Study On Three-dimensional Radio Wave Perspective Response Characteristics Of Collapse Column In Coal Mining Face

The transparency of coal face is an important guarantee for safe and accurate mining of coal mine.Mine geophysical exploration is an important means of geological exploration of coal seam working face.With its advantages of portability and good effect,it has become a conventional and necessary means of coal seam geological structure exploration.At present,there is little research on the hidden collapse column in the working face,and the exploration still can not meet the needs of safety production.Through theoretical analysis,numerical simulation and field test,this paper systematically studies the radio wave response characteristics of horizontal and fluctuating coal seams with collapse columns in coal mining face.The main research results are as follows:Based on the experimental results,it is recognized that the dip angle of coal seam will have a great impact on the field value of radio wave.When the dip angle of coal seam increases,the field strength value of radio wave H_Xcomponent decreases gradually.The radio wave field strength is related to the position,size and physical parameters of the collapse column.Compared with the horizontal coal seam with collapse column,the field strength attenuation value of H_Xcomponent of radio wave at the collapse column in the inclined coal seam is reduced.According to the actual geological situation of a coal mine working face,this paper constructs a geological model with elliptical collapse column,and carries out numerical simulation experiments.In the experimental results,the radio wave field value first decreases and then increases,forming obvious concave or"V"shape characteristics,and further summarizes the characteristics of the radio wave field value curve of the coal seam collapse column.In order to verify the above theoretical understanding,the actual detection of radio wave fluoroscopy in coal mine working face is carried out at the frequency of 0.365MHz.Five groups of transmitted radio wave field data near the verified collapse column are selected for comparative analysis.The measured response characteristics of radio wave perspective of the collapse column are consistent with the numerical simulation results,forming an obvious concave or"V"shape.Through the combination of theoretical analysis,numerical simulation and field test,the distribution law of radio wave theoretical field value of coal seam collapse column is analyzed.The characteristics of radio wave field value curve transmitted by collapse column are summarized and verified,which provides theoretical cognition and data interpretation reference for radio wave perspective detection.Figure[35]table[7]reference[105]...