UHPC组合桥面铺装层对铁路钢桥面板影响分析

Analysis of Effect of UHPC Composite Deck Pavement on Mechanical Performance of Railway Steel Deck

为了解铁路钢桥采用超高性能混凝土(UHPC)组合桥面铺装时钢桥面板的力学特性及UHPC层厚度对其结构性能的影响,以银西高铁银川机场黄河特大桥正交异性钢桥面系及铺装结构为背景进行研究。采用ANSYS软件建立包括钢轨、轨枕、道砟层、铺装层以及正交异性钢桥面板的主梁及铺装结构有限元模型,对比在高速铁路列车荷载作用下采用普通C40聚丙烯纤维网混凝土铺装层(原铺装设计)和UHPC组合桥面铺装层时的钢桥面板结构受力,并分析UHPC层厚度对易损细节受力的影响。结果表明:采用UHPC组合桥面铺装层可显著降低钢桥面板典型细节的应力极值;随着UHPC层厚度的增加,其上表面最大拉应力、钢桥面板各细节应力峰值均降低;UHPC层厚度变化对其上表面纵向拉应力的影响大于对横向拉应力的影响。

The orthotropic steel deck system and pavement of the Yinchuan Airport Huanghe River Bridge are studied to examine the effect of ultra-high performance concrete(UHPC)composite deck pavement on the mechanical property of the steel deck as well as the impact of UHPC thickness on structural behavior of the steel deck.A finite element model that simulates the details of the main girder and pavement system was developed by ANSYS,including the rail,sleeper,ballast layer,and paving course.Under the loads of high-speed railway vehicles,the structural behaviors of the steel deck with normal C40 poly propylene-fiber-mesh-reinforced concrete pavement(original pavement design)and with UHPC composite pavement,respectively,were compared,and the effect of UHPC thickness on the damage-vulnerable details was analyzed.The results show that the UHPC composite deck pavement can significantly reduce the stress extremes of the typical structural details of the steel deck.As the UHPC thickness increases,the maximum tensile stress in the upper surface and the stress peaks of structural details of the steel deck are all lowered.Compared with the transverse tensile stress,the longitudinal tensile stress of the upper surface of the UHPC pavement is more sensitive to the variation of the UHPC thickness.