基于双剪理论的饱和/非饱和渗流边坡稳定性分析

根据Bishop非饱和有效应力假定建立了适用于非饱和土的双剪统一强度理论。基于非饱和土双剪统一强度理论使用二维显式有限差分程序FLAC,以某边坡模型试验为例,考虑土体强度的中间主应力效应及渗流的影响,分析了地下水位升降导致的饱和/非饱和渗流条件下边坡稳定性分析问题。饱和及非饱和渗流的计算分析均说明忽略中间主应力效应的计算结果与边坡模型试验结果不相符。地下水位下降过程中,按相关联流动法则计算得出边坡只存在一条滑动面,而非相关联流动法则计算结果显示边坡存在多条滑动面。

Slope Stability Analysis Under Saturated or Unsaturated Seepage Flow Based on Twin Shear Theory

Based on the assumption of Bishop unsaturated effective stress ,the twin shear unified strength theory for un-saturated soil is developed in this paper .The twin shear unified strength theory for unsaturated soil and two-dimensional explicit finite difference code FLAC is adopted to simulate a slope model test subjected to rising and lowering water lev-els .The influence of the intermediate principal stress and saturated or unsaturated seepage flow are taken into account , the stability analysis of the slope model test is processed with FLAC code with the water level variation .The results of the saturated and unsaturated seepage flow calculation both show that the results of the slope stability analysis is not corre-spond with that of the slope model test .A signal slide surface is yielded during the drop down progress of water level with the associated flow rule ,and several slide surfaces are yielded with the non-associated flow rule .