The landslip occurred around 230 metres above the carriageway following a period of heavy rainfall near midnight on Saturday night at Glen Kinglas. Teams from the Bear Scotland alliance of Eurovia, Jacobs and Breedon Group had been on high-alert during the Met Office yellow weather warning.
Mitigation measures installed next to the A83 blocked the landslip from reaching the carriageway. The specially designed rock-bunds were the result of an engineering solution using rock excavated during the construction of further landslip mitigation measures three miles away.
Engineers estimate that the rock bunds helped prevent the A83 from being closed by up to two days as a result of the landslip.
Geotechnical engineers have assessed the landslip along with teams from Bear Scotland for safety with plans now under way to remove the debris from behind the bund. Short-term lane closures will be in place while teams mobilise plant and heavy machinery to remove the material from the bund.
The rock-bunds form barrier to hold material from a potential landslip on the hillside parallel to the A83. The 28,000 tonnes of rock used to create them was re-used during excavations of the nearby £2.24m catch-pit project at the Rest and be Thankful, where three large ‘pits’ were created to help provide further resilience against potential landslips in the area.
The excavated rock was transported three miles to Glen Kinglas and used to construct the bunds.
Eddie Ross, Bear Scotland’s north west representative, said: “We’re pleased that this innovative and sustainable method of landslip resilience has been effective, demonstrating that this engineering design and extensive studies of the geotechnical landscape in the area have been a success.”