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HomeMy WebLinkAboutCT 14-01; STATE STREET MIXED USE 30; FINAL SOILS REPORT; 2020-03-22GHOSTRIDER, INC. PO Box 1120 Fallbrook CA, 92088 (760)-473-5052 March 22, 2020 City of Carlsbad 1635 Faraday Avenue Carlsbad, CA 92008 Attn: City Building Official Subject: Off site Soil Work Certification 3080-3088 State Street (CB152398) Carlsbad, CA 92008 City of Carlsbad Building Official: twghostriderOl@yahoo.com Please be advised that during the time period of 3/8/2019 to 3/21/2020, Ghostrider, Inc. completed off site soil inspections for subgrade improvements at project: "State Street Mixed Use 30" that has the street address of 3080-3088 State Street Carlsbad, Ca 92008. Note that on 3/21/20, Ghostrider Inc. completed observations of offsite subgrade sections mentioned in this report. See map below for specific locations (Figure 1). See Table 1 for specific density results. Field Observation Summary: • Earthwork construction observed and tested was performed by R & R Construction. • Existing vegetation and improvements were removed within the proposed limits of the subject sections. • A representative of Ghostrider, Inc. was on-site to observe the sidewalk, trench and curb & gutter sections. (See Figure 1 for Specific Sections) and (Table 1 for Specific Density Results) • Contractor backfilled with native soils in 611 -8" lifts and compacted with a mechanical compactor. Contractor placed top 4" -6" of sections with Class II Base and compacted with a mechanical compactor. Lifts were checked with a ½" Dia. soils probe by a Ghostrider Inc. representative. Conclusion: In my professional opinion, the sections highlighted in the map herein have been completed in substantial conformance with lines and grades shown on the approved precise civil plans. Contractor placed native material in approximately 6" lifts and compacted. Top 6" -8" was compacted class 2 base. All sections were compacted by means of a mechanical compactor (wacker/jumping jack). The attached exhibit illustrates the locations of offsite remediation for sidewalks, trench work, curb and gutter. All highlighted sections were checked with a ½" dial soils probe. Probed sections were found to be firm and unyielding. Probe did not penetrate more than 4.00" into compacted sections 12" below finished grade. Probe did not penetrate more than 1.00" into compacted sections within 0"-12" of finished grade. Locations Xl-X5 (shown on map) were checked for relative compaction by means of nuke gauge testing (results in table 1 ). The mentioned sections have been completed in substantial conformance with the approved plans and specifications and the permit. "The site is adequate for its intended use." Respectfully submitted, d·4 c=J rrl~ Jerry L. Michal Consulting Geotechnical Engineer GE2515 GHOSTRIDER, INC. PO Box 1120 Fallbrook CA, 92088 (619) 379-0735 twghostriderOl@yahoo.com September 13, 2018 City of Carlsbad 1635 Faraday Avenue Carlsbad, CA 92008 Attn: City Building Inspector Subject: Geotechnical Observation and Testing During Earthwork-Rough Grading for Building Pad at Location 3080 State Street Carlsbad, CA 92008 Reference: Geosoils, 2015, "Geotechnical Update, 3080 State Street, City of Carlsbad, San Diego, California," dated March 23, 2015. All: In Accordance with your request and authorization, we have performed geotechnical observation and testing during earthwork operations for the proposed subject construction at the subject property. Rough grading operations for the subject lots were conducted in conjunction with the overall rough grading operations. Testing and inspection services were performed by a representative of Ghostrider Inc., who was onsite as requested during the period of August 10, 2018 through September 5, 2018. FIELD OBSERVATION AND TESTING The following is a summary of our geotechnical observations and testing performed during earthwork for the subject construction of the building pad: • Earthwork construction observed and tested by Ghostrider was performed by Richards and Richards Construction. • Existing vegetation and improvements were removed within the proposed limits of the subject lots. • The potentially compressible materials identified in the referenced reports (Geosoils 2015) within the subject proposed lot were removed to relatively competent materials, to depths of approximately 3 feet below the grades that existed prior to earthwork construction. • Removal and over excavation bottoms exposing relatively competent materials were compacted to at least 90-95 percent relative compaction (based on ASTM Dl557). • Field density tests were taken at periodic intervals and