Liquefaction Discrimination of Sand Based on Cone Penetration Test Combined Shear Wave Velocity Test

Abstract:

A method of cone penetration test （CPT） combined shear wave velocity （V_s） test （CPT-V_s combination method） was proposed based on logistic regression algorithm. In connection with the liquefaction cases of Tangshan earthquake， the comparison was done among CPT-V_s correlation method， q_c/G₀ method and CPT-V_s combination method. It is shown that the site liquefaction discrimination rates of CPT-V_s correlation method， q_c/G₀ method and CPT-V_s combination method are 89%， 78% and 100%， respectively， and the overall accuracies of liquefaction discrimination of the three methods are 94%， 50%， and 94%， respectively； the application scope of CPT-V_s correlation method is limited by parameter values， and the q_c/G₀ method is too conservative， resulting in a large discrimination error in the non-liquefied area； the method proposed is not affected by the limitation of parameter values， and can give satisfactory results.