Work to repair a landslip which happened more than two years ago is now in full swing at the site near Rothbury.
The repairs follow refinement of the design to allow for new drainage, bolstering measures and the relocation of wildlife from the site.
The damage, that started on Boxing Day 2012 and worsened during the following winter and spring, has been closed to all vehicles and pedestrians for nearly two years and four months.
Peter Brewis, who is a senior engineer for Northumberland County Council, said that it has been a very complex process. He explained that a geotechnical investigation and study of groundwater has led to a proposal to build a wall along the side of the road to provide permanent deep drainage so that the land remains stable.
Mr Brewis told the Gazette that there are three ‘very separate operations’ taking place at the same time which is why, at its peak, the works will cost £1million a month.
Mr Brewis said: “Contractors give me a spend profile, week-by-week, month-by-month and the peak spend happens when all the operations are going on at the same time. There will be piling going on, which is machines sticking concrete columns in the ground, as they move forward behind them another group build a reinforced beam on top of the columns, behind them starts the construction of the anchors.”
All of these processes will secure the road so that the road remains stable in the long term.
Coun Steven Bridgett, who represents Rothbury and Coquetdale, said: “Obviously a lot of residents have wanted to see this progress as quickly as possible, but they’ve started work on site today, it’s a robust solution and unlike the electoral rhetoric we’re hearing at the moment about the A1, we’re actually getting something done here.”
The site has proven to be very complex in terms of the ground conditions, particularly the need to deal with groundwater springs. This has led to the extensive drainage works being carried out on site which will need to be further enhanced during the construction of the project.
Eight bore holes, up to 55 metres deep have been installed, together with 80 well points six metres deep. These have been tested and commissioned and will be used to control ground water during the construction works.
It’s a robust solution and unlike the electoral rhetoric we’re hearing at the moment about the A1, we’re actually getting something done here.Coun Steven Bridgett
Coun Ian Swithenbank, policy board member for streetcare and environment at the county council, said: “This project has taken a great deal of time to reach this phase, given the complexity of the site. A big part of the process has been understanding what is taking place 30 to 60 metres underground. By gathering detailed data on this, it has allowed us to develop a robust solution that we are confident will stand the test.”
The original budget for the scheme stood at £7.6million, which included £4.9million of government funding. The nature of the ground and the amount of further drainage to be undertaken will require the council to commit a further £1.5 million extra funding for the scheme. Therefore the council’s contribution has increased by £1.5million to £4 million.
The construction works are planned to be completed by October. The deadline moved by eight weeks from August because of the need for extended commercial and technical negotiations with the contractor.