福建安砂水电站大坝左岸边坡稳定性分析

Slope stability analysis on left bank of Ansha Hydropower Station dam in Fujian Province

安砂水电站建成以来,大坝左岸边坡仍有掉块现象。文章通过分析原有资料和实地调查,对存在问题的左岸和厂房后边坡,进行地质构造、岩石结构情况研究,综合考虑其构造地貌、坡度、地下水、岩石中缓倾角断层、节理或地层层面相互作用,引入同时考虑地震力E和重力W共同作用下,岩石结构面组合稳定性图解分析等方法,对大坝左岸近坝岸坡进行地震边坡稳定性评价。分析结果认为:大坝左岸岸坡高陡岸坡的上段、中段剖面中的一些结构面及组合面存在下滑及接近下滑的危险。

Rock fall occasionally happened on the left bank slope of the station after the Ansha hydropower station has been constructed.Based on the analysis of exstent data and the site investigation,the geological structure and the rock texture condition of the slope are synthetically studied.Considering the mutual effect of the earthquake force(E) and gravity(W),after the analyzing of the interaction of topography,structure,groundwater,small angle faults,joints and rock strata,this paper evaluates the stability of left bank slope at the Ansha Water-Power Station Dam in Fujian which is induced by earthquake by means of the rock structural plane combination stability illustration.The results show that there are potential dangers of slope stability and landslide on the soft strctural layers and their combination of the upper segment of the left bank slope under the influence of groundwater and earthquake.