襄渝二线铁路羊子岭隧道下穿既有线施工技术

Construction Technology of Yangziling Tunnel Going underneath Existing Railway in Xiangyu Additional Railway

系统地阐述了襄渝增加二线铁路工程之下穿既有线羊子岭隧道,在超薄层覆盖段且围岩以自承能力差的弱～中膨胀土为主、地下水丰富的不利环境中,采用便梁、锚固桩等先加固既有线路、后洞内设置超前支护联合系统支护,分部开挖,及时监控量测的的综合施工技术,并于现场设置有效的既有线安全防护措施,施工安全顺利地经过了既有线地段,确保了既有线铁路运营安全,对今后类似工程的施工具有参考应用价值。

It is systematically expounded in this paper the additional railway project going underneath existing Yangziling Tunnel in Xiang-Yu Railway. The environment is adverse, as it is in overlay segment of extra-thin layer, where the weak- medium expanding soil is the majority of the cofferdam, and of poor self-beating capacity, and where the underground water is abundant. Firstly, temporary girders and anchor piles reinforce existing lines ; advance supports united system is set up in the cave ; the excavation is carried out in sections. Comprehensive construction technology of timely monitoring and sur- veying is used, and effective existing lines safe protection measures are set up on site. This construction smoothly passes existing line section, ensures the safe operation of existing railway, and can be valuable reference to similar projects in the future.