关键词: 等效剪切波速, 计算深度, 场地分类

Abstract: Based on analysis of the shear wave velocity data of 823 boles from the northern,eastern,southern,northeastern and northwestern areas of China,we studied the difference of the equivalent shear wave velocities calculated with the soil-and-rock depths of 20m and 30m,respectively.We also discussed the features and differences among the Chinese,American and European seismic regulations in site classification using the parameter of equivalent shear wave velocities of boles.Our results indicated that:① The equivalent shear wave velocity will increase about 10 to 60m/s when we increase the calculation depth of soil-and-rock from 20m to 30m.The average increase is about 24m/s.② Comparing with the American and European seismic regulations,the current Chinese seismic regulation(GB 50011-2001)requires the information of the equivalent shear wave velocities calculated with the soil-and-rock depths of 20m,as well as the depth of the overburden in the site when classifying the site.However,it is usually difficult to obtain the usable overburden depth in many engineering sites to serve the site classification.Therefore,it is necessary for us to use for reference of American and European seismic regulations to increase the depth of soil-and-rock when calculating the equivalent shear wave velocity so as to get a more reliable parameter to serve for the site classification.

Key words: equivalent shear wave velocity, depth of soil-and-rock for calculation, site classification