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Home My WebLink AboutCT 2018-0008; GRAND JEFFERSON; FINAL SOILS REPORT; 2022-08-18 GEOTECHNICAL | ENVIRONMENTAL | MATERIALS August 16, 2022 Revised August 18, 2022 Project No. 3803-SD Rincon Homes 5315 Avenida Encinas, Suite 200 Carlsbad, California 92008 Attention: Mr. Kevin Dunn Subject: Final Report of Geotechnical Services Post Grading The Grand Jefferson 786 Grand Avenue, Carlsbad, California References: See Page 5 Dear Mr. Dunn, GeoTek, Inc. (GeoTek) is pleased to present the results of geotechnical testing and observation services during post grading construction associated with the subject project. This report has been revised to include an approximate field density test location map. Rough grading of the subject building pads was completed under the observation of, and with testing by, Hetherington Engineering, Inc (HEI) and certified in their as-graded report dated February 2, 2021 (HEI, 2021). GeoTek continued where HEI, could not support the project. A review of the readily available reports and field reports were performed. GeoTek was considered to be the geotechnical engineer of record for the development upon our first date of observation and testing on June 14, 2022. It is to the best of GeoTek’s knowledge that post grading construction presented in this report has been completed, as noted on the dates of observations and field testing, in general accordance with the approved geotechnical reports (HEI, 2018 and 2021) for the site, applicable provisions of the 2019 California Building Code (CBC) and city of Carlsbad guidelines. This report provides a brief summary of site conditions observed during the post grading construction for the subject site. GeoTek, Inc. 1384 Poinsettia Avenue, Suite A Vista, CA 92081-8505 (760) 599-0509 Off, (760) 599-0593 Fa. www.geotekusa.com Rincon Homes August 18, 2022 Post Grading Compaction Report Project No. 3803-SD 786 Grand, Carlsbad, California Page 2 SUMMARY OF GEOLOGIC AND SOILS CONDITIONS Based on the field observations and testing during post grading site construction, the following is noted:  Foundation footing excavations for residential buildings were qualitatively evaluated with a soil probe in random locations and found to be firm and unyielding. Building foundation excavations were found to be excavated in suitable compacted fill.  Offsite public improvements for new asphalt pavement, which includes subgrade preparation along Jefferson Street. Subgrade was compacted to at least 95% of the maximum dry density as determined by ASTM D 1557.  Offsite Jefferson Street asphalt-concrete (AC) was compacted to at least 95% maximum density as determined by ASTM D 2950 test procedures. During field operations, the AC supplier was contacted and the hveem value was provided to GeoTek by the supplier. FIELD TESTING Field density (compaction) tests were taken at periodic intervals and random locations to verify the compaction efforts by the contractor. The field density (compaction) testing for the subject site was performed using a portable nuclear gauge, in general accordance with ASTM D 6938 test procedures. A summary of field density (compaction) test results is presented in Table 1 and attached to this letter report. The approximate locations of field density tests are shown on Plate 1, Plot Plan. Plate-1 from Heatherington’s As-Graded report (Heatherington, 2021) was utilized as a base map. Documented information presented on Plate-1, other than those noted to be performed by GeoTek, are related to Heatherington’s As-Graded report. LABORATORY TESTING Moisture-Density Relationships SUMMARY OF LABORATORY MAXIMUM DRY DENSITY AND OPTIMUM MOISTURE CONTENT TEST RESULTS (ASTM D1557) Soil Type Description Maximum Dry Density (pcf) Optimum Moisture Content (%) 1 Red Brown Silty Sand 131.0 9.0 AC-1 Asphalt Concrete 