某水电站碎裂松动岩体形成机制及稳定性分析

碎裂松动岩体是指一系列具有碎裂结构且各向结构面均有张开的岩体,其碎裂特性和松动特性对工程建筑长期稳定性有着巨大影响。采用现场地质调查为主要手段对研究区碎裂松动岩体赋存地质条件和变形破坏迹象进行了研究,并从卸荷、冻融和地震三方面分析了其成因机制。运用二维离散元UDEC模拟碎裂松动岩体在各工况下的稳定性,发现地震作用对碎裂松动岩体稳定性影响明显大于暴雨作用,且其变形过程由暴雨工况下的由下至上逐层次破坏转化为岩体先解体,再发生整体滑动。

Analysis on Formation Mechanism and Stability of Cataclastic Loose Rock Mass in a Hydropower Station

The cataclastic loose rock mass is defined as having a cataclastic structure and each structure surfaces are open, the cataclastic and loose features of which have great effects on the long-term stability of engineering construction. Through the detailed field geological survey, the hosting geological conditions and signs of deformation and failure of the cataclastic loose rock mass are studied, and the formation mechanism is analyzed in three aspects: unloading, freeze-thaw cycle and earthquake. By simulating the stability of the cataclastic loose rock mass under various operating conditions by universal distinct element code, it is found that the seismic action has an greater influence on the stability of the cataclastic loose rock mass than heavy rain, and in heavy rain conditions, the damage of rock mass is from down to top, while in the condition of earthquake, rock mass collapse first, then integral slide occurs.