The Analysis Of The Mechanical Properties Of Semi-rigid Base Asphalt Pavement

About 90 percent of the high-grade highway in our country is asphalt pavement,90 percent of asphalt pavement will adopt semi-rigid base. The advantages of semi-rigid base could provide reliability assurance for reducing the thickness of asphalt layer and decreasing the building cost. With the increasing of transportation and the loading of vehicles, the early damage caused by the disadvantages of semi-rigid base and the over-loading will cut short the life span and reduce the service quality of pavement on large degree. So, we have to analyze the mechanical state of pavement under different combination of vehicle loads and pavement structure parameters, then we could determine the reasonable structure and position of layers under different transportation volumes to make sure that the pavement could meet the performance requirement of pavement under different transportation volumes.In this paper, ANSYS program is used to carry out the mechanical analysis of semi-rigid base asphalt pavement. Orthogonal test method is used to analyze and check the mechanical indicators (stress, strain and deflection) of pavement under different structure parameters combination. We analyze the affecting trend of different structure parameters on the same indicator and make out the order of the mechanical indicators'sensibility on the structure parameters (vehicle load, the thickness and modulus of surface layer, the thickness and modulus of semi-rigid base, the thickness and modulus of subbase layer, the modulus of). We use ANSYS program to calculate and get the change trend of mechanical indicators of the whole pavement structure, the bottom of surface layer, semi-rigid base and subbase under different overloading ratio and structure parameters.This paper will analyze the calculating result from the following aspects:comparing with the allowable stress of different layers of pavement; selecting the reasonable thickness and modulus; analyzing the influence of environment temperature and semi-rigid base modulus on the stress of pavement; analyzing the fatigue life span of pavement.