双频透射无线电波勘探方法及应用研究

Dual-frequency transmission radio wave-based exploration method and its application

  • 摘要: 煤层可作为高频电磁波的导波层,无线电波透视技术适用于工作面煤层内的地质构造探测。目前无线电波透视法通常采用单一频率进行探测,在煤层工作面勘探过程中常存在频率选择不当和探测精度不足等方面问题。为此,提出了双频透射无线电波勘探方法。基于理论分析,利用双频透视场强数据和衰减系数参数,推导了基于双频无线电波测量数据的煤岩介质吸收因子γ计算公式。采用有限元数值模拟方法,模拟并分析了无异常构造煤层和含断层煤层工作面两种工况,实验结果表明:双频吸收因子对煤层地质异常的响应更加敏感,验证了双频透射无线电波勘探方法的有效性。通过比对现场实验数据及回采钻探结果,再次验证了双频吸收因子γ对地质异常的响应特征优于单频衰减系数。上述实验结果证明,双频法可提高煤层工作面无线电波探测地质异常的效果,为无线电波精细化勘探和矿井地质透明化提供一个新的方法和思路。

     

    Abstract: Coal seams can act as the guided wave layers of high-frequency electromagnetic waves, and radio wave perspective technology can be used to detect geological structures within coal seams of a working face. Presently, radio wave perspective methods usually use a single frequency, leading to some problems such as improper frequency selection and limited detection accuracy in the exploration of mining faces. In response, this study developed a dual-frequency transmission radio wave-based exploration method. Based on theoretical analysis, as well as the field strength of dual-frequency perspective and attenuation coefficient, this study derived the calculation formula for the absorption factor γ of coals based on the measurement data of dual-frequency radio waves. Furthermore, using the finite element numerical simulation method, this study simulated and analyzed the conditions of coal seams bearing no anomalous geological structures and those containing faults. The experimental results show that the dual-frequency absorption factor was more sensitive to the geological anomalies of coal seams, verifying the effectiveness of the dual-frequency transmission radio wave-based exploration method. The comparison between the field experimental data and the mining drilling results also verified that the dual-frequency absorption factor γ exhibited better responses to geological anomalies than the single-frequency attenuation coefficient. The above experimental results show that the dual-frequency transmission radio wave-based method can improve the detection effects of geological anomalies within coal seam mining faces, providing a new method and idea for radio wave-based finescale exploration and the ascertainment of mine geology.

     

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