Abstract: Partial section of diversion tunnel of Yangfanggou hydropower station is located in intensely carbonated tunnel of metamorphic siltstone with carbonaceous slate, and surrounding rock has the characteristic of poor stability or even instability. By scientific and reasonable arrangements of excavation procedure, supporting type and supporting sequence, and the installation of lock beam and waist-lock anchor bar bundle at the specified time and special region, the deformation of surrounding rock is effectively controlled and the construction safety is guaranteed, worthy reference.

Key words: metamorphic siltstone with carbonaceous slate, tunnel, deformation, lock beam, waist-lock anchor bar bundle

摘要： 杨房沟水电站导流洞的部分洞段位于碳化严重的变质粉砂岩夹碳质板岩洞段中，围岩稳定性差或不稳定。通过科学合理安排洞挖程序、支护型式和支护顺序，并在特定的施工时机和施工部位设置锁定梁和锁腰锚筋束，有效地控制了围岩变形，保证了施工安全，这种技术值得同类工程借鉴。

关键词: 变质粉砂岩夹碳质板岩, 隧洞, 变形, 锁定梁, 锁腰锚筋束