Ausenco designed the realignment of the Dunsmuir Tunnel at Stadium Station for Phase 1 of SkyTrain.
The existing tunnel had to be realigned, re-profiled and separated to connect to the new Stadium Station.
The Dunsmuir Tunnel was built in 1931 and was a single line rail structure. The twin SkyTrain tracks are stacked one above the other in the tunnel.
This required the lowering of the tunnel invert to achieve the necessary increase in height.
At the eastern end a re-alignment of the tunnel was required, which resulted in a complete, underground break-out section, twin bored tunnels and a twin reinforced concrete cut and cover box tunnel section.