基于静力触探与剪切波速联合测试的砂土液化判别方法

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

摘要:

基于逻辑回归算法提出一种静力触探（CPT）与剪切波速（V_s）联合测试方法（CPT?V_s联合方法），并结合唐山地震液化案例对CPT?V_s相关性方法、q_c/G₀方法和CPT?V_s联合方法进行了比较。结果表明：3种方法的场地液化判别准确率分别为89%、78%和100%，整体液化判别准确率分别为94%、50%、94%；CPT?V_s相关性方法适用范围受参数值限制，q_c/G₀方法过于保守，造成非液化区误判；CPT?V_s联合方法不受参数值限制，可给出较为满意的结果。

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.