Research on the Meso-mechanism of the Evolution of Wet Expansion Cracks in Expansive Soil Based on Discrete Element Method
摘要
In order to study the law of crack evolution in expansive soil caused by wet expansion under rainfall conditions, the moisture migration model corresponding to the heat conduction equation was derived by borrowing the analytical ideas of heat conduction theory. A discrete element numerical model of swelling deformation of expansive soil under humidity-stress coupling was established and the meso-mechanism of swelling crack evolution of expansive soil was revealed based on PFC. The results show that after the infiltration of rainfall infiltration, the shallow surface appears slight swelling deformation; with the further continuous rainfall, the surface wet expansion deformation expands significantly to the deep soil, and the wet expansion deformation further expands to the deep soil, but the depth of the affected soil layer gradually tends to be stable, and the shallow soil layer shows slight uplift and slight cracks. Finally, multiple penetrating cracks appear in the expansive soil foundation, and the surface soil uplifts significantly. The research results can be used to avoid the diseases caused by the characteristics of expansive soil in engineering construction, and provide theoretical reference for the improvement of engineering foundation in expansive soil area.