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DEC 31 2002 11 : 1O8M GREGG DRILLING 92531?0302 p. 1 <br /> EGG GREGG IN SITU, INC. <br /> Geotechnical and Environmental In Situ Testing Contractors <br /> CONE PENETRATION TESTING (CPT) <br /> Gregg In-Situ's Cone Penetrometer Tests(CPT)are <br /> carried out using an integrated electronic piezocone. <br /> The piezocone is pushed using a specialty designed CPT <br /> s, rig.With a force capacity of 20 to 25 tons. <br /> tip,M. <br /> A compression type cone is used for each CPT sound- <br /> ing. Piezocones with rated load capseltles of 5,10 or 20 <br /> tons are used depending on soli conditions. The 5 and <br /> t 10 ton cones have a tip area of 10 sq carr and a friction <br /> titu <br /> sleeve area of 150 sq cm. The 20 ton cones have a tip <br /> area of 15 sq cm and a friction sleeve area of 225 sq em. <br /> A pore water pressure transducer is located directly be- <br /> hind the cone 8p. Each fitfer is saturated in glycerin un- <br /> der vacuum pressure prior to each CPT sounding. Pore <br /> Pressure Dissipation Tests(PPDT)are recorded at 5 <br /> Triaxial Geophones I second intervals during pauses in penetration. The equi- <br /> `c Librium pore water pressure from the dissipation test can <br /> Or Accelerometer ?: be used to identity the depth to groundwater, <br /> (Vp&VS) l° <br /> <Lr The piezocones are capable of recording the following <br /> parameters at 2.5 and 5 cm increments <br /> =r, -Tip Resistance(qc) <br /> -Sleeve Friction(ft) <br /> ,r -Dynamic Pore Pressure(U) <br /> Inclinometer(I) -Resistivity (rho)with added module <br /> Ultra Violet Induced Fluorescence(UVIF) <br /> Thermistor <br /> The measured parameters are.printed simultaneously on <br /> I•.:i« a printer and stored on a computer disk in ASCEII format <br /> Friction Sleeve(FS) For future analysis. All CPT's are carried out in actor- <br /> r dance with ASTM D-5778-95. A complete set of base- <br /> Load Cells tines readings are taken prior to each sounding to deter- <br /> F: mine any zero load offsets. <br /> <: The inferred stratigraphic profile of each CPT location is <br /> I . included on each CPT plot. The stratigraphic interpreta- <br /> 3 Pore Pressure dons are based on relationships between cone bearing <br /> Porous Filter Transducer U (qcj and friction ratio(Rf). The frr--tion ratio is a calcu- <br /> Ele-ment lated parameter(frfgc) used in conjunction with the cone <br /> Cone Tip(Q(;) bearing to identify soil behavior type. Generally,soft <br /> cohesive solls have low cone bearing and high friction <br /> ratios. Cohesionless soils(sands)have a high cone <br /> bearing and low friction ratios. The classification of soils <br /> is based on correlations developed by Robertson at al <br /> (1988). It is not always possible to clearly identify a soil <br /> type based on qc and Rf alone. Correlation with existing <br /> solis Information and analysis of pore pressure measure- <br /> ments should also be usad in determining sail type. <br /> Los Angeles(corporate)-San Francisco-Houston -Charlston <br /> Vancouver•Salt Lake City• New Jersey <br /> Tel.(562)427-6899•Fax(562)4242329•Website:www.greggdritfing.com <br />