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At location CPT-1, shear wave measurements were obtained at approximately 5-foot intervals. <br />The shear wave is generated using an air-actuated hammer, which is located inside the front <br />jack of the CPT rig. The cone has a triaxial geophone, which recorded the shear wave signal <br />generated by the air hammer. <br />The above parameters were recorded and viewed in real time using a portable computer and <br />stored on a diskette for future analysis and reference. A complete set of baseline readings <br />was taken prior to each sounding to determine temperature shifts and any zero load offsets. <br />Monitoring base line readings ensures that the cone electronics are operating properly. <br />4. 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 ground surface. The soil dassification on the CPT plots <br />is derived from the normalized CPT Classification Chart (Robertson, 1990) and presents major <br />soil lithologic changes. The stratigraphic interpretation is based on relationships between cone <br />resistance (qc), sleeve friction (fs), and penetration pore pressure (u). The friction ratio (Rf), <br />which is sleeve friction divided by cone resistance, is a calculated parameter that is used to <br />infer soil behavior type. Generally, cohesive soils (days) have high friction ratios, low cone <br />resistance and generate excess pore water pressures. Cohesionless soils (sands) have lower <br />friction ratios, high cone bearing and generate little (or negative) excess pore water pressures. <br />Output from the interpretation program CPTINT provides averaged CPT data over one-foot <br />intervals. The CPTINT output indudes Soil Classification Zones (uses =non normalized chart), <br />SPT N Values, Undrained Shear Strength (Su) and Cydic Stress Ratio (CSR). A summary of <br />the equations used for the tabulated parameters is provided in the CPTINT Correlation Table <br />in the Appendix. <br />The interpretation of soils encountered on this project was carried out using correlations <br />developed by Robertson et al, 1990. It should be noted that it is not always possible to dearly <br />identify a soil type based on qc, fs and u. In these situations, experience, judgment and an <br />assessment of the pore pressure data should be used to infer the soil behavior type. <br />If you have any questions regarding this information, please do not hesitate to call our office at <br />(714) 901-7270. <br />Sincerely, <br />KEHOE TESTING & ENGINEERING <br />Steve Kehoe, P.E. <br />President