大跨度钢管混凝土拱桥桥上轨道平顺性检算及设计优化

Track Regularity Checking and Design Optimization on Long Span CFST Bridge

文章以成渝客运专线资阳沱江特大桥工程为研究对象,研究大跨度钢管混凝土拱结构变形对高速铁路无砟轨道静态高低平顺性的影响,研究表明:(1)大跨度钢管混凝土拱结构变形温度敏感性强,对轨道长波平顺性影响较大,对短波、中波平顺性影响较小。结构收缩徐变对轨道高低不平顺的影响初期较为明显,后期逐步减小并且具有单向不可逆性;(2)应开展桥梁-轨道一体化设计,统筹梁体合拢温度、无砟轨道施工温度等关键设计参数,减小桥梁变形对轨道平顺性的影响;(3)应执行设计-施工-维护一体化理念,优化设计参数,严控施工条件,适时开展维修养护,减小并逐步消除收缩徐变影响;(4)研究成果可为大跨度钢管混凝土拱桥桥上无砟轨道的广泛应用提供有力的技术支持。

Taken the example of Ziyang Tuojiang River Bridge in the Chengdu-Chongqing Railway Project,the influence of the deformation of long span CFST arch on the high-speed railway ballastless track geometry status is studied.Research conclusions:(1)The deformation of long span CFST arch is highly temperature-sensitive and has obvious influence on track irregularity of long wave,but little influence on track regularity of short and medium wave.The shrinkage and creep of the long span CFST arch has significant effect on track irregularity in the initial stage and the efect which has unidirectional irreversibility decreases gradually in the later stage;(2)It is necessary to carry out the bridge-track integration design,coordinate the key design parameters such as the closure temperature of beam body and the construction temperature of ballastless track,so as to reduce the influence of bridge deformation on track regularity;(3)To reduce and gradually eliminate the impact of shrinkage and creep,the design concept of construction-maintenance integration should be implemented by optimizing design parameter,controlling of construction condition and timely maintenance;(4)This research result provides technical support for the wide application of ballastless track on long span CFST Bridge.