Analysis of Equivalent Shear Wave Velocity and Its Calculation Depth of Deep Sediment Layers in Suzhou Region

Shear wave velocity is an important parameter for evaluating the dynamic behavior of soil.In seismic design codes,the equivalent shear wave velocity is used as the key indicator to classify sites.However,the different calculation depths were chosen in different seismic codes.The correlation of equivalent shear wave velocities vs,20 and vs,30 corresponding to the depths of 20 m and 30 mare statistically analyzed on the basis of the measured data of shear-wave velocity from 446 boreholes in Suzhou study region.According to the site category standards in the seismic codes of GB50011-2010,NEHRP and Eurocode 8,the spatial distribution characteristics of site categories in Suzhou region are compared.The results exhibit a significant linear correlation between vs,20 and vs,30,and the corresponding determination coefficient R2 is 0.888.There are significant difference in spatial distributions of site categories presented by the codes of GB50011-2010,NEHRP and Eurocode 8.Furthermore,the equivalent shear wave velocitie