Coal Mine Shaft Investigation & Treatment, Wigan
As part of a planning application we developed a Coal Mining Risk Assessment, which highlighted the presence of a suspected abandoned mine shaft on neighbouring land, but close to the development (residential) site boundary.
There were no records for the shaft, other than the fact that proven workings were at at a depth of 162m beneath the site.
Unfortunately, the area that needed to be investigated for the suspected mine shaft was covered by a building. As a result, a separate planning application was required to demolish the building in order to facilitate the shaft site investigation.
Trenching on a 20m square grid basis, showed that the mine shaft was indeed located beneath the demolished building structure.
As a result, a mine shaft cap was designed, with a programme of grouting implemented. The shaft proved to be 62m deep and a 5m exclusion zone around it applied.