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Home My WebLink AboutCT 02-29; CASA LA COSTA; SUPPLEMENTAL PROJECT GRADING REPORT; 2011-08-31C1O29 0AG ADVANCED GEOTECHNICAL SOLUTIONS, INC. 1 S 5333 Mission Center Road, Suite 390 San Diego, California 92108 Telephone: (619) 850-3980 Fax: (714) 409-3287 NEW POINTE COMMUNITIES, INC. August 31, 2011 16880 West Bernardo Drive, Suite 230 P1W 1004-02 San Diego, CA 92127 Report No. 1004-02-D-7 Attention: Mr. Scot Sandstrom Subject: Supplemental Project Grading Report, Condominium Complex, Lot 11, Villas de La Costa, Carlsbad, California References: 1) As-Built Geotechnical Report, Proposed Condominium, Lot 11, Villas de La Costa, Carlsbad, California prepared by Advanced Geotechnical Solutions, Inc., dated December 16, 2010 (P1W 1004-02) Project Grading Report, Proposed Condominium, Lot 11, Villas de La Costa, Carlsbad, California prepared by Advanced Geotechnical Solutions, Inc., dated October 15, 2010 (P1W 1004-02) Geotechnical Response to Review Comments from the City of Carlsbad for Proposed Condominium, Lot 11, Villas de La Costa, Carlsbad California prepared by Advanced Geotechnical Solutions, Inc., dated August 11, 2010 (P1W 1004-02) Geotechnical Investigation and Foundation 'Design Recommendations for Proposed Condominium, Lot 11, Villas de La Costa, California, prepared by Advanced Geotechnical Solutions, Inc., dated June 23, 2010 (P1W 1004-02) Gentlemen: In accordance with your request presented herein is Advanced Geotechnical Solutions, Inc.'s (AGS's) summary of observations and test results obtained during the recently completed onsite grading and improvement operations at the site of the subject Proposed Condominium, Lot 11, Villas de La Costa, Carlsbad, California. Based on the results of the testing and observations by representatives of AGS, the work described herein is considered to be in general conformance with City of Carlsbad Grading Code, the recommendations presented in the referenced geotechnical report and is considered suitable for its intended use. This .report addresses onsite grading and improvement operations for the subject site as reflected on the site plan prepared by Hunsaker and Associates. Onsite improvements and precise grading for the subject sitewas conducted in April and May 2011. Geotechnical observation and testing services for this phase of work was provided on a part-time, "as-requested" basis and are summarized in the text of this report and the developed data are presented in Table I. The approximate locations of compaction tests under the purview of this report are shown on the accompanying reduced scale Precise Grading Plan for Villas de La Costa prepared by Hunsaker and Associates (Plate 1). ORANGE AND L.A. COUNTIES INLAND EMPIRE SAN DIEGO AND IMPERIAL COUNTIES (714) 786-5661 (619) 708-1649 (619) 850-3980 August 31, 2011 Page 2 P1W 1004-02 Report No. 1004-02-D-7 1.0 ONSITE GRADING Presented herein is a summary of observations collected during onsite grading operations. The subject site was rough graded to approximate building pad elevation in October 2010 under the testing and observation of AGS (Reference 2). Additional onsite grading was performed in April and May 2011 and consisted of minor fills area northeast of the building pad and precise grading of subgrade soils for the parking area, driveways, hardscape, and sidewalk. Prior to placing any fill on the site, the grading contractor removed dry, loose, and compressible pre-existing artificial fill soils. Unsuitable soil removals were on the order of 12 to 18 inches below existing grades. The excavation bottoms were observed by a representative of this firm after the completion of removals. The exposed soils were then scarified to an approximate depth of 4 to 6 inches, brought to above optimum moisture content and compacted in-place to a minimum of 90 percent of the laboratory maximum dry density in accordance with ASTM Test Method D-1557.. Fill materials, consisting of the soil types summarized in Table I, were then placed in thin, loose, lifts (approximately 8 inches), brought to slightly above optimum