The NSW Government is today providing an update on the Great Western Highway following four weeks of intensive geotechnical investigations and testing at Mitchells Causeway.
The Great Western Highway has been closed for a minimum of three months since 8 March after Transport for NSW identified serious cracking and defects in the road at Mitchells Causeway.
Monitoring equipment installed within the road surface and in the causeway's dry-stone walls has provided geotechnical experts with extensive data on the condition of the sub-structure and constant updates on movements within the causeway that have made the road unsafe.
The investigations have confirmed the 200-year old fill underneath the road has deteriorated significantly, resulting in voids and gaps within the causeway structure. Without the proactive monitoring, which Transport for NSW enhanced late last year, the detection of the road defects and bulging of the sandstone walls risked the structure collapsing before it could be repaired.
This work has provided Transport for NSW with the clearest picture yet of the condition of the site and has been necessary to inform a solution that will enable the road to safely reopen.
As a next step, Transport for NSW will engage engineering and construction experts from across Australia and internationally to help finalise a solution.
Experts in geotechnical, complex road construction techniques have been invited to a technical briefing on Thursday 23 April, where they will be provided with detailed geotechnical and site condition data to help develop and test solutions to safely reopen the causeway.
This will support a fast-tracked, collaborative procurement process to bring a contractor on board as quickly as possible.
The NSW Government is continuing to engage with impacted communities and will provide further updates on next steps as further information becomes available.
For the latest information on the Great Western Highway at Victoria Pass, including detours and extra public transport service timetables visit www.transport.nsw.gov.au/gwhvictoriapass.
Minister for Roads, Jenny Aitchison said:
"The past four weeks of detailed geotechnical work has given us a much clearer understanding of what is happening beneath Mitchells Causeway.
"We now know the underlying bedrock remains strong, which means we can focus on repairing the damaged sections and getting this critical route reopened as quickly and safely as possible.
"The time taken to thoroughly understand what's happening beneath the surface has been critical to getting this right. This month crews will begin test piling so we keep the work moving forward.
"I want to acknowledge how tough the past few weeks have been for locals and businesses across the Blue Mountains, Little Hartley, Lithgow, Central West and beyond, and for the many people who rely on this road every day.
"I want to sincerely thank the community for their patience during this time.
"We are absolutely focused on reopening this vital route as quickly and as safely as possible, and by working with leading engineering experts from across Australia and around the world, we're making sure we deliver the best possible solution for the community."
Member for the Blue Mountains, Trish Doyle:
"These geotechnical findings are an important step forward in tackling what is a complex and challenging situation. They give us a clear picture of what's happening beneath the road and mean the focus can now turn towards getting a safe, practical solution in place.
"I have seen and heard firsthand just how much this closure has impacted people across the Blue Mountains and beyond. From families trying to get to work and school, to local businesses doing it tough - this has been a challenging time for our community, and I understand how deeply it's being felt.
"I want to thank my community for the patience and resilience they've shown over the past few weeks. I know it hasn't been easy, but people have really looked out for each other, and that's what makes this community as strong as it is."
Transport for NSW Secretary, Josh Murray said:
"We have gathered enough data to inform a construction solution, which will now be shared with key players in the engineering and road construction industry. They'll be invited to add solutions to repair and reopen the highway in the safest, fastest manner.
"Accurate data was collected over a period of weeks, with seismic testing wrapping up in recent days. All this information will be shared with industry to test our repair methodology and move quickly into delivery.
"We are committed to working collaboratively with industry partners, who will help deliver the final fix, to reinstate access to this critical east-west link between Sydney and the Central West and bring relief to road users, freight operators and regional communities."
