Project involved construction of a 550-metre 22-span concrete bridge over Pioneer River and a two-span concrete bridge over Lagoon Creek in Mackay.
Associated works included 3km of new approach roads and roundabout construction with bulk earthworks, drainage, landscaping, and pavements.
Pioneer River is tidal and of important ecological significance and feeds into the Basset Basin and Round Top Island National Park and Bakers Creek Conservation Park. It contains sensitive fauna and flora including dugongs, crocodiles, porpoises, fisheries, turtles, sea grass and mangroves. Environmental controls included:
- Bunds to capture concrete overspill from the bridge piles
- Geofabric “flags” were located around the ends of the construction platform bund secured to vertical star pickets that would wrap around the earth face of the bund end and provide protection from erosion from the swirling water movements
- Sediment traps on the river banks
- Rehabilitation of disturbed areas in advance of the wet season.
The project was completed one month ahead of program. Key to achieving this were innovations in construction methodology and plant selection, for example:
- Building a sand access platform extending midway into the river, from which bridge construction activities could take place.
- Introduction of a Cluster Hammer during the piling works to shatter the exceptionally hard rock, which could not be drilled and excavated by conventional means.