Study On The Application Of TEM In The Survy Of The Water Of The Coal Mining Goaf

China is a big country of consumers of coal, and coal producing. Along with the mining to the deep, the left goaf is also increasing. The problem of water of the goaf has always been the concern of the people who are in charge of the safety management. In order to avoid the mining accidents, we must find a way to detect such water of goaf. Through the survey of the goaf, we can determine whether there is water and where the boundaries are. In order to eliminate hidden dangers, the CASST of Sichuan Province carried out the experiment of investigation in a coal mine in the East Sichuan area. The experiment includes: 1, using the time-domain electromagnetic method, also including two situation: on the ground(using fixed-loop device) and in the wells(using dipole device), detecting the goaf, and discussing the water-bearing property; 2,collecting and reorganizing the material about the coal geology, hydro geological and so on; 3, the application of 3-D laser scanning technology in digital mine modeling, and depending the model scanning the data of TEM as well as the comprehensive geological data. Finally, composing a three-dimensional mine model.As one of the main content, TEM has important significance to this work. The study was based on mine water prevention and control of the pilot work, focus on the surface of the TEM, namely the fixed-loop device. In this paper, the research content includes: 1 d forward, which uses fixed loop device, launch in different area, different tem field uniform half space resistivity values, different layer or three layer model under the conditions of response characteristics. At the same time, the use of smoke ring inversion method for one dimensional inversion and forward the results of the analysis of various models of the relationship of the resistivity and apparent depth, studies the characteristics of smoke ring inversion results. Concluded that, like the "peak" and the underground resistivity abnormal formation has the law of the corresponding relationship each other, and verify the semi-quantitative explanation characteristics of smoke ring inversion. Also, found the problems existing in the resistivity curve and the field where can be improved.According to the conclusion on the smoke ring inversion, this paper also set out to improve the interpretation precision of the inversion results of treatment. In the field of TEM, in addition to using resistivity to show the characterization of underground geological information, we can also use other physical parameters. We adopt relative dielectric constant which can characterize the physical parameters of the dielectric properties of dielectric materials, to convert the resistivity. This paper use the huge difference between water that low resistance and the surrounding rock that high resistance in the relative dielectric constant to get the corresponding relationship between the relative dielectric constant and the resistivity of the different underground geologic body and to further highlight the anomaly of water, lower abnormal high resistance of surrounding rock. In this paper, based on the theory of linear regression equation method, we derive the experience formula of the conversion of the relative dielectric constant and resistivity which suit for the theoretical model. By comparing the original inversion results, verify the feasibility and correctness of inversion data which is processed by the empirical formula. What’s more, the conversion of relative dielectric constant and resistivity, can also maintain the actual raw data on the physical characteristics of underground geological bodies. In practice, using the empirical formula to process and validate the results of TEM of mined-out area researching, and we proved the correctness of delimiting the boundaries of goaf water by using the results of TEM in the pilot work. Finally, by integrating the results of TEM with the model of 3D laser scanning, we build the three-dimensional model goaf water area of coal mine, and depending on the various geological data, we present preliminary treatment solutions.