库岸边坡倾倒变形岩体特征分析及稳定性评价

Characteristic analysis and stability evaluation of tilted and deformed rock mass of reservoir bank slope

西南某水电站库岸边坡岩体倾倒变形类型分为倾倒溃屈、倾倒松动、倾倒松弛及倾倒蠕变。总结了该工程倾倒变形岩体的平面及空间分布特征,通过倾倒岩体稳定性定性分析得出倾倒溃屈、倾倒松弛与倾倒蠕变对岸坡稳定性影响小,倾倒松动岩体对工程影响较大,二维极限平衡分析得出倾倒松动岸坡岩体整体稳定性满足规范要求,三维离散元分析得出倾倒松动的垂直影响范围约在高程1600m以上,倾倒变形程度随高程增高而增强。

The types of rock mass collapse and deformation on the bank slope of a hydropower station in southwestern China can be divided into toppled buckling,toppled loosening,toppled relaxation,and toppled creep.The plane and spatial distribution characteristics of toppled and deformed rock mass are summarized.Qualitative analysis of stability of toppled rock mass shows that toppled collapse,toppled relaxation and toppled creep have little influence on bank slope stability,while toppled and loose rock mass has greater influence on engineering.The two-dimensional limit equilibrium analysis shows that the overall stability of the toppled and loose rock mass meets the requirements of the code.Three-dimensional discrete element analysis shows that the vertical influence range of toppling loosening is above 1600m of the elevation,and the degree of toppling deformation increases with the elevation.