长联大跨连续梁桥无缝线路布置方案

西安机场线渭河特大桥采用长联大跨连续梁,主桥连续梁联长900 m,最大温度跨度715 m,具有温度跨度大且多跨连续梁相接的特点,需合理设计无缝线路。针对该工况提出5个无缝线路布置方案,采用有限单元法进行无缝线路附加力计算,从钢轨强度、桥墩受力两方面进行方案比选后,现场调研国铁类似工况,确定最终推荐方案。得出结论:(50+8×100+50)m连续梁两侧梁端布置单向钢轨伸缩调节器,满足钢轨强度检算的要求且能有效减小相邻连续梁固定墩受力,无需布置双向钢轨伸缩调节器。

Arrangement Schemes of Continuous Welded Rail for Long Span and Long Unit Continuous Girder Bridge

The long span and long unit continuous girder was applied in Wei River grand bridge of Xi'an Airport Line.The span of the continuous beam of the main bridge was 900 m and the largest temperature expansion length was 715 m with the characteristics of long temperature expansion length and multi-long-span continuous girders.As a consequence,the reasonable arrangement for continuous welded rails is needed.Five options of laying continuous welded rails are offered in the paper;the longitudinal force due to temperature variation is calculated by the finite element method.Judging from the rail strength,the pier force and the field investigation in similar railway projects,the authors conclude that the scheme of the one-way rail expansion joints (REJ) on both sides of the (50 +8 × 100 +50) m continuous girder without two-way REJ can meet the requirements of check calculation of rail stresses and efficiently decrease the fixing pier force of the adjacent continuous girder.