基于PFC2D的岸坡覆盖层失稳堵江模拟研究

Simulation Research on River Blocking by Instable Cover Layer of Reservoir Bank Based on PFC2D

基于PFC2D颗粒流方法,建立覆盖层边坡模型,设定多个库水位的条件下,模拟覆盖层边坡破坏过程,预测形成的堰塞坝高度。结果表明,库水位越高,堰塞坝高度越高。当覆盖层中饱和土体占1/3时,破坏规模较大,形成的堰塞坝高度要高于其他水位条件下的模拟结果,即存在一个较危险的水位区域。水位低于危险区时,主要发生坡脚塌岸;危险水位区域内,整体下滑;水位高于危险水位区,主要是饱和土体发生失稳。该方法不适用于库水位升降的动态过程模拟,仅适用于静水位模拟。

Based on the PFC2D particle flow method, the cover layer model of reservoir bank is established, and the failure processes of cover layer under different water levels of reservoir are simulated and the heights of dammed weir in river are predicted. It is concluded that the higher the water level of reservoir, the higher the dammed weir height. When the proportion of saturated soil in cover layer is 1/3, the damage scale is larger and the height of damming weir is higher than that under other water levels, which means that there is more dangerous water level range. When the water level is lower than the dangerous water level, the main failure mode is slope collapse. In the dangerous range of water level, the slope results in overall failure. When the water level is higher than the dangerous range, the destruetion is mainly the saturated soil. This method is not suitable for the simulation of dynamic process of reservoir water level fluctuation, and is only applicable to the simulation under static water level.