大跨桥上线路调坡及板式道床铺设方法研究

Research on the Route Gradient Adjustment and Track Slab Paving Method on Long-span Bridge

研究目的:研究目的:深圳地铁某大跨桥为(90+150+90)m连续梁桥,在混凝土收缩徐变效应下,成桥后数年内梁面标高会持续变化,因此梁面设置了一定的预拱度;同时由于桥梁存在一定的施工误差,导致梁面平顺性欠佳。另一方面,由于桥上采用预制板道床,铺轨时道床厚度的可调整范围较小,消化桥梁施工误差的能力有限。在上述不利条件下,如何保证轨道的高平顺性,确保行车安全,是亟待解决的问题。研究结论:(1)以"调坡后线路+成桥预拱曲线"作为轨面标高理论控制线,运营期间安全风险可控,且轨道结构高度均匀,适合预制板式道床的铺设;(2)通过线路调坡、以相对标高控制铺轨、在铺轨及运营期间加强轨面高程监测等措施,可有效保证大跨桥上的铺轨精度和轨道平顺度;(3)本研究成果对城市轨道交通领域大跨桥上施工误差处理及板式道床铺设具有一定的指导意义。

Research purposes:A certain bridge of Shenzhen Metro is a continuous beam bridge with spans(90+150+90)m.Under the effect of concrete shrinkage and creep,the elevation of the beam surface will continue to change within a few years after construction,so a certain pre-camber is set for the beam.At the same time,due to the construction errors of the bridge,the regularity of the beam surface is imperfect.On the other hand,as precast track slab is adopted on the bridge,the adjustable range of track bed thickness during track construction is small and the ability to digest bridge construction errors is limited.Under the above unfavorable conditions,how to ensure the high regularity of track and ensure the safety of train running is a problem to be solved.Research conclusions:(1)Taking the"adjusted route gradient+pre-camber"as theoretical control line of track elevation,the safety risk during operation is controllable,and the thickness of ballastless track is uniform,which is suitable for the laying of pre-casted track slab.(2)Track precision and regularity on the long-span bridge is effectively ensured by adjusting route gradient,controlling relative height difference between rail top and beam surface while track construction,and continuously monitoring during track construction and operation.(3)The research results have certain guiding significance for the bridge construction errors treatment and construction of ballastless track slab on metro longspan bridge.