Numeric Simulation of Subsidence of Loess Soil under Wetting in a Limited Area

Abstract

Loess and loess-like soils, when exposed to water, lose their strength characteristics, and physical and mechanical properties and change their original structure. The stress-strain state is transformed in these soils when wetted. Therefore, the problem of building on loess soils and studying the mechanisms of subsidence of loess soils is relevant. In this article, we consider the problem of determining the subsidence and stress state of the loess soil stratum under its own weight on a limited wetted area. To determine the distribution of water in soil, the method of changing stationary states is used, and to determine the subsidence and stress state, the finite difference method is used. The initial conditions are obtained by solving problems for the natural wetting of the layers of loess soil. The numerical results obtained of the subsidence of the free surface of the layer of loess soil 40 m thick agree well with experimental data on the duration of wetting at a limited size of the source of water. The effect of the duration and moisture content on the process of subsidence and transformation of the stress state are determined. An increase in the size of the water source in soil led to an increase in the high moisture content of the area and an increase in the subsidence of the free surface of loess soil.