Transient Electromagnetic Three-component Responses On Typical Mine Hazard Water

Water bursting in mine is the second largest coal mine disaster except coal and gas outburst. Collapse column, goaf water and fault is the waterhead of water bursting in mine. Therefore, to identify these mines hidden location and extent of water is the key to avoiding water bursting accident.Currently, coal mine disaster geophysical methods to detect water is mine DC resistivity method and mine transient electromagnetic method. But mine transient electromagnetic method is convenient, high efficiency and low resistivity body, reflecting the sensitivity and other characteristics, so it is widely used in coal mine disasters and water exploration. But it only measure the secondary transmitted magnetic field components. We can not define the distribution and occurrence of hazard water body because the lack of information on the horizontal component. So it has theoretical significance to measure the horizontal component of the secondary transmitted magnetic field and study the three-component response of the secondary transmitted magnetic. It also has great guidance for data processing and interpretation of the actual detection.Based on the basic theory of mine transient electromagnetic method, physical modeling similarity criterion, we use the physical simulation method to find the three components of the electromagnetic transients of the typical waterhead of water bursting in mine including collapse column, goaf water and fault. Though simulating the goaf water, data analysis, interpretation and coal mine test, we can get the conclusions.(1) When collapse column, goaf water and fault is symmetry on the measure line(X-axis), transient electromagnetic signal of Z component is strongest. The X component is an order of magnitude smaller than Z component. We can determine the low resistivity body boundary through the X component. Because of the Y component on the receiving coil due to abnormal body symmetry, the measure of sensor signals cancel each other out, so the received signals are interfering in the air.(2) When collapse column, goaf water and fault is not symmetry on the measure line(X-axis), transient electromagnetic signal of Z component is strongest. The X and Y component is an order of magnitude smaller than Z component. We can determine the low resistivity body boundary through the X and Y component.(3) The results of Goaf water numerical simulation of three-component response is consistent with the physical simulation. When detection coil is close to the goaf water, Z components is significant increasing.We can roughly determine the boundaries of the goaf water.In the boundary of goaf water, X component induction signal reaches the maximum. When in the middle position of goaf water, X component becomes the minimum. Because of the Y component on the receiving coil due to goaf water, the measure of sensor signals cancel each other out.(4) The detective result of goaf water test is consistent with the simulation result. Then we can illustrate the inversion of the three-direction component of the comprehensive explanation to better reflect the development of coal mine water hazard typically by three-component information interpretation and greatly improve the accuracy of interpretation of mine transient electromagnetic method.