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Home My WebLink AboutCT 08-06; HIGHLAND JAMES SUBDIVISION; FINAL SOILS REPORT; 2021-06-07 FINAL AS-GRADED GEOTECHNICAL REPORT HIGHLAND JAMES SUBDIVISION 3 LOTS, 3975, 3979, 3981 JAMES DRIVE CARLSBAD, CALIFORNIA PREPARED FOR: VECK INVESTMENT PROPERTIES, LLC ATTN: MS. ELIZABETH TEMPLE 3970 & 3980 HIGHLAND DRIVE CARLSBAD, CALIFORNIA PREPARED BY: CONSTRUCTION TESTING & ENGINEERING, INC. 1441 MONTIEL ROAD, SUITE 115 ESCONDIDO, CALIFORNIA 92026 CTE PROJECT NO.: 10-12998G JUNE 17, 2021 A Universal Engineering Construction Testing & Engineering, Inc. Sciences Company Inspection I Testing I Geotechnical I Environmental & Construction Engineering I Civil Engineering I Surveying 1441 Montiel Road, Suite 115 I Escondido, CA92026 I Ph (760) 746-4955 I Fax (760) 746-9806 I www.cte-inc.net S:\Projects\10-12000 to 10-12999 Projects\10-12998G\Rpt_As-Graded Compaction (10-12998G).doc TABLE OF CONTENTS SECTION PAGE 1.0 BACKGROUND .......................................................................................................................1 2.0 PROJECT INFORMATION ......................................................................................................1 3.0 FILL PLACEMENT ..................................................................................................................2 4.0 TESTING ...................................................................................................................................2 5.0 ADDITIONAL CONSTRUCTION OBSERVATION ..............................................................3 6.0 CONCLUSIONS AND RECOMMENDATIONS ....................................................................3 7.0 LIMITATIONS ..........................................................................................................................3 TABLES TABLE I COMPACTION TEST SUMMARY TABLE II LABORATORY TEST DATA FIGURES FIGURE 1 SITE INDEX MAP FIGURE 2 COMPACTION TEST LOCATION MAP Final As-Graded Geotechnical Report Highland James Subdivision 3975, 3979, 3981, James Drive, Carlsbad, California June 17, 2021 CTE Job No. 10-12998G S:\Projects\10-12000 to 10-12999 Projects\10-12998G\Rpt_As-Graded Compaction (10-12998G).doc Page 1 1.0 BACKGROUND This document provides information regarding testing of compacted fill for the grading operations completed in 2017 for the improvements for the proposed Highland James Subdivision located at 3975, 3979, 3981 James Drive in Carlsbad, California. Our work was authorized through CTE proposal numbers G-3702A/G-5189. The project consists of three two-story residential structures, with paved driveways, retention basins, flatwork, utilities, and other associated improvements. The site is bounded by two undeveloped lots and Highland Drive to the southwest, James Drive and residential structures to the northwest and southeast. For the recent grading described in this report, removals were generally performed to the depth of competent native materials ranging from a minimum of 4.0 to 9.5 feet below finished pad grade. The overexcavation bottoms were observed and probed by CTE for competency and scarified and moisture conditioned prior to the placement of compacted fill. The attached Figure 1 shows the approximate location of the site and surrounding area, and Figure 2 provides a Compaction Test Location Map. 2.0 PROJECT INFORMATION This report includes a summary of test results and observations performed by CTE during the placement of compacted fill for the proposed building pads and associated improvements. Conditions encountered at the site were generally as anticipated in the referenced soils report (CTE, Final As-Graded Geotechnical Report Highland James Subdivision 3975, 3979, 3981, James Drive, Carlsbad, California June 17, 2021 CTE Job No. 10-12998G S:\Projects\10-12000 to 10-12999 Projects\10-12998G\Rpt_As-Graded Compaction (10-12998G).doc Page 2 2016). Overexcavated was performed to a minimum depth of two feet below the bottom of proposed foundations or deeper to competent materials. Overexcavation bottoms were observed by CTE prior to scarification and placement of compacted fill. Site grading was conducted with heavy duty compaction equipment (e.g., excavator with sheep’s foot compactor, rubber-tired loader with full bucket, water truck, etc.). 3.0 FILL PLACEMENT Fill soils were generally placed in uniformly compacted lifts at a minimum two percent above optimum moisture content. Compaction was performed to the appropriate minimum values (90 percent for building pad areas), as determined by ASTM D1557. Backfill placement and compaction were performed in substantial conformance with the project geotechnical recommendations provided in the referenced geotechnical documents. 