Study on slope deformation mechanism under combined infiltration of rainfall and groundwater

Abstract

[Objective] In order to explore the characteristics of soil and water change and the mechanism of slope deformation and failure under the combined infiltration of rainfall and groundwater. [Methods] Therefore, two model tests of different groundwater infiltration head height and rainfall phase combination were designed with silty clay to monitor soil volume water content and pore water pressure, and to study the response characteristics of soil and water in the slope and the instability mode. [Results] The result show that the seepage field inside the slope changes under the combined infiltration of rainfall and groundwater. When the groundwater infiltration head is low, the soil at the bottom of the slope receives groundwater and rainfall infiltration, and the soil at the foot of the slope and the middle and upper part of the slope receives rainfall infiltration. When the groundwater infiltration head is high, the soil in the bottom, foot and middle of slope receives groundwater infiltration, and the soil in the upper slope receives rainfall infiltration. And the wetting front develops in parallel to the slope top, slope surface and slope bottom. [Conclusion] When the soil in front of the slope is saturated, the slope is dominated by flow slip. However, when the groundwater infiltration head is low, the flow slip range is small and it takes a long time to reach the unstable equilibrium.

Keywords

rainfall and groundwater infiltration / physical model test / seepage field / instability mode