A collapsed drain has been discovered in the hillside above where a major road on the outskirts of Sheffield has been hit by a landslide.
Traffic on the A57 between Crosspool and Rivelin has been reduced to a single lane, controlled by traffic lights, since last year.
Investigations have been taking place to determine the cause of the landslip, which has been continuing to move – delaying the start of repairs.
Recent tests by Sheffield Council’s contractor Amey have revealed a collapsed drain buried deep in the hillside which they believe could have caused the land movement.
Engineers are on site this week to carry out tests on the drain to assess its condition.
Graeme Symonds, network director at Amey, said: “People will see a lot of activity on site in the coming days.
“We are bringing in a team to drill down five metres into the hillside as our recent tests have shown there is a collapsed drain there which could have caused the land movement.
“We need to get a camera down into the drain so we can see exactly what is happening, where the drain has collapsed and how much of it is affected.
“This will allow us to develop the right solution to what is a complex problem. But we would like to reassure people that it is our priority to get this moving as quickly as possible.”
Amey is considering different solutions to the landslip, which could include use of electric current to dry out the bedrock and stabilise the shifting hillside. Repairs are set to start later in the year.