瀑布沟水电站库首右岸拉裂变形体成因机制与稳定性分析

The mechanism and stability of evaluation for the deforming and cracking slope located on the right shore of Pubugou reservoir head

瀑布沟水电站大坝为砾石土心墙堆石坝,库首右岸拉裂变形体位于拦河坝右岸坝轴线上游约780 m左右,对岸布置有电站进水口等建筑物。一旦边坡失稳,对大坝等水工建筑物影响重大。拉裂变形体前后缘平面长约400 m,宽约360 m,高差达450 m。根据拉裂体的地形地貌、岩体结构特征、堆积物特征和变形破坏现象,边坡平面上分为两个区,剖面上分为松动带、拉裂变形带和正常岩体三个带。前期设计按照综合考虑各因素后,进行分区和分期支护、整体控制的加固措施,分别完成了一期及二期治理。结合近期监测成果分析,进行了稳定性复核评价,表明Ⅱ区变形稳定,无异常变形的迹象;Ⅰ区松动带出现变形现象。综合分析后建议进行三期支护处理。

Pubugou power station dam is the gravel-soil-core rock-fill dam. The deforming and cracking slope is located on the right shore of Pubugou reservoir head,780 m upstream the dam axis,facing the power intake and other structures. If the slope failed,it would be a great danger to the gravel-soil-core rock-fill dam and and other structures. The edge of the mass is 400 m long,360 m wide and 450 m high. According to the topography,rock mass structure characteristic,deposit characteristics and deformation damage phenomenon,the slope plane is divided into two areas,section is divided into loose zone,cracking deformation zone and three normal rock zone. After the preliminary design according to the comprehensive considering various factors,partition and installment support,the overall control of reinforcement measures,completed the first phase and second phase of governance. Combined with the recent monitoring data analysis,the author revaluates the stability. The result shows that the Ⅱ area deformation stability, no abnormal signs of deformation; the Ⅰ area deformation phenomenon in a loose zone. After comprehensive analysis,it is suggested that the three periods of supporting processing.