Method and test of mine seismic multi-wave and multi-component

Multi-wave and multi-component seismic exploration has developed rapidly in recent years, while its re- search and application in mine seismic is still insufficient. The wave field in mine full space is complex as the compo- nents of effective wave and interference wave in the excited body wave,coal seam channel wave,tunnel sound wave and surface wave change with the selection of imaging wave type. At the same time,seismic wave aliasing from multiple directions in space inevitably leads to the false appearance of undirected imaging,which affects the accuracy of mine seismic exploration. In order to make full use of different types of waves for imaging,a multi-wave and multi-component seismic method based on the polarization characteristics of seismic waves is proposed in this paper. This method ob- tains accurate polarization characteristic parameters through time-window adaptive polarization analysis methodavoiding the problem of incorrect polarization parameter caused by inaccurate selection of time window. The polarization filtering function constructed on the basis of the scattering principle includes a polarization factor and a direction factor,which can be updated in real time with the change of spatial position of the imaging point and wave type. The polarization factor can suppress the nonlinear interference wave by using the polarization coefficient of the signal so as to extract the linear polarization wave such as P-S wave and Love channel wave,and improve the signal-to-noise ratio of the mine seismic signal. According to the spatial relationship between the spatial position of the imaging point and the vibration direction of the particular wave type,the direction factor can not only separate the waves with different vibration direc- tions (such as P-wave and S-wave),but also obtain the seismic wave signals at any point in the space. Thereby,multi- wave migration imaging for any position in space is realized. The result of field tests shows that the detection accuracy can be improved by carrying out P-wave and S-wave imaging respectively in rock tunnel and the two are mutually veri- fied. Meanwhile,the spatial position of the exploration area is not constrained by the seismic line,which can realize the seismic exploration outside the range of the survey line and solve the problem of limited construction space of mine seismic exploration. By carrying out channel-wave and body-wave imaging respectively in coal roadway,the problem of limited detection distance of channel-wave reflection is solved. Therefore,three-component reception is recommended in channel-wave exploration. Ideally,six-component record of channel-wave and body-wave can be formed by adopting the three-component of the coal seam and the three-component of the roof at the same time,which can the basic data for joint exploration of channel-wave and body-wave.