库水位下降情况下滑坡的稳定性分析

Analysis on stability of landslide during reservoir drawdown

库水位的下降是库岸产生滑坡的重要原因。为了研究库水下降时坡体的稳定性,根据布西涅斯克非稳定渗流微分方程,得到了库水位等速下降时坡体内浸润线的简化计算公式。在此基础上,通过算例分析了滑带土抗剪强度、库水下降速度、下降高度以及坡体的渗透系数等对坡体稳定系数的影响。结果表明在库水位的下降过程中,坡体存在一个最危险的水位,在这个水位坡体的稳定系数最小,该位置一般在滑体的下1/3处。

The Boussinnesq differential equation for unsteady seepage flow is applied to analyze the phreatic line in the bank of reservoir during drawdown and a simplified formula is proposed. The effects of soil shear strength, drawdown rate, drawdown depth and permeability of soil on stability of landslide are analyzed. It is found that a critical water level is existed, at which the safety factor of the landslide reaches the minimum. This level is always at the elevation of 1/3～1/4 height of the landslide.