煤矿井下随掘地震震源特征及探测性能研究

煤矿智能化背景下，随掘地震已经成为掘进工作面安全掘进的地质保障关键技术之一，可实时、超前、精细探明掘进前方的隐蔽地质构造，如采空区、断层、陷落柱等，有效促进掘进生产安全高效。不同于广泛采用的反射槽波超前探测技术，随掘地震采用了掘进机掘进时震动信号作为激发源，替代了常规地震勘探中的炸药震源，具有震源绿色、安全、成本低、可重复、探掘同步等优点。由于掘进机震源在激发方式、能量、频率、带宽等方面与炸药震源差别较大，因此其探测性能受到很多关注。从随掘地震的震源机制、波场特征、传播距离、成像准确率等方面进行研究，详细分析其探测性能，认为随掘地震波场中槽波和横波发育，可利用槽波或横波进行超前探测；Y分量具有更好的信噪比优势，但在实际应用时考虑到反射面的走向，相同设备量情况下，Z分量更有优势；随掘地震的直达横波传播距离可达700 m以上，横波超前探测距离可达到300 m以上；随掘地震的直达槽波传播距离可达400 m 以上，槽波超前探测距离可达到170 m以上；常规掘进速度下，反射波叠加次数可达到16次，相比常规的一次探测，信噪比可提升4倍，有效提高了探测精度和准确度。后续将通过大量的随掘应用数据进一步修正随掘地震技术的性能参数。 

Characteristics and detection performance of the source of seismic while excavating in underground coal mines

Against a background of intelligent coal mines, seismic while excavating has become one of the key geological guarantee technologies for safe excavation in the mining face. It can detect hidden geological structures in real-time, in advance and finely, such as goafs, faults, and collapsed columns, effectively promoting safe and efficient excavation and production. Different from the widely used advanced detection technology of reflection in-seam wave, the vibration signal of the tunneling machine is used as the excitation source, which replaces the explosive source in conventional seismic exploration. It has the advantages of environmental frendliness, safety, low cost, recyclability and combined exploration and excavation. Great differences between the TBM(Tunnel Boring Machine) source and the explosive source in excitation mode, energy, frequency and bandwidth cause much attention to the former’s detection performance. By studying the focal mechanism, wave field characteristics, propagation distance and imaging accuracy of the seismic-while-excavating, its detection performance is analyzed in detail. It is considered that the in-seam wave and shear wave in the wave field of the seismic caused by excavation is sufficient, and can be used for advanced detection. The Y component has the advantage of better signal-to-noise ratio, but with the trend of reflection surface being considered in practical application; the Z component has more advantages with the same amount of equipment. The direct S-wave propagation distance of seismic-while-excavating can reach more than 700 meters, and the advance detection distance of S-wave 300 meters. The propagation distance of direct in-seam wave of seismic-while-excavating can exceed 400 meters, and the advance detection distance of in-seam wave 170 meters. At a normal excavating speed, the reflected waves can be superposed for 16 times. Compared with a conventional detection, the signal-to-noise ratio can be increased by 4 times, which effectively improves the detection accuracy. The performance parameters of the seismic-while-excavating technology will be further modified through a large number of application data.