关键词: 引水隧洞, 岩溶, 软基处理, 锦屏水电站

Abstract:

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.

Key words: diversion tunnel, karst, soft foundation treatment, Jinping Hydropower Station