Great Southern Region Bridges

Project Overview

Fortec was engaged by Main Roads WA to deliver structural repairs, scour protection, and refurbishment works across eight regional road bridges throughout the Great Southern region of Western Australia.

The project encompassed a combination of targeted structural interventions and full bridge refurbishments. Key works included scour remediation using fibre reinforced concrete apron slabs and rock armour, repair and replacement of deteriorated timber piles, stringers and halfcaps with steel sections, installation of reinforced concrete deck overlays, widening of bridge approaches, and construction of new safety barriers.

Several bridges required specialised methodologies, including pile wrapping and resin repairs, tidal-zone programming, and heritage monitoring during excavation. All works were undertaken in accordance with project-specific documentation and Main Roads standard drawings.

The project was designed to extend the operational life of these critical regional transport assets, enhance structural performance, improve hydraulic resilience, and increase road user safety.

Fast Facts

  • CLIENTMain Roads Western Australia
  • LOCATIONGreat Southern, WA
  • YEAR OF COMPLETION2025

Scope of Works

  • Installation of fibre reinforced concrete apron slabs, grouted rock, and rock armour protection to mitigate scour and hydraulic undermining (Bridge 0562 and 4223A).
  • Replacement of deteriorated timber piles, pile wrapping and resin repairs, banding of split piles, and urgent pile remediation including tidal-zone works.
  • Replacement of timber stringers, halfcaps, and full caps with structural steel sections to improve durability and load capacity.
  • Construction of reinforced concrete deck overlays (7.2m–8.2m between kerbs), approach widening, and installation of new safety barriers (Bridges 4223A and 4312A).
  • Wingwall extensions, concrete crack repairs, corbel replacements, sheeting repairs, and sill beam installation with expansion seals.
  • Heritage monitoring during excavation (Bridge 4313) and programming of works around tidal movements (Bridge 4332).

Key Points of Interest

  • Multiple bridges across dispersed regional locations
  • Combination of full refurbishments and targeted structural interventions
  • Transition from timber to steel elements for longevity
  • Hydraulic and tidal exposure considerations
  • Maintaining traffic access and safety

Challenges and Outcomes

  • Remote site logistics and resource coordination
  • Extended service life of bridge assets
  • Improved structural integrity and load performance
  • Enhanced scour resilience
  • Increased roadway safety through widened decks and new barriers
  • Reduced long-term maintenance requirements

Fortec is pleased to announce the successful completion of its first-ever fauna crossing over Hanrahan Rd in Albany, Western Australia. This is the first in a set of five to be installed, helping endangered possums and phascogales cross the busy Albany Ring Rd project.

The project involved the installation of two 18 m posts, each embedded 5.5 m deep in the ground. The foundation for the piles was completed by Groundex, who drilled 750mm diameter holes to 6m deep, and stabilised these with steel liners, in anticipation of the posts.

The posts were secured into the liners with concrete and further stabilised with 2 hulk anchors each. Tension wires and netting were installed between the poles, with additional rope connections to the surrounding trees, providing a safe crossing for wildlife. Th project was finalised with the installation of cameras making it possible to review the bridge usage by wildlife.

The works were completed using a variety of access equipment, as working in proximity to busy traffic lanes and unstable ground conditions required it. Critical activities were conducted during the night, with minimal impact on the public.