Determination of Rock Mass Structure near Tunnel by Phase Velocities of Seismic Surface Waves

The field research of the geomechanical behavior of rock mass was carried out in the neighborhood of an abandoned railway tunnel by means of multi-channel analysis of seismic surface waves. For the interpretation of the results, the spectral dispersion images of waves along the tunnel were selected and analyzed. That made it possible to obtain the velocity patterns of waves in enclosing rock mass, and to identify the low-velocity zones in it. The results prove the applicability of the method of determining structure and condition of adjacent rock mass surrounding underground structures.