It is often unclear how a slab is supported. Depending on the ground conditions and slab requirements the slabs can be supported with piles, ground beams or straight onto the ground itself.
Radar is able to not only determine which of the above construction methods has been used but also map the beam or pile cap locations and provide information on their reinforcement details. GPR can also map the extents of pad foundations and provide details of grillages.
By scanning the slab radar picks up data about the subsurface. This data is then processed by our experienced surveyors looking for tell tail signs of the foundation details. These details are presented to the client as a written report along with a CAD drawing showing the locations and extents of detected foundations.
It should be noted that the detection of foundations cannot be guaranteed due to the numerous possible construction methods. GPR will be able to detect mass concrete foundations but it is unlikely to detect them if they are not in direct contact with the structural slab. Should reinforcement, either bars or I-sections, be present within the foundations GPR has a much higher chance of detecting them. With regards to piles, it is highly unlikely that GPR will be able to detect the piles themselves and the piles are more likely to be located by an increase of reinforcement associated with them.
GPR will only be able to provide information on the extents of the foundations in plan, the depth to the top of the foundations and the top layer of reinforcement, if present. GPR is very unlikely to be able to determine the thickness of the foundations or any bottom reinforcement details.