帕德玛大桥铁路连接线无砟轨道系统设计

Design of Ballastless Track System for Padma Bridge Rail Link

研究目的:帕德玛大桥铁路连接线是孟加拉国首条铺设无砟轨道的铁路,也是我国工程技术人员首次在120 km/h、25 t轴重客货共线条件下开展的大跨钢桁梁上无砟轨道设计和简支梁上无砟道岔设计,设计过程中面临着结构限界和轨道自重受限、2350 mm超宽梁缝及7.5‰超大梁端转角、简支梁上无砟无缝道岔群布设等难题,亟需对轨道结构及部件开展系统研究,以指导铺轨实践。研究结论:(1)提出了底座板与桥面板一体化设计的单层长枕埋入式无砟轨道,克服了大跨度钢桁梁上结构限界和轨道自重受限的难题;(2)研发了±800 mm调整量梁端伸缩装置及钢轨伸缩调节器一体化装置,解决了2350 mm宽梁缝、7.5‰梁端转角条件下的轨道结构自适应调整问题;(3)基于“岔梁墩一体化”模型开展了岔桥相互作用分析,解决了25 t轴重条件下简支梁上的无砟无缝道岔群设计难题;(4)上述创新实践指导了孟加拉国首条无砟轨道铺设,对海外工程复杂桥梁结构上无砟轨道设计具有一定的参考作用。

Research purposes:Padma Bridge Rail Link Project is the first railway in Bangladesh to lay ballastless track.It is also the first time for Chinese engineers and technicians to carry out the design of ballastless track on long-span steel truss girder and ballastless turnout on simply supported beam under the condition of 120 km/h speed and 25 t axle load mixed passenger and freight railway.The design faces a series of challenges such as limitations of both clearance space and track weight,2350 mm ultra-wide beam seam and 7.5‰ultra-large beam-end rotation angle,and the layout of seamless turnout groups with ballastless track on simply supported beams.So it is urgent to carry out systematic research on track structure and components to guide track construction.Research conclusions:(1)A single-layer long sleeper embedded ballastless track with integrated design of base plate and bridge deck is proposed to solve the problem of clearance space and track weight limitation on large span steel truss bridge.(2)An integrated device of bridge movement joint and rail expansion joint is developed with design expension of±800 mm to solve the problem of adaptive adjustment for track structure under the condition of 2350 mm wide beam seam and 7.5‰beam-end rotation angle.(3)Based on the"turnout-beam-pier"integrated calculation model,the interaction analysis between turnout and bridge is carried out to solve the design problem of seamless turnout groups with ballastless track on simply supported beams under 25 t axle load.(4)The above innovative practice has guided construction of the first ballastless track in Bangladesh,which has a certain reference value for the design of ballastless track on complex bridge structures in overseas projects.