考虑横向接地应力的沥青路面剪应力分析

Shear stress analysis of asphalt pavement based on transverse contact stress

采用ABAQUS软件建立三维半刚性路面结构模型,单轴双轮加载模式,每个轮胎荷载简化成5条可移动的应力、长度和宽度不同的条带非均布荷载,使用Fortran语言编写程序Dload和Utracload子程序,用以施加垂直荷载、水平荷载和横向荷载.分析模拟车辆在考虑横向力作用下的路面剪应力分布状况.结果表明:当横向力系数增大时,路表正剪应力减小,负剪应力增加.最大正剪应力出现的位置位于轮胎两侧边缘;中间荷载带的负剪应力逐渐增加并超过轮胎边缘剪应力,最大负剪应力由边缘位置向中间荷载带转移.横向力系数与路面不同层位不同点位(5个荷载带中点和轮隙中心点)剪应力呈线性增加关系,横向力系数对路面剪应力影响最大,对其他层位剪应力的影响随深度增大依次减小.

ABAQUS software was adopted to establish the model of semi-rigid pavement structure with uniaxial two-wheel load mode and each tire load simplified to five mobile non-uniform load with different stress,length and width.Compiling Dload and Utracload subroutines by Fortran program,the vertical,horizontal and transverse loads were applied.The relationship between transverse stress and pavement shear stress was analyzed.The results show that the pavement surface shear stress distribution has significant relationship with transverse stress.When the lateral friction coefficient is increased,the positive shear stress is decreased with increased negative shear stress.The location of the maximum positive shear stress is at the tire edges of both sides.The negative shear stress at intermediate load belt is increased gradually and over tire edge shear stress,and the maximum negative shear stress transfers from the edge to the middle.The lateral friction coefficient is increased linearly with different point shear stress at different asphalt pavement layer.The influence of lateral friction coefficient on surface shear stress is most obvious,while in other layers of asphalt pavement,the influence on shear stress is decreased with the increasing of depth.