The structure is a part of an 80 km-long drift which interconnects two reservoirs with water supply dams in Liaoning Province (in the north-east of China).
Back-up installation behind a gripper TBM with tunnel conveyor – whereat the heavy steel work had to be manufactured in China. The complete plant, designed based on Chinese steel profiles, was assembled in a workshop prior to the 2’000km transport to the tunneling site for final assembly. The job site assembly took place underground at the end of the 2km long access tunnel.
The back-up installation consists of a 150 m-long steel structure supported on auxiliary rails. The rock is consolidated in the L2 zone by means of two independent shotcrete systems, consisting of 2 shotcrete robots, delivery pumps and handling systems.
The excavated muck is transferred via a conveyor belt directly onto the tunnel belt. Supply material and material subject to wear is transported by rail to the tail of the TBM and, from there, using a special crane, to the storage location on the material transloading bridge or directly to the installation point on the TBM.