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Home My WebLink AboutMS 08-03; NOLAN MINOR SUBDIVISION; FINAL SOILS REPORT; 2020-07-13 FINAL REPORT OF GEOTECHNICAL TESTING AND OBSERVATION SERVICES DURING POST-GRADING CONSTRUCTION FOR Frank and Joann Nolan Family Trust 73311 Las Brisas Court Carlsbad, California PREPARED FOR Frank and Joann Nolan Family Trust 73311 Las Brisas Court Carlsbad, California 92009 PREPARED BY GeoTek, Inc. 1384 Poinsettia Avenue, Suite A Vista, California 92081 PROJECT NO. 3281-SD3 JULY 13, 2020 GEOTECHNICAL | ENVIRONMENTAL | MATERIALS July 13, 2020 Project No. 3281-SD3 Frank and Joann Nolan Family Trust 73311 Las Brisas Court Carlsbad, California 92009 Attention: Mr. and Mrs. Frank and Joann Nolan Subject: Final Report of Geotechnical Observation & Testing Services During Post-Grading Construction 73311 Las Brisas Court Carlsbad, California Dear Mr. and Mrs. Nolan: We are pleased to present herein the results of our geotechnical testing and observation services during post-grading earthwork construction associated with the subject project. This report includes observation and testing pertinent to the water lines backfill as well as, foundation excavation observations, easement/driveway’s subgrade, aggregate base, and asphalt-concrete construction for the subject project. Enclosed are field density and moisture content test results, and results of laboratory testing. Grading of the subject building pad was completed under the observation of, and with selective testing by, GeoTek, Inc. (GeoTek) as reported on September 14, 2017 (GeoTek, 2017. Post grading observation and selective testing was performed between the dates of September 15, 2017 and April 3, 2020 on a part-time, on-call basis. The following summarizes our observations and testing during post grading construction. 1. SUMMARY OF GEOLOGIC AND SOILS CONDITIONS Based on our field observations and testing during site post grading, we note the following:  The entrance driveway had been originally designed as curvilinear alignment. However, due to hard rock conditions, the driveway alignment was built in a linear alignment. The final design resulted in a rectilinear driveway that cuts into the west facing entrance pad slope. GeoTek, Inc. 1384 Poinsettia Avenue, Suite A Vista, CA 92081-8505 (760) 599-0509 Offic, (760) 599-0593 Fa: www.geotekusa.com Frank and Joann Nolan Family Trust July 13, 2020 Final Report of Post-Grade Compaction Report Project No. 3281-SD3 Carlsbad, California Page 3  The slope face along the driveway entrance was designed to be built at a slope gradient of 2:1 (h:v). However, due to hard rock conditions the lower 2 feet of slope was cut into bedrock at a slope gradient ratio of 1.5:1.  Visual classification of the soil in the field, compared to the soil description from laboratory testing, was the basis for determining the maximum dry density value and optimum moisture content applied to each soil density test.  Backfills for wet utilities were placed and compacted to at least 90% of the maximum dry density, at or slightly above optimum moisture content relative to ASTM D 1557.  Asphalt-concrete (AC) for the water connection along Piragua Street associated with the project was placed and compacted to at least 95% of the wet density relative to ASTM D2041.  Field asphalt concrete density tests were compared against a plant supplied laboratory maximum density. 2. FIELD AND LABORATORY TESTING 2.1 FIELD TESTING Field density tests were taken at periodic intervals and random locations to check the compaction efforts by the contractors. The field density testing for the subject site was performed using a nuclear gauge, in general accordance with testing procedure ASTM D 6938 for soils and ASTM D 2950 for asphalt concrete. Density test locations performed for rough grading of the building pad are presented on Figure 1. The results of the field density testing conducted for the herein reported site area are included in the attached Tables 1 through 3. 2.2 LABORATORY TESTING The following information presents a summary of the laboratory testing procedures and results. 