卡拉水电站上田滑坡体稳定性分析及评价研究

摘 要] 为了分析卡拉水电站工程区某滑坡体的稳定性,通过对其滑坡成因、地形地貌、地质构造、 岩土力学参数敏感性等内在因素分析可知,滑坡体随着坡面隆起和坡内扩容加剧,在外界作用下易导致 边坡失稳破坏;其层面与节理裂隙的不良组合为边坡变形失稳提供了边界,陡倾坡内的裂隙,为地下水 的入渗创造了条件;滑坡稳定性随着岩土力学强度参数的提高而增强。通过对降雨、水位升降和地震等 外在因素的敏感性分析可知,库水位骤升骤降对滑坡的稳定性影响较大;短期降雨影响较小,但时间增 长滑坡失稳概率增加;地震峰值对滑坡稳定性影响较为明显。同时根据分析结果对滑坡体进行了工况 及荷载组合,并对各工况组合进行了稳定性计算及评价,得出水位下降时滑坡稳定性处于极限状态,在 蓄水地震工况下失稳概率较大。

Stability Analysis and Assessment Research of the Shangtian Landslide Mass in the Kala Hydropower

Abstract:To study the stability of a landslide mass at the Carla hydropower station, this work analyzes a series of internal factors such as the landslide mechanism, landform, geological structure and geotechnical parameter sensitivity. The result shows that with the slope uplifting and slope dilatancy intensifying of the landslide mass, slope instability tends to occur. Poor combination of bedding planes with joint fissures may provide a boundary for slope deformation and instability, and fissures in the steep slope of fractures make infiltration of groundwater possible. Landslide stability is enhanced with the increasing geotechnical strength parameters. Sensitivity analysis on external factors including rainfall, water level fluctuation and earthquakes illustrates that sharp fluctuations of water level exert a major influence on the landslide stability. Short-term rainfall has a little effect on landslide stability, but with increasing time, it will make slope instability more possible. The earthquake peak value exerts a prominent effect on landslide stability. Furthermore, based on the analyses above, various combinations of the conditions of landslide and loads are considered, and calculation and evaluation of stability are conducted according to these combinations. The conclusion is that landslide stability is in its limit state when the water level drops, and instability probability is bigger under the conditions of storage and seismic activity.