土体K_0加卸载过程中水平应力变化研究

采用JCY型K0固结仪,对不同密实度的砂土、饱和粉土和饱和粉质黏土进行K0加卸载试验,采用K0加卸载模型对土体加卸载过程中的水平应力σ′h和竖向应力σ′v的关系进行描述,结合土体物理力学特性对K0加卸载模型参数进行探讨。试验结果表明:对于黏性土和非黏性土,土体加载过程中σ′v-σ′h关系为线性,卸载过程中σ′v-σ′h关系为非线性;土体竖向应力σ′v卸荷至零时,土体中的残余水平应力σ′h与土体黏性相关,采用土体的K0加卸载模型可对土体K0加卸载过程中的σ′v-σ′h关系进行良好的描述;土体的K0加卸载模型参数K0(NC)和α与其内摩擦角φ′相关。

THE CHANGE IN HORIZONTAL STRESS OF SOILS DURING K0 LOADING-UNLOADING

The K0 loading-unloading tests for sand,saturated silt and silty clay were conducted,using the JCY consolidation apparatus,then the σ′v-σ′h relationships during the tests were described by K0 loading-unloading model. The parameters of K0 loading-unloading model were discussed. Several results were concluded. The σ′v-σ′h relationship is linear during loading,and it is unlinear during unloading. When the vertical stress σ′v equals to zero during unloading,the residual horizontal stress is affected by the viscosity of the soil. The σ′v-σ′h relationship during K0 loading-unloading can be calculated by K0 loading-unloading model. The parameters K0(NC) and α are affected by the friction angle φ′.