地震作用下高堆尾矿坝永久变形与稳定性分析

综合采用时程分析法、整体变形分析法（等效节点力法和软化模量法）、极限平衡法等方法，以小打鹅尾矿库为例，分析了该高堆尾矿坝的永久变形和动力稳定性。分析了干滩面长度、尾矿堆积坝高度、设计地震加速度等影响因素对尾矿坝的安全系数和永久变形的影响，以及地震作用下尾矿坝安全系数的时程变化规律。结果表明：尾矿坝的地震永久变形与一般土石坝的存在差异，其水平方向的永久变形大于竖直方向的永久变形，且永久变形与坝高不一定呈单调递增关系；地震中尾矿坝的最小安全系数与各影响因素大体呈线性关系，而坝顶处的震陷与各影响因素之间呈非线性关系；地震过程中尾矿坝瞬时安全系数具有波动降低的特点，为此，完善了地震作用下尾矿坝最小平均安全系数的计算方法。该研究表明小打鹅尾矿库坝体的抗震性能能够满足相应抗震设防要求。

Analysis of the permanent deformation and stability of high tailings dam under earthquake action

The permanent deformation and dynamic stability of high tailings dam are analyzed by using time-history analysis method, global deformation analysis method (equivalent nodal force method and modulus soften method) and limit equilibrium method with Xiaodae tailings pond as an example. This paper analyzes the influence of length of dry beach, height of tailings dam and seismic acceleration on the safety factor and permanent deformation of tailings dams, and analyzes the time-history change laws of safety factors of tailings dams. It is found that the permanent deformation of the tailings dam is different from that of the general earth-rock dam. The permanent deformation in the horizontal direction of the tailings embankment is greater than that in the vertical direction, and the permanent deformation is not monotonous with the dam height. The minimum safety factor of the tailings dam in the earthquake is linearly related to the influencing factors, and the seismic subsidence at the crest has a nonlinear relationship with the influencing factors. The calculation methods of the minimum average safety factor for seismic safety are improved based on the characteristics of the fluctuation and reduction of the transient safety factors in the earthquake. The results show that the seismic performance of the tailings dam of Xiaodae tailings pond can meet the requirements of the corresponding seismic fortification.