| Coal mines goaf are being in mining areas in China, which the boundary of coal mine goaf is not clear. Meanwhile, when water yield property is stronger, the safety production of coal mine goaf must be checked. At present, the methods of geophysical exploration in coal mines goaf are divided into two categories, the surface ground and mine. But the surface detection is limited by the detection range, the actual excavation production is difficult to guide. Underground digging in advanced detection technology is one of the effective methods,which is to probe ahead if there is a coal mine goaf roadway, and is also the most widely used method. But because short of the detection methods and data processing, the data of inversion interpretation is limited.This report mainly focuses on the background the researcher mentioned before. This study from the point of artificial field and the basic theory of advanced detection, establishes the geoelectric model that using the finite element numerical simulation software COMSOL,which is combining the experience of field during the internship. This model comes to the conclusion that observation voltage becomes to the direct ratio with excitation current, and the exceptional response of low resistance of roadway must be treated to a clear identification.This study discusses the changed excitation current and low resistance body potential distribution regularity of the spatial location model, and then disposing the data which is calculated by theory. Finally, the detection results are formed. This study put forward the idea which is to improve the "normalization" correction, comparing two kinds of methods. This can conclusion that exceptional response becomes to the inverse ratio with the head-on distance of low resistance roadway. When the roadway position more than 30 m from head-on, the "false anomaly" is hard to avoid. After improvement of correction in "normalization", the anomaly characteristics can make easier to distinguish on before.Introducing a few experiments by Xiang Ning coal mine, this study discusses the comparative advantages and disadvantages of two methods, and the problems should be paidattention in practice, finally a conclusion can be formed.The actual detection environment tend to be very complex, this paper that puts forward the correction method is based on ideal conditions. Therefore, this technology effect still need study and summary in the practical application, even so, the summary of previous instance found that this method is still have obvious effect. |
