铁路钢筋混凝土系杆拱桥设计研究

Research on the Design of Railway Reinforced Concrete Tied Arch Bridge

系杆拱为简支梁拱组合体系,具有受力合理、造型美观、建筑高度小、跨越能力大等特点。SYK 45+070玉溪西至玉溪南昆玉上行正线特大桥以小夹角上跨玉磨铁路正线,受到净空高度的限制,考虑到美观的要求,该桥采用了1~68 m下承式预应力混凝土拱桥。文章以该桥为工程背景,重点介绍了系杆拱桥拱肋、横撑、系梁以及吊杆的设计;利用三维有限元软件Midas Civil建立计算模型,通过吊杆索力计算和调整优化,使全桥受力均匀合理;另外本文还针对该桥进行了动力特性计算分析。计算结果表明,该桥各项指标均满足规范要求。同时,通过对系杆拱结构设计的介绍和静动力特性的计算分析,为系杆拱在铁路上的应用提供了经验。

Tied arch br idge , simply-supported beam arch combination system, has characters of reasonable stress, beautiful shape, low bui lding height and large span c a p a c i ty, etc. SYK 45 ＋070 Kunyu upstream main l in e large bridge from West Yuxi to South Yu x i over crosses Yumo rai lway main l in e w ith small included angle. Considering headroom constraints and requirements of attractive appearance, 1 ？68 m through prestressed concrete arch bridge is adopted. Taking this bridge as the engineering bac kgro und, the paper emphatically introduces the design of arch r ib s , transverse braces, t ie beam and suspender. The calculat ing model is established by using the three-dimensional f in i te element software Midas Civi l. Calculation and optimization of cable force are m ad e, to make stress of the whole bridge uniform and reasonable. In addi t ion , the dynamic characteristics of the bridge are calculated and analyzed. Calculation results show that al l the indicators of the bridge meet the requirements of the spe cif ica tion. A t the same t im e , through the introduction of tied arch structure design and analysis of static and dynamic charac ter is tic s, experience fo r the appl ication of t ied arch on the railway is provided.