Study on detection of channel wave reflection method applied to geologic structure

The geological conditions are very complex in the north diggings of Jincheng. In order to eliminate the potential hazardous effect from geologic structure on mining safety and help to establish a forecasting mechanism for disasters resulting from geological structure , the wave velocities in No.3 coal seam as well as roof and floor rock are tested using rock acoustic test system. Based on detecting techniques of channel wave reflection method, we employed envelope computation and CMP stacking technology to optimize data treatment procedures. After having applied this methodology to investigate the geologic structure in No.3 coal seam, the idea and future development of refined channel wave detection method was proposed. This work found that the wave velocity of No.3 coal seam is relatively lower with physical property parameters from No.3 coal seam noticeably different from those from roof and floor rock, which provides favorable physical conditions for channel wave detection. The velocity of channel wave is 1 000～1 200 m/s in this area. Bands with frequency falling in 50～300 Hz are suitable for for smoothing the reflection data of channel wave and enhancing the signal-to-noise ratio. Although channel wave reflection method is a good option for the detection of geologic structure in No.3 coal seam in the north mining areas of Jincheng, the fact that the reflecting interface of seismic event may happen to be fault or collapse column boundary, makes necessary combining other methods for more comprehensive and accurate illustration