Abstract: Accurately and vividly analyzing the propagation law of microseismic wave in different media of coal and rock can provide strong theoretical basis for active seismic exploration in the coal mine and the inversion on the media structure in the different regions. In this paper, based on two-dimensional media models in the coal mine, including the general homogeneous medium model of coal/rock, the multi-media model combing the coal and rock, the fault-bearing medium model of coal and rock and water-bearing two phase medium model of coal and rock, the wave field simulations of different media above are carried out using the high-order finite-difference method and the wave field characteristics are analyzed. The results show that the high-order finite difference method is powerful in accurately obtaining the wave field characteristics of P- and S-wave in different media models. Different wave field characteristics appear in different media models. In the multi-layered media of coal and rock, the reflection, transmission and transition of P and S wave occur at the interfaces of different media, and the transmissive wave, the transmitted converted wave, the reflected wave and the reflected converted wave appear. In the fault-bearing media model of coal and rock, not only the transmissive wave, the transmitted converted wave, the reflected wave and the reflected converted wave can occur , but also the diffracted wave can appear at the fault. In the water-bearing two-phase medium model of coal and rock, not only the fast P-wave and shear-wave, but also the slow P-wave can occur. The snapshots of the wave field at different time can further vividly describe the dynamic characteristics of the wave field, and they can provide the theoretical foundation for analyzing the micro-seismic wave field in the coal mine.

Key words: coal and rock, wave equation, high order finite difference method, different medium, wave field simulation