中文摘要：

采用空心圆柱扭剪仪对原状饱和软黏土开展交通荷载诱发主应力幅值与主应力轴旋转耦合加载路径下的不排水试验研究。通过与循环三轴压缩试验对比,探讨主应力轴旋转对孔压、变形和应力–应变的影响。分析广义剪应力对循环刚度和非共轴性的影响。试验结果表明,相比较循环三轴试验,交通荷载应力路径下所诱发的主应力轴旋转使孔压和应变显著变大,应力–应变滞回圈刚度显著弱化。循环耦合加载路径下,存在剪切应力–应变和正偏应力–应变2种响应,应力–应变刚度呈现各向异性弱（强）化,应变增量矢量有显著的非共轴性,非共轴性有显著分段特征。较低剪应力水平下,应变路径轨迹趋于稳定,循环刚度表现为强化,非共轴性趋于增大;而较高剪应力水平下,应变路径轨迹趋于破坏,随循环弱化,非共轴性减小。

英文摘要：

A series of undrained tests were conducted with hollow cylinder apparatus for undisturbed saturated soft clay under coupled loading path of principal stress magnitude and principal stress rotation induced by traffic loading. The effects of principal stress rotation on pore pressure,deformation and stress-strain relationship were studied by comparing the results of cyclic triaxial tests and traffic loading path tests. The effects of the generalized shear stress level on the stiffness of stress-strain and non-coaxiality were also investigated. Test results show that compared to cyclic triaxial tests,the pore pressure and strain are significantly larger and the stiffness of stress-strain loops experiences a dramatic reduction under principal stress rotation induced by traffic loading. During cyclic coupling loading,two different cyclic responses,i.e.,the shear stress-strain relation and the normal differential stress-strain relation,were observed. The shear stiffness over stress-strain loops exhibited an anisotropic cyclic degradation and the strain increment vector displayed non-coaxility,which varied in different sections of the loop. In addition,in the lower shear stress level tests,the trajectory of strain paths tends to be stable,accompanied by the stiffness hardening and increase of non-coaxiality. In the higher shear stress level tests,the strain path envelopes tend to fail,accompanied by the stiffness degradation and reduction of non-coaxiality.