New geotechnical information will help guide the long-term repair plan for the Great Western Highway after detailed investigations at Mitchells Causeway.
The highway has been closed since 8 March for safety reasons after serious cracks and defects were found in the road structure. The closure is expected to last for at least three months.
Monitoring equipment placed in the road surface and the causeway’s dry-stone walls has collected detailed information about the condition of the structure. The data has tracked movement and changes within the causeway.
Investigations found that the 200-year-old material under the road has weakened over time. This has caused gaps and empty spaces within the causeway structure.
The monitoring work helped identify the problem early and reduced the risk of further damage. It has provided a clearer understanding of the site and will support the development of a safe repair solution.
Engineering and construction experts from Australia and overseas will now be invited to help finalise the repair approach. A technical briefing will provide experts with detailed information about the site conditions and investigation results.
The process will support the selection of a contractor to begin repair work as soon as possible.
Further updates will be provided as more information becomes available. Local communities affected by the closure will continue to receive information about the next steps.