冲击碾压改建路面施工对路基动力效应的试验研究

Dynamic Effect of Crushing and Rendering Pavement Construction on Subgrade

针对冲击碾压对在旧水泥混凝土路面改造过程中形成的动力效应和破碎产生机理,以某一工程为对象,利用有限元分析软件,开展对冲击碾压破碎水泥混凝土板的静态力学分析和瞬态动力效应分析,获得不同行驶路线下的水泥混凝土路基应力状态和破碎产生机理。研究结果表明:静态力学下,面板角形成最大位移,板底产生最大应力,板角处最先形成断裂带。轮压处周边位置板块出现翘曲变形,存在纵横弯曲现象;瞬态动力下,板底最先形成横向断裂带,并由下向上扩展,面板中部出现横向断裂,由板底向上扩展。当碾压3遍后,板中部横向裂缝扩展至板全宽,形成断裂破碎。完成一定遍数冲压后,横向断裂扩展至面板表层,贯穿整个板块,并将水泥混凝土面板层整体分割成均匀碎块。

Aiming at the dynamic effect of impact rolling on the old cement concrete pavement and the mechanism of crack generation.Based on the finite element analysis software,the static mechanical analysis and transient dynamic effect analysis of impact crushed cement concrete slab are carried out to obtain the stress state and crack generation mechanism of cement concrete subgrade under different routes.The results show that under static mechanics,the maximum displacement is formed at the angle of the roadbed,the maximum stress is produced at the bottom of the roadbed,and the initial crack is formed at the angle of the slab.There is warping deformation and vertical and horizontal bending in the plate around the wheel pressure,and the bottom of the plate is first formed under transient power transverse cracks,and expand from the bottom up,the middle of the panel appears transverse cracks,and from the bottom of the plate upward expansion.After rolling three times,the transverse cracks in the middle part of the plate extend to the full width of the plate,forming the transverse and longitudinal staggered cracks.After a certain number of stamping,the transverse crack extends to the surface layer of the panel,runs through the whole plate,and divides the cement concrete into uniform fragments.