基于三峡库区库水位和降雨统计分析的八字门滑坡稳定性评价

目的]分析三峡库区水位及降雨对八字门滑坡的影响,为八字门滑坡的稳定性作出评价。方法]利用滑坡的监测资料对八字门滑坡的变形进行定性分析,然后在对库区水位及降雨定量分析的基础上确定20种工况,利用Geo-Studio计算八字门滑坡的稳定性。结果]八字门滑坡10个GPS监测点累积位移监测曲线均为阶梯形状并随着时间呈增长趋势,形态变化具有同步性。20种工况下八字门滑坡稳定系数大于1,当库水工况不变降雨工况变化时,最小稳定系数变化较小。当降雨工况不变库水工况变化时,最小稳定系数变化较大。最小稳定系数在库水位稳定在175水位、库水位稳定在145水位、2014年库水位波动、平均库水位、2013年库水位波动5种工况下依次减小。结论]八字门滑坡整体处于稳定状态。降雨和库区水位对八字门滑坡稳定性存在影响,库区水位对八字门滑坡稳定性的影响较大,库区水位变化幅度越大,八字门滑坡稳定性就越差。

Stability Evaluation of Bazimen Landslide Based on Reservoir Water Level and Rainfall Statistical Analysis in Three Gorges Reservoir

Objective] The impact of the Three Gorgesreservoir water level and rainfall on Bazimen landslide is analyzed to evaluate its stability.Methods] Landslide monitoring data were used for qualitative analysis of Bazimen landslide deformation. Based on the quantitative analysis of water level and rainfall in the reservoir area, 20 different kinds of working conditions were then determined, and the stability of Bazimen landslide was calculated through Geo-Studio.Results] The accumulated displacement monitoring curves from 10 GPS monitoring points in the Bazimen landslide were all ladder-shaped and increased with time, and they showed a synchronous morphologic change. Under the 20 different kinds of working conditions, the stability coefficient of the Bazimen landslide was more than 1. When the rain fall condition changed, the minimum stability coefficient varied mildly under the constant reservoir water level. When the reservoir water level changed, the minimum stability coefficient varied greatly under the constant rainfall. The minimum stability coefficient was successively reduced under five different conditions including stable reservoir water level at 175 m and 145 m, reservoir water level fluctuation in 2014, average reservoir level, and reservoir water level fluctuation in 2013.Conclusion] The Bazimen landslide is in a stable state, its stability is affected by rainfall and reservoir water level, and reservoir water level is the main factor. The stability of Bazimen landslide will be worse with the larger water level change in the reservoir area.