饱和砂土最大动剪切模量的不同试验对比研究

对233个饱和砂土土样室内试验确定的最大动剪切模量和同一位置现场原位试验确定的最大动剪切模量进行了对比研究。结果表明:两者相差很大,室内试验结果基本上小于现场试验结果,埋藏深的土样相差更大;室内试验的最大动剪切模量与深度符合幂函数规律,且与砂土的密实度有关,与砂土的颗粒成分关系不大。通过工程实例,比较了2种试验最大动剪切模量对地震反应分析的影响,得到了室内试验最大动剪切模量与现场剪切波速的统计经验关系式。该经验关系式对工程场地地震反应分析具有一定的参考应用价值。

Comparative Analysis on Dynamic Shear Modulus of Saturated Sandy Soils in Laboratory and Field Tests

The dynamic shear modulus of saturated sandy soils has been analyzed comparatively between laboratory and field tests for 233 samples of the saturated sandy soils. The analysis indicates that the values of the dynamic shear modulus obtained in laboratory are different from those obtained in field; and the deeper the samples are embedded, the more the difference. The dynamic shear modulus and the embed-ded depth of the soil satisfy the law of a power function, which depends upon its compactness but not sig-nificantly on its grain composition. Through real engineering projects, the influence of the maximal dy-namic shear modulus from the two kinds of tests on seismic responses has been compared to obtain a statis-tical empirical formula of the dynamic shear modulus in laboratory and the shear wave velocity in field. The formula is of a certain help for the seismic response analysis of real engineering sites.