三峡库区新集镇典型高切边坡破坏机理研究

Study on Failure Mechanism of High-Cut Side Slope in Xinji Town of Three Gorges Reservoir Area

利用刚体极限平衡法和有限元数值模拟法,建立了边坡稳定性评价模型,对秭归县新集镇千担湾边坡变形破坏机制和边坡稳定性进行了研究。结果表明,有限元强度折减法计算所得的安全系数与传统的刚体极限平衡法结果接近。边坡破坏时,滑体中下部塑性屈服区与上部拉裂破坏区贯通而形成了滑面。传统极限平衡法不能考虑这种特殊的破坏机制,而假设破坏沿原有某一滑带产生,因此,用数值方法计算边坡稳定性,其结果更接近实际。

This paper establishes the model for evaluating the slope stability with rigid block ultimate equilibrium method and strength reduction method and discusses the deformation and failure mechanism and stability of side slope in Zigui County Xinji Town Qiandan Bay. The result indicates that the safety factor calculated by strength reduction finite element method is close to that by the traditional rigid block ultimate equilibrium method. When side slope fails, middle and lower plastic yielding regions connect with upper failure regions to form a sliding surface. Traditional rigid block ultimate equilibrium method cannot consider this special failure mechanism, but suppose that failure occurs along some sliding zone. Therefore, the result of slop stability obtained with numerical calculation method is closer to the actual value.