红叶二级水电站引水隧洞 2号支洞下游 4+ 0 42～ 4+ 0 68m段塌方是本工程施工难度最大的部位之一。由于岩体完整性差等不利因素 ,采用常规的锚喷、挂网及钢支撑支护均不可行。为确保施工人员及机械安全 ,采取了堆渣回填、混凝土回填空腔、二次开挖光面爆破等一系列措施 ,顺利地完成了塌方段的支护工作 Hongye 2 hydropower station diversion tunnel on the 2nd branch hole 4 + 0 42 ~ 4 + 0 68m section of the collapse is the construction of one of the most difficult parts. Due to the poor integrity of the rock mass and other unfavorable factors, the use of conventional anchor spray, hanging net and steel support are not feasible. In order to ensure the safety of construction workers and machinery, a series of measures such as heap slag backfill, concrete backfill cavity and secondary excavation smooth blasting were adopted, and the support work of the landslide section was successfully completed