中文摘要：

采用柔性真三轴仪对上海粉细砂进行了一系列不同中主应力系数条件下的真三轴试验,针对中主应力对粉细砂强度特性的影响进行了系统分析。基于真三轴试验结果对Mohr-Coulomb强度准则的形状函数进行了改进,并采用试验结果对强度准则进行验证。结果表明,建立在真三轴试验基础上的强度准则能更准确地反映砂土三维应力状态下的强度特性。

英文摘要：

In order to investigate the effect of intermediate principal stress on strength of sands,a series of true triaxial compression tests of Shanghai silty sand under different intermediate principal stress coefficients are performed on flexible true triaxial apparatus.Then the Lode angle dependent shape function of Mohr-Coulomb＇s strength criterion is modified based on true triaxial tests results;and the true triaxial test results of Shanghai silty sands are simulated.The results show that the strength criterion based on true triaxial tests can describe the strength characteristics of sand in true 3D state preferably.