京唐铁路潮白新河特大桥节段预制胶拼法建造关键技术研究

为推动我国铁路桥梁建造技术科技进步,北京至唐山铁路潮白新河特大桥DK101+167.09～DK102+173.94段采用节段预制胶拼法建造技术,对其结构设计、拼装方案及预应力布置、连续梁结构检算以及主要工程数量等进行了分析研究,研究结果表明:(1)(48+80+48) m连续梁与40 m简支梁相接,连续梁梁端及跨中等高段与相邻简支梁的梁高和外轮廓一致,能较大程度节省预制模板费用,且全桥整体美观、协调;(2)预制节段之间的预应力连接器采用喇叭状的异形波纹管加密封圈方案,以保证密封性能,方便施工;(3)(48+80+48) m连续梁采用一次拼装3对预制节段即"小节段预制、大节段拼装"的平衡悬臂拼装工艺,该方案施工速度快,而且节段之间预应力锚槽、连接器布置少;(4)预制拼装方案的预应力含量比悬臂浇筑方案高。

Research on Key Technology of Precast Segments for Beijing-Tangshan Railway Chaobai Xinhe Super Major Bridge

To promote the technological advancement of railway bridge construction technology in China, the DK101+167.09～DK102+173.94 section of the Beijing-Tangshan railway is built with precast segments. The structure design, assembling method, prestressed reinforcement arrangement, structure calculation and the number of main projects are analyzed. The analysis results show that:(1)The(48+80+48) m continuous beam and the 40 m simply supported beam are connected, the height and outer contour of the continuous beam end and the uniform section are consistent with the adjacent simply supported beam, and the cost of formworks can be greatly saved and the bridge is overall aesthetic and coordinated;(2)The prestressed reinforcement connector between precast segments adopts a trumpet shaped pipe with a sealing ring to ensure sealing performance and facilitate construction;(3)Three pairs of precast segments are erected at one time by balanced cantilever assembling method for the(48+80+48)m continuous beam, namely"small segment prefabricated and large segment assembled". The construction of this method is faster and the anchor grooves and connectors between segments are less;(4)The prestress content of the precast and assembled beam is higher than that of the cantilever casting beam.