移动荷载作用下连续配筋混凝土路面三维有限元分析

Effects of vehicle dynamic loading on CRCP by 3D finite element method

利用有限元软件ABAQUS建立了连续配筋混凝土路面的三维有限元模型,利用用户子程序VDLOAD模拟了行车荷载的动力加载作用,分别采用梁单元和rebar单元模拟CRCP面板中的纵、横向钢筋的加筋作用,取得了较好的计算效果.计算分析中考虑了交通荷载、车速、纵向配筋率、钢筋布置位置和面板厚度等不同的内外影响因素,以路面结构的应力、应变与竖向位移为主要评价指标,揭示CRCP路面的动力响应特征.分析认为:CRCP路面的动力响应对于交通荷载的大小较为敏感;从纵向钢筋的受力角度看,宜在面板上部配置钢筋;钢筋在动力作用下发生屈服或者破坏的可能性较小,应该关注路表裂缝渗水所引起的病害;低纵向配筋率时,增加CRCP面板厚度的方法不可取,而薄板高配筋率的建设方案更加有利于今后路面的维护和改建.

A 3D finite element model of a continuously reinforced concrete pavement （CRCP） was developed by using finite element method （FEM） software named ABAQUS. The vehicle load is simplified to be a moving load and has been implemented into a user subroutine VDLOAD. Beam elements and rebar elements are adopted to simulate the steels in CRCP slab. Influence factors, such as longitudinal reinforcement content, driving velocity, traffic load applications, the position of reinforcement and slab thickness, were evaluated to analyze the dynamic stress and displacement of the pavement by the indexes including the stress and strain state and the vertical displacement of CRCP. It is concluded that the dynamic response of CRCP is sensitive to the traffic load; the steels should be placed in the upper position of the CRCP slab ; there is little probability that steels in CRCP are subject to yield or fracture under traffic load. Engineers should pay attention to the distress induced by water seepage through the cracks. Increasing the thickness of the slab to improve the pavement per formance or to extend the service life of CRCP is not reasonable in the construction practice when the longitudinal reinforcement content is low. The scheme that using thin slab with high longitudinal reinforcement content has more economic advantage and is conducive to the maintenance and reconstruction engineering of CRCP.