Three-Dimensional Finite Element Analysis on Subgrade Dynamic Stress Response under Moving Load

Subgrade stress under static vehicle load is different from that under moving load. In order to study the law of subgrade dynamic stress under moving vehicle load, the paper established the three-dimensional analysis model with finite element software and calculated the subgrade dynamic stress of different depth. It is concluded that subgrade dynamic stress decreases with the increase of depth and the smaller the depth is, the faster the degradation is. To a certain depth, subgrade dynamic stress changes a little. Meanwhile, the paper analyzed the effect of surface layer modulus and thickness, roadbase modulus and the thickness, subgrade modulus on subgrade dynamic stress. It is concluded that surface layer modulus and thickness have little effect on subgrade dynamic stress , subgrade dynamic stress decreases when roadbase modulus and the thickness increase, especially for the depth of the subgrade is relatively small. Subgrade dynamic stress increases with the increase of subgrade modulus. Increase trend is more obvious when the depth is small.