The Gateway Additional Lanes project is the first stage in a proposed six lane upgrade of the Gateway Motorway north of Brisbane. Designed to be consistent with planning for future works, it involves the construction of an additional lane over approximately 2.5 km of the northbound carriageway from Sandgate Road to the Deagon Deviation, replacement of two existing road bridges over Cabbage Tree Creek (northbound and southbound), widening of the existing northbound bridge over Depot Road, and construction of a new off-ramp bridge.
The narrow and constrained site adjacent to the live motorway presented unique challenges when it came to safe pitching of the very long single lengths of PSC piles in a way that ensured zero harm to workers and commuters, while minimising delays on the busy motorway. This challenge drove the team to develop and implement a new and innovative mechanical lift connection using cast in block-outs in the pile (a TMR approved deviation from the rigid rules on standard pile design).
The project team worked collaboratively with temporary work designers to devise an elevated temporary structure which allowed its assembly from behind creek banks with crawler cranes. This elevated structure allowed for 13 piles to be pitched in one work shift, which greatly reduced temporary traffic closures and disturbance to the marine environment.