1. China Coal Research Institute,Beijing　 100013,China; 2. Xi’an Research Institute,CCTEG,Xi’an　 710077,China

采空区严重威胁煤矿安全和矿工生命,矿井瞬变电磁超前探测是一种对其有效的探测方法,但效果受巷道环境影响较大。提出一种巷道孔口旋转发射、孔内三分量接收的工作方法。通过时域有限差分三维数值模拟分析了孔中数据特征,提出了孔中沿发射法线方向数据的三分量合成和校正技术,采用二分搜索算法实现了孔中数据峰值点后方衰减段的全期视电阻率计算。计算了三维数值模型数据的各个孔深单独及叠合成像结果,对掘进工作面前方的采空区取得了良好的成像效果。结合山西煤矿井下的工程试验,对该方法超前探测采空区性质、形态和规模的实用性和有效性进行了检验。研究表明:孔巷瞬变电磁动源定接收探测方法是井下物探与钻探的有机结合与相互补充,能够有效应用于采空区探测。

Transient electromagnetic advanced detection method is an effective way to explore goaf which regards as a vital threat to coal mine safety and miner’s life. But its application effect is influenced by the roadway environments. This paper presented an operating method which adopts a rotated transmitting terminal located in roadway orifices and three-component receiving terminal located in down-hole. By analyzing the feature of down-hole data using 3D FDTD, this paper presented a technology to synthesize and adjust the three-component down-hole data along with the normal direction. The decline phase’s completely period apparent resistivity,after the peak point of down-hole data,was cal- culated using binary search algorithm. Different hole depth data,in 3D numerical model,was processed to isolated and superimposed imaging. The imaging results showed that it has acquired favorable effect in exploring goaf in front of the driving face. In order to test the practicability and availability of this operating method in detecting goaf’s shape,char- acteristics and dimensions,the author’s research group has conducted an engineering test in Shanxi’s coal mine. The research showed that dynamic source and fixed reception roadway-borehole TEM detection method is a great combina- tion of underground geophysical exploration technology and drilling technology,and makes them supplement to each other. It is an effective application in goaf detection.

FAN Tao. Experimental study on the exploration of coal mine goaf by dynamic source and fixed reception Roadway-Borehole TEM detection method[J]. Journal of China Coal Society,2017,42(12):3229-3238.