M80 Junction 9 | Road Subsidence Work

Works to repair subsidence in the slip road exiting the northbound M80 at Junction 9 will commence on Monday 18 November.

The slip road was closed for safety on 28 June, as a result of significant subsidence in the carriageway. Since August, traffic has been using a temporary link road that was constructed to bypass the area where subsidence occurred.

For the safety of road users and the workforce, the temporary link road will be closed during repair work between 20:00 and 06:00 on Monday to Friday nights, from Monday 18 November for four weeks.

Traffic wishing to exit the northbound M80 at Junction 9 during these overnight closures will be diverted northwards on the M80 to turn at Junction 10, before returning southbound to exit via the M80 Junction 9 southbound off-slip. This will add approximately 10 miles and 11 minutes to affected journeys.

The repair will involve excavating an area of approximately 1000m2 of the slip road to a depth of 1.5 metres and then reconstructing it with layers of stone and carefully positioned geotextiles for reinforcement, before a new sub-base and road surface is laid.

The design of the repair was informed by extensive site investigations to determine the cause and extent of the subsidence. Following a desktop survey undertaken by the Coal Authority into legacy mining in the area, eight boreholes were drilled by their ground investigation contractor. BEAR Scotland subsequently arranged for four more boreholes to be drilled in the area around the subsidence, and six trial pits were dug to see if there was any evidence of poor ground conditions that may be associated with shallow mine workings. The conclusion of these investigations was that neither a mine shaft nor clear evidence of historical mine workings were discovered.

Tommy Deans, BEAR Scotland’s South East Network Manager, said: “We now have a clear programme for the repair and reinstatement of this slip road.

“We’re grateful to road users for their patience and understanding while we completed site investigations and design work. It was important that this process was thorough, as we needed to understand the ground conditions that led to the subsidence and there was a possibility of unrecorded mine workings at this location.

“We’re now confident we have a designed a repair that is fit for purpose and look forward to getting the road reopened before Christmas.”