Bridges

The M1 Pacific Motorway extension to Raymond Terrace project is required to complete a free-flowing dual carriageway route between Sydney and Brisbane. The project connects the M1 Pacific Motorway at Black Hill and the Pacific Highway at Raymond Terrace and includes 10 kilometres of motorway. The project will provide improved route reliability in relation to congestion, flood immunity and high demand holiday peak travel.

At the centre of this project stands the 77-span, 2.55-kilometre-long Viaduct. The Viaduct alignment is designed to accommodate various interfaces along its length, including spanning various local access roads, New England Highway, Main Northern Rail Line (ARTC), Hunter River, and Hunter River floodplain. To meet these constraints, the alignment includes both horizontal and vertical curves and the Viaduct consists of varying spans lengths and skewed piers.

The Viaduct consists of precast Super-T girders which are predominantly designed to be simply supported, except Span 8 and Span 9 over the ARTC track which are made continuous. The carriageway width is typically maintained at a constant 21.6 m, and transitions to 26.71 m past Span 72. The substructure typically comprises portal piers with concrete headstock supported by two circular columns and piles, both bored cast-in-place concrete and driven steel tubular piles are adopted across the alignment.

The key design aspects and construction methodology adopted, including the design efficiencies achieved in deck and substructure, as well as standardisation of details will be presented. Further discussions on material savings, improved sustainability and constructability, urban design refinements, and the use of 3D modelling and automation for documentation of the design are also presented. In conclusion, a series of recommendations from the design and construction process are presented, offering valuable insights for future projects.

At the time of writing, the design is complete, and construction is ongoing.