隧道侵限段施工换拱技术

Arch Replacement Technology for Tunnel Intrusion Section

在进行高速公路隧道施工的过程中,时常会发生初期支护变形过大的情形,从而引发侵限或者初期支护不足等问题。初支换拱就是在隧道围岩发生变形时,为保证充足的二衬空间,将围岩压力适时适度释放后,再次进行支护施工的一种有效方法。结合云南省江通高速某隧道侵限段换拱技术实例,对换拱技术应用要点进行分析,以保证隧道安全及二衬空间尺寸,有效解决了隧道初期支护侵限的问题,最大程度保证了隧道施工质量。

During the construction of Expressway tunnel,excessive deformation of initial support often occurs,which leads to problems such as intrusion limit or insufficient initial support.Initial support arch replacement is an effective method for supporting construction again after timely and moderate release of surrounding rock pressure to ensure adequate secondary lining space when surrounding rock of tunnel is deformed.Combining with an example of arch replacement technology in a tunnel intrusion section of Jiangtong Expressway in Yunnan Province,this paper analyses the key points of application of arch replacement technology,to ensure the safety of the tunnel and the space size of the secondary lining.It effectively solve the problem of intrusion limit of initial support of the tunnel and ensure the construction quality of the tunnel to the maximum extent.