高速铁路大跨度连续刚构梁桥预拱度设置对无砟轨道的影响研究

无砟轨道铺设于桥上时,轨道的高低平顺取决于桥梁的最终线形。为研究轨道铺设过程中预拱度的设置对大跨度连续刚构梁桥的成桥线形和轨道高低不平顺的影响,根据某连续刚构桥上铺设无砟轨道的工程实际参数,采用经验公式为桥梁设置预拱度,利用有限元法建立完整的桥梁结构模型,分析不同预拱工况下铺设无砟轨道的桥梁成桥线形及轨道高低不平顺变化规律。结果表明:预拱度的设置和轨道二期恒载会造成桥上轨道的高低不平顺,且长波不平顺影响最为显著,设计时需对桥梁线形形成的轨道长波高低不平顺进行检算,设置合理的预拱度以满足规定的限值要求。

Study of Influences of Pre-Camber Setting of Long-Span Continuous Rigid Frame Beam-Bridge on Ballastless Track of High-Speed Railway

When the ballastless track is laid on the bridge,the regularity of the track depends on the final line shape of the bridge.In order to study the influence of pre-camber setting on the bridge shape of the long-span continuous rigid frame bridge and on the irregularity of the track during the track laying process,this paper uses the empirical formula to set the pre-camber of the bridge in accordance with the actual engineering parameters of laying a ballastless track on a continuous rigid frame bridge,employs finite element method to establish the complete bridge structure model,and then analyzes the changing rules of the final bridge line shape and the irregularity of the track under different pre-setting conditions.The results show that the setting of pre-camber and the second-phase dead load will cause the irregularity of the track on the bridge,and the long-wave irregularity is the most significant.The long-wave irregularity generated by the bridge line shape should be checked in the design,and reasonable pre-camber should be set to meet the specified limit requirements.