关键词: 有限元法, 槽波, 断层, 时频谱

Abstract: Fault is one of the common abnormal structures in coal measure strata. The study of fault geometry is an effective method to improve the accuracy of fault detection. Based on the elastic wave theory, a 3D coal-bearing strata model is established, and the finite element numerical simulation method is used to analyze the influence of fault throw and dip on the channel wave. From the record of channel waves and the time-frequency spectrum, it can be seen that the blocking effect of fault on channel wave increases with the increase of fault distance and inclination. For channel waves after fault, when there is a fault less than coal thickness, with the increase of fault distance, the frequency of the peak energy is higher, and the occurrence time is advanced. When there is a fault larger than the coal thickness, the frequency of the peak energy is lower, and the occurrence time is delayed. With the increase of the fault inclination, the main frequency is lower, and the occurrence time is delayed. It is not easy to judge the fault location for faults less than 1/2 coal thickness. The results can provide theoretical support for the detection of fault geometry, and are of great significance for the precise detection and signal interpretation of channel wave.