降雨过程中土质浅层滑体体积含水量变化研究

Study on Volumetric Moisture Content of Soil Shallow Landslide during Precipitation Process

降雨是滑坡地质灾害的主要诱发因素之一,尤其是对于土质滑坡,连续的降雨能够使得土质滑坡浅表层滑体迅速饱和形成暂态饱和区,从而导致浅表层土质滑体的基质吸力降低,引起浅层滑动,而反映土体中暂态饱和区变化的主要指标为土体体积含水量。该文选取某一降雨诱发型土体滑坡为例,采用Geo-slope软件模拟连续降雨6d条件下土质浅层滑体内的暂态饱和区变化情况,并分析由滑坡后缘至前缘4个靠近地表(深度小于5m)点的体积含水量变化趋势以及连续6d降雨过程中浅层滑体的稳定性变化趋势,提出了降雨入渗过程中土质滑坡发生浅层滑动的体积含水量变化模式。

Precipitation is one of the main inducing factors to landshde geological hazard, especially for the soil landslide. During the last rainfall process, the shallow part of the soil landslide will be saturated immedi- ately and the temporary saturated zone is formed, which would lead the matric suction of the shallow landslide body reduction and slipping. While, the volumetric moisture content is the main index reflecting the variation of temporary saturated zone. Taking the participation-induced soil shallow landslide as an example in this paper, the temporary saturated zone of shallow landslide body was simulated by the Geo-slope software during 6d last rainfall. Meanwhile, the 4 points＇ volumetric moisture contents are analyzed from the back of the landslide to the front, which are near the slope surface and their depths are less than 5m, and the landslide stabilities are calculated during 6 days last rainfall. At last, the changing model of volumetric moisture content in soil landslide is put forward when the shallow sliding occurred during the continuous precipitation process.