隧道初期支护侵限处理施工技术

隧道初期支护侵限处理是指初期支护侵入二次衬砌限界后对初期支护进行破除,并重新支护的一种处理方法。为了保证二次衬砌的设计厚度,必须对已变形并侵限的初期支护进行拆换处理,针对大岐山隧道进口初期支护侵限处理施工,介绍了采用的拱部径向注浆、设置临时支撑、初期支护破除、侵限钢架处理等一系列隧道初期支护侵限处理施工技术措施,确保了施工安全。上述措施可供类似工程参考。

Treating Construction Techniques for Intruding Limits Inside the Tunnel

The treatment for limit-intruding during the initial support for a tunnel means that the initial support is removed when it intrudes the limits of the secondary support and then is re-supported and re-lined.To ensure the designed depth of the secondary lining,the initial deformed and limit-intruding support and lining have to be removed and replaced.With the treating construction for the limit-intruding of the initial support and lining at the inlet section of the Daqishan Tunnel as a practical example,introduced in the paper are the construction techniques and technical measures adopted for the project,such as the radial slip-casting for the arch section,the removal of the initial support and lining,the treatment of the limit-intruding steel racks,etc.,all of which help ensure the safe construction.And all the techniques mentioned above may serve as a useful reference for other similar projects.