三峡泄滩滑坡滑动带土的改进Mesri蠕变模型

Modified Mesri's Creep Model for Soils in Sliding Zone of Xietan Landslide in the Three Gorges

为进行滑坡建模和稳定数值分析的需要,进行了三峡泄滩滑坡体滑动带土的三轴排水蠕变试验.在此基础上,给出了排水条件下粘性土的Mesri蠕变模型,即剪应力 应变关系采用双曲线模型、应变 时间关系采用幂函数来描述土体的弹粘塑性;提出了改进Mesri蠕变模型,其应变 时间关系采用分段拟合方法.模型计算曲线与试验数据的比较表明,改进Mesri蠕变模型较Mesri蠕变模型对粘性土蠕变性能的拟合能力得到了显著改善.

In order to provide the basement of a further numerical analysis, the drained triaxial compression creep tests with a constant stress were carried out for soils in the sliding zone of Xietan landslide in the Three Gorges. Based on these tests, a shear stress-strain-time function, namely, Mesri's creep model, in which a hyperbolic line was adopted for describing the shear stress-strain behaviour and a power function for the strain-time behaviour, was given. A modified Mesri's shear stress-strain-time model was proposed. In this model, the strain-time behavior of the soils was simulated by subsection. Through contrast of computed curves based on the two models and test data, the result shows that the modified Mesri's model has an advantage over the Mesri's model in the simulation capability for creep behaviours of clay.