不同基层状态下的沥青路面荷载应力分析

为比较在行车荷载作用下,基层未开裂及开裂状态不同时沥青路面结构内的应力响应情况,采用有限元方法对不同工况分别建立模型,计算分析水泥稳定碎石基层沥青路面在不同水平荷载、层间条件时,结构内的应力分布。分析表明,层间粘结状态是影响裂缝扩展的重要因素;面层-基层粘结不好时,面层底部的拉应力和剪应力值都急剧增长,即使基层不开裂,面层内也会产生由下而上的横向裂缝及沿行车方向的纵向裂缝;已开裂但尚未沿深度方向贯穿基层的横向裂缝在荷载作用下会迅速反射至面层;待基层收缩裂缝充分发展并进行处治后,再铺面层可减少和延缓反射裂缝。

Analysis on stress of Pavement with Different Crack states in Base

In order to compare stress responses in pavement structure with various base states under vehicle load,finite element method were used to establish model for different projects,and then distribution of stresses in semi-rigid base asphalt under various horizontal loads and interbeded conditions were calculated.Analysis result indicates that(1) interlaminar combination is an important factor to influence evolution of base crack;(2) both tensile stress and shearing stress increase dramatically when joint condition between surface and base is bad;even no base crack,both down-top transverse crack and longitudinal crack along moving direction of vehicle appear;(3) those cracks that its depth is less than base thickness reflects to pavement surface quickly.Therefore,to spread asphalt pavement after shrinkage cracks in base were fully developed and treated can reduce and postpone reflecting crack.