三峡库区枣子树包滑坡稳定性和治理研究

Study on Stability and Treatment of Landslide in Zaozishubao of Three Gorges Reservoir Area

摘要:

每年的库水位下降期间，三峡库区的许多滑坡都出现了较大的变形。从三峡库区枣子树包滑坡的结构和变形特征出发，分析了其成因机制及其稳定性状况；采用有限元法模拟了库水位下降时滑坡地下水渗流场，并将所得孔隙水压力用于滑坡的极限平衡分析，探讨了水位下降速率对滑坡稳定性的影响机理和规律。研究表明：该滑坡是早期岸坡岩体产生滑移-弯曲破坏后堆积并经漫长改造形成的，目前处于基本稳定状态，预计在加大库水位下降速度后处于欠稳定状态；滑坡稳定性系数随库水位下降而降低，库水位下降速度越大，稳定性系数降低越大；相对于库水位下降速率，强降雨对滑坡稳定性影响更明显；为提高滑坡整体稳定性，提出了抗滑桩的加固措施。研究方法和成果对滑坡的评价与治理具有较好的参考价值。

Abstract:

Many landslides in Three Gorges reservoir area have large deformation during the drawdown of reservoir water level every year. In this paper, based on the landslide structure and deformation characteristics of Zaozishubao in Three Gorges reservoir area, the formation mechanism and stability situation are analyzed; groundwater seepage fields are simulated by using finite element method when the reservoir water level falls, the pore water pressures are used for the analysis on limit equilibrium of landslides, the influence mechanism and laws of the drawdown rate of water level on accumulations’ stability are discussed. The analysis results showed that the landslide was formed by accumulation and transformation after sliding and bending failure of rock mass in the early stage, it is now in stable condition, but it is predicted to be in unstable state when drawdown rate of water level increases. The stability coefficient of landslide will decrease along with the reservoir water level falls, the faster water level drops, the greater stability coefficient decreases. Intensive rainfall has greater influence on the stability of landslide than the water level drawdown. The anti-slide pile reinforcement measures are proposed to improve the stability of landslide, the research methods and results have good reference value for the evaluation and treatment of the landslide.