random locations to check the compaction efforts by the contractor. Field density testing was performed in accordance with sand cone methods. All sections were also checked with a soils probe. Based on our observations, the test results presented herein (Appendix A) should be considered representative of the level of compaction achieved during overall preparation of the building pad(s) and slopes. Approximate field density test locations shown in Figure 1. Appendix A: LABORATORY TESTING Maximum Density and Optimum Moisture The Laboratory maximum dry density and optimum moisture content for soils utilized as fill were determined in general accordance with ASTM Test Method Dl557-00. Test results for the soils used in the filling operations are presented in Table 1. TABLE 1 SUMMARY OF MAXIMUM DENSITY ANO OPTIMUM MOISTURE Soil Type Description Maximum Dry Optimum Moisture Density (PCF) Content(%) 1 Red Brown SILTY-SAND (SM) I 128.2 7.6 ~ ---.. ----- FIELD TESTING Field compaction was achieved by methods of a mechanical compactor and heavy machinery. Compaction efforts were periodically checked by means of soils probe and sand cone tests that were periodically taken throughout the remediation of the building pad. Test results for the compaction efforts performed by the contractor are presented in Table 2. Locations of testing can are shown in the map (Figure 1 ). Table 2 Project Name: 3080 State Stroet Teat Date No.. 10-A..a 1 10,Auo 2 13-Aua 3 13-Aua 4 14-Aua 5 14-Aua 6 15,Auo 1 16-Aua 8 16-Auo 9 17-Aua 10 17-Aua 11 20-Aua 12 21'4ua 13 21-Aua 14 21-Auo 15 21-Auo 16 21-Auo 17 FIELD DENSITY TEST RESULTS Flold Dry Optimum Relatlvo Required Teat Elev. of Max Relative Typo Location Test Moisture Density Moisture (pcf) Compaction Compaction (%) (pcf) (%) (%) ,.,_, SC Southeast Quadrant -1.S' 5.79% 117.29 7.60% 128.2 91.49% 90.00% SC Southeaat Quadrant -2.S' 5.01% 116.25 7.60% 128.2 90.118% 90.00% SC Souti-st Quadrant SG 8.70% 126.03 7.60% 128.2 98.31% 95.00% SC Southffat Quadrant SG 7.99% 122.47 7.60% 128.2 95.53% I 95.00% SC Solrthweat Quadrant ..J' 7.69% 123.25 7.60% 128.2 96.14% 90.00% SC SouU-St Quadrant -2' 6.28"4 122.43 7.60% 1%8.2 95.S4% 90.00% SC SOUU-st Quadrant SG 6.82% 118.88 7.60% 128.2 92.72% 90.00% SC Northeast Quadrant -3' 5.65% 117.56 7.60% 128.2 91.70% 90.00% SC NortheHt Quadrant -2' 6.14% 115.63 7.60% 128.2 90.20% 90.00% SC Northeast Quadrant SG 6 .. 2•% 127.5 7.60"4 128.2 99.45% I 95.00% SC Northout Quadtant SG 4.96% 118.17 7.60% 128.2 n ,a.,,. 95.00% SC Nol'theaat Quadrant -2· 6.83% 122.82 1.~% 128.2 95.80% 90.00% SC Not1hwNt Quadrant -1' 6.611% 115.94 7.60% 128.2 90.'3% 90.00% SC Northeut Quadrant SG 7.93% 121.99 7 .60"4 128.2 95.15% 95.00% SC Southwest Quadrant SG 4.79% 111.82 7.60% 128.2 87.l,% 90.00% SC Southweat Quadrant SG 6.29% 121.06 7.60% 128.2 94.'3% 90.00% SC Northwut Quadrant SG 5.53% 119.19 7.60% 128.2 92.97% 90.00% N ASTM D69Ja.10 • Slanda<d Test Method toe In-Place Oensty and ~er Con!~ a Sod and So,1-A~a by Nud....-Mell1ods (Shallow Oeptt,) NG · Nuclear Gauge FG • Fm,shed Grade SG-Subgrado BG-Basegn,de Elewbons of l8SI are depth below proposed $Ut,gr,,de = 95 00% 0< above compactl()(\ where needed ; Fa~ed test • Note: The density results that were below required were remediated and re-checked by means of sand cone. Test #11 was superseded by Test #14. Test #15 was superseded by Test #16. All the tested locations were in conformance with the Geotechnical Report. Conclusion: In my professional opinion, the sections highlighted in the report herein have been completed in substantial conformance with lines and grades shown on the approved precise civil plans and the Geotechnical Report. Contractor placed native material in approximately 6" -1 0" lifts and compacted. All sections were compacted by means of a mechanical compactor (wacker/jumpingjack) and/or heavy machinery. The exhibits included in this report illustrate the locations and results of the building pad remediation for the subject site. All sections were checked with a ½" dial soils probe. Probed sections were found to be firm and unyielding. Probe did not penetrate more than 4.00" into compacted sections. Locations 1- 17 (Shown on Map -Figure 1) were checked for relative compaction by means of sand cone testing (results in table 2). Test results show that the compaction efforts were in compliance with the project standards and specifications. The mentioned sections have been completed in substantial conformance with the approved plans, Geotechnical Report, specifications and the permit. "The site is adequate for its intended use." Respectfully submitted, a c/f71_J~ Je~ichal Consulting Geotechnical Engineer GE2515