降雨对类土质滑坡微观结构及稳定性的影响分析

Impact Analysis of Rainfall on Soil Class Landslide Microstructure and Stability

以福建省永泰滑坡为例,利用电镜试验分析了类土质滑坡土体的微观结构,掌握了降雨对类土质土体微观结构的影响,并基于数值模拟方法从宏观上研究了不同降雨模型对类土质滑坡稳定性的影响。结果表明,含水率及干湿循环对土体微观结构的影响较为显著,表现为土体含水率越高,干湿循环的次数越多,土颗粒之间的连接减弱、定向性变差及排列趋于无序,进而造成其微观结构的破坏;另外,在总降雨量保持不变的情况下,不同降雨模型对滑坡稳定性的影响也较为显著,表现为高强度降雨工况对滑坡稳定性的影响低于低强度降雨工况对滑坡的影响,前期降雨对滑坡稳定性影响最大,后期次之,中期对滑坡稳定性影响最小。

Taking Yongtai landslide in Fujian Province for an example,electron microscope was used to analyze the microstructure of soil landslide.And then the impact of rainfall on soil microstructure was obtained.Based on the numerical simulation method,the impact of different rainfall model on the landslide stability was also analyzed.The results show that the impact of water content and wetting-drying cycles on soil micro-structure is significant;the higher moisture content of the soil and the more number of wet and dry cycles can weaken the connection between soil particles,make the directional variation worse and arrangement tends to disorder;it causes the microscopic structure be damaged.In addition,in the case of total rainfall remains constant,different models of rainfall on landslide stability is also significant;the impact of high intensity rainfall conditions on the stability of landslide is lower than that of low intensity rainfall conditions;the impact of early rainfall on the stability of landslide is the largest,followed by the later period and medium stage.