水位变动对库岸古滑坡稳定性影响研究

Stability of bank ancient landslide under water level fluctuations

水库蓄水及水位骤降可能诱发古滑坡复活或部分复活,乃至产生新的滑坡是多数新建大型水利枢纽工程必须面临的工程地质问题。基于水位变动对库岸古滑坡作用机理分析,以某大型库岸古滑坡为研究对象,通过数值模拟探讨水位变动对库岸古滑坡变形及整体稳定性的影响,结果表明:库岸古滑坡对水位变化敏感,随库水位上升向库区方向变形逐渐增大,坡脚和滑动带塑性区不断发展;当水位骤降时将导致局部失稳,并有可能引发渐进性破坏。研究成果对同类工程的边坡治理及边坡预警具有指导意义。

Reservoir impounding and rapid drawdown would trigger the ancient landslide or part reactiva- tion, and even new landslide. It is an engineering geological problem which most of all large-scale water conservancy projects must encounter. The mechanism of the effect of water level fluctuations on bank landslide was analyzed. Taking a landslide near a water-control project as the research object, the deforma- tion and stability of the landslide under the condition of water level fluctuations was studied by numerical simulation. The results showed that： bank landslide was sensitive response to water level fluctuations. As the water level rise, the deformation towards to reservoir increased, and the plastic zone of toe and slip band developed. In the condition of rapid drawdown, it would lead to slope local instability, even develop into progressive failure. The results obtained have some guidance meanings for bank slope treating and bank slope warning.