Laserfiche WebLink
GREGG IN SITU, INC. ADVANCED GEO <br /> January 16, 2002 South Cherokee Lane <br /> 01-100TX Lodi, Ca <br /> In situ groundwater samples were taken at three locations Groundwater samples were <br /> collected using a Hydropunch® type groundwater sampling system (figure 2) The <br /> groundwater sampler operates by pushing 1 75 diameter hollow rods with a retnevable <br />' tip A stainless steel filter screen is attached to the tip At the desired sampling depth, <br /> the rods are retracted exposing the filter screen and allowing for groundwater infiltration <br /> A small diameter bailer is then used to collect groundwater samples through the hollow <br /> rod <br /> 3.0 CONE PENETRATION TEST DATA <br />' The cone penetration test data is presented in graphical fomn Penetration depths are <br /> referenced to existing ground surface This data includes CPT logs of measured soil <br />' parameters and a computer tabulation of interpreted soil types along with additional <br /> geotechnical parameters and pore pressure dissipation data <br /> rThe stratigraphic interpretation is based on relationships between cone bearing (qc), <br /> sleeve fnction (ft), and penetration pore pressure (U). The friction ratio (Rf), which :s <br /> . sleeve fncfion divided by cone beanng, is a calculated parameter which is used to infer <br /> fsoil behavior type Generally, cohesive soils (clays) have high friction ratios, low cone <br /> bearing and generate large excess pore water pressures Cohes:onless sods (sands) <br /> have lower friction ratios, high cone beanng and generate little in the way of excess <br /> pore water pressures <br /> The interpretation of sods encountered on this protect was carried out using recent <br /> correlations developed by Robertson et al, 1988 It should be noted that tt is not always <br /> possible to clearly identify a soil type based on qc, fs and U In these situations, <br /> experience and judgement and an assessment of the pore pressure dissipation data <br /> should be used to infer the soil behavior type The soil classification chart (figure 3) <br /> used to interpret soil types based on qc and Rf is provided in the Appendix <br /> Interpreted output requires that depth of water be entered for calculation purposes, <br /> where depth to water is unknown an arbitrary depth in excess of 10 feet of the deepest <br /> sounding is entered as the groundwater depth <br /> I <br /> E <br /> l <br />