Pre-stressed concrete bridge looks beaut at Bloomfield

A remote location for a new bridge in far north Queensland has presented a number of unique challenges for the project team tasked with replacing the original concrete causeway, which was severely damaged by flooding during Cyclone Yasi and subsequently closed in early 2011.

Philip Pearson, Engineer (Civil) for the Department of Transport and Main Roads’ (DTMR) Far North District Program Delivery & Operations explained, “The new bridge has improved flood immunity and will significantly improve reliability of the river crossing during the annual wet season.”

The remote location, around 75km south of Cooktown, was tricky in terms of road access and water levels. “The DTMR undertook a route survey of the Wujal Wujal access road and determined that 19m long precast pre-stressed reinforced concrete deck units were the best choice. In addition, the existing low-level causeway was frequently inundated with water due to tidal flows and rainfall runoff. The construction team worked closely with Rocla to ensure that the precast pre-stressed reinforced concrete deck units were delivered to site within specific timeframes to allow each deck unit to be lifted off the truck and placed onto the headstocks.”

The bridge design consisted of reinforced concrete cast insitu 1200mm diameter piles, reinforced concrete cast insitu headstocks, precast pre-stressed reinforced concrete deck units and reinforced concrete cast insitu deck slab. As a TMR Registered supplier of precast pre-stressed deck units, Rocla was chosen to supply the deck units through a tender process.

The Bloomfield River bridge project received excellent support from the local community and Wujal Wujal Aboriginal Shire Council, which, through its involvement in the project, were able to deliver ‘Stage 2’ of the community footpath project.