moisture content, and compacted to a minimum of 90 percent of the laboratory maximum dry density in accordance with ASTM Test Method D-1 557. Compaction was achieved by equipment wheel rolling. Compaction tests were taken during the course of grading for every one to two feet of fill placed. A summary of compaction tests pertaining to grading within the subject lot is presented in Table 1. The approximate locations of these tests are shown on the accompanying plan (Plate 1). Maximum depth of fill under the purview of this report was approximately 5 to 6 feet. 2.0 PARKING LOT AND DRIVEWAY SIIBGRADE The subgrade soils within the parking and driveway areas were processed then compacted utilizing a steel drum roller and equipment wheel-rolling. Field density tests were taken periodically during and after completion of compaction operations. Field density test results obtained in the field indicate that the subgrade soils, at the locations tested, were compacted to a minimum of 90 percent of the laboratory maximum dry density in accordance with ASTM Test Method D-1557 with above optimum moisture content. A summary of the density test results is presented in Table I and the approximate test locations are shown on the attached Plate I. 3.0 SIDEWALK SUBGRADE Subgrade soils for the sidewalks located at the property frontage along Levante Street and at the rear of the parking area adjacent to Via Iris were processed then compacted utilizing a steel drum roller, equipment wheel-rolling, and/or walk behind vibratory compactors. Field density test results obtained in the field indicate that the subgrade soils, at the locations tested, were compacted to a minimum of 90 percent of the laboratory maximum dry density in accordance with ASTM Test Method D-1557 with above optimum moisture content. A summary of the density test results is presented in Table I and the approximate test locations are shown on the attached Plate I. 4.0 CURB AND GUTTER The existing curb and gutter along the property frontage at Levante Street was removed and replaced. Removal of the existing curb and gutter exposed aggregate base materials on the order of 6 to 8 inches ADVANCED GEOTECHNICAL. SOLUTIONS, INC. August 3l,2011 Page P1W 1004-02 Report No. 1004-02-D-7 thick overlying previously placed fill soils. During our initial observation of the exposed curb and gutter subgrade, localized yielding areas were noted likely due to recent rain events. The yielding areas were subsequently overexcavated until firm and compacted soils were encountered. The overexcavated areas were replaced with aggregate base materials and were on the order of 6 to 12 inches deep. Subgrade for curb and gutter around parking area adjacent to Via Iris was processed then compacted utilizing a steel drum roller, equipment wheel-rolling, and/or walk behind vibratory compactors. Field density test results obtained in the field indicate that the subgrade soils, at the locations tested, were compacted to a minimum of 90 percent of the laboratory maximum dry density in accordance with ASTM Test Method D-1557 with above optimum moisture content. A summary of the density test results is presented in Table I and the approximate test locations are shown on the attached Plate I. 5.0 BASE MATERIALS Base materials underlying the driveways and parking areas within the subject site were compacted utilizing a steel drum roller, equipment wheel-rolling, and/or walk behind vibratory compactors. Field density test results obtained in the field indicate that the subgrade soils, at the locations tested, were compacted to a minimum of 95 percent of the laboratory maximum dry density in accordance with ASTM Test Method D-1557. A summary of the density test results is presented in Table I and the approximate test locations are shown on the attached Plate I. 6.0 UTILITY-HOUSE CONNECTIONS Minor trench backfill was placed at the house connections for sewer and water services and was on the order of 2 feet in depth. The backfill consisted of onsite trench spoils that were moisture conditioned to above optimum then compacted utilizing walk behind vibratory