Cross River Rail — Roma Street Underground Station

The new Roma Street underground station is one of four new underground stations being delivered by Cross River Rail, the 10.2 km dual-track suburban rail line extension under construction beneath the Brisbane River and CBD. The Roma Street station is being constructed as part of the Tunnel, Stations and Development (TSD) package, which also includes the 5.9 km twin tunnels from the Southern Tunnel Portal near Dutton Park to the Northern Tunnel Portal in Spring Hill, and the four new underground stations at Boggo Road, Woolloongabba, Albert Street and Roma Street. The package is delivered by the CBGU JV — a joint venture of CPB Contractors, BAM International Australia, Ghella and UGL. The station comprises a 280 m long station cavern with up to 24.4 m excavated span and approximately 15 m of rock cover, five smaller connecting tunnels (adits) and three shafts, including a 20 m deep station box that accommodates the main station entrance, lifts and escalators. The cavern was excavated by sequential excavation in the Neranleigh-Fernvale Group rock mass — weakly metamorphosed sandstone (meta-greywacke and arenite), phyllite and subordinate quartzite and meta-basalt — within the regional Normanby Fault Zone, requiring heavier primary support and localised foundation treatment where intersecting the up-to-20 m wide fault zone of intact rock, rock breccia and clay gouge. The 20 m station box was fully excavated with 38,382 m³ of spoil removed, then constructed using 7,520 m³ of concrete and 14,700 t of steel up to ground level (L0); the 280 m cavern permanent lining required a further 13,100 m³ of concrete and 1,800 t of steel. Roma Street will become South East Queensland's most significant transport interchange, with more than 46,000 weekday users projected by 2036, linking suburban bus and rail, Brisbane Metro, and regional and interstate coach and train services.