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HomeMy WebLinkAboutTract Map 21383 Parcel 15-17 Geotechnical ObservationsGEOCON W E S T, I N C. 44)GEOTECHNICAL ENVIRONMENTAL MATERIALS 1 Project No. T2658-22-01 December 11,2015 Diamond Hearts Ranch,LLC 525 Plaza Del Cid Chula Vista, CA 91910 Attention:Mr. Beng Hoe Ooi Subject: INTERIM REPORT OF GEOTECHNICAL OBSERVATION AND TESTING SERVICES DURING SITE GRADING PA 14-0008 PLANT'S CHOICE PARCELS 17 OF PM 21383 TEMECULA,CALIFORNIA GRADING PERMIT NO. LD15-0946 Dear Mr. Ooi: This interim report of testing and observation services has been prepared in accordance with the request of Keeton Construction to document grading performed for the building pads areas at the Plant's Choice development in Temecula, California. Earthwork for the buildings began on November 23, 2015 and was completed on December 4, 2015. Earthwork operations were conducted by Keeton Construction. Earthwork for the Building on Parcel 17 consisted of overexcavating the site soils in the area of the building pad to a depth of at least 1 foot below the proposed building foundations, until firm overexcavation bottoms were achieved. Removals extended horizontally a distance of at least 5 feet beyond the building perimeter. Removal bottoms in the building area were observed by a representative of Geocon, and the approved removal bottoms were scarified, moisture conditioned, and compacted to at least 90 percent of the laboratory maximum dry density as evaluated by ASTM International (ASTM) D1557. Fill was then moisture conditioned, placed in six to eight inch lifts and compacted to at least 90 percent of the laboratory maximum dry density until design grades were achieved. At your request, we provided observation and testing of the fill placement for the building areas on Parcels 15 and 16. However, earthwork for these buildings did not include overexcavation and recompaction of the soils in the building area. Following clearing and grubbing, the exposed soils were scarified, moisture conditioned, and compacted to at least 90 percent of the laboratory maximum dry density. Fill was then placed and compacted to the design grades. Overexcavation and recompaction of 41571 Coming Ploce,Suite 101 Murrietc,Colifornio 92562-7065 Telephone 951.304.2300 fax 951.304.2392 the soils in the building areas on Parcels 15 and 16 will need to be performed prior to their use for sport of future structural improvements. Laboratory tests were performed on a sample of the finish grade soils from the building area in Parcel 17. The soils were tested for expansion index (EI) and corrosion screening. Based on the laboratory test results, the site soils in the building area in Parcel 17 have an EI of 17, which Would classify as very low in accordance with ASTM D4829(EI of 20 or less). Results from the laboratory water-soluble sulfate content tests indicate that the on-site materials at the location tested possess a sulfate content of 0.002% equating to an exposure class of SO (Negligible) to concrete structures as defined by 2013 CBC Section 1904.3 and ACI 318. Table 1 presents a summary of concrete requirements set forth by 2013 CBC Section 19043 and ACI 318. TABLE 1 REQUIREMENTS FOR CONCRETE EXPOSED TO SULFATE-CONTAINING SOLUTIONS Water-Soluble Maximum Minimum Sulfate Exposure Sulfate Cement Water to Compressive Exposure Class Percent Type Cement Ratio Strength(psi) by Weight by Weight Negligible SO 0.00-0.10 2,500 Moderate Sl 0.10-0.20 11 0.50 4,000 Severe S2 0.20-2.00 V 0.45 4,500 V+Pozzolan Very Severe S3 2.00 or Slag 0.45 4,500 Laboratory testing indicates the site soils have a pH of 8.1, a minimum electrical resistivity of 2,340 ohm-cm, possess 75 parts per million chloride, and 0.002% sulfate (20 ppm). As shown in Table 2 below, the site would be not be classified as "corrosive" to improvements, in accordance with the Caltrans Corrosion Guidelines(Caltrans, 2012). TABLE 2 CALTRANS CORROSION GUIDELINES Corrosion Resistivity pH