compactors and equipment wheel-rolling. Due to the shallow depth of the utility lines, compactive effort was evaluated by probing the backfill soils. Probe testing of the service connection backfill indicates the soils are firm and unyielding and were adequately compacted and suitable for the intended use. ADVANCED GEOTECHNICAL. SOLUTIONS, INC. August 31, 2011 Page 4 P1W 1004-02 Report No. 1004-02-D-7 7.0 LIMITATIONS This report presents information and data relative to onsite construction operations for the subject site. A representative(s) of this firm probed and tested at random locations in an effort to determine whether compliance with the project compaction, specifications, and applicable Building Code was being obtained. The presence of our personnel during testing operations does not involve any supervision or direction of the contractor or his work forces. The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to contact the undersigned. Resnectfullv Submitted y PAUL J. DERISI, Vice President CEO 2536, Reg. Exp. 5-31-13 Distribution: (6) Addressee Attachments: Table I - Laboratory Summary and Field Density Test Results Plate I - Compaction Test Location Plan VIkOFESS/ A. No. 2314 J. No.2536 a.1 CERTIFIED c t ENGINEERING GEOLOGIST Exp. 541-13 a!A P''rECH' , ADVANCED GEOTECHNICAL SOLUTIONS, INC. August 31, 2011 SUMMARY OF LABORATORY Page 1 of Table 1 P1W 1004-02 MAXIMUM DRY DENSITY AND Report No. 1004-02-D-7 OPTIMUM MOISTURE CONTENT TABLE 1 OPTIMUM MAXIMUM MOISTURE DRY CONTENT DENSITY SOIL TYPE DESCRIPTION (%) (Pd) A Light Brown Silty to Clayey Sand 13.9 118.0 B Class II Aggregate Base 7.6 133.5 I004-02-D-7 Onsite Compaction Test Table Final/Max Table ADVANCED GEOTECHNICAL SOLUTIONS, INC. August 31, 2011 FIELD DENSITY TEST RESULTS Page 2 of Table 1 P1W 100402 TABLE 1 (cont'd) Report No. 1004-02-D-7 TEST NUMBER/LOCATION/ELEVATION KEY S - Sewer Trench I - Irrigation Trench SD - Storm Drain Trench E - Electrical Trench JT -Joint Utility Trench W - Water Trench RTW- Retaining Wall FTG - Footing FG - Finish Grade SG - Subgrade CG - Curb and Gutter Subgrade B - Base AC Asphalt Concrete Finish Grade BC - Asphalt Concrete Base Course CC- Asphalt Concrete Cap Course -R,R1,R2- Indicates Retest * Rock Correction- Estimated Percent Retained on #4 Sieve (Method A) or 3/4 inch (Method C), Maximum Dry Density and Optimum Moisture Content adjusted per ASTM D 4718 Date Test Number Location Depth or Elev. Soil Type Rock Corr.* Moisture (%) Dry Density (pcf) Rel. Comp. (%) Proj. Spec. (%) Test Type (S/N) Pass or Fail Opt. Field Max. Field 4/26/11 104 Raised Pad - Community Area 281 A 0 13.9 15.9 118.0 108.4 91 90 N Pass 4/26/11 105 Raised Pad - Community Area 283 A 0 13.9 14.2 118.0 110.1 93 90 N Pass - 4/27/11 106CG Curb & Gutter - Levante Street SG B 0 7.6 8.4 132.4 122.8 92 90 N Pass 4/27/11 107CG Curb & Gutter - Levante Street SG B 0 7.6 7.9 132.4 125.6 94 90 N Pass 5/20/11 108 Parking Area 5G A 0 13.9 14.0 118.0 112.2 95 90 N Pass 5/20/11 109 Parking Area SG A 0 13.9 14.7 118.0 110.8 93 90 N Pass 5/23/11 110 Sidewalk - Levante Street SG A 0 13.9 15.1 118.0 109.9 93 90 N Pass 5/23/11 111 Sidewalk - Levante Street SG A 0 13.9 15.8 118.0 106.7 90 90 N Pass 5/23/11 112B Parking Area BG B 0 7.6 7.8 132.4 126.7 95 95 N Pass 5/23/11 113B Parking Area BG B 0 7.6 8.1 132.4 127.0 95 95 N Pass 5/25/11 114 Driveway - Lot 3 SG A 0 13.9 16.1 118.0 107.5 91 90 N Pass 5/25/11 115 Driveway - Lot 2 SG A 0 13.9 14.3 118.0 108.9 92 90 N Pass 5/26/11 116 Raised Pad - Community Area 284 A 0 13.9 14.0 118.0 111.4 94 90 N Pass 5/26/11 117 Raised Pad - Community Area 284.5 A 0 13.9 14.4 118.0 112.6 95 90 N Pass 1004-02-D-7 Onsite Compaction Test Table Final/Tests ADVANCED GEOTECHNICAL SOLUTIONS, INC. NOTE: BASE MAP TAKEN FROM 40-SCALE PRECISE GRADING PLANS FOR VILLAS DE LA COSTA, CARLSBAD, CALIFORNIA, SHEET 3 OF 3, PREPARED BY HUNSAKER AND ASSOCIATES -ga 104 LEGEND: Approximate location of field 207 density test 280 Approximate elevation of ED removal bottom PLATE I Compaction Test Location Plan (GAGS ADVANCED GEOTECIINHAL SOLUTIONS, INC Project: Report: Date: PM 1004-02 100402-0.7 8/31/2011