Study of the behaviour of the clay around a heat source by frequency analysis of the seismic wave
Wave propagated into soft rock is not completely described by linear elastic theory. It can be seen that soils filter different frequencies in different ways. ME2i uses this factor to control injections into soils, posts and so on. The Mol experiment aims to prove that small changes in heated clay can be detected by frequential seismic analysis. A cross-hole investigation system has been installed and tests have been performed for two years with a shear-hammer named MARGOT built to work inside horizontal boreholes. Before heating the tests show the same results every time: (i) main frequency at 330 Hertz; (ii) maximal frequency at 520 Hertz; During heating: (i) the rays at 330 and 520 Hertz disappear; (ii) the frequencies in the range 100 - 300 Hertz predominate; After heating spectra regain their original shape. These results show that the effect is clear around a heated zone.
Bibliographic Reference: EUR 14338 FR (1993) 92 pp., FS, ECU 10.50
ISBN: ISBN 92-826-5147-9
Record Number: 199310403 / Last updated on: 1994-11-29
Original language: fr
Available languages: fr