Fitzroy River Bridge

Project Overview

The existing Fitzroy River Bridge structure was a single lane bridge built in 1975 and was damaged due to flooding in December 2022 & January 2023. MRWA decided to demolish the damaged bridge and replace it with a new Dual Lane 268m long 8 span bridge.

The new bridge construction was fast tracked due to the interruption to freight and passenger vehicles travelling on the Great Northern Highway if the Fitzroy River flowed. The new bridge was constructed using the Incrementally Launched Method of bridge construction and the superstructure consisted of a composite steel girder with concrete deck bridge with typically 35m spans to Piers constructed using precast concrete external shells with inistu reinforced concrete poured inside. The Piers were founded on concrete filled driven steel tubular piles.

The construction method and design where optimised to minimise the construction time of this important piece of road infrastructure. Piling commenced in Early June 2023 and with the construction of abutments and Piers and a 105m long casting bed on the west side for the prefabrication of the deck steel the first Bridge segment was launched in early September 2023 and the 8th and final deck segment was launched in early October 2023.

Fast Facts

  • CLIENTFitzroy Bridge Alliance
  • LOCATIONKimberley, WA
  • YEAR OF COMPLETION2023

Scope of Works

Fortec was engaged FBA to perform the launching works including supply of launching bearings.

The scope includes:

  • Design of site-specific launching services including temporary works
  • Technical advice on bridge launching
  • Supply & design of launching equipment including launch bearings, side guides, launching jacks and pulling cables and nose deflection jacks
  • Supply of on-site launching services including launching technicians and engineering support
  • Jacking system for change out of temporary launch bearings for permanent bearings

Highlights

  • The pull out design with the jacks mounted on a rear pulling beam allowed for a very fast setup and  launching cycle with the pulling cables remaining in place for the next segment erection
  • The launch bearing design meant that static sliding pads were used with the ‘rusting steel” bridge girders to minimise labour during launching due to the remoteness of the site
  • 268m of bridged in 8 launch segments was launched in one month
  • Bridge launching up to 52m in one day was achieved