148 - GEOTEK Rincon Homes August 18, 2022 Post Grading Compaction Report Project No. 3803-SD 786 Grand, Carlsbad, California Page 3 CONCLUSIONS AND LIMITATIONS The purpose of this report is to present a summary of observation and testing services provided by GeoTek during the post grading operations that were performed on the subject property. More specifically, the scope of this report includes a presentation of data obtained during post-grading operations and a discussion of operations performed by the contractor. Post grading for the subject multi-use structure has been completed under the observation of, and with selective testing by, GeoTek, Inc. (GeoTek). It is to the best of GeoTek’s knowledge that site post grading construction discussed in this report has been completed in general accordance with the approved geotechnical reports (HEI, 2018 and 2021) for the site, applicable provisions of the 2019 California Building Code (CBC) and city of Carlsbad guidelines. GeoTek’s observations 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. GeoTek’s 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 (compaction) test locations and elevations, as well as the location of compacted fill, are only approximately located. The accuracy of the 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 Rincon Homes August 18, 2022 Post Grading Compaction Report Project No. 3803-SD 786 Grand, Carlsbad, California Page 4 GeoTek appreciates the opportunity to be of continued service on this project. Please contact the undersigned if you have any questions. Respectfully submitted, GeoTek, Inc. Christopher D. Livesey, Edwin R. Cunningham CEG 2733 RCE 81867 Associate Vice President Project engineer Enclosures: Table 1 – Field Density Test Table Plate 1 – Plot Plan (Field Density Test Location Map) Distribution: (1) Addressee via email GEOTEK CamScanner Approximate location of density test and removal bottom, from Heatherington As-Graded report Approximate location of street asphaltfield density test Approximate location of street subgradefield density test 3 3 21 5 5 4 3 2 1 3 3 21 5 4 3 2 1 by GeoTek, Inc. by GeoTek, Inc. LOr1J 1/A/'>JS l' IJ,IJfG\JJ --.--, -. -----------: ' t,Uno.()"Snac".Jlt! . ' "'"""' LDTTf IW'SJS ,_,"°""" 10 ------ LOT'fS I/A/'535 Al'N"""'1-0>«J ·-- LOTl!J w,p5J5 ~ "'"''""' ro..,._ -"'C .._c. __ a;.\fW,lffDA"~,,~ """"'~ ~ s J I Ol$n',C .:. __ '. ro NS$~·£ 19"1 0 c=rn <Wlf</1/G • . ' 1. ~:~ :--~.!!_S. .. ' Im ' I a, IHI 0 0 ' . ' FF7==FJ. APPROXIM.ATE lOCATIOH Of 0£HsrTY TEST APPROXIUATE ElEVAnoN OF REMOVAL BOTTOW (FEET) PLOT PLAN HETHERINGTON ENGINEERING, INC. -------'"-==~c=-=~----I ,..ca,..,_ GEOTECHNtCAL CONSUL TANT$ ~CT NO. 8617.1 ) PLATE NO. RINCON HOMES 768 Grand Ave Carlsbad, CA GeoTek, Inc. Subgrade 8/15/2022 Project No.: 3803-SD DATE Test No.Location Lot No. Sta No. Elev/ Depth Moisture Content (%) Dry Density (pcf) Soil Type Maximum Density (pcf) Test Type Relative Compaction (%) 6/14/22 1 25 ft from intersection SG 7.8 126.7 B-1 131.0 N 97 2 30 ft from intersection SG 10.1 125.1 B-1 131.0 N 95 3 40 ft from intersection SG 8.6 127.2 B-1 131.0 N 97 4 25 ft from intersection SG 8.0 127.2 B-1 131.0 N 97 5 40 ft from intersection SG 7.9 126.1 B-1 131.0 N 96 TABLE 1 SUMMARY OF FIELD DENSITY TESTS Subgrade Note: N = Nuclear Guage Test FG = Finished Grade Test All elevations are approximate NAME IN CAPS ITALICS. Job Name Location, CA GeoTek, Inc. Asphalt 8/15/2022 Project No.: 3-SD DATE Test No.Location Lot No. Sta No. Elev/ Depth Moisture Content (%) Total Density (pcf) Soil Type Maximum Density (pcf) Test Type Relative Compaction (%) 7/11/22 1 Grand Ave Street AC - 148.5 AC 148.0 N 99 2 Grand Ave Street AC - 146.3 AC 148.0 N 99 3 Jefferson St.AC - 147.2 AC 148.0 N 99 TABLE 1 SUMMARY OF FIELD DENSITY TESTS Asphalt Note: N = Nuclear Guage Test FG = Finished Grade Test All elevations are approximate