三峡水库水位上升对香溪河流域典型滑坡的影响分析

在三峡水库蓄水后,香溪河流域众多滑坡出现变形失稳现象。白家堡滑坡、耿家坪滑坡、白马滩滑坡在蓄水后的变形特征各不相同。对库水位上升后3个滑坡的变形特征及其渗透性进行了比较研究,表明影响滑坡响应时间的主要因素是滑体的渗透性。以白家堡滑坡为例,利用摩根斯坦-普赖斯法,对不同c、值,进行75~175 m水位线的稳定性系数演算,发现各c、值不同水位线下稳定性系数曲线的变化规律有2种类型,即下降—平直型和下降—上升型,这种变化规律与浸水部位密切相关。

Analyses of Typical Landslides in Xiangxi River Valley Affected by Impounding

After impounding of Three Gorges Reservoir,many landslides deform in Xiangxi River Valley,such as the Bai Jiabao,Geng Jiaping,Bai Matan landslides,with different deformation characteristics.Analyses of the deformation characteristics and permeability coefficients of these landslides show that the main factor influencing the response time is permeability of landslide materials.Taking the Bai Jiabao landslide as an example,stability compuations utilizing the Morgenstern-Price method show that the safety factor of the landslide mass varies with the water level from 75m to175m with various values of c andφ.The curves of variations of safety factors with the water level have the two typical types,i.e.,down-up and down-flattening,which are closely related to the location of submerged part of landslide.