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i <br /> March 27, 2000 CH2M HILL <br /> Del Monte Site <br /> Stockton, CA <br /> i <br /> The CPT/sampling holes were grouted using our support rig. The grouting procedure <br /> consists of pushing a hollow CPT rod with a "knock out" plug back down the hole to the <br /> test hole termination depth. Grout is then pumped under pressure.as the tremie pipe is <br /> pulled from the hole. <br /> 3.0 CONE PENETRATION TEST DATA & INTERPRETATION <br /> The cone penetration test data is presented in graphical form in the attached Appendix. <br /> Penetration depths are referenced to existing ground surface. This data includes CPT <br /> logs of measured soil parameters and a computer tabulation of interpreted soil types along <br /> _ with additional geotechnical parameters and pore pressure dissipation data. <br /> iThe stratigraphic interpretation is based on relationships between cone bearing (Qc), <br /> sleeve friction (Fs), and penetration pore pressure (Ut). The friction ratio (Rf), which is <br /> sleeve friction divided by cone bearing, is a calculated parameter that is used to infer soil <br /> behavior type. Generally, cohesive soils (clays) have high friction ratios, low cone bearing <br /> and generate large excess pore water pressures. Cohesionless soils (sands) have lower <br /> friction ratios, high cone bearing and generate little in the way of excess pore water <br /> pressures. <br /> Pore Pressure Dissipation Tests (PPDT's) were taken at various intervals in order to <br /> measure hydrostatic water pressures and approximate depth to groundwater table. In <br /> addition, the PPDT data can be used to estimate the horizontal permeability (kh) of the soil. <br /> The correlation to permeability is based on the time required for 50 percent of the <br /> measured dynamic pore pressure to dissipate (6). A summary of the PPDT data is <br /> provided in Table 2. The PPDT plots are provided in the Appendix. <br /> i <br /> 1 The interpretation of soils encountered on this project was carried out using recent <br /> correlations developed by Robertson et al, 1990. It should be noted that it is not always <br /> possible to clearly identify a soil type based on Qc, Fs and Ut. In these situations, <br /> experience and judgment and an assessment of the pore pressure dissipation data should <br /> be used to infer the soil behavior type. The soil classification chart used to interpret soil <br /> types based on Qc and Rf is provided in the Appendix. <br /> li <br /> I <br />