By Lynda Myer
Considering that in April 2023 a 110m deep mine shaft had collapsed at the public park and play area, Van Elle‘s ground investigation business Strata Geotechnics carried out investigations at Solvay Banks Park in Wrexham, Wales, at the end of August,while it recently completed works at this site.
Although the collapse was reported to the Coal Authority by Wrexham Council at the time, emergency works were needed to stabilize the area until a further investigation could be completed.
Strata Geotechnics was brought in recently to carry out the ground investigation works on behalf of the Coal Authority. The public sector body previously said that investigation and surveying were a priority due the location of the shaft collapse.
In order to excavating boreholes at a length of 34m and incline of 30° from vertical, implementing a rotary open drilling technique, the Strata Geotechnics team used a Comacchio MC 12 rig, whereas the rig was chosen for the job as it can be operated in confined spaces.
Additionally, the digging process of boreholes up to a depth of 9m was done using cable percussion drilling methods by contractor, and a rotary core drilling approach to extract samples from 2m beneath the rock surface.
The ground investigation works will enable the Coal Authority to design an appropriate remediation strategy for the collapsed shaft.
Being almost on the same depth as the collapsed shaft, there are also two further shafts, which were already known to the Coal Authority, in the vicinity. The Coal Authority will consider whether the other shafts will also require remedial works.
