Study on the stability analysis of rainfall slope based on G-A model considering moisture content

Abstract

In this paper, the moisture content on the wetting front is obtained by using the Van Genuchten (VG) model of unsaturated soil, and then the distribution of moisture content in the upper part of the wetting front is simplified as a trapezoid. The Green-Ampt (G-A) infiltration model of infinite slope with unsaturated characteristics is derived. The analytical expression of safety coefficient (FOS) of infinite slope with rainfall is solved by combining the limit equilibrium method with the unsaturated soil shear strength theory phase. The results show that: 1) compared with the traditional G-A model and the combined rectangular and 1/4 oval model, the upper part of the wetting front is simplified to a trapezoidal model, which has great advantages in infiltration rate and cumulative infiltration, especially when the slope is large or the rain intensity is heavy; 2) since the distribution of soil moisture content above the wetting front is considered, the matrix suction at the wetting front is not neglected, and the safety coefficient calculated by the method proposed in this paper is closer to the actual situation than the traditional G-A model.

GIS and Cellular Automata based slope rainwater movement process model and its application

“…However, there are problems in engineering practice such as difficulty determining boundary conditions, and its complex differential equations and numerical solution process also limit its practical application [9] . Compared with other empirical formula methods, the G-A model based on capillary theory has gained widespread attention in recent years due to its concise and clear physical meaning, easy-to-obtain calculation parameters, and convenient direct application in engineering practice [10][11][12][13][14] . The research results of predecessors have greatly extended the applicability of the model, but have ignored the objective fact of the existence of unsaturated layers.…”