Particle velocity response of surrounding rock of a circular tunnel subjected to cylindrical P-waves

摘要

The influence of blast waves on tunnels is crucial in civil engineering. The analytical solutions for the particle velocity response of surrounding rock of a circular tunnel subjected to cylindrical P-waves were derived in this paper. The radial velocity scaling factor (RVSF) and hoop velocity scaling factor (HVSF) were evaluated and discussed. The influence of scaled distancer∗ between the wave source and the axis of tunnel and the wavelength-to-radius of tunnel ratioλ∗ were also discussed. The results showed that the global maximums of RVSF and HVSF are located at the near side to the wave source and its location is different with differentr∗, especially for HVSF; the global maximums of RVSF and HVSF decrease with an increasingr∗; the influence ofλ∗ on RVSF and HVSF is complex, but the obstructing effects of the tunnel on the propagation of waves decreases with an increasingλ∗; whenr∗ ≥ 15, a cylindrical P-wave can be approximately treated as a plane P-wave.