水位骤降作用下浔江岸堤滑坡稳定性分析及治理方案研究

Stability analysis and treatment study for Xunjiang River embankment landslide under sudden water level drop

为研究水位骤降对滑坡稳定性的影响,以浔江三布堤滑坡为例,根据详细的现场勘察及水库运营资料,利用FLAC 3D有限差分岩土分析软件,对水位骤降条件下堤岸滑坡的稳定性进行模拟计算,从滑坡稳定性系数、滑动面及滑坡位移等方面分析,并结合现场勘察对该滑坡治理方案进行模拟。结果表明浔江水位从十年一遇洪水位(37.2 m)骤降至正常水位22.3 m后,堤岸滑坡稳定性系数从1.60降至0.81,由于水位快速持续下降引、诱发滑体失稳破坏;进行压石护坡治理后,水位骤降工况下堤岸滑坡稳定性系数从0.81增加到1.20,为滑坡治理提供了高效且低成本的治理方案。

In order to study the impact of sudden water level drop on landslide stability,taking the Sanbu dike of Xunjiang River as example,based on detailed on-site investigation and reservoir operation data,the stability of bank landslide under sudden water level drop condition was simulated and calculated by use of FLAC 3D finite difference geotechnical analysis software.The landslide stability coefficient,sliding surface and landslide displacement were analyzed,and the landslide treatment scheme was simulated in combination with on-site investigation.The results showed that after the water level of Xunjiang River decreased from the once-in-a-decade flood level of 37.2m to the normal water level of 22.3m,the stability coefficient of bank landslide decreased from 1.6 to 0.81.Due to the rapid and continuous decline of water level,the instability and failure of the landslide body were caused or induced.After slope protection treatment with compacted rockfill,the stability coefficient of bank landslide increased from 0.81 to 1.2 under the condition of sudden water level drop,which is an efficient and low-cost scheme for landslide treatment.