摩擦系数变化对边坡滑动过程的影响

常规的滑坡计算方法认为土的内摩擦角保持不变，但是实际上土的摩擦系数在边坡滑动过程中是变化的。本文考虑边坡滑动过程中摩擦系数的变化，基于摩擦系数随运动过程变化的本构关系，采用物质点法对边坡滑动过程进行模拟计算。计算中用质点离散滑坡体，记录区域信息，每个计算时间步后将变形的网格抛弃，新的时间步采用未变形的网格。算例边坡滑动过程中惯性数始终比较小，在低惯性数下，摩擦系数变化的计算结果与摩擦系数取其下限值的结果比较接近。进一步对比分析了不同界限摩擦系数对边坡滑动过程的影响，发现界限摩擦系数越小，滑坡体形状越扁平，滑坡前沿滑动距离越远。

INFLUENCE OF THE FRICTION COEFFICIENT ON THE PROCESS OF LANDSLIDES

It is thought that the internal friction angle of soil remains unchanged in traditional calculation methods for landslides. In fact, the internal friction angle of soil changes with slope sliding. We analyzed the process of landslides in consideration of the change of the internal friction angle of soil by the material point method. In the material point method, material points with regional information discretizes the slope body. It abandons deformed grids after a computational time step. New grids are employed in the next step. For the example in this paper, since the inertia parameter was small, the results in consideration of the change of the internal friction angle of soil are close to those with a fixed value of lower limit parameter. we further compared the influence of different bounds of friction coefficient on the process of landslides. The shape of the landslide will be flatter with larger sliding distance if the bound of friction coefficient being smaller.