论文部分内容阅读
传统矿井电磁波透视层析成像技术只考虑电磁波的传播距离而忽视传播的方向性,造成探测复杂构造时的层析成像分辨率较低。依据电磁波在煤岩介质中的传播规律推导出了与入射角有关的新振幅衰减常数。引用新振幅衰减常数并基于代数重建算法建立了层析成像数学模型,编制了程序软件。利用新振幅衰减常数层析成像算法分别对平行和交叉断层进行数值模拟。通过与传统衰减常数层析成像的效果进行对比,结果表明:改进后的新振幅衰减常数层析成像效果更好,对断层的位置、走向、延展长度等情况反映清晰准确;在介质背景衰减场不易确定的情况下,绝对衰减层析成像方式优于相对衰减层析成像方式;平行关系的断层构造分辨率要高于交叉关系的断层构造。通过在某采煤工作面的电磁波层析成像中成功圈定了一组隐伏的平行断层构造实例,说明采用新衰减常数的层析成像技术效果提高明显。
Traditional mine electromagnetic wave tomography only considers the propagation distance of electromagnetic wave while neglecting the directionality of propagation, resulting in a lower tomographic resolution when detecting complex structures. According to the propagation law of electromagnetic wave in coal rock medium, the new amplitude decay constant related to the incident angle is deduced. A new amplitude decay constant is referenced and a mathematical model of tomography is established based on algebraic reconstruction algorithm. The new amplitude attenuation constant tomography algorithm is used to simulate the parallel and cross-section faults respectively. Compared with the traditional attenuation constant tomography, the results show that the improved tomographic imaging of the new amplitude decay constant is more effective and the position, direction and extension length of the fault are clearly and accurately reflected. In the medium background attenuation field Difficult to determine the case, the absolute attenuation tomography imaging method is superior to the relative attenuation tomography; parallel relationship of the fault structure resolution is higher than the cross-fault structure. A set of concealed examples of parallel faults was successfully delineated in the electromagnetic tomography of a coal mining face, which shows that the effect of tomography using the new decay constant is obviously improved.