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

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