Simulation And Application Of Multi-channel And Multi Frequency Electro Perspective Detection Of Floor In Deep Mining Coal Face

With the continuous increase of coal mining depth in China,the problem of floor water damage in coal mining face is becoming more and more serious.It is urgent to improve the detection accuracy and efficiency of floor water damage in coal mining face.Therefore,it is of great significance to further carry out the research on multi-channel and multi-frequency electro perspective detection method of frequency domain induced electric field.Based on the existing research results,this paper simulates the frequency domain audio electro perspective detection technology of coal mining face,including:(1)the whole space uniform geoelectric model a without IP effect,the whole space uniform geoelectric model B under IP effect and the whole space low resistance sphere geoelectric model C under IP effect are constructed by COMSOL software,The electrical response characteristics and error of the above three geoelectric models under electric field are analyzed in turn.The comprehensive comparison shows that the software has high accuracy and reliability,and can be applied to the numerical simulation of electric field in frequency domain.(2)Based on the geoelectric model C,the electric field response characteristics of low resistivity spheres under different conditions are analyzed by calculating and drawing the apparent complex conductivity and video divergence curves of local electric models.The results show that the change trend of the apparent complex conductivity and video divergence response curves of each model is roughly the same;When the power supply point is located on the left side of the spherical center on the XY plane,the apparent complex conductivity/dispersion curve shows "high on the left and low on the right",that is,the maximum value is greater than the background value and the minimum value is less than the background value;When the power supply point is located on the right side of the ball center on the XY plane,the apparent complex conductivity/dispersion curve is "low on the left and high on the right",and the apparent complex conductivity/dispersion curves of the power supply points on both sides of the ball center intersect near the ball Center;When the power supply point is facing the spherical center on the XY plane,the apparent complex conductivity/dispersion curve is symmetrical about the spherical center position,and there is an extreme value at the spherical center position;The apparent complex conductivity curve and video divergence curve are normalized respectively.The results show that the change rate of video divergence parameter is significantly greater than that of apparent complex conductivity,indicating that the video divergence parameter has a more sensitive response to the changes of low resistance sphere size and spatial position in frequency domain electric field.(3)It is concluded that the shape of apparent complex conductivity/dispersion response curve is easy to change with the change of model size and spatial position.Moreover,the video divergence parameter has a more sensitive electrical response to the change of the size and spatial position of the low resistance sphere in the frequency domain electric field than the apparent complex conductivity parameter,which provides a good theoretical basis for using the video divergence parameter as a parameter to judge the hydrogeological situation of the detection area in engineering practice.(4)Based on the existing data processing software,aiming at the shortcomings of cumbersome steps and complex operation in the matching design between the collected field data and the observation system established by the software,the observation system is redesigned to be convenient and fast and meet the field detection requirements of the actual working face.(5)Through the field engineering practice,combined with the two parameters of complex conductivity and dispersion rate,through the high conductivity and high frequency dispersion characteristics often shown in the water rich area,the multiplicity of solutions in the abnormal area can be reduced to a certain extent.Figure[58]Table[8]Reference[73]...