Vertical dynamical analysis model of heavy vehicle-pavement-subgrade during spring-thawing period

Aimed at problem of serious pavement and subgrade disease under heavy vehicle during the spring-thawing period in seasonal frozen region, taking three axles heavy vehicle as an example, a vertical dynamical physical model of heavy vehicle-pavement-subgrade system during the spring-thawing period in seasonal frozen region was developed. Based on the D'Alembert principle, the dynamic differential equations of heavy vehicle, pavement and frozen subgrade layer were presented, and the dynamic equations were solved by Wilson-θ method. Numerical simulation results show that the proposed pavement-subgrade model is able to display the subgrade characteristics and weak stiffness in seasonal frozen region. With increasing of the vehicle body mass and decreasing of the subgrade thawing layer stiffness, the pavement average peak values of the vibration displacement and acceleration increase linearly. With increasing of the traveling speed, the average peak value of pavement vibration acceleration increases, numbers of dominance frequency and frequency channel increase, however, the distribution of average peak value of pavement vibration displacement presents the wave shape. When the frozen subgrade layer thickness increases, the average peak values of pavement vibration displacement and acceleration decrease. When the thickness is lower than 0.3 m, the values keep steady.