As part of the $2.8 billion Sydney Metro City and Southwestern (SMCSW) Tunnels and Station Excavation Works contract (TSE), BG&E was appointed by JHCPBGJV to undertake the detailed design of the Barangaroo Station excavation and Hickson temporary road bridge.

Following this, BG&E was appointed by JHCPBGJV to design the stations’ permanent structure.

BG&E’s third contract on the project was awarded by Besix Watpac – providing temporary works and construction advice during the commissioning and fitout of the station and construction of the permanent surface works and roads.

Project Details

The station excavation is typically rectangular in plan with proposed bulk excavation level to be at approximately RL – 24.5 metres.

The retention system is comprised of soldier pile walls, with jet grouting between piles and anchors for the western retaining wall and headwalls. A shotcrete face will be constructed in front of the soldier piles.

The shotcrete wall is connected to the piles with dowels. The soldier-piled solution is intended to provide a tanked solution for the structure sitting above the sandstone bedrock. A blinding layer will be provided at the base of the excavation, with a longitudinal fall to facilitate drainage.

To allow the station excavation and construction activities to continue, a temporary acoustic roof and steel bridge structure for public access were provided. To maintain public access to the Station along the Hickson Road heritage retaining wall, a two-lane suspended public access bridge was built over the full length of the box excavation. The public access bridge was supported on temporary piles and steel girders traversing the excavation.

At a later stage, the temporary bridge steel girders were extended to provide construction access alongside the western retaining wall, and two future bridge crossings over the excavation were also required for construction access.

In the scope for Besix Watpac, the temporary bridge had to be partially demolished while the new road over the station was built, with the road then being rediverted to be supported over the station box.