交通荷载作用下旧沥青路面裂缝对加铺层的影响

利用有限元对不同裂缝宽度、不同荷载作用位置、不同轴载等对加铺层中应力分布以及计算点位应力值进行了分析和对比,发现考虑裂缝时加铺层中的计算点位的应力值均比不考虑裂缝时大;随着荷载位置的变化,简化模型中的最大拉应力和剪应力的作用位置逐渐从模型中下部转移到加铺层底和加铺层中,应力值也随之发生大幅度增加;交通荷载作用下横向裂缝对加铺层的影响远远超过纵向裂缝。这表明在进行加铺层设计时不仅仅要考虑旧路面的剩余模量,更重要的是要考虑裂缝对加铺层的影响。

Influence of Pavement Cracking on the Overlay under Traffic Load

Rehabilitation is the most common way to improve the performance of the existing asphalt pavement.The cracks of the existing pavements are seldom considered in the rehabilitation design.The authors manage to analyze the condition of distribution and value of stress in the overlays under the influence of different width of cracks,different positions and value of the traffic load.By comparison,some conclusions have been reached which are different from those based on common sense.The stresses in the overlays on the cracks are bigger than those without cracks.Meanwhile the max tension and the shear stress in the simplified model will move upward with the increase of crack width.In addition,traffic load has much more influence on the overlays on the transverse cracks than those on the longitudinal cracks.These conclusions also prove that it is improper during the overlay design just to considere the residual modulus of the existing pavements and it is most important to pay more attention to the influence of the existing cracks on the overlay.