土坡稳定分析的颗粒流模拟

Simulation of slope stability analysis by particle flow code

边坡的失稳破坏运动是一个存在岩土体的滑动、平移、转动的复杂过程,具有宏观上的不连续性和单个块体运动的随机性。采用颗粒流模拟土坡的变形破坏全过程,不需要假定滑移面的位置和形状,颗粒根据所受到的接触力调整其位置,最终从抗剪强度最弱的面发生剪切破坏,因此离散元法是模拟边坡变形破坏力学行为的比较理想的途径。运用PFC(颗粒流)程序对砂性土坡和黏性土坡分别进行数值模拟,分析细观参数对土坡破坏型式的影响。结果显示,土性对边坡的破坏型式有很大的影响,随着颗粒黏性的增大,边坡破坏类型从塑性破坏向脆性破坏过渡。

The slope failure is a complicated process with the rock soil body＇s slide, translation and rotation, which has uncontinuity in macroscopic view and randomness of a single block movement. It is unnecessary to assume position of slip surface and the shape on using particle flow code（PFC） to simulate the deformation and failure of soil slope; and particles adjust their position according to their contact forces received, and finally slope occur sheafing failure from the weakest surface. Therefore, the discrete element method is comparatively ideal approach to simulate the mechanical behavior of side slope deformation and failure. The influences of microscopic parameters on slope failure＇s forms of sandy slope and clay slope are analyzed respectively by PFC numerical simulation. The results reveal that the soil property greatly influences the form of soil slope failure; with the increase of the particle viscidity, the types of the slope failure transit from plastic failure to brittle failure.