 0 122.5 91.8 07/17/20 27 + 3 10.7 113.l 0 122.5 92.3 07/1 7/20 28 +5 11.5 112.9 0 122.5 92.2 07/17/20 29 +7 10.3 113 .1 0 122.5 92.3 07/1 7/20 30 +7 11.0 112.8 0 122.5 92.1 07/17/20 Page T-2 Remarks Finished grade " " " Finished grade "