Design of Precast Concrete Segmental Lining for the Montreal Express Link (REM) Airport Tunnel
The Réseau Express Métropolitain (REM) will be the fourth largest electric and fully-automated light-rail transit network in the world designed to facilitate mobility across the Greater Montreal region in Canada. REM will connect downtown Montreal to the airport, requiring the development of an entirely new 3.6 km long bored tunnel that runs below the international airport runways. This 7m-diameter tunnel will be excavated by a hybrid TBM that progresses through saturated soft ground and competent rock. Simultaneous installation of precast fiber-reinforced concrete (FRC) segments provides initial support and final lining for 125-year intended service life of tunnel. This paper discusses the implementation of the structural and geotechnical analyses on the design of FRC segments for governing load cases occurring from the time of segment production to the final service stage. Three-dimensional (3D) nonlinear finite element analyses (NFEA) on TBM thrust jack forces and 3D NFEA TBM excavation simulations are presented. Structural demand is compared with nominal capacity of FRC segments which is validated by statistical analyses performed on 100s of specimens tested in the segment precast plant.