4.0 TESTING Testing was performed to supplement field observations. Testing of compacted fill addressed by this report was conducted, as scheduled by the general contractor, between May 9, 2017 and May 22, 2017. Field-testing of the compacted fill soil was conducted in accordance with ASTM D-6938-17 (nuclear method). Results indicate that fill materials in the areas tested were compacted to at least 90 percent of the laboratory maximum dry density, as required, in accordance with ASTM D 1557. Final As-Graded Geotechnical Report Highland James Subdivision 3975, 3979, 3981, James Drive, Carlsbad, California June 17, 2021 CTE Job No. 10-12998G S:\Projects\10-12000 to 10-12999 Projects\10-12998G\Rpt_As-Graded Compaction (10-12998G).doc Page 3 Tabulated results of the field compaction testing are provided in the attached Table I, “Compaction Test Summary.” Laboratory determination of the reference compaction values for the fill materials is provided in Table II, “Laboratory Test Results.” Figure 2 shows the approximate location of the compaction tests performed. 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. 6.0 CONCLUSIONS AND RECOMMENDATIONS CTE concludes that the soil engineering and geologic aspects of the grading are in general compliance with the referenced and approved geotechnical documents and the approved grading/improvement plans (City of Carlsbad Drawing No. 483-6B). Additional future improvements, if planned, should be designed and constructed in accordance with the recommendations of the referenced soils report and subsequent geotechnical documents. However, CTE should confirm site conditions if/when site grading or construction recommences. 7.0 LIMITATIONS As limited by the scope of the services that CTE agreed to perform, opinions presented herein are based on observations, test results, and understanding of the proposed site development. CTE’s service was performed according to the currently accepted standard of practice by reputable consultants. No warranty, express or implied, is given or intended with respect to the performance Final As-Graded Geotechnical Report Highland James Subdivision 3975, 3979, 3981, James Drive, Carlsbad, California June 17, 2021 CTE Job No. 10-12998G S:\Projects\10-12000 to 10-12999 Projects\10-12998G\Rpt_As-Graded Compaction (10-12998G).doc Page 4 of the project in any respect. Submittal of this report should not be construed as relieving the grading contractor of his responsibility to comply with the project requirements. The recommendations presented in the geotechnical documents have been developed in order to reduce the potential adverse effects of differential soil settlement and expansive soils. However, even with the design and construction precautions provided, some post-construction movement and associated distress should be anticipated. This report is also subject to the same limitations as our previous geotechnical documents. The opportunity to be of service is appreciated. If you have any questions regarding testing conducted, observations made during construction or recommendations presented herein, please do not hesitate to contact this office. Respectfully submitted, CONSTRUCTION TESTING & ENGINEERING, INC. Dan T. Math, GE #2665 Aaron J. Beeby, CEG #2603 Principal Engineer Senior Engineering Geologist MCB/AJB/DTM:ah Final As-Graded Geotechnical Report Highland James Subdivision 3975, 3979, 3981, James Drive, Carlsbad, California June 17, 2021 CTE Job No. 10-12998G S:\Projects\10-12000 to 10-12999 Projects\10-12998G\Rpt_As-Graded Compaction (10-12998G).doc Page 5 ATTACHMENTS Figure 1 Site Index Map Figure 2 Compaction Test Location Map Tables I Compaction Test Summary Table II Laboratory Test Results REFERENCES Geotechnical Investigation Proposed 5-Unit Residential Subdivision 3980 Highland Drive, Carlsbad, California CTE Job #10-12998G, dated November 9, 2016 TABLE I COMPACTION TEST SUMMARY Job Name: Highland James Subdivision Job No. 10-12998G Job Address: 3975, 3979, 3981 James Drive Date: 6/17/2021 Date Test Location Elevation Density Moisture Relative Soil No. or Depth pcf Content Compaction Type Feet % Dry % Weight 5/9/2017 1 Lot 1 132.5 124.6 12.4 94% 1 5/9/2017 2 Lot 1 132.5 122.1 12.7 92% 1 5/9/2017 3 Lot 2 132.5 122.5 12.8 92% 1 5/9/2017 4 Lot 2 132.5 121.3 13.7 91% 1 5/11/2017 5 Building Pad Lot 3 123.5 122.7 11.7 99% 1 5/11/2017 6 Building Pad Lot 3 125.5 120.5 11.4 91% 1 5/11/2017 7 Building Pad Lot 3 128.0 120.1 12.1 91% 1 5/11/2017 8 Building Pad Lot 3 129.0 119.8 11.6 90% 1 5/11/2017 9 Building Pad Lot 3 129.5 121.9 12.2 92% 1 5/11/2017 10 Building Pad Lot 2 127.0 121.6 11.3 92% 1 5/11/2017 11 Building Pad Lot 2 129.0 122.2 11.5 92% 1 5/12/2017 12 Building Pad Lot 1 FG 121.3 11.5 91% 1 5/12/2017 13 Building Pad Lot 1 FG 120.8 12.3 91% 1 5/12/2017 14 Building Pad Lot 2 130.0 122.2 11.9 92% 1 5/12/2017 15 Building Pad Lot 2 131.0 123.6 11.7 93% 1 5/12/2017 16 Building Pad Lot 2 FG 121.9 12.2 92% 1 5/12/2017 17 Building Pad Lot 3 130.0 123.1 11.4 93% 1 5/12/2017 18 Building Pad Lot 3 131.0 122.4 12.1 92% 1 5/22/2017 19 Building Pad Lot 3 131.0 120.1 13.0 97% 2 5/22/2017 20 Building Pad Lot 3 FG 119.6 13.3 96% 2 ** TEST FAILED, SEE RETEST 1 TABLE II LABORATORY TEST DATA Job Name: Highland James Subdivision Job No. 10-12998G Job Address: 3975, 3979, 3981 James Drive, Carlsbad, CA Date 6/17/2021 Maximum Optimum Sample No.Dry Density Moisture Soil pcf Content Description %wt 1 132.7 9.2 2 124.0 11.0 Reddish Brown brown SM light brown SC (Import) 2