ABSTRACT
Snowy 2.0 is a 2000 MW pumped hydro-electric expansion of the existing Snowy Scheme in Australia. A special part of the project is the Inclined Pressure Tunnel (IPS), with an internal diameter of about 10 m, which will experience extraordinary hydraulic conditions, where internal pressure variations reach up to 70±25 bars during transients. The lining solution, currently under study, is a single pass segmental lining where special steel couplers, named as FACS (Force-Activated Coupling System), are placed in the longitudinal joints between the segments to provide tensile resistance. The innovative joint connection comprises pin-socket steel couplers with cup springs that deforms during assembly of tunnel segments, providing hence pre-compression of the joints. The connections create a continuous heterogeneous ring, reducing the risk of joint misalignment and dislocation and preventing joint openings during operation. This paper provides an overview of the solution FACS, discussing design aspects and construction and testing of prototypes.
