TechnicalNote Geophysics for Detection of Mine Workings
Given limited historical/remediation information and the influence posed by presentday site conditions (e.g. fill material, buildings, services, roads etc), shallow mineworkings have historically proven to be difficult targets for geophysics. TerraDat addresses this by adopting an integrated survey approach comprising a number of different geophysical techniques that target both direct (e.g. shaft lining/cap, void space) and indirect physical properties (e.g. localised variations in drainage patterns or backfill material) of buried targets.
Localised variations associated with ground settlement or in-fill material (metallic debris)
Rapid Coverage Reinforced Cap / support structure
Integrated Survey Approach Vertical and areal characterisation
Density contrast associated with void space or backfill material
Shaft-related geophysical targets
*Cost Effective *Non-invasive *Rapid Ground Coverage *Environmentally Friendly *Swift Mobilisation/Global Coverage
Typically, TerraDat utilises a combination of Electromagnetic, Magnetic and Microgravity techniques. These can be complimented with Ground Penetrating Radar and Resistivity techniques should further information be required.
Mining legacy
Mining activity has left a legacy of workings such as bell pits, shafts and adits that have a significant influence on both modern developments and existing infrastructure. A lot of mining activity is well documented, but in some cases, the reliability and accuracy of this information can be uncertain. A TerraDat geophysical survey coupled with selective intrusive investigations can provide a rapid and cost-effective means for locating shallow abandoned mine-workings.
Circular anomaly associated with capping structure 10m
Ground conductivity survey targeting shaft cap
Ground truthing of circular geophysical anomaly
Clay rich back-filled bell pit
Resistivity section over a former bell pit Contact Simon Hughes for more info; simon@terradat.co.uk
TerraDat (UK) Ltd - Tel (08707 303050) www.terradat.co.uk