Application of Comprehensive Geophysical Prospecting Technology in Goaf Exploration of Coal Mine

Coal mine goaf survey is the basis of site construction suitability evaluation, geophysical prospecting is an important means of goaf investigation. Transient Electromagnetic Method (TEM) and Controllable Source Audio frequency Magnetotelluric method (CSAMT) are widely used in goaf investigation. This paper discusses the working principle, parameter selection and interpretation principle of TEM and CSAMT. Taking a coal mine goaf exploration in Zhangqiu District of Ji'nan City as an example, the comparison and analysis of the acquisition results of the two geophysical methods show that: ① the change trend of the apparent resistivity of the two methods is similar; ② The overall range of the apparent resistivity changes little; ③ The abnormal reflection of the goaf and fault is slightly different. The conclusion of the two methods is basically the same, and the results of geophysical exploration are basically consistent with the drilling results, which shows that the transient electromagnetic method and the controllable source audio frequency magnetotelluric method can effectively find out the distribution of the goaf, and obtain better geological survey results.