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rTEC ConeTec <br /> Geotechnical and Environmental Site Investigation Contractors <br /> ConeTec CPT Interpretations as of January 7, 1999 (Release 1 00.19) <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 /> The 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 + O-a) •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 Soil <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 Sod 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 Descnpbon Equation Ref <br /> Parameter <br /> Depth mid layer depth <br /> AvgQt - - Avag <br /> ered corrected tip{Qt)--__- _ _ _----- AvgQr= 1 <br /> n — <br /> AvgFs- � Averaged sleeve fnct�on(Fs) 1 <br /> AvgFs=—EFS, <br /> n <br /> o ----- -_--- <br /> AvgRf=100/o• AvgFs <br /> AvgQt <br /> AvgUd Averaged dynamic pare pressure(Ud)- ------- T - - --- 1 — ---- - <br /> AtigUd=- Ud, <br /> - - - — -- ---- - n - <br /> SBT Sal Behavior Type as defined by Robertson and Campanella <br /> 1 <br /> 1 <br />