行车荷载作用下沥青路面动力特性试验

Experiment on dynamical characteristics of asphalt pavement under vehicle load

为研究行车荷载作用下不同类型沥青路面的实际动力特性,通过现场车辆加载试验获取了实测动态应变响应数据,分析了车辆轴质量、车速以及路面温度等影响因素对动态响应的影响作用,构建了沥青层底应变响应预估模型,并对预估模型进行了统计检验。研究结果表明:在车辆动力荷载作用下,沥青路面结构在面层和基层底主要呈拉应变受力状态,应变响应过程体现出粘弹性特征;荷载作用时间随车速增加近似呈线性关系增大,且纵向荷载作用时间大于横向荷载作用时间;面层底弯拉应变随温度和轴质量的增加逐渐增大,随车速的提高逐渐减小;路面高温及车辆超载的综合作用会显著加剧沥青层的疲劳损伤;明确了路面温度、车辆轴质量、车速及其耦合作用对不同类型路面结构沥青层底应变响应影响的显著性,在此基础上可建立能够满足工程分析要求的沥青路面面层底应变响应预估模型。

In order to study the actual dynamical characteristics of different kinds of asphalt pavements,the dynamic strain data from field measure were obtained through vehicle load test.The influences of axle load,speed and pavement temperature on dynamic response were analyzed.The prediction models for strain at the bottom of asphalt surface were established and statistical test was performed on it.The results show that the dynamic response at the bottom of surface and base are tensile strain,and the response processes reflect typical viscoelastic performance.Load duration is in linear growth with the increment of vehicle speed,and the longitudinal load duration is longer than the lateral one.Bending strain increases with the increment of pavementtemperature and vehicle load,and as vehicle speed increases,the strain response becomes smaller slightly.Fatigue damage of asphalt surface may be aggravated obviously due to the synergistic effects of high-temperature and overload.The significances of influencing factors such as pavement temperature,vehicle load,speed and their coupling influences have been evaluated;furthermore,prediction models for dynamic strain at the bottom of asphalt surface have been established on this basis,that can meet the demand for engineering analysis.