三峡库区降雨型滑坡体型特征分析

Geometric Characteristic Analysis of Rainfall-induced Landslides in Three Gorges Reservoir Area

滑体作为降雨的载体,其体型特征与降雨入渗过程联系密切,是控制降雨型滑坡稳定性的关键内因。三峡库区降雨型滑坡(水利工程中稳定性对降雨敏感的滑坡一般统称为降雨型滑坡)众多,深入揭示降雨型滑坡的体型特征对于库区滑坡灾害的识别和防治具有重要意义。为此,搜集了三峡库区275个降雨型堆积层滑坡资料,统计分析了其体型特征。结果表明,坡度、坡表及滑带形状等体型特征均符合正态分布;就宏观体型特征而言,库区内降雨型滑坡体型狭长、厚度偏薄、坡度较缓;进一步结合典型滑坡降雨入渗过程的数值模拟发现,该体型滑坡受雨面积较大且入渗雨水更易侵入滑带,使降雨的作用较显著,不利于降雨条件下滑坡稳定。

The geometric characteristics of landslide are closely related to the rainfall infiltration process,which is the key internal factor to control the stability of rainfall-induced landslides.There are many rainfall-induced landslides in the Three Gorges Reservoir area,and it is of great significance to deeply reveal the body shape characteristics of rainfall-in-duced landslides(landslide whose stability is sensitive to rainfall in hydraulic engineering are generally referred to as rain-fall-induced landslides)for the identification and prevention of landslide disasters in the reservoir area.In this paper,the data of 275 rainfall-type sedimentary landslides in the Three Gorges Reservoir area were collected,and their body shape characteristics were statistically analyzed.The rainfall-type landslides in the area are narrow and long,thin in thickness and gentle in slope.Combined with the numerical simulation of the rainfall infiltration process of typical landslides,it is found that the landslides of this type have a larger rain-receiving area and infiltrated rainwater is more likely to infiltrate the sliding bed,which makes the effect of rainfall more significant,and is not conducive to the stability of the slope under rainfall conditions.