典型岩质顺层岸坡在库水位上升过程中的稳定系数变化特征

The Variable Characteristics of the Factor of Safety for Typical Rock Bedded Slope during the Course of Reservoir Water Level Rise

水库蓄水运行后,其岸坡水文地质条件较蓄水前发生较大的变化,对岸坡的稳定性造成不利影响,甚至可能引起岸坡失稳。在水库蓄水运行过程发生失稳的岩质滑坡中,岩质顺层岸坡的失稳破坏最为典型,例如意大利瓦依昂水库滑坡、我国湖南柘溪水库的塘岩光滑坡和三峡水库的千将坪滑坡。为了深入研究库水淹没深度对岩质顺层岸坡稳定性的影响,选取典型易滑岩质顺层岸坡为研究对象,建立岩质顺层岸坡概化模型,采用数学和力学理论推导方法,建立概化的岩质顺层岸坡稳定系数与库水淹没岸坡深度之间的数理关系。以千将坪岸坡为例,计算分析了该岸坡的稳定系数在库水位上升过程中的变化。结果表明,该岸坡稳定性系数随着库水淹没岸坡深度的增加而逐渐降低。该研究成果可为其他类似的岩质顺层岸坡在库水位上升过程中的稳定性评价提供参考。

Hydrogeological condition variation of the reservoir bank slope has greatly taken place after a reservoir impoundment,which will has an adverse effect on the stability of the bank slope,even may cause slope instability.Rock bedded slope failure is a very typical one which is easy to slide during the reservoir operation,such as Vajont landslide in Italy,Tangyanguang landslide in Zhexi Reservoir Area in Hunan province of China and Qianjiangping landslide in the Three Gorges reservoir Area.In order to further research the effects of submerged depth on the stability of rock bedded slope,this paper chose typical rock bedded slopes as research objects to establish the generalizing rock bedded slope model.Mathematical and mechanical methods were adopted to establish mathematical relation between the factors of safety of generalizing rock bedded slope and slope depth submerged by reservoir water.Qianjiangping slope is taken as a case to calculate the variation of the factor of safety during the course of reservoir water level rise.The calculating results indicate that the factor of safety decreases gradually with the increase of slope depth submerged by reservoir water.The research results can provide references to stability evaluation of the other similar rock bedded slopes during the course of reservoir water level rise.