Application of Comprehensive Geophysical Prospecting Method in Fine Detection of Goaf

The mining process involves many complex problems, which are easy to cause environmental pollution and safety. The comprehensive geophysical exploration method combined with drilling method is used to carry out fine exploration of goaf. Firstly, the high density resistivity method was carried out, the data was collected by Wenner device, and the sudden change characteristics of apparent resistivity presented in the profile map of the goaf were summarized. The first-order derivative method was proposed to process the data, which was easier to distinguish the goaf boundary and scope. Transient electromagnetic method and microtremor detection were used to deduce the goaf by high-density electrical method for measurement. The transmitting current of 15A was used in TEM, the fretting detection was a linear acquisition