基于沥青道路土基应力参数的轴载换算

Vehicle Axle Load Conversion Based on Stress Parameters of Asphalt Road Soil Foundation

为研究基于沥青道路土基应力的轴载换算方法,选取了RIOHTRACK足尺试验路的4种沥青路面结构,分析了其在不同使用状态、不同轴重车辆加载作用下土基内部的应力响应,据此推得以土基应力为指标的轴载换算系数,分析了不同轴重下的轴载换算系数及轴载换算系数与季节、路面结构使用状态之间的关联性。同时,以选取的4种结构为原型,分别在APBI程序中建立了计算模型,计算了不同轴载不同轮迹偏移作用下路基内部的应力响应,明确了试验结果的合理性,给出了不同结构下的轴载换算系数变化规律及其建议值。结果表明:由土基应力试验数据推得的轴载换算结论的准确性不会受试验过程中轮迹偏移的明显影响;不同季节及不同路面的使用状态对半刚性基层路面、强基薄面结构路面及复合式结构路面的轴载换算系数影响较大,对全厚式沥青路面则影响不显著;在试验选取的轴重范围之内,不同轴重对应的轴载换算系数在所有路面结构中均未呈现出明显的差异性规律;对于全厚式沥青路面结构,轴载换算系数宜取为4.61,对于强基薄面结构、半刚性基层路面结构及复合式路面结构,轴载换算系数宜取为5.96。

In order to study the vehicle axle load conversion method based on soil foundation stress of asphalt road,selecting 4 asphalt pavement structures of the RIOHTRACK full scale experimental road,the internal stress response of the soil foundation under different road conditions and different vehicle axle loads are analyzed.The vehicle axle load conversion factor based on soil foundation stress are derived accordingly,the conversion factor of axle load under different axle weights and the correlation of axle load conversion factor with season and pavement structure condition are analyzed.At the same time,based on the selected 4 structures as the prototype,the calculation models are established respectively in the APBI program,the internal stress responses of the soil foundation under different axle loads and different wheel track offsets are calculated,thus the rationality of the experiment result is clarified,and the change rules and recommended values of the axle load conversion factors under different structures are given.The result shows that(1)the accuracy of the axle load conversion conclusion derived from the soil foundation stress test data will not be significantly affected by the wheel track offset during the test;(2)the change of seasons and pavement conditions has strong impact on the vehicle axle load conversion factor of semi-rigid base pavement,thin-surface strong-base pavement and composite structure pavement,but it has no significant influence on the conversion of full-thickness asphalt pavement;(3)within the range of axle loads adopted in the experiment,the axle load conversion factors corresponding to different axle loads have not shown obvious differences in any pavement structures;(4)the vehicle axle load conversion factor should be 4.61 for full-thickness asphalt pavement structure,while the vehicle axle load conversion factor should be 5.96 for thin-surface strong-base structure,semi-rigid base pavement structure,and composite pavement structure.