特大断面偏压公路隧道临时支护拆除方式研究

摘要

Twin-side heading way is mainly used in large section load tunnel, temporary support play an important role during the construction. For the un-biasing tunnel, removing left firstly or right temporary support is not important, however, for biasing tunnel, removing left firstly or right temporary support has large effect on the internal force of preliminary bracing. By the numerical calculation on Longtoushan large section load tunnel, the paper analyzes temporary support's removing way effects on bending moment and axial of preliminary bracing, and put up the proper temporary support's removing way on the large section load tunnel based on the twin-side heading way.%特大断面公路隧道大多采用双侧壁导坑方式施工,临时支护在施工过程中起着至关重要的重要.对于不偏压隧道先拆除左或右侧临时支护影响不大,而对于偏压隧道,埋深浅侧的临时支护先拆除,还是埋深深侧的临时支护先拆除对初期支护受力有较大影响.通过对广州龙头山特大断面隧道公路偏压隧道的数值计算,分析了偏压隧道左、右侧导洞的临时支护拆除方式对初期支护弯矩和变形的影响,提出了特大断面偏压隧道基于双侧壁导坑开挖方式的临时支护合理的拆除方式.