2.3 MOISTURE-DENSITY RELATIONSHIPS The laboratory maximum dry density and optimum moisture content for the soils were determined in general accordance with test method ASTM D 1557. The laboratory maximum GEOTEK Frank and Joann Nolan Family Trust July 13, 2020 Final Report of Post-Grade Compaction Report Project No. 3281-SD3 Carlsbad, California Page 4 density for asphalt concrete mixtures was determined in accordance with ASTM D 2041. The table below presents the soil type used for this project. SUMMARY OF LABORATORY MAXIMUM DRY DENSITY AND OPTIMUM MOISTURE CONTENT TEST RESULTS (ASTM D 1557/2041) Soil Type Description Maximum Dry Density (pcf) Optimum Moisture Content (%) A Reddish Brown Silty Sand 130.1 9.6 B Brown Clayey Silty Sand 126.6 10.7 C Import Fill Brown Clayey Silty 127 10.4 D Escondido Sand and Gravel 118 E* Plant, Asphalt 143 - CMB CMB 113.5 14.5 *Plant Provided 3 CONCLUSIONS Field density tests indicate that the materials were compacted to project specifications at the time and locations tested. Where a test showed a value less than project minimums relative to the laboratory standard, the area was subjected to additional work and retested to verify minimum project compaction specifications were achieved. As a result of design modifications to the entrance easement, certain aspects of the adjacent fill slope were steepened. The limited section 1.5:1 slope was checked by GeoTek staff and based on the rock quality and hardness is considered geotechnically suitable for its intended purpose. Increased maintenance may be required in the long term along this section as the material experiences greater downward forces. 4 LIMITATIONS The purpose of this report is to present a summary of observation and testing services provided by this firm during the post-grading operations that were performed on the subject property between September 15, 2017 and April 3, 2020. More specifically, the scope of this report includes a presentation of data obtained during post grading and a discussion of operations performed by the grading contractor. GEOTEK Frank and Joann Nolan Family Trust July 13, 2020 Final Report of Post-Grade Compaction Report Project No. 3281-SD3 Carlsbad, California Page 5 Preparation for, and placement of, compacted fill was monitored by representatives of this firm. All soils tested were found to meet or exceed the minimum degree of compaction specified in the job requirements. Field density tests were performed at random locations throughout the area of the job that is within the scope of this report. Our observations and testing were performed in such a manner as to be reasonably certain that the soils tested are representative of the work, and that the work, in general, essentially complies with the job requirements. Our services were performed in accordance with engineering principles generally accepted at this time and in this area. No warranty is expressed or implied. It should be understood that field data, including density test locations and elevations, as well as the location of compacted fill, are only approximately located. The accuracy of our field technician's estimated locations will vary depending on the survey control available at the time the estimations were made. No warranty as to the actual extent of the filled area, nor of its relationship to the planned structural improvements, is expressed or implied. This report is subject to review by the controlling authorities for this project. GeoTek accepts neither responsibility nor liability for work, testing, or recommendations performed or provided by others. GEOTEK Frank and Joann Nolan Family Trust July 13, 2020 Final Report of Post-Grade Compaction Report Project No. 3281-SD3 Carlsbad, California Page 6 We appreciate the opportunity to be of service on this project. Please contact the undersigned if you have any questions. Respectfully submitted, GeoTek, Inc. Christopher D. Livesey, Chris E. Lillback Timothy E. Metcalfe, CEG 2733 PE, 35007 CEG1142 Project Geologist Senior Project Engineer Principal Geologist Enclosures: Figure 1 – Field Density Test Location Map Table 1 – Summary of Grading Density Tests Table 2 – Summary of Driveway Density