High-speed train motion-induced Rayleigh waves applied to the detection of subsurface cavities

This paper aims at using the Rayleigh waves which travel in the front of high speed trains (HST) to detect underground cavities within a silty ground. First, computer results show that subsurface cavities provide a filtering effect on the spectra of Rayleigh waves within a wavelength range in relation with the depth of the cavity. Then, seismic data have been collected at the front of the HST on a specific test-site. They show a 3 to 6 dB magnitude variation on the power spectra in the vicinity of the cavity axis for the wavelengths ranging from 8 to 20 meters. A similar result has been observed from the background noise but affecting larger wavelengths.