G-tec is involved at different stages of the realisation of major road or train tunnels.
Before tunnelling, surface and borehole geophysical surveys are used in conjunction with borehole information to construct a geological model along the tunnel route (rock type, contacts, faults, karstic problems, etc.).
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While tunnelling, geophysical measurements are realized from the tunnel face in horizontal boreholes to investigate the rock mass ahead of the face: presence of fractures, cavities, loose material, etc. The early detection of such features greatly enhances the safety of the works.
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After the tunnelling operations, radar carried out on the tunnel walls are used to detect voids behind the lining.
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Geophysics: GPR - Borehole radar - Crosshole Seismic tomography - Electromagnetics
Other: Geotechnics - Geology
