隧道扩建合理开挖步序的研究

Research on Proper Excavation Steps in Tunnel Extension

目前隧道的扩建施工技术仍然是借鉴新修隧道的施工方法,没有专门针对隧道扩建的施工方法,因此,需要积极探索适用于隧道扩建的新施工方法。以重庆市机场路拓宽改造工程的渝州隧道扩建为依托,从合理拱轴线的角度出发,确定隧道扩建的合理断面形式,再根据不同的拱跨和拱高来确定隧道扩挖合理施工步序,证明是一种可行的办法。它适用于类似重庆地区坚硬岩石地质的隧道扩建,为今后隧道的改扩建施工设计提供了依据。

Aiming at extension project of tunnel,the new suitable method of extension need to be explored.On the basis of the airport road widening and reconstruction project of Yu-zhou tunnel in Chongqing,the reasonable sections of tunnel expansion are determined from the perspective of the rational arch axis,and then under the different arch span and arch high spread,a reasonable construction excavation for tunnel is also determined.This method is proved to be a viable option.It applies to the similar expansion of the hard rock of geological tunnel in Chongqing area.The tunnel construction designing provides a basis of renovation and expansion in the future.