黏性土卸载屈服特性试验研究

通过扰动的粉质黏土室内固结排水卸载剪切试验，分别得到真三轴和普通三轴侧向卸载条件下的应力-应变曲线。对这些曲线分析可知，它们表现为应变硬化和非线性，其初始阶段呈直线状，很快转变为曲线；真三轴试验（轴向应力 为常量、减围压 、保持应变 0）相比普通三轴试验（ 为常量、减 ，且中主应力 ），真三轴试验屈服发生在应力差（ ）值较高、轴向应变值 较小处；将试验取得的各屈服点进行整理分析，认为这种土在卸载条件下的屈服表现较适宜于Matsuo-Nakai屈服强度准则。

Experimental study of yield property of clayey soil under unloading

By shear test of disturbed silty clay at true triaxial apparatus and triaxial apparatus under isotropic consolidation drainage and lateral unloading, the stress-stain curves are obtained. Analysis shows: these curves are nonlinear and strain hardening; curvilinear shape changes from original straight line into curve; stress value of yield point is larger at true triaxial lateral unloading test( constant, is decreased, 0) than at triaxial lateral unloading test; strain value of yield point is smaller at true triaxial lateral unloading test than at triaxial lateral unloading test. Analysis shows: Matsuoka-nakai strength criteria is suitable for sdudy yield property of Wuhan silty clay at lateral unloading.