移动荷载下粘弹性层状沥青路面动力响应模型

A MODEL TO STUDY THE DYNAMIC RESPONSE OF VISCO-ELASTIC LAYERED SYSTEM UNDER MOVING LOAD

交通荷载下沥青路面动力响应研究是建立路面动态设计体系的基础,是目前道路界研究的热点问题之一。将车辆荷载视为移动荷载,沥青路面结构视为层状体系结构,路面材料视为粘弹性材料,基于连续体系统动力学和线性理论,建立了沥青路面动力学模型。模型中将车轮荷载处理为间距足够大的周期荷载,采用Fourier变换技术,在求解移动简谐荷载作用下沥青路面动力响应基础上,得到任意复杂分布形式的车轮荷载作用下的沥青路面动力响应。以一种典型的半刚性基层沥青路面为例,分析了其动力响应规律,与加速加载试验结果进行对比,在沥青面层底部动态应变时间历程曲线、动力响应横向分布规律和最大动应变数值等3个方面,理论分析结果与试验结果吻合良好,验证了模型的可靠性。

Researches on the dynamic response of asphalt pavement under traffic loads became a hot issue in recent years,which is the basis to establish the dynamic design system for asphalt pavement.Based on the continuum dynamics and linear theory,an asphalt pavement dynamic model is established,treating a vehicle load as a moving load,and disposing the asphalt pavement structure as a layered system,and regarding the road material as visco-elastic material.The wheel load is treated as a cyclic loading whose spacing is large enough in the model.Using Fourier transform technique,the dynamic response under a moving wheel load with arbitrary form could be obtained,based on solving the dynamic response of asphalt pavement under a moving harmonic load.Taking a typical semi-rigid asphalt pavement as an example,the dynamic response regulations are studied,and the calculated results are compared with the accelerated pavement testing（APT） results.The calculated results are consistent with the test results on the strain time relationship,the lateral distribution of the dynamic response under the action of the wheel,and the maximum strain at the bottom of the asphalt surface layer,which prove the reliability of the model.