土质边坡的饱和-非饱和渗流分析及特殊应力修正

Simulation of seepage flow on soil slope and special stress-correction technique

基于连续多孔介质原理与混合体原理引入流-固耦合模型,采用FISH语言编制程序,建立了初始渗流场设置函数、饱和-非饱和渗流分析模块、特殊应力修正模块以及非饱和单元抗剪强度修正模块,实现了利用FLAC3D进行饱和-非饱和渗流分析,同时基于饱和-非饱和渗流场修正非饱和区土体单元的有效应力以及抗剪强度,完成了将FLAC3D中饱和土流-固耦合计算原理扩展到非饱和土中。在二次开发的分析模块基础上对Liakopoulos砂柱排水试验进行数值模拟,验证了计算模型和计算程序的正确性。同时也研究了降雨入渗对土质边坡的渗流场、位移场以及稳定性演变过程的影响,揭示了降雨诱发边坡失稳的机制。

Introducing the fluid-mechanical interaction model based on continuous porous media theory and mixture theory, applying FISH language to program, the initial seepage field setting function, the saturated-unsaturated seepage analysis module, the special stress-correction module and shear strength correction module are established. Saturated-unsaturated seepage analysis is conducted with FLAC3 D. The effective stress and shear strength of soil zone in the semi-saturated region is modified based on the saturated-unsaturated seepage field and the principle of fluid-mechanical coupling for completely saturated element and extended to unsaturated soil element in FLAC3 D. Based on these analysis modules from secondary development, the water drainage experiment from a sand column conducted by Liakopoulos is numerically simulated to verify the correctness of the model and program. The effect of rainfall infiltration on the seepage field, displacement field and stability evolution of soil slope reveals the mechanism of rainfall-induced failure of slope.