Application of Ground Penetrating Radar (GPR) technique to detect and analyse the geotechnical state of the water constructions and installations

Document Type : Original Article

Author

National Research Inst. of Astronomy & Geophysics, Helwan, Egypt.

Abstract

Abstract:
The ground penetrating radar is the top technology of the near surface investigation of the soil. Applying the radar frequency bands (high to low) help to inspect the soil and subsoil textures from the super shallow depths to the considerable depths mostly requested by the geotechnical and constructional assessments. Depending on the depth and the case subjected, it helps to detect and probably monitor the concrete voids and concrete steel deformation in, bridges top-plate and the barrier columns, tunnels, cavities, etc.
Water constructions and installations could be the most complicated tasks where the other geophysical techniques, probably but GPR, mightn’t be capable to be conducted. In here, we show the contribution of the GPR techniques to evaluate and post a solution on some geotechnical problems in the water installations. Siphons are water structures constructed when a draining line intersect with a channel or a canal, in this case the drainage would be piped and installed to pass underneath the channel. Although the structural designs of siphons could be counted, a big lack of information about these designs is missing. Normally, bridges and roads are constructed over these siphons to make the community cross over the channel sides, but in some cases, it is much more complicated, for example when a rail way passes over the siphon, or when the siphon should cross underneath wide water paths. Within this part of the 
application, the GPR was utilized to inspect and analyze the geotechnical situation and provide real contribution to solve the specific problems.
Subsidiary Channel’s installations; the subsidiary channels are smaller channels constructed on the sides of big channels or canals, they would be used to distribute water to the lands on the sides and most important to regulate the irrigation process. In some cases, the extensive motion and activity in the big canals cause erosion on the inner shores resulting the shrinking of the road widths on the two sides, other cases, when the heavy traffic duty, probably truckers and heavy machines, or just re-design requires the widening of the roads and in turn cover the subsidiary channels. The constructional elements are pipes, inspection rooms, and valve houses. The GPR was used in more than a phase of this process such as inspecting the pipe states, the twists, the inspection room deformations, and the covering soils before paving.