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CPT Interpretations <br /> Interpreted Description Equation Ref <br /> : Parameter <br /> E.Stress <br /> 6v Effective vertical overburden stress at Mid Layer Depth Estress=Tstress-uq <br /> For hydrostatic option: <br /> Equilibrium pore pressure determined from one of the <br /> following user selectable options: u,r=y •(D-D j <br /> Ueqwhere u„r is equilibrium pore pressure <br /> 1) hydrostatic from water table depth yN,is unit weight of water <br /> 2) user supplied profile D is the current depth <br /> D,M is the depth to the water table <br /> Cir=(-r.74.a <br /> Cn SPT N60 overburden correction factor where Q„'is in tsf <br /> 0.5<C„<2.0 <br /> SPT N value at 60%energy calculated from q/N ratios <br /> Neo assigned to each SBT zone. This method has abrupt N See Figure 1 4,5 <br /> value changes at zone boundaries. <br /> SPTN Value at 60%energy. This method is a slight <br /> modification of the Jefferies and Davies technique <br /> Neo(!c) whereby the gtfN ratio varies across soil classification See Figure 1 5,8 <br /> zones based on the Ic parameter. This techniques is <br /> limited to zones 2 through 7 on the normalized Soil <br /> Behavior Type Chart _ <br /> (Nj)6o ` SPT Neo value corrected for overburden pressure (Nr)w=Cn •Neo i 4 <br /> •(N,)so <br /> sPr <br /> Where: KSPT is defined as: <br /> 4(Ns)m Equivalent Clean Sand Correction to(Ni)6o 0.0 for FC<5% 4 <br /> 0.0167•(FC-5) for 5%<FC<35% <br /> 0.5 for FC>35% <br /> FC-Fines Content in% <br /> (Nth Equivalent Clean Sand(Ny)eo (N1)6oa=(N1)o + A(N1)6o 4 <br /> r <br /> Su Undrained shear strength-Nkt is user selectable SU q N 1,5 <br /> k Coefficient of permeability(assigned to each SBT zone) a 5 <br /> Bq= <br /> AU <br /> qt-Cr. <br /> Bq Pon:pressure parameter where: au=a-uR 1.5 <br /> and u=dynamic pore pressure <br /> ueR=equilibrium pore pressure <br /> Normalized qt for Soil Behavior Type classification as Q1=qt or. <br /> 2,5 <br /> at defined by Robertson, 1990 <br /> Normalized Friction Ratio for Soil Behavior Type Fr=100%• fs <br /> 2,5 <br /> Fr classification as defined by Robertson, 1990 qr-Cr, <br /> SBTn Normalized Soil Behavior Type as defined by Robertson See Figure 2 2,5 <br /> and Campanella <br /> GREGG <br /> CPTSUMM-1.20C-Rev.02-07-31 <br />