旧路改造沥青路面结构优化及力学响应分析

Structural Optimization and Mechanical Response Analysis of Asphalt Pavement for Old Road Reconstruction

为探究加铺层材料及层间接触条件对旧路改造沥青路面力学响应的影响,选取山西省某省道旧路改造工程,采用Bisar3.0软件分析轴载变化条件下不同路面结构的力学特性,并研究加铺层与旧基层之间层间接触条件变化对路面结构受力特性的影响。计算表明:在所选取的荷载作用下,旧路改造沥青路面结构中上面层采用SBS改性沥青混凝土(加3‰玄武岩纤维)铺筑,结构内各受力指标大小相对比较均衡,整体性能优于SBS改性沥青混凝土和高模量沥青混凝土;加铺层与旧基层层间接触条件劣化为光滑状态,结构内沥青层层底拉应变和沥青层剪应力指标变化最为明显,并在层间接触位置处拉应变指标产生突变,极易诱发裂缝病害。

In order to explore the influence of overlay materials and interlayer contact conditions on the mechanical response of old road reconstruction asphalt pavement,an old road reconstruction project of a provincial highway in Shanxi province is selected,and the mechanical characteristics of different pavement structures under the condition of axle load change are analyzed by using Bisar3. 0 software,and the influence of the change of interlayer contact conditions between overlay and old base course on the mechanical characteristics of pavement structure is studied. The calculation shows that: under the selected load,the upper layer of the old road reconstruction asphalt pavement structure is paved with SBS modified asphalt concrete( plus 3‰ basalt fiber),the stress indexes in the structure are relatively balanced,and the overall performance is better than that of SBS modified asphalt concrete and high modulus asphalt concrete;the contact conditions between overlay and the old base course deteriorate into a smooth state,the tensile strain at the bottom of the asphalt layer and the shear stress index of the asphalt layer in the structure change most obviously,and the tensile strain index changes suddenly at the contact position between the layers,which is very easy to induce crack diseases.