锦屏二级水电站引水隧洞岩溶段处理措施及施工

锦屏二级水电站3，4号引水隧洞部分洞段岩溶发育，其中，在3号隧洞底板开挖过程中，揭露出一大型溶洞。为保证引水洞运行安全须对岩溶进行处理。在对开挖揭露出的大型岩溶腔特点进行分析的基础上，采取了较新颖的混凝土回填+拱桥的加固处理形式以及井桩梁施工，其中，在隧洞中进行井桩梁施工亦是首次尝试。详细介绍了施工过程和处理方法，其经验可资借鉴。

Treatment measure and construction method for karst section of diversion tunnel of Jinping Hydropower Station

A number of karst caves were developed in partial sections of No.3 and 4 diversion tunnels of Jinping Hydropower Station, in which, a large-scale karst cave was exposed during the floor excavation of No.3 diversion tunnel. To ensure the safety of the tunnel operation, on the basis of the analysis of the characteristics of the large karst cave exposed in excavation, the reinforcement measures of fresh concrete backfilling and arch bridge were adopted, and the well-pile-beam was used for the first time in tunnel construction. A detailed introduction to the construction process and treatment measures is given to provide reference for other similar projects.