Abstract:

In consideration of multiple wave reflections, frequency domain analysis method was adopted to solve one-dimensional wave propagation in layered jointed rock. Firstly, the overall transfer matrix of one-dimensional wave propagation along multiple parallel joints was constructed by using wave theory and linear displacement discontinuity model. Solution for one-dimensional wave propagation in frequency domain can be obtained with boundary conditions. Subsequently, discrete Fourier transform and inverse discrete Fourier transform were used to transform the solution from frequency domain to time domain. Finally, SV wave propagation through joints of different spaces and numbers was studied by the above methods, and the simulation result was compared with that from discrete element program UDEC. The results showed that the transmission coefficient |T_N| (ratio of transmitted wave amplitude to incident wave amplitude) rose first, then declined, and finally became stable with the increasing of joint spacing. During the rising stage of T_N, it has less dependence on the number of joints. Through comparison with UDEC results, the method in this paper was found to be feasible.

Key words: multiple joints , stress wave , discrete Fourier transform , frequency domain , discontinuity model of linear displacement