Recorded or suspected mine workings identified in the desk study are targeted by insitu investigations. Several phases of investigation may be necessary to check the location and near surface condition of the mine working and also to check its condition at greater depth. Investigation techniques that are used include :-
- Non-invasive geophysical investigation techniques (ground penetrating radar, electrical conductivity, magnetometry, microgravity etc) to search for concealed, shallow mine workings
- Underground Inspection. In some circumstances where it is safe to do so we are able to undertake underground inspections.
- Exploratory trenching using a mechanical digger. This method is good (where space permits) for investigating near surface mine workings (backfilled surface excavations, mine shafts, buried structures etc) down to rockhead level .
- Probe drilling. Inclined and vertical drilling is often used to check for mine workings at greater depth.
The results of the Insitu Mining Investigation are compiled into a comprehensive report with plans, sections and photographs of the mine workings encountered and advice on any remedial engineering safety works.