库水位涨落条件下滑坡地下水渗流场动态特征

摘要

In order to investigate the impact of reservoir water level fluctuation on the dynamic responses of groundwater seepage of landslide. The transient seepage of Shiliushubao landslide as a research object was discussed under five different water level fluctuation rates and different seepage coefficient magnitudes. The research results show that the groundwater seepage line is affected by water level fluctuation rate and permeability coefficient. Under the condition of the rise of water level, landslide appears generally as a synchronous impoundment type when permeability coefficient is above 1 × 10 -4 m/s and greater than the water level rising rate. Under the condition of the descend of water level,seepage line will be characterized by a sudden drawdown when the permeability coefficient is less than 1 × 10 -6 m/s;reservoir water level will drop slowly if the coefficient is from 1 × 10 -4 to 1 × 10 -5 m/s;and seepage line and reservoir water level will descend synchronously as the coefficient exceeds 1 × 10 -4 m/s.%为探讨库水位升降对滑坡地下水的动态作用机理，以三峡库区石榴树包滑坡为例，采用有限元法，模拟了5种工况下库水位升降速率及不同渗透系数下滑坡体内地下水的暂态渗流场特征。研究结果表明：滑坡体内地下水渗流浸润线受水位升降速率与坡体渗透系数的共同影响；库水位上升条件下，当滑体渗透系数大于1×10-4 m/s，且水位上升速率小于渗透系数时，滑坡体表现为蓄水同步型。库水位下降条件下，当滑体渗透系数小于1×10-6m/s时，库水位发生骤降；渗透系数介于1×10-4～1×10-5m/s之间时，库水位表现为缓降；渗透系数大于1×10-4 m/s时，渗流浸润线与库水位保持同步下降。