Numerical Study of Subgrade Humidity Field Evolution under Different Rainfall Infiltration Affected by Initial Water Contents

Abstract

To study the effects of initial water contents on subgrade humidity field distribution and evolution, 5 numerical models with different initial water contents are investigated in this study and the distributions of the subgrade humidity field affected by different initial water contents are obtained through the numerical rainfall infiltration test. The effects of different initial water contents on the humidity values of disturbed zone, extended distances and humidity gradients are also explored. The results show that the distribution and the change of the humidity fields caused by rainfall infiltration are affected by the initial water contents. The subgrade humidity of the same side of the disturbed zone increases linearly as the initial water contents increase and the further away from the slope surface, the larger the increase gradients are. The extended distance of the disturbed zone increase approximate linearly with the increase of the initial water contents. The higher the initial water content, the larger the infiltration coefficients and the faster the extend speeds. The disturbed zone can be divided into the front and the back zones. The humidity of the back zone is larger while the gradient is smaller than the front zone and the humidity gradient of the front zone decreases exponentially.