为准确把握黄土坡临江I号崩滑体在水库运营期间的变形及稳定性演化动态,采用试验隧洞群的形式充分揭露崩滑体的地质结构及空间形态,并构建崩滑体双层滑带地质模型。采用饱和-非饱和渗流有限元算法获取其在水库运营期间地下水渗流场的动态变化过程,以此为基础研究崩滑体的变形和稳定性演化规律。研究表明,崩滑体的变形主要发生在库水位下降期间,且呈明显的牵引式运动特征,变形演化规律与GPS监测点实测数据相符;崩滑体的浅层滑坡在演化过程中受地下水渗流场动态变化的影响较大,因此,其稳定性系数的波动幅值也较大,其临界失稳水位下降速度为2.0 m/d。综合分析认为,黄土坡临江I号崩滑体整体稳定性相对较好,但浅层滑坡在降雨和库水位下降过程中存在局部失稳的可能。
In order to accurately grasp the deformation and stability evolution law of Huangtupo riverside slump-mass No.I during the reservoir operation, exploration tunnel group was firstly used to expose the geological structure and spatial form of the slump-mass, a geological model of double sliding zone was established based on the exposed information. Then the dynamic groundwater seepage field could be obtained by saturated-unsaturated seepage finite element method, based on which the deformation and stability evolution process was studied. The research showed that the deformation of slump-mass mainly occurred in front of shallow landslide during the drop of the water level, and has significant traction movement characteristics. The deformation evolution law was verified by measured data of global positioning system (GPS) monitoring point. Stability of the shallow landslide was fluctuated obviously during the evolution process because of the dynamic fluctuation of groundwater seepage field’s, and its critical instability velocity of drawdown of water level is 2.0 m/d. Consequently, the overall stability of Huangtupo riverside slump-mass No.I is fine; but there still exists a possible that the front of shallow landslide may be instable locally under rainfall and reservoir water level drawdown.