中小跨度桥上无缝线路铺设条件研究

Study on Condition of Laying Continuously Welded Rails on Railway Bridge

应用桥梁、钢轨相互作用原理及计算模型,分析了铁路简支梁桥上有碴轨道铺设无缝线路时钢轨纵向附加力的作用机理及分布规律,并总结了桥上铺设无缝线路时轨道结构的检算项目,给出了算例.研究表明,当跨度L≤32m的刚性墩台钢筋混凝土简支梁桥上铺设60kg/m无缝线路,不论桥梁有多长,只要钢轨温升Δt≤44℃,钢轨温降Δt≤49℃时,无缝线路钢轨能够满足断缝、强度和稳定性的要求,可对桥梁全长不作限制,也可对轨道结构不进行检算.

Allowance range of rail temperature and length of bridge is given in the third of No.3.6.3 in Major Repair Specification of Railway Track published in China in 1997. The laying condition of continuous welded rails (CWR) is studied in this paper.Applied interaction principle and calculation model between railway bridges and CWR, the theory of rail longitudinal additional forces of CWR with ballast on railway simply supported beam bridges is analyzed.Check items of CWR track construction on railway bridges are concluded. An example is presented. If the span of simply supported beam of railway bridges is not larger than thirty-two meters,the temperature decrease of the rail is not larger than 44℃, and the temperature increase of the rail is not larger than 49℃,the calculated results will show that the pull-apart of rail, stress and stability of rail satisfy the need of the criterion, so it is not necessary to calculate and check track construction.Different types of bridges of railway simple supported bridge and continuous supported bridge should give different allowance range.