U型河段三面临空变形体稳定性分析

Stability analysis of the three-side hanging deformation body in a U-shape river reach

以某水电站F3,F9断层上盘变形体为对象,开展了U形河段三面临空变形体稳定性分析。首先从变形体的形态特征和地质条件入手,对其形成机制和运动趋势进行了初步分析;其次,根据潜在的滑移趋势,选取了2个代表性剖面,采用有限元方法计算了代表性剖面在3种工况下的破坏区域,通过对比分析破坏面积发现变形体沿代表性剖面1方向的稳定性较好,而沿代表性剖面2的较差;最后,采用刚体极限平衡法(M-P)和有限元应力法对代表性剖面2进行抗滑稳定计算,结果表明,在各种工况下,变形体抗滑稳定均能满足工程要求。通过研究F3,F9断层上盘变形体的稳定性,探讨了变形体稳定性分析的新思路,对类似工程具有一定的借鉴意义。

Based on the upper plate deformation body of F3 and F9 faults in a hydropower station, stability analysis was made on the three - side hanging deformation body in a U - shape river reach. First, the forming mechanism and movement tendency was analyzed on the basis of morphology and geological conditions of the deformation body ; then, according to the sliding trend, 2 representative sec- tions are selected and calculated by finite element method to determine their failure zones in 3 operation conditions. In comparison with the failure areas, it is found that the stability of deformation body along representative section 1 is better than that along representative section 2. Finally, the stability against sliding of representative section 2 was calculated by rigid body limit equilibrium method （ M - P） and finite element stress method. The results show that the stability against sliding of deformation body can meet the requirements of a project at various operation conditions. The paper studies the stability of deformation body on the upper plates of F3 and F9 faults and discusses the new concept of stability analysis of deformation body, which provides reference for similar projects.