Geoscience experts have used their specialist rope access skills and inflatable boats to extract concrete samples from inside Sheffield’s Megatron culvert.
The culvert is a concrete tunnel beneath Sheffield that carries the River Sheaf. The work is part of a project that has seen a section of the river uncovered for the first time in 100 years. It is located in the centre of Sheffield, where the River Sheaf meets the River Don, and is part of a larger £15 million endeavour to create a new public park.
The 70-metre-long culvert was built over a section of the River Sheaf in 1917, as part of work to create the Castle Market, at a time when the river was badly polluted with sewage and slaughterhouse run-off, according to Sheffield City Council.
RSK Geosciences’ project manager, Stephen Owen said:
“Two buildings, Alexandra House and Exchange Place Studios, stand close to the edge of the culvert. Before the culvert can be removed, it is necessary to understand what is behind the concrete and how this could affect the structural integrity of these nearby buildings.”
Stephen explained that they carried out ground-penetrating radar surveys above ground, in addition to collecting concrete cores from inside the culvert. Five horizontal concrete cores were taken. Endoscope surveys of the core holes were carried out, along with covermeter surveys – a method of using electromagnetic measurements to measure the position, depth and size of the reinforcements within the concrete – of the walls, arches and roof of the culvert.
