Using GPR, Electromagnetics (EM), Micro-gravity and Electrical Imaging / Resistivity, GEOTEC Surveys map the sub-surface environment, for a range of features.
Geophysical Approaches & Applications
Typical features which can be located are:
- mine shafts, coal shafts and buried wells
- old foundations/ building lines, footings and pile caps
- basements & cellars
- tunnels, cavities and underground voids,
- dissolution features
- buried tanks
Tools & Techniques
GEOTEC Surveys Ltd evaluates the objective of each survey in line with the site characteristics in order to assign the best tools for meeting the needs of the client. We also look to use a number of methodologies in conjunction with one another in order to provide the best possible result, where possible.
Ground Penetrating Radar (GPR):
Ground Penetrating Radar (GPR) is a versatile tool which can be used to meet a range of objectives which are summarised below:
We can use a range of systems and antennae to survey to a variety of depths (0.5m to 10m) within a myriad of different environments and also have the capacity to use a Vehicle-Mounted GPR System.
EM31 / CMD Explorer:
We combine GPR Surveys with the EM31 / CMD Explorer in many cases to assist us in locating features such as mineshafts, air raid shelters, tunnels, dissolution and buried structures, as shown by the examples below:
Example of a Mineshaft Survey
Example of a Roman Road
Example of a Buried Structure and Void following a sinkhole discovery
This tool has a depth penetration of 6m below the ground surface and is particularly good at achieving data collection across larger areas over a shorter time frame than other methods, however is susceptible to the presence of surrounding metallic interference.
An EM61 offers a non-invasive alternative for UXO (Unexploded Ordnance) or UXB (Unexploded Bomb) Surveys. This is essentially a survey to detect and map significant buried metallic objects which may be synonymous with UXO. We offer this as an initial feasibility survey to assist clients before deciding whether they need support from a specialist provider.
Example of unexplained anomalies detected on a railway embankment
Micro-gravity is a much more time consuming method, however, as this is not affected by surrounding metallic interference, it overcomes a number of the limitations encountered by EM approaches and has a theoretical unlimited depth penetration.
Example of a Micro-gravity survey
Although these approaches do not offer a depth reading for detected features, they provide an excellent tool for identifying their existence and position on a horizontal plane.
If you would like to discuss any of the above approaches, please call Julian, Tom or Luke on 01428 686168 to identify whether any of these or a combination, would meet your requirements.