Abstract: The Dapo Tunnel of the Qianzhang Changzhou Railway is a Level I high-risk tunnel, which is quite difficult to construct and has many major construction problems. Many research results of domestic and foreign scholars have been used for reference in the construction process.The engineering background and main geological conditions of the Dapo Tunnel are introduced. And the tunnel construction difficulties and corresponding countermeasures in fault fracture zones, water and mud inrush zones, various lithological contact zones, and shallow buried areas are summarized in the article, which can serve as a reference for the similar projects.

Key words: Dapo Tunnel, construction countermeasures, unfavorable geological section, tunnel construction, level I risk

摘要： 黔张常铁路大坡隧道为Ⅰ级高风险隧道,修建难度大,存在诸多施工重大问题,施工过程中借鉴了国内外学者的诸多研究成果。文中介绍了大坡隧道的工程背景及主要地质情况,总结了断层破碎带地段、涌水与突泥地段、各种岩性接触带与浅埋地段的隧道施工难题及相应对策,可供类似工程参考。

关键词: 大坡隧道, 施工对策, 不良地段, 隧道施工, I级风险