Bridging over mining country

Running through a mining area near Sydney, the "Spring Farm" motorway is susceptible to ground subsidence throughout its service life. To provide robustness to major structures, mageba bridge bearings and expansion joints with large movement and rotational capacities are incorporated into the superstructure.

Mining is Australia is not limited to the most remote parts of the country, but takes place even close to major cities where highways must be constructed. In such cases, the highways must be built to accommodate any ground subsidence that may result from the mining activities – as was required, for example, in the case of the Spring Farm Parkway outside Sydney. The four-lane highway of Stage 1 crosses an area that will be subjected to longwall mining, so its main bridge structure had to be designed to accommodate large movements and rotations. Having supported the bridge designers from the project’s early stages, mageba went on to design, manufacture and test the required components. These included:

Were it not for the mining activity in the area, the bridge’s movements and rotations could have been facilitated by smaller, simpler bearings and expansion joints – but thanks to the expert support provided by mageba’s team in Sydney, the optimal solution could be developed to meet this structure’s special subsidence-related challenges. 

Bridge designer: Jacobs
Owner: Transport for NSW
Contractor: Georgiou Group Pty Ltd

The Spring Farm Parkway near Sydney will pass through a mining area that might be expected to experience significant subsidence in the years following its construction

The RESTON®SPHERICAL bearings on this bridge axis were designed to carry loads of 2570 kN and to accommodate longitudinal movements of +/- 365 mm, with a large preset of 185 mm from centre

Unloading of TENSA®MODULAR expansion joints following transport to site from mageba’s production facility in Shanghai

Installation of two TENSA®MODULAR expansion joints, one for each carriageway, at one end of the bridge structure

Some of the TENSA®MODULAR expansion joints are equipped with noise-reducing surfacing to minimise noise emissions under traffic

Several TENSA®GRIP single-gap expansion joints were also supplied to accommodate smaller longitudinal movements