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GREGG IN SITU, INC FUGRO - WEST, INC <br /> April 4, 1995 Shell Oil Facility <br /> Stockton, CA <br /> The cones were pushed using GREGG IN SITU's CPT rig, having a down pressure <br /> capacity of approximately 25 tons Seven CPT soundings were performed to depths of <br /> approximately 20 to 25 feet below ground surface Test locations and depths were <br /> determined in the field by Fugro - West, Inc personnel <br /> In situ groundwater samples were taken at each location Groundwater samples were <br /> collected using the Hydropunch groundwater sampling system The Hydropunch <br /> operates by pushing 1 75 or 1 5 inch diameter hollow rods with a retrievable tip A <br /> stainless steel filter screen is attached to the tip At the desired sampling depth, the rods <br /> are retracted exposing the filter screen and allowing for groundwater infiltration A small <br /> diameter bailer is then used to collect groundwater samples through the hollow rod <br /> Soil samples were taken using a piston type soil sampler The soil samples were <br /> collected in approximately 1 1/8 inch diameter stainless steel sample rings A figure of <br /> the soil sampler is provided in the Appendix <br /> The CPT/Hydropunch 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 treme 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 <br /> along 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 which is used to infer <br /> soil behavior type Generally, cohesive soils (clays) have high friction ratios, low cone <br /> bearing and generate large excess pore water pressures Cohesionless soils (sands) <br /> have lower friction ratios, high cone bearing and generate little in the way of excess pore <br /> water pressures <br />