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Home My WebLink AboutCT 06-15; TABATA RANCH; FINAL SOILS REPORT; 2017-10-27TABLE OF CONTENTS SECTION PAGE 1.0 BACKGROUND ....................................................................................................................... 1 2.0 PROJECT INFORMATION ...................................................................................................... 1 3.0 FILL PLACEMENT .................................................................................................................. 2 4.0 TESTING ................................................................................................................................... 3 5.0 ADDITIONAL CONSTRUCTION OBSERVATION .............................................................. 3 6.0 CONCLUSIONS AND RECOMMENDATIONS ................................................................... .4 7.0 LIMITATIONS .......................................................................................................................... 4 TABLES TABLE! TABLE II FIGURES FIGURE 1 FIGURE2 COMP ACTION TEST SUMMARY LABORATORY TEST DATA SITE INDEX MAP COMP ACTION TEST LOCATION MAP \\ESC _ SERVER\Projects\ I O-l 3292G\Compaction Repo1t\Rpt_ Comp (I 0-13292G) I 0-17 .doc As-Graded Geotechnical Report Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California October 27, 2017 1.0 BACKGROUND Page 1 CTE Job No. 10-132920 This document provides information regarding testing of compacted fill for the recently completed Tabata Ranch Subdivision located on Lemon Leaf Drive in Carlsbad, California. The site was previously graded based on the preliminary geotechnical investigation performed Vinje & Middleton Engineering, Inc. (Job No. 01-364-P) dated August 2, 2006 and subsequent Update Recommendations provided by CTE (2016). CTE reviewed the previously prepared report and was in general agreement with the data, conclusions; and recommendations. CTE previously provided an interim as-graded document for Lots 1-5 dated July 6, 2015 and modified August 2, 2015 (attached). Our work was authorized through CTE proposal no. G-3871, dated August 23, 2016. Based on the previously performed limited geotechnical report and as-grade documents, the site consists of Quaterna1y Previously Placed Fill soils overlying sedimentary bedrock units of the Eocene Age. The attached Figure 1 shows the approximate location of the site and surrounding area. 2.0 PROJECT INFORMATION This report includes a summary of test results and observations perfmmed by CTE during the recent placement of compacted fill for the proposed strnctures and associated improvements. Conditions encountered at the site were found to consist of previously placed fill and residual soils overlying sedimentary bedrock. Previously placed fill and other disturbed near surface soils were generally found to consist ofloose, silty sand. These materials were removed beneath improvement areas p1ior to placement of compacted fill as part of the recent grading operation. As indicated, \\ESC _ SERVER\Projects\l O-l 3292G\Compaction Repo1t\Rpt_ Comp (IO-l 3292G) I 0-17.doc As-Graded Geotechnical Report Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California October 27, 2017 Page2 CTE Job No. 10-132920 loose and disturbed surface soils and previously placed fill were excavated between elevations 253 (msl) and 272 (msl), depending on location. The exposed bottoms of excavations were observed, tested, and confirmed ( as appropriate) prior to placement of the compacted fill. Exposed areas to receive fill were then scarified, moisture conditioned, and compacted in general accordance with project requirements. Following subgrade preparation, fill materials were moisture conditioned, placed in lifts, and compacted. Excavations and compaction within the improvement areas were conducted with a D8 dozer and a 980 loader. Mountain Movers was the grading contractor for the project. Grading on the subject site also consisted of parking and drive areas, minor excavations, wall backfill, and utility installation. Minor grading and compaction testing for utility tie-ins conducted in the adjacent Lonicera Street right-of-way is also documented herein. 