Air Voids

From settlement to sinkholes, voids can cause a major problem on any site. Not only could theyaffect your design, budget and programme, but they could result in major injury.  

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Whether siting a crane, erecting scaffolding, or simply working on a site, if voids are present, it’s essential that you know about them before starting work or bringing any heavy equipment onto site.

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Air voids can be associated with a whole array of features; from natural causes, such as sink holes and sea water ingress, to leaking pipes, below ground structural voids such as burials and basements, and voids in walls caused by chimneys flues and structural delamination.

 

The Answer – A GPR Survey (but it all depends on the size and scale of the voids)

 

Ground Penetrating Radar (GPR) is an ideal technique to locate voids. The large electrical contrast between solid materials and air generates a high amplitude response, which should stand out clearly against the background reflections. Voids create a characteristic strong response with an area of ringing to help us identify voids before the manifest themselves at the surface.