Research On Dynamic Response Of Flexible Asphalt Pavement Under Multiple Wheel Random Loads

With the continuous advance of pavement construction,pavement design and pavement damage theory research have also been put forward higher requirements.The repeated effect of vehicle loads is one of the main causes of asphalt pavement damage.In this paper,according to the structure and material characteristics of flexible asphalt pavement,the three-dimensional finite element models of asphalt concrete pavement and SMA pavement model are established,which take full account of the soil-based elastic-plastic and viscosity.The dynamic response of two flexible asphalt pavements under the heavy vehicle multiple wheels random loads is simulated.The stress and strain changes of two kinds of flexible asphalt pavements are analyzed.The trends of stress and strain of asphalt concrete pavement under different vehicle speeds are also analyzed.The results show that,the asphalt concrete pavement produces more stress and strain under the three direction random loads comparing to vertical,longitudinal,transverse random loads alone on the pavement.It can be seen that the method is not accurate enough,which is only considered the vertical loads of the vehicle.The maximum stress and strain of the asphalt concrete pavement surface are increasing with the speed.The analysis also shows that the asphalt concrete pavement and SMA pavement damage in different ways under the vehicle random loads.The fatigue failure of the asphalt concrete pavement starts from cement stabilized macadam bottom layer and the failure of the SMA pavement starts from the bottom layer of asphalt(bottom of the Sup25).The research results of this paper can provide guidance for structural design and damage evaluation of flexible asphalt pavement.At the same time,it can provide reference for pavement response calculation and pavement life prediction.