Response characteristics of dynamic stress of subgrade soil under vehicle loads

In order to analyze the dynamic response characteristics of subgrade soil, based on the theory of the layered visco-elasticity system and the dynamic equation and constitutive equation which employs complex compliance to represent the dynamic stress-strain features, an analytic model for the mechanical behaviors of the subgrade soil subjected to vehicle loads is established by means of the transfer matrix method. The model is validated by the observed data. According to the proposed model and the theory of static mechanics, the distribution rules of dynamic and static stresses with depth are investigated. The influences of vehicle loads, load frequency, loading times, soil depth, soil complex compliance and soil density the values and distribution rules of the vertical dynamic stress in subgrade soil are discussed. Some meaningful conclusions are drawn.