两河口水电站引水进口边坡变形稳定性分析

ANALYSIS OF STABILITY ON WATER INLET SLOPE DEFORMATION OF LIANGHEKOU OF LIANGHEKOU HYDROPOWER STATION

两河口水电站引水进口边坡主要由砂、板岩组成的陡倾横向坡,最大开挖坡高215 m。本文根据边坡的地质结构及变形破坏特征,分析了边坡的破坏模式及稳定状况。在此基础上,采用三维有限元数值模拟的方法,模拟了工程边坡的分步开挖过程。分析表明,边坡稳定性主要受f34-1等中缓倾角结构面及Ⅴ级岩体的控制,具有沿中缓倾角结构面及Ⅴ级岩体发生滑移破坏的趋势,塑性破坏区主要分布在Ⅴ级岩体及其断层内,水平深度一般为35 m,研究成果对边坡的支护设计具有重要意义。

The water inlet slope of Linghekou H ydropower station is steep-dip cross fall, which is made up of sandstone and slate. The excavation maximum of slope is 215 m high. The article, based on the geologic structure and the characteristics of deformation-failure of the slope, analyzes the failure mode and steady-state situation of the slope. On that basis, the method of three-dimensional finite element numerical simulation is carried out, which simulates the slope excavation in stages of the engi- neering slope. The analysis shows that, the slope stability is mainly controlled by middle and low-angle dip faults, such as the f34-1 fault and the grade- V rock mass,the slope has a tendency of sliding down on the low-angle dip faults and in the grade- V rock mass. The plastic damage zone is mainly distributed in the grade- V rock mass and the fault zone, the general depth in the horizontal direction is 35 m. The research results are great importance to the design for shoring.