铁路隧道小净距下穿既有公路隧道施工技术

Construction Technology of Railway Tunnel Underpassing Existing Highway Tunnel with Small Clear Distance

结合丹大铁路草莓沟2号隧道下穿既有盘道岭公路隧道交叉段跨度大、间距小、岩石破碎等施工难点的工程实例,总结铁路隧道下穿施工采用超前洞身双层大管棚、三台阶法、控制爆破、双层钢架初期支护等工艺特点、施工工艺流程及控制要点,可为类似工程的施工提供参考。

According to the engineering example of the No.2 tunnel of Dandong-Dalian Railway passing through the existing section of Pandaoling highway tunnel with large span,small distance and broken rock,the technical features,construction process and control points of advance hole double pipe shed,three steps method,controlled blasting,double-shelves initial support are summarized,which can provide reference for the construction of similar projects.