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CONIIC <br /> T <br /> _ <br /> 4� (C® eTeC <br /> Geotechnical and Environmental Site Investigation Contractors <br />' ConeTec CPT Interpretations as of January 7, 1999 (Release 100 19) <br /> ConeTec's interpretation routine should be considered a calculator of current published CPT correlations <br /> and is subject to change to reflect the current state of practice The interpreted values are not <br />' considered valid for all soil types The interpretations are presented only as a guide for geotechnical use <br /> and should be carefully scrutinized for consideration In any geotechnical design Reference to current <br /> literature is strongly recommended <br /> tThe CPT Interpretations are based on values of tip, sleeve friction and pore pressure averaged over a <br /> user specified Interval (typically 0 25m) Note that Qt Is the recorded tip value, Qc, corrected for pore <br /> pressure effects Since all ConeTec cones have equal end area friction sleeves, pore pressure <br /> ' corrections to sleeve friction, Fs, are not required <br /> The tip correction is Qt = Qc + (1-a) o Ud <br /> ' where Qt is the corrected tip load <br /> Qc is the recorded tip load <br /> Ud is the recorded dynamic pore pressure <br /> ' a is the Net Area Ratio for the cone(typically 0 85 for ConeTec cones) <br /> Effective vertical overburden stresses are calculated based on a hydrostatic distribution of equilibrium <br /> pore pressures below the water table or from a user defined equilibrium pore pressure profile (this can be <br /> ' obtained from CPT dissipation tests) The stress calculations use unit weights assigned to the Soli <br /> Behaviour Type zones or from a user defined unit weight profile <br /> Details regarding the interpretation methods for all of the interpreted parameters is given in table 1 The <br /> appropriate references referred to In table 1 are listed In table 2 <br /> The estimated Soil Behaviour Type is based on the charts developed by Robertson and Campanella <br /> ' shown in figure 1 <br /> ' Table 1 CPT Interpretation Methods <br /> Interpreted Description Equation Ref <br /> Parameter <br /> ' Depth mid layer depth <br /> AvgQt I Averaged corrected tip(Qt) gQ Q ' <br /> ,4 v t=— t <br /> n <br /> AvgFsI Averaged sleeve fnct3ori(Fs) .4vgFs=;i Fs <br /> AvgRf Averaged friction ratio(Rf) ,4vgQvgRf=1 A <br /> 00%� �gt <br /> ' AvgUd Averaged dynamic pore pressure(Ud) <br /> ,4 vg Ud=1�Ud, --- <br /> ' SBT Soil Behavior Type as defined by Robertson and Campanella <br />