中文摘要：

为研究主应力轴旋转情况下饱和软黏土的变形及强度特征,采用先进的空心圆柱扭剪仪（HCA）对软黏土进行了一系列不排水剪切试验。试验采用等压固结模式对软黏土空心薄壁试样进行固结,并在3种不同中主应力系数情况下,对试样进行不同主应力轴旋转角度下的不排水剪切试验;剪切过程中保持平均应力、中主应力系数及主应力轴旋转角度不变,只增加偏应力,研究不同中主应力系数情况下主应力轴旋转角度对软黏土应力应变特征以及强度特性的影响。研究结果表明：不同主应力轴旋转角度下天然软黏土的变形及强度特征存在明显的差异,在中主应力系数b=0.5的非轴对称加载情况下,不排水剪切强度随着主应力轴旋转角度的增大呈勺形变化;在b=0的轴对称压缩条件及b=1的轴对称拉伸条件下,随主应力轴旋转角度的增加,不排水剪切强度均呈递减趋势。

英文摘要：

The hollow cylinder apparatus （HCA） was used to study the deformation behavior and strength characteristics of soft clay under rotation of principal stress axes. A series of undrained shear tests were carried out on saturated soft clay under isotropic consolidation mode. The focus was on the effect of rotational angle of principal stress axes on stress- strain behavior and strength characteristics of soft clay under different coefficients of intermediate principal stress. During the shear tests, the average stress value remained unchanged along with the rotational an- gle of principal stress axes and the coefficient of intermediate principal stress, while the deviator stress was increased. The results show that the stress--strain behavior and undrained strength characteristics of natural soft clay are different obviously with different rotational angles of prin- cipal stress axes. The curve of undrained shear strength appears scoop style with the increase of rotation- al angle of principal stress axes under isotropic consolidation mode with b= 0. 5. The undrained shear strength decreases with the increase of rotational angle of principal stress axes with b= 0 andb=1. 2 tabs, 5 figs, 15 refs.