包家山隧道大断面斜井进正洞挑顶技术

结合包家山隧道1＃斜井与正洞交叉口处的施工实例，介绍大断面斜井（横断面84.315m2）进正洞的挑顶施工技术。在充分了解地质条件的基础上，制定了“超前支护、分部开挖、加强支护、随挖随护、及时封闭、加强监测”的施工方案。重点阐述接头部位的施工方法，对施工经验进行了总结，可供同类工程参考。

Technology of Roof Ripping Between Large Cross-Sectional Inclined Shaft and Main Tunnel:Case Study on Baojiashan Tunnel

The technology of roof ripping between large cross-sectional inclined shaft （ with the cross-sectional area reaching 84. 315m^2） and main tunnel is presented, with the roof ripping construction between No. 1 inclined shaft and main tunnel of Baojiashan tunnel as an example. The construction scheme of advance reinforcement, sequential excavation, strengthened primary reinforcement, supporting immediately after excavation, timely ring closing and strengthened monitoring is established on basis of fully understanding of the geological conditions. The construction method for the connection section is focused. The construction experience is summarized. The paper can be served as reference for similar projects in the future.