考虑地下水作用的滑坡时间预测研究

PREDICTION OF LANDSLIDING TIME UNDER ACTION OF GROUNDWATER

结合三峡库区堆积层滑坡的具体情况讨论了地下水对滑坡的物理化学和力学作用,论证了地下水物理化学作用对三峡库区松散堆积层滑坡稳定性的影响远小于地下水动力作用对滑坡稳定性的影响。在此基础上,引入总压力水头,提出将地下水对滑坡的各种力学作用简化为总压力水头,结合加卸载响应比方法的思路,分别建立了基于库水位涨落和降雨影响的滑坡预测模型。重庆巫山县某堆积体滑坡过程的数值模拟结果表明,该方法可以定量判断滑坡所处的稳定性状态和演化阶段,将滑坡失稳前位移响应比剧增作为滑坡体即将失稳的前兆,可对滑坡时间进行预测。对巴东某滑坡的监测数据分析也证实,加卸载响应比能直接对滑坡稳定状态进行评价、对失稳时间作出预报。

In consideration of the physical,chemical and mechanical effects of groundwater to landslides around the Three Gorge Reservoir,this paper demonstrates that the mechanical effect of groundwater on the stability of the landslides in the area of the Three Gorge Reservoir is much greater than the physical and chemical effects of groundwater.Based on this knowledge,the total pressure head in a landslide body is introduced.Different mechanical effects of groundwater are simplified into a total water pressure head.Landslide prediction model of rainfall,reservoir level fluctuation are established with load and unload response theory（LURT）.Numerical simulation results of landslide process indicate that this method can estimate the stability state and evolution stage of a landslide quantitatively.Take LURT leaping as the failure boding of a landslide,the sliding time of the landslide can be predicted.Analysis of Badong landslide monitoring data also indicate that LURT method can judge the steady-state and sliding time of landslide directly.