Tests Table 3 – Summary of Water Utility Subgrade Density Tests Distribution: (1) Addressee G:\Projects\Projects 3000 to 3999\Projects 3250 to 3299\3281SD3 Nolan Res_LaBrisas\Post Grade 3281-SD3 Post Grade Report_Draft.docx GEOTEK Frank and Joann Nolan Family Trust July 13, 2020 Final Report of Post-Grade Compaction Report Project No. 3281-SD3 Carlsbad, California Page 7 REFERENCES 1) “Nolan Residence, Piragua Street, Carlsbad, California” as prepared by James A. Chin, Architect, various dates 2) “Precise Grading Plan Review, 7331 Las Brisas Court (3252 Piragua Street) Carlsbad, California” By GeoTek, Inc. dated October 22, 2018 3) Report of Geotechnical Testing and Observation, Proposed Residential Lot, 3252 Piragua St. Carlsbad, California , by GeoTek, Inc. dated Sept 14, 2017 4) “Grading Plan For 7331 Las Brisas Court, Precise Grading Plan Design Drawing No 481-5A, Sheet 4 of 4” prepared by BHA, Inc. Plot date September 25, 2017 5) Preliminary Geotechnical Evaluation, Proposed Residential Development, 7331 Las Brisas Court, Carlsbad, California By GeoTek, Inc. Dated February 25, 2008 GEOTEK FRANK AND JOANNE FAMIILY TRUST 3252 Piragua St. Carlsbad, CA GeoTek, Inc. Grading 7/6/2020 Project No.: 3281-SD3 Page 1 of 3 DATE Test No.Location Elev/ Depth Moisture Content (%) Dry Density (pcf) Soil Type Maximum Density (pcf) Test Type Relative Compaction (%) 7/17/17 1 Center of Pad -4' 10.5 121.5 C 127.0 N 96 7/18//17 2 NE area of Pad -2' 11.3 117.3 C 127.0 N 92 3 SW area of Pad FG 9.3 115.1 C 127.0 N 91 11/30/17 4 North Slope (east)-3' 7.7 117.0 C 127.0 N 92 5 North Slope (west)-6' 7.0 115.1 C 127.0 N 91 TABLE 1 SUMMARY OF FIELD DENSITY TESTS Grading Note: N = Nuclear Guage Test FG = Finished Grade Test All elevations are approximate FRANK AND JOANNE FAMIILY TRUST 3252 Piragua St. Carlsbad, CA GeoTek, Inc. Driveway 7/6/2020 Project No.: 3281-SD3 Page 2 of 3 DATE Test No.Location Elev/ Depth Moisture Content (%) Dry Density (pcf) Soil Type Maximum Density (pcf) Test Type Relative Compaction (%) 10/18/19 1 Driveway Approach SG 11.3 121.3 B 126.6 N 96 2 Driveway Approach SG 10.9 122.7 B 126.6 N 97 3 Curb/Gutter Stat. 0+10 SG 11.4 122.4 B 126.6 N 97 4 Curb/Gutter Stat. 0+20 SG 12.1 121.8 B 126.6 N 96 5 Curb/Gutter Stat. 0+35 SG 11.6 122.9 B 126.6 N 97 3/31/20 6 Easement South of Property SG 13.0 124.0 A 130.1 N 95 7 Easement South of Property SG 12.3 123.6 A 130.1 N 95 4/3/20 8 Easement South of Property Base 14.8 115.8 CMB 120.5 N 96 9 Easement South of Property Base 12.7 116.5 CMB 120.5 N 97 TABLE 2 SUMMARY OF FIELD DENSITY TESTS Driveway Note: N = Nuclear Guage Test FG = Finished Grade Test All elevations are approximate NAME IN CAPS ITALICS. Job Name Location, CA GeoTek, Inc. Water 7/6/2020 Project No.: 2 -SD3 Page 3 of 3 DATE Test No.Location Elev/ Depth Moisture Content (%) Dry Density (pcf) Soil Type Maximum Density (pcf) Test Type Relative Compaction (%) 9/15/17 1 Water Line Lateral - Subgrade -3.5' 9.5 126.8 A 130.1 N 97 2 Water Line Lateral - Base -2' 16.6 118.0 D 118.0 N 100 9/18/17 3 Water Line Laterial - Base -4" 10.4 116.0 D 118.0 N 98 4 Asphalt near (1/2') - Street AC AC - 135.7 E 143.0 N 95 TABLE 3 SUMMARY OF FIELD DENSITY TESTS Water Note: N = Nuclear Guage Test FG = Finished Grade Test All elevations are approximate 1 3 2 4 5 Legend 5 Approximate Location of Approximate Fill Limit Approximate Limits of Density Test Project 1384 Poinsettia Avenue, Suite A Vista, California 92081NPN: 3281-SD3 DATE: July 2020 Frank and Joann Nolan Family Trust 73311 Las Brisas Court Carlsbad, CA 92009 Figure 1 Field Density Test Location Map 0 5 10 20 Scale: 1" = 10' Plan adapted from "AS BUILT" by bHA, Inc. CONNECT 4" PVC SD TO EXIST D-75. IE 405.6 . 8" SEWER MAIN ROTECT IN PLACE s, ~ ~ ',1 s, ~(FL 402.6) ~. / \ / \~ / 1) )< / / / 0 0 <r _____---f,B"x18" BROOKS ~ CATCH BASIN ~~ )2 LF OF 4" PVC SD @ 11.7% (SEE DETAIL 'A 1/ \ / /\ If) 0 <r / \~ ~ \ / / / ~ -\ 0 -0 u, \ 0 -0 "' \ \ 400 EXISTING 4" SEWER LATERAL FF FP. FF 409.75 FS 409.58 2" STEP FF 409.75 FS=409.25 6" STEP FF 409.75 FS 409.58 2" STEP 0 409. 75 409.0 FF 409.75 FS=409.58 2" STEP 0 ..... ·· .. ~· / . / <Ii . ' v. . / / GEOTEK SDG&E VEH ACCESS GA