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March 3, 1999 Cambria <br /> Shell Station <br /> Ripon, CA <br /> I The CPT holes were grouted using our support rig The grouting procedure consists of <br /> using a PVC tremae pipe <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 /> The 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 fncfion 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 Qissipation 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 4o 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 (t50), <br /> 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 /> I <br /> I <br /> 1 <br /> Ii� <br /> I <br />