Analysis of Change Rule of Moisture Content for Soil-slope under Rainfall Infiltration

摘要

Rainfall is one of the main factors to induce landslides, and it mainly causes the moisture content of landslide mass to increase by the process of rainfall infiltration. In this paper, the rain-induced soil-slope is taken as an example, the percolation process of rainfall in landslide mass is described, and the relationship between slope failure mode and slope moisture content increase in high intensity rainfall is studied. Transit seepage caused by rainfall infiltration is simulated by adopting the SEEP/W software, and moisture contents of shallow soil are analyzed from the back to the front of landslide. And by using SLOPE/W software, the landslide stabilities are calculated during continuous precipitation process. The study shows that rainfall mainly influences the upper soil, so the shallow part of soil-slope will be saturated immediately and the temporary saturated zone is formed, which would lead the matric suction of the shallow slope body to reduce and slip. That is to say, rainfall is more likely to cause shallow slope and local slope. At last, the changing model of moisture content in soil-slope is put forward when shallow slope occurs during the process of continuous rainfall, and combining the real time monitoring data of moisture content and pore water pressure, the shallow slope stability can be qualitatively evaluated. This model can be as reference for the monitoring, early warning and prevention of rainfall-induced shallow landslide.