Laserfiche WebLink
Ll <br /> GREGG Cone Penetration Test Data & Interpretation <br /> Soil behavior type and stratigraphic interpretation is based on relationships between cone <br /> bearing (q,), sleeve friction (fa), and pore water pressure (u2). The friction ratio (RA is a <br /> calculated parameter defined by 100fjq, and is used to infer soil behavior type. Generally: <br /> Cohesive soils (clays) <br /> • High friction ratio (R� due to small cone bearing (q,) <br /> ® Generate large excess pore water pressures (u2) <br /> Cohesionless soils (sands) <br /> O Low friction ratio (Rf) due to large cone bearing (q,) <br /> o Generate very little excess pore water pressures (u2) <br /> A complete set of baseline readings are taken prior to and at the completion of each <br /> sounding. to determine temperature shifts and any zero load offsets. Corrections for <br /> temperature shifts and zero load offsets can be extremely important, especially when the <br /> recorded loads are relatively small. In sandy soils, however, these corrections are generally <br /> negligible. <br /> The cone penetration test data collected from your site is presented in graphical form in <br /> Appendix CPT. The data includes CPT logs of measured soil parameters, computer <br /> calculations of interpreted soil behavior types (SBT), and additional geotechnical parameters. <br /> A summary of locations and depths is available in Table 1. Note that all penetration depths <br /> referenced in the data are with respect to the existing ground surface. <br /> Soil interpretation for this project was conducted using recent correlations developed by <br /> Robertson et al, 1990, Figure SBT. Note that it is not always possible to clearly identify a soil <br /> type based solely on q,, f, and u2. In these situations, experience, judgment, and an <br /> assessment of the pore pressure dissipation data should be used to infer the soil behavior <br /> type. <br /> �osro <br /> 10 �, � ZONE Qt/N SBT <br /> 11 1 2rsen,sitive, fine greained <br /> 9 2 1nic materials <br /> 3 184 1.5cla to clacT 5 2ey silt to silty clay <br /> 6 2.5 Sandy silt to clayey silt <br /> 7 3 Silty sand to sandy silt <br /> 10 8 4 Sand to silty sand <br /> 9 5 Sand <br /> 10 6 Gravely sand to sand <br /> 11 1 Very stiff fine grained* <br /> + 12 2 - Sand to clayey sand* <br /> a <br /> *over consolidated or cemented <br /> o � s 4 5 s 7 e <br /> Firkdm Rano (96). FU <br /> Figure SBT <br />