基于非连续变形分析的黄河上游某电站库岸边坡稳定性分析

为深入研究黄河上游某电站库岸边坡倾倒变形的诱发因素和破坏机理,通过建立库岸边坡的二维非连续变形分析(DDA)概化分析模型,对比分析了水位变动导致的瞬时变形和蠕变作用产生的时效变形对库岸边坡整体变形的影响,模拟库岸边坡整体和细部的变形形态,并采用校验模型将计算结果与实测变形进行对比,验证了应用DDA数值模拟方法的合理性。研究结果表明:库岸边坡倾倒变形的诱发因素是蓄水作用,变形与水位变动具有明显的相关性;该库岸边坡变形主要为时效变形,由于蓄水扰动引起的直接变形较小,在研究变形中必须考虑蠕变作用;DDA模拟岸坡整体和细部的变形形态与真实情况较为吻合,持续的倾倒变形致使局部块体失稳,但对库岸边坡整体变形的影响较小。

Case Study on Slope Stability of Reservoir Bank of a Hydropower Stationon the Upper Reaches of the Yellow River Based on Discontinuous Deformation Analysis

In order to study the inducement factors and failure mechanism of reservoir bank slope overturning deformation on a hydropower station in upstream of the Yellow River, a two-dimensional discontimuous deformation analysis (DDA) general analysis model for reservoir bank slope was established, and the effects of instantaneous deformation caused by water level change and aging deformation caused by creep on the overall deformation of reservoir bank slope were compared and analyzed. The deformation form of the whole and the details of reservoir bank slope was simulated and verified. The calculated results were compared with the measured deformation by the calibration model to verify the correctness and accuracy of the DDA. The result showd that the induced factor of slope overturning deformation on reservoir bank was impounding effect, and there was obvious correlation between deformation and water level change. The deformation of reservoir bank slope was mainly time-dependent deformation. Creep must be considered in the study of deformation because of small direct deformation caused by impounding disturbance. The deformation form of DDA simulated bank slope as a whole, which is consistent with the real situation and lasts for a long time. The toppling deformation results in local block instability, but has little influence on the overall deformation of reservoir bank slope.