Chloride(ppm) Sulfate(ppm) Exposure ohm-cm) Not Corrosive 5.5 1,000 500 2,000 Corrosive 5.5 or less 1,000 500 or greater 2,000 or greater Gcmon Project No.U658-22-01 2 - December I I.2015 Gcocon does not practice in the .field of corrosion engineering. Therefore, further evaluation by a corrosion engineer should be performed if improvements that could be susceptible to corrosion are planned. Meld density test results are. shown in the attached Table I and laboratory maximum densities for applicable soil types are shown in the attached Table IL Field density test locations will be presented in our final report of testing and observation services during grading upon completion of grading for the remainder of the site. It is our opinion that the grading of subject building pad has been performed in substantial conformance with the project geotechnical recommendations and that the recommendations in our referenced Updated Geotechnica! Recommendations letter are applicable to the design and construction of the building. The conclusions contained herein apply only to our work with respect to grading at the locations indicated, and represent conditions at the date of our final observation, December 4, 2015. Any subsequent grading or backfill should be done in conjunction with our observation and testing services. As used herein, the term `observation" implies only that we observed the progress of the work with which we agreed to be involved. Our services did not include the evaluation or identification of the potential presence of hazardous or corrosive materials. Our conclusions and opinions as to whether the work essentially complies with the job specifications are based on our observations, experience, and test results. Subsurface conditions, and the accuracy of tests used to measure such conditions, can vary greatly at any time. We make no warranty, expressed or implied, except that our services were performed in accordance with engineering principles generally accepted at this time and location. Geocon Project No.n658-22-01 3 - December 11,2015 We will accept no responsibility for any subsequent changes made to the site by others, by the uncontrolled action of water, or by the failure of others to properly repair damages caused by the uncontrolled action of water. The findings of this report may be invalidated wholly or partially by changes outside our control. Therefore,this letter is subject to review and should not be relied upon after a period of one year of the date of this report. If you have any questions regarding this report, or if we may be of further service, please contact the undersigned at your convenience. Very truly yours, GEOCON WEST,INC. e*QIF t c Ur Z Wi MO'00 /I.1 u No.2E00 8 a+E . i^49 Chet E. Robinson ar Paul D. Theriault q"IC 0F GPI GE 2890 CEG 2374 CER:PDT:hd Attachments: References Table I, Summary of Field Density Test Results Table II, Summary of Laboratory Test Results Geocon Project No.T2658-22-01 4- December 11,2015 REFERENCES I.California Department of Transportation (Caltrans), Division of Engineering Services, Materials Engineering and Testing Services, Corrosion Guidelines, Version 2.0, dated November, 2012. 2.Geocon West, Inc., Assumption of Role as Geotechnical Engineer of Record and Updated Geotechnical Recommendations, PA 14-0008 Plant's Choice, Parcels 15, 16, and 17 of PM 21383, Southeast Corner of Winchester Avenue and culler Road,, Temecula, California, Project T2658-22-01, dated August 31,2015 3.Matrix Geotechnical Consulting, Inc., Geotechnical Investigation for the Plant's Choice, Proposed Industrial Building Project, APN(s): 909-310-015-016, and -017, City of Temecula, County of Riverside, California, Project No. M I 1 14-011, dated September 30, 2013. 4.Markham Development Management Group, Inc. (MDMG), PA 14-0008 Plants Choice, Precise Grade Plane, Sheets I through 6, undated. 5.W. Dean Davidson, Architect, Office + Warehouse, Plain's Choice, huc., 42284 Winchester Blvd., Temecula, CA 92590, Structural Plans, Sheets S-1 through S-13 and S-S, dated February 16, 2015.. Geocon Project No.T2658-22-01 5 - December 11,2015 TABLE 1 low) GEOCON SUMMARY OF FIELD DENSITY TEST RESULTS Project Name: Plant's Choice Project No.:T2658-22-01 Elev.or Relative Max. Opt. Field Field Required Test No. Date Location Depth Curve Rock Dry Moist Dry Moisture Compaction Relative feet) No. M Density Content Density Content (%) Compaction pcf) (%) (pef) (%) Pre. No. Re. BTM 1 11/24/15 Parcel 17 Building,West 1033 1 0 124.6 10.3 113.8 13.6 91 90 2 11/24/15 Parcel 17 Building,South 1034 1 I 1 0 124.6 1 10.3 1 113.1 14.2 1 91 90 3 11/24/15 Parcel 17 Building,West 1035 1 0 124.6 10.3 114.4 13.3 92 90 4 11/24/15 Parcel 17 Building, East 1034 1 0 124.6 10.3 112.8 12.9 91 90 5 11/25/15 Parcel 17 Building,West 1035 1 0 124.6 10.3 110.9 8.8 89 90 5 A 11/25/15 Parcel 17 Building, West 1035 1 0 124.6 10.3 112.4 13.0 90 90 BTM 6 11/25/15 Parcel 17 Building,East 1033 1 0 124.6 10.3 113.3 14.0 91 90 7 1 11/25/151 Parcel 17 Building,North 1034 1 0 124.6 10.3 114.9 13.4 92 90 8 11/25/15 Parcel 17 Building,East 1034 1 I 1 0 124.6 1 10.E 1 114.6 14.5 1 92 90 9 11/25/15 Parcel 17 Building,North 1035 1 0 124.6 10.3 112.7 13.1 90 90 10 11/30/15 Parcel 17 Building,East 1036 1 0 124.6 10.3 113.8 14.2 91 90 11 11/30/15 Parcel 17 Building, West 1036 1 0 124.6 10.3 114.4 13.7 92 90 FG 12 12/02/15 Parcel 17 Building,North 1037 1 0 124.6 103 114.1 11.9 92 90 FG 13 12/02/15 Parcel 17 Building,South 1037 1 0 124.6 10.3 115.8 11.3 93 90 14 1 12/03/151 Parcel 16 Building,West 1034 1 0 124.6 10.3 113.6 12.4 91 90 15 12/03/15 Parcel 16 Building,East 1034 1 0 124.6 10.3 1 114.9 13.5 92 90 16 12/03/15 Parcel 16 Building,North 1035 1 0 124.6 10.3 115.5 13.1 93 90 17 12/03/15 Parcel 16 Building,South 1035 1 0 124.6 10.3 114.0 13.9 91 90 18 12/03/15 Parcel B Building,West 1031 1 0 124.6 10.3 115.2 11.9 92 90 19 12/03/15 Parcel 15 Building, East 1031 1 0 124.6 10.3 113.9 12.8 91 90 20 12/04/15 Parcel 15 Building,North 1032 1 0 124.6 10.3 114.0 12.1 91 90 21 1 12/04/151 Parcel 15 Building,South 1032 1 0 124.6 10.3 114.8 12.6 92 90 J TABLE 1 GEOCON EXPLANATION OF CODED TERMS TEST NO.PREFIX AC Asphalt.Concrete IT Irrigation Trench SM Sewer Main AD Area Drain 1T Joint Trench SR Slope Repair BTM Bottom of Overexcavation M Moisture Test ST Slope Test B Base VISE Mechanically Stabilized Earth Wall SW Sidewalk CG Curb/Gutter RG Regrade 5Z Slope Zone DW Driveway RWL Reclaimed Water Lateral UT Utility Trench ET Electrical Trench RWM Reclaimed Water Main WB Wall Backfill ETB Exploratory Trench SBT Subdrain Trench WL Water Lateral FB Footing Backfill SD Storm Drain WM Water Main FG Finish Grade SG Subgrade, GT Gas Trench SL Sewer Lateral TEST NO.RE. A.B.C. Retest of previous density test failure following additional moisture conditioning or recompaction. R Fill in area of density lest was removed during construction operations. ELEVATION OR DEPTH Cooresponds to the elevation or the depth,in feeL of the in-place density/moisture content test.The value has been rounded to the nearest whole foot. CURVE NO. Corresponds to the curve numbers presented in the summary of the laboratory maximum dry density and optimum moisture content test resluts. The field representative selected the curve no.based on the laboratory test results and field observations. ROCK-ROCK CORRECTION The laboratory maximum dry density and optimum moisture content can be adjusted for in-place soil that possesses rock larger than%inch. The curve no. is adjusted for the percentage of inch rock in accordacne with ASTM D 4718 or Woodward Clyde guidelines. Project Name: Project No.: Rock Correction:- TABLE 2 SUMMARY OF MAXIMUM DRY DENSITY OPTIMUM MOISTURE CONTENT TEST RESULTS Max.Dry Opt Moist Water Curve No. Description Density Content Specific Expansion Expansion Soluble Sulfate Severity pc aka) Gravity Index Classification Sulfate 0 I CLAYEY SAND WITH TRACE GRAVEL(SC),dark brown. 124.6 10.3 2.65 2 3 4 5 6 7 8 9 10 I 12 13