卡拉水电站田三滑坡体稳定性敏感因素分析

为了分析卡拉水电站工程区滑坡体的稳定性,以库区内田三滑坡体为例,对其滑坡成因、地形地貌、地质构造等内在因素进行分析。结果表明:滑坡体随着坡面隆起和坡内扩容加剧,在外界作用下更易失稳破坏;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入渗创造了条件。通过对库水位升降、降雨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体的稳定性影响较大;短期降雨对滑坡体稳定性影响较小,但是随着降雨时间增长滑坡体失稳概率增加;地震峰值对滑坡体稳定性影响较为明显。根据分析结果对滑坡体进行工况及荷载组合,并对各工况组合进行稳定性计算及评价,结果表明,受蓄水和暴雨影响,滑坡体的稳定性变差,在蓄水地震工况下失稳概率较大。

Sensitive factors analysis of stability of Tiansan Landslide at Carla Hydropower Station

To study the stability of the Tiansan Landslide in the project area of the Carla Hydropower Station,the landslide causes,landform,and geological structure were analyzed.The results show that landslide instability is most likely to take place under the effects of external factors and internal factors including landslide slope uplift and intensification of slope expansion.A poor combination of planes and fissures provides boundaries for slope deformation and instability.The fissures of the steep slope provide favorable conditions for infiltration of groundwater.Through sensitivity analysis of the external factors including rainfall,water level fluctuation,and earthquakes,it was found that a sharp increase or decrease in water level has a significant effect on the landslide stability.Short-term rainfall affects the landslide stability insignificantly,and the instability probability will increase with the increase of time duration of rainfall.The earthquake peak affects the landslide stability.According to the analysis,combinations of landslide conditions and loads were made,and the stability calculation and assessment were conducted.The results show that the instability probability was higher under water storage and seismic conditions,resulting from a low stability of the landslide affected by water storage and rainstorms.