The Coal Authority has said that work to stabilise ground on the “biggest subsidence damage claim in its history” at the West Allotment housing estate near Newcastle is nearing completion.
The organisation previously published an alert about the project but declined to name the site, however, full details have now been presented in the Coal Authority’s new annual report.
The cost of the claim has not been revealed but new Coal Authority CEO Lisa Pinney said that the organisation has proved itself to be resilient in rising to the challenge of managing the scale of the work.
GE understands that Soil Engineering Geoservices has been undertaking grouting work to stabilise the site and that the area will soon be ready for redevelopment.
In total 18 houses out of 35 affected by the subsidence, which started in July 2016, were demolished to allow the stabilisation to be undertaken. According to the Coal Authority, the unrecorded mine, which was believed to be around 120 years old, had higher than normal extraction rates at 70% compared to 45% to 50% found at other mines nearby. This high extraction rate of the mine, which was at more than 30m below ground surface, along with fracturing in the sandstone above resulted in collapse and ground movement at surface.
The case study in the annual report states: “This incident is the largest single event
we have ever dealt with in our 24 year history.”
The Coal Authority has confirmed that monitoring is still underway as the site is prepared for redevelopment.
Coal Authority head of public safety and subsidence Tim Marples said: “Our experts are experienced at dealing with the complex impacts historic coal mining has on the public, properties and land. As part of the coal mining legacy we deal with a wide variety of incidents, including mining shaft collapses, shallow
coal working collapses, subsidence damage claims whilst also managing a programme of mine entry inspections.”