3.0 FILL PLACEMENT Fill soils consisting of onsite stock piled materials were generally placed in uniformly compacted lifts at above optimum moisture content. Compaction was performed to the appropriate minimum values (90% for building pad areas and 95% for pavement sub grade areas), as determined by ASTM D1557. Grading was perf01med using standard construction equipment, followed by mixing, moisture conditioning, and compaction procedures. Backfill placement and compaction were performed in overall confo1mance with geotechnical recommendations. \\ESC _ SERVER\Projects\1 0-l 3292G\Compaction Repo1t\Rpt_ Comp ( I 0-132920) 10-17.doc As-Graded Geotechnical Report Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California October 27, 2017 4.0TESTING Page 3 CTE Job No. 10-132920 Testing was performed to supplement field observations. Testing of compacted fill addressed by this repo1t was conducted, as scheduled by the contractor, between October 19, 2016 and May 10, 2017. Field-testing of the compacted fill soil was conducted in accordance with ASTM D-6938-08a (nuclear method). Results of the field-testing indicate that fill materials were compacted to at least 90 percent or 95 percent of the laboratory maximum dry density, as required, in accordance with ASTM D 1557. Fill material was generally compacted at above optimum moisture content. Tabulated results of the field compaction testing are provided in the attached Table I, "Compaction Test Summary." Laboratmy determination of the reference compaction values for the fill materials is provided in Table II, "Laboratmy Test Results." Figure 2 shows the approximate location of the compaction tests performed. Based on site observations, it appears the Expansion Index (E.I.) for onsite materials were generally found to have a very low expansion potential (EI < 20). 5.0 ADDITIONAL CONSTRUCTION OBSERVATION Additional grading and backfilling, if any, should be observed and tested by CTE. In addition, prior to any significant future development, an appropriate update geotechnical investigation and report should be completed. \\ESC _ SERVER\Projects\l O-l 3292G\Compaction Repo11\Rpt_ Comp (I O-l 3292G) 10-17.doc Page 5 As-Graded Geotechnical Report Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California October 27, 2017 CTE Job No. 10-132920 Attachment: Interim As-Graded Geotechnical Report Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad, California CTE Job No. 10-121010, dated July 6, 2015, Modified August 2, 2015 References: Summary for Testing of Compacted Fill for Lot 5 Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California CTE Job No. 10-132920, dated February 6, 2017 Summary for Testing of Compacted Fill for Lots 1 and 2 Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California CTE Job No. 10-132920, dated November 16, 2016 Summary for Testing of Compacted Fill for Lot 3 Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California CTE Job No. 10-132920, dated May 10, 2017 Update Geotechnical Recommendations for Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad California CTE Job No. 10-132920, dated August 26, 2016 Geotechnical and Update Repo1t and Grading Plan Review Proposed Tabata Ranch Subdivision Lemon Leaf Drive, Carlsbad, California Vinje & Middleton Engineering Job# 01-364-P, dated August 2, 2006 Preliminary Geotechnical Investigation Proposed 4-Lot Subdivision, Tabata Ranch Off Camino De Las Ondas and Lonicera Street, Carlsbad, California Vinje & Middleton Engineering Job# 01-364-P, dated October 24, 2001 \\ESC _ SERVER\Projects\10-13292G\Compaction Report\Rpt_ Comp ( I O-l 3292G) I 0-17.doc TABLE I COMP ACTION TEST SUMMARY Job Name: Tabata Ranch Job No. 10-132920 Job Address: Lemon Leaf Drive, Carlsbad Ca Date: 10/27/2017 Date Test Location Elevation Density Moisture Relative Soil No. or Depth pcf Content Compaction Type Feet %Dry % Weight 10/19/2016 1 S.E Side Lonicera St AC 139.6 -96% 1 10/19/2016 2 N.E Side Lonicera St AC 138.8 -96% 1 10/19/2016 3 N.E Side Lonicera St AC 139.3 -96% 1 10/19/2016 4 S.W Side Lonicera St AC 137.8 -95% 1 10/19/2016 5 CTR Westside Lonicera St AC 139.9 -96% 1 10/19/2016 6 N.W Side Lonicera St AC 139.2 -96% 1 10/19/2016 7 N.E Side Lonicera St AC 138.4 -95% 1 10/27/2016 8 Lot #1 Pad SG 118.9 10.4 94% 2 10/27/2016 9 Lot#l Pad SG 115 .5 10.7 92% 2 10/27/2016 10 Lot#2 Pad SG 118.4 10.4 94% 2 10/27/2016 11 Lot #2 Pad SG 117.7 10.3 93 % 2 1/31/2017 12 Lot#5 SG 109.1 13.1 95% 3 1/31/2017 13 Lot#5 SG 110.7 13.3 96% 3 1/31/2017 14 Lot#5 SG 109.8 13.3 95% 3 5/10/2017 15 Building Pad #3 FG 110.6 12.7 96% 3 5/10/2017 16 Building Pad #3 FG 111.3 12.5 97% 3 10/26/2017 17 1st Level Retaining Wall Lot 3, NW SG 106.3 13.8 92% 3 10/26/2017 18 1st Level Retaining Wall Lot 3, N SG 104.9 14.3 91 % 3 10/26/2017 19 1st Level Retaining Wall Lot 3, NE SG 104.5 14.0 91 % 3 10/26/2017 20 1st Level Retaining Wall Lot 3, E SG 104.7 13.7 91% 3 10/26/2017 21 Upper Level Retaining Wall Lot 3, NW SG 105.2 14.3 91% 3 10/26/2017 22 Upper Level Retaining Wall Lot 3, NE SG 104.2 13.9 90% 3 10/26/2017 23 Upper Level Retaining Wall Lot 3, NE SG 104.6 13.8 91% 3 10/26/2017 24 Upper Level Retaining Wall Lot 3, E SG 103.9 14.2 90% 3 10/26/2017 25 Upper Level Retaining Wall Lot 3, E SG 104.8 14.4 91% 3 ** TEST FAILED, SEE RETEST Job Name: Job Address: Sample No. 2 3 Tabata Ranch TABLE II LABORATORY TEST DATA Job No. 10-132920 Lemon Leaf Drive, Carlsbad Ca Date 10/11/2017 Maximum Dry Density pcf 145.1 125.9 115.2 Optimum Moisture Content %wt 9.5 12.3 2 Soil Description Asphalt Concrete Light Brown Silty Sand Yellowish Brown Silty Sand