Physical Simulation And Application Of TEM Dipole Device On Concealed Water Source In Coal Mine

Mine flood is one of the most important threats to safety production of coal mine,most of mine flood can be avoided by early prediction.Mine transient electromagnetic method is a commonly used geophysical method of advanced detection in underground mines.Most of the studies of this method are focused on coincident loop device,but the studies are few about dipole device.However,due to the separation of the transmitting coil and the receiving coil,dipole device is less affected by the primary field,and has a great advantage over coincident loop device.Systemically researching on this method will enrich the technical means of the prediction of mine concealed water source,so as to improve the technical level of mine flood prevention and control andthe technical level of mine flood prevention will improve.In order to research the law of transient response of dipole device,this paper established the geological model of the mine concealed water source geological models to carry out the physical simulation experiment,according to the characteristics of the typical mine concealed water sources and the similarity of physical simulation,carrying out contrastive experiment by coincident loop device.The experimental contents include the positioning of recording point,the dipole moment,the resolution and the depth of detection.Then the characteristics of the dipole device are summarized,and the mine experiment is carried out to verify it.The experimental results show that:The experiment about the point positioning shows that the position of the abnormal body can be accurately located by using the middle point of the transmitting coil and the receiving coil as the recording point,but can not located by using the middle point of the transmitting coil or the receiving coil as the recording point.;The experiment about the dipole moment shows that when dipole moment is 40 cm,the amplitude of potential profile is than 30 cm dipole moment and 50 cm dipole moment.,so the optimum dipole moment is 40cm;The experiment about the resolution shows that when the shapes and configurations of abnormal bodies change,dipole device has a higher resolution than coincident loop device;The experiment adout detection depth shows that coincident loop device detects deeper than dipole device,and the inductive signal is stronger than loop device under the same conditions.The actual application of the mine shows that dipole device has a higher resolution than coincident loop device,the result of the detection is basically the same as the result of the physical simulation experiment,which proves the feasibility of the method.