COMPARISON OF THE SPT, CPT, SV AND ELECTRICAL METHODS OF EVALUATING EARTHQUAKE INDUCED LIQUEFACTION SUSCEPTIBILITY IN YING KOU CITY DURING THE HAICHENG EARTHQUAKE.

The capability of SPT, CPT, Shear Wave Velocity and Electrical methods to evaluate earthquake induced liquefaction susceptibility of soil deposits consisting of sensitive clayey silts and silty clays, saturated with pore fluids of low and high salt concentrations is examined. Five liquefied and one non-liquefied sites in Ying Kou City, affected by the Haicheng earthquake of 1975, were selected for the study. The SPT method predicted that all sites would liquefy. The CPT method utilizing the SPT-CPT correlation provided similar predictions. The currently available shear wave velocity correlation for liquefaction for stiff site is shown to be inadequate to predict the observed behavior. The threshold shear strain approach predicted that all sites are susceptible to liquefaction. The predictions made by the electrical method from consideration of the stress ratio required to cause liquefaction and the pore pressures developed during earthquake are shown to be in accordance with the observed behavior in all cases.