Ground Penetrating Radar
GPR is becoming increasingly popular in the construction industry. For many major companies, a full utility survey and GPR is the minimum requirement before permits to dig can be obtained. With the ever-growing utility sector increasing their networks with fibre cables and plastic pipes this is where the GPR comes into play as your standard CAT and Genny aren't able to locate many of these services.
How it works
GPR uses an antenna to send electromagnetic waves into the ground which then causes a reflection shown on the screen. The image shown is examined by the surveyor to determine possible services, voids and disturbances in the ground a reading can then be taken to give an accurate depth. Using stats, markers and knowledge from years of experience the surveyor can then determine what these signatures may be.
Types Of GPR Survey
A GPR survey can be done by either on-site analysis and mark up, or by post-processing.
Post-processing is when an area is marked up and gridded out using a road wheel. Dependent on the required specification of works the spacing between each section varies. Once a grid has been marked out, the surveyor will then proceed to do lateral and longitudinal scans. Once completed, the stats will be sent to the office for processing where a map of the scans can be seen in further detail allowing greater accuracy and perception of possible service in the area.