The project involves the design and construction of two new rail underbridges along the Ulan Line in the NSW Hunter Valley.
The two new bridges will replace three existing bridges that are nearing the end of their structural design life and are a risk to the reliability of the rail network. Cardno, engaged by Laing O'Rourke and ARTC, will also assist in the design and construction of a temporary access bridge, box culvert, retaining walls, and geotechnical investigation and design.
The shorter of the two underbridges crosses the New England Highway near the town centre of Muswellbrook and comprises a single 28m span, replacing the current two-span steel bridge. The new configuration allows the existing pier to be demolished.
The new design consists of two post-tensioned segmental beams with precast deck units to be stitched together on site. The design also includes temporary sheet pile walls to support the track during construction.
The longer of the two underbridges will be built alongside two existing bridges that cross Muscle Creek and the Hunter River. The new design is an incrementally launched concrete trough girder bridge with an overall length of 176 m, comprising 4 continuous spans varying in length from 30m to 50 m.
The site features challenging topography with steep embankments to both waterways and the need for a separate temporary access bridge during construction. The scope also includes proof check of the launching nose and the foundation for the casting yard.
Cardno’s multidisciplinary team continues to undertake detailed bridge design, geotechnical investigations and design, hydrology & hydraulics investigation and temporary works design and proof check of launching nose.
Around 30% of Hunter Region rail traffic (both passenger and freight) rely on the safe operation of the three Muswellbrook bridges. The replacement works will ensure optimal rail network reliability and safety.
Geotechnical and hydraulic investigations began in early 2020, with the construction of the two underbridges started in the second half of the year. The project is expected to be completed by June 2022.