18/04/2024
- Harbury Cutting Emergency Response 🛤️
❗Issue:
Harbury Cutting constructed by Brunel in the 1840s, stands as the world's largest and deepest hand-dug rail, at an incredible 34m deep. In early 2015, a significant geotechnical failure struck, causing a 4m drop in the embankment crest which unleashed over 300,000 tonnes of material onto the track. The collapse also damaged part of the west portal, a curved mass brickwork structure spanning over 50m wide and 15m high.
👷 Response:
An emergency plan was initiated by Network Rail & Murphy to stabilise the cutting and portal. VA's Geo Team was enlisted to undertake soil nailing on the slope adjacent to the portal and install anchors through the structure to prevent further collapse.
As part of the works that were already ongoing due to a previous slip, Murphy had requested that VA install a 290m catch fence to limit the movement of the landslide, which would not directly affect the active rail track.
Network Rail & Murphy instigated an emergency plan to stabilise the cutting and portal. VA's Geo Team was brought in to undertake the soil nailing to the slope adjacent to the portal and install anchors through the portal to ensure that it did not collapse any further.
⚠️ Challenges Overcome:
- Continuous monitoring was required due to the ongoing movement of the slope.
- A vertical fault line of limestone, discovered during trial drilling, necessitated updates to the original design.
- Large excavators up to 67t were needed to install 20m-long soil nails.
- Coordinating various equipment and personnel on-site was complex, requiring precise management.
- Tight deadlines demanded 24/7 work, with teams mobilized from across the UK.
- The damaged Brick Portal section required meticulous coring, drilling, grouting, and plate installation.
- VA's repair team, supported by Murphy, re-cased the portal's centre section using matching bricks, with safety measures in place for trains below.
🏆 Result:
The completion of the Emergency Works was a huge success, finishing weeks ahead of schedule on March 13th. Mark Carne, Chief Executive of Network Rail, commended the efforts.
“Thousands of passengers, and thousands of tonnes of freight, rely on this vital route every day. We have been working around the clock and are able to re-open the railway three weeks ahead of the original estimate"
(Mark Carne - Chief Executive, Northern Rail)
This was a huge responsibility with immense pressure to deliver and our team performed incredibly well.
One for the VA History Books...
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