高速铁路斜拉桥上无缝线路断缝值研究

Rail broken gap study on continuous welded rail on cable-stayed bridge of high-speed railway

为探明斜拉桥上无缝线路钢轨断缝值的规律特点,采用一种可靠的非线性梁轨相互作用模拟方式,建立了塔-索-轨-梁-墩-桩一体化的斜拉桥有限元模型,以中国高速铁路线上某(32+80+112)m单塔斜拉桥为例,分析讨论了线路纵向阻力模型、斜拉桥纵向约束方式、断缝出现位置、列车活载以及主梁和拉索温度变化等因素对断缝值的影响,得出以下结论:可根据《铁路无缝线路设计规范》(送审稿)选取纵向阻力模型;塔梁刚结或以固定支座相连时可有效减小断缝值;断缝出现在桥塔处时,断缝值最小(1.0cm),伸缩调节器应设置在桥塔处;制挠力及主梁温度变化对断缝值影响较大,分析时应予以考虑.

In order to investigate the regulation characteristics of the rail broken gap of continuous welded rail（CWR） on the cable-stayed bridge,an integral finite element model of cable stayed bridge for track-bridge interaction was established via applying a reliable nonlinear simulation method for track-bridge interaction,involving the effect of the substructure（pier,abutment,piles）.Then taking a single-tower cable-stayed bridge with a span of（32＋80＋112） m on high speed railway in China as a case study,factors such as longitudinal resistance model,longitudinal restraint of the cable-stayed bridge,the rail fracture position,the live load,the temperature varying of bridge deck and cables on the rail broken gap were discussed.It can be concluded that longitudinal resistance model described in code for railway CWR design is recommended;when the bridge tower and the bridge deck is fixed or connected with fix support,the rail broken gap is reduced effectively;the minimal rail broken gap is about 1.0 cm when rail fractures near the bridge tower,so it＇s better to set rail expansion joint at the bridge tower;the braking-deflection action and the temperature varying in the bridge deck have larger impact on the rail broken gap,therefore,they should be one of the key consideration in analysis.