With resurfacing works, inherited brownfield sites and poor or no utility infrastructure records, losing a manhole cover has sadly become a relatively common problem.
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SUMO uses one of two methods of Ground Penetrating Radar (GPR).
1. High Density Ground Penetrating Radar (GPR), which records readings every 8cm. In the example below the survey revealed one anomaly which did not correlate with the visible manholes on the ground, and this was plotted on the drawing which was subsequently issued to the client.
Above : Timeslice plot (plan view) of High density GPR showing the location of a buried manhole.
2. SUMO also used Dual Frequency (DF) GPR systems, consisting of 300Mz and 800MHz antennae. The added benefit is that this can be interpreted on site, to show the location of a buried manhole instantly, meaning that there are no site delays whilst waiting for the data to be processed and interpreted.
Above left : GP survey in progress using a dual frequency (DF) GPR system.
Above right : Photograph taken on a site by one of our clients after a buried manhole was exposed through excavation a day after our survey on site.
“Thanks to the team at SUMO who played a key part in identifying buried infrastructure at our site. Your GPR survey has been invaluable in helping unlock and drive forward the project to completion.”
Edward Pearson, Design Manager, Balfour Beatty
Geophysical Engineering Surveys
Air Raid Shelters
Cellars & Basements
Post Tension Cables
Underground Storage Tanks
Air Voids
Chimney Flues
Rebar
Water Engineering
Badger Setts
Earthing Installations
Sinkholes
Burials
Geological Application
Soil Thermal Resistivity Testing
Buried Foundations
Landfills
Structural Investigations
Buried Manholes
Mineshafts
