Survey of Submerged Void Beneath Train Station Platform
Kidsgrove, Staffordshire

The Brief

Geoterra was appointed by Arcadis, Galliford Try and Network Rail to carry out a subsurface multibeam sonar scan survey of a submerged void discovered beneath Platform 4 at Kidsgrove Station in Staffordshire. A surface laser scan would also be carried out so that a 3D CAD plan drawing could be created so the sonar survey could be overlain allowing for accurate positioning.

The survey data was required to assess the exact size and location of the submerged void found beneath the platform area, as well as any potential further collapses undermining the surface features and causing the void to grow. The void is believed to be part of an upper coal seam running underneath the station locale.

The Solution

Access to the void was provided by a 110mm diameter borehole drilled by Arcadis. Geoterra’s experienced geospatial engineers, in collaboration with our partners Flodim, utilised a specialist multibeam sonar scanner and carried out a 3D sonar scan survey of the submerged void.  A surface laser scan was also carried out using the ZEB REVO mobile scanner, incorporating the site compound and all platforms.

The survey was fully geo-referenced to OSGB 36.  

The Deliverables

Geoterra provided Arcadis, Galliford Try and Network Rail a fully geo-referenced 3D sonar survey point cloud of the void beneath Platform 4 for viewing in Cloud Compare. 3D cross-sections and plans of the submerged void were also provided. An updated topographical plan showing the location and size as well as a 3D mesh was provided to Arcadis, Galliford Try and Network Rail to understand the condition of the void before any further work was undertaken. Finally, a full report detailing the sonar survey findings was compiled and provided to both Arcadis, Galliford Try and Network Rail so they could further understand the void feature at Platform 4.