Application of the multi-channel transient rayleigh wave method to highway goaf detection
多道瞬态瑞雷波技术在公路采空塌陷区探测中应用

The rock mass in mined-out area is characterized by abnormal structures such as primary strata structural discontinuity, loosening, fissures, caves and so on, compared with the un-mined area. On the basis of the geophysical field condition in the goaf area analyzed, the effectiveness and key measurements of the multi-channel transient Rayleigh wave method to detect mined-out area are discussed in this paper, taking the subsided highway as an example. The abandoned mines under the highway and anomalies in the mined area can significantly affect propagating and scattering of Rayleigh wave, producing an abnormal wave field and frequency- wavenumber spectral, a decrease in the major amplitude and the phase velocity of Rayleigh waves in a broad frequency range, and strong multiple modes of Rayleigh waves and so on. In conclusion, the continuous acquisition of multichannel Rayleigh wave data along linear transects has great promise in detecting location of underground goafs, collapse zones and loosening abnormalities associated with highway subsidence.