利用土工静力-动力液压三轴-扭转多功能剪切仪,对使用真空抽吸法制备的黏土试样,进行了耦合循环剪切试验。探讨了主应力轴连续旋转下,空心试样在微幅应变下的动力特性研究。试验结果表明:耦合试验得到的竖向分量动弹性模量和扭向分量动剪切模量的发展趋势与常规动力特性试验的动模量发展趋势基本一致;实测的竖向毛。比由扭向分量换算得到的Emax偏低,实测的扭向Gmax比由竖向分量换算得到的Gmax偏高;竖向和扭转向阻尼比的结果比较接近。
The stress-controlled coupled vertical and torsional coupling shear tests under undrained condition were conducted using an apparatus for static and dynamic universal triaxial and torsional shear soil testing. Through a series of tests on hollow saturated clay, the rotation of principal stress under coupling cyclic shear with tiny amplitude strain behaviour was investigated. The observation shows that the tendency of dynamic modulus under coupling test with the effect of rotation of principal stress axes was similar with dynamic modulus under conventional dynamic test. Moreover, the measured Emax under coupling test is lower than the Emax calculated by shear modulus with torsional component, and the measured Gmax under coupling test is higher than the Gmax obtained from elastic modulus with vertical component. In addition, the vertical component of damping ratio and the torsional component of damping ratio were very close.