This 23 km upgrade of the Pacific Highway to a four-lane divided highway extends from approximately 700 m north of the Oxley Highway / Pacific Highway Interchange (i.e. the turnoff to Port Macquarie) to Barrys Creek at Kundabung (midway between Port Macquarie and Kempsey). The project has eight transverse and mainline bridge structures including a roundabout interchange and a main carriageway crossing of the North Coast Railway, together with a range of flora/fauna measures including fauna underpasses. Our scope included the replacement of deep culverts under the existing highway, requiring extensive traffic staging.
A key feature was the large number of bridge structures, which included major crossings over the Hastings River and Wilson River with lengths of 571 m and 523 m respectively. Both of these river crossings are single bridges, each being 10 Super-T beams wide. The 14-span Wilson River Bridge is approximately 23 m wide, has a clearance of approximately 8 m and is founded on a mix of bored and driven tubular piles to suit the geological profile. It was constructed from a temporary rock platform, using a side-lifter truss for the majority of the 140 Super-T beams. On the wider, 15-span crossing of the deeper Hastings River the methodology for erection of the 150 Super-Ts was by using the lifting truss and large barges.
Around half of the project was a duplication of the existing Pacific Highway, while the balance is on a new alignment traversing floodplain, soft soils, SEPP14 wetlands and sensitive environmental areas. There is approximately 6 km of embankment on floodplain terrain (including 4.8 km on soft soils) and the upgrade has a 1-in-100-year flood immunity. Significant flood relief structures were required on the Hastings and Wilson River floodplains, with the lengths of the six floodplain bridges being 262 m, 239 m, 193 m, 149 m, 136 m and 88 m.
Paving on the project was a mixture of Plain Concrete Pavement together with Continually Reinforced Concrete Pavement topped with Stone Mastic Asphalt in some areas to reduce noise. On 17th November 2017 our team opened an 18 km section of dual carriageway between the Oxley Highway Interchange and Haydons Wharf Road to traffic, five months early. Overall completion was achieved in July 2018.
GENERAL INFORMATION
- Location: Pacific Highway, Oxley to Kundabung, NSW.
- Contract type: Design and construction.
- Project value: $612 million.
- Year of project completion: 2018
KEY ASPECTS
- Overall Length: 23 km
- Hastings River Bridge: 571.58 m
- Wilson River Bridge: 523.72 m
- Floodplain Bridges: 1,067 m
- Earthworks: 1,800,000 m3
- Drill & Blast: 450,000 m3
- SMZ & Verge: 350,000 m3
- Soft Soils: 4.8 km