Statement from Derbyshire County Council:
On the 31st of December 2020 the Authority was made aware of open cracking and subsidence on a 30m stretch of the C319 Oker Road running from Cross Green to the village of Oker. Following a visit by an engineer the recommendation was to close the road to protect the safety of general public, in particular motorists. This is a historic area of subsidence that the Authority designates as Will Shores Slip (S26067), with records of varying degrees of work being undertaken dating back to 1985.
The Authority commissioned a geotechnical site walkover and inspection of the site, this was undertaken on the 5th of January, the recommendations of this in the short term were to carry out minor works to prevent water ingress into the substructure of the carriageway, undertake an investigation of the existing drainage system and implement a safe access route for pedestrians, cyclists and equestrians. The Authority intends to carry out these works the week commencing the 18th of January.
The longer term recommendations were to undertake monitoring of the localised area to ascertain the direction and scale of any movement and to carry out a geomorphological investigation and desk study of the site with a view of undertaking a intrusive ground investigation. This will enable us to assess the nature of the ground and the extent and cause of the movement. Initial thoughts as to why the movement has occurred is that a rise in groundwater levels has triggered movement beneath the road most probably along shear surfaces. However the exact cause of the movement will be clarified following the completion of a ground investigation and issue of subsequent reports.
The Authority has applied for a temporary road closure until August 2022. Please be aware that this is not the date we anticipate the road to be closed until, this is the longest period we can legally close the road for and thus to save staff time and resources extending the closure in the near future it has been done for this length of time.
A suggestion of simply rebuilding the highway retaining wall is not practical at this stage. Whilst part of the long term engineering solution will be to do this, the concern is that the wall itself is sat on a shallow shear surface and that the ground beneath the wall will continue to move regardless of what is built on top of it. With the onset of climate change and increasing periods of wet weather this is a problem we have experienced elsewhere throughout the County.
Unfortunately we cannot commit to firm dates on when we anticipate the road to be reopened, as it is unreasonable to commit to this before we know the findings of the ground investigation. Please be assured that we will keep you informed as and when key information and dates are known. However please be assured that our intention is to procure a ground investigation at the site as soon as practicably possible.
For any queries please email [email protected], or call on 01629 538664.
Where is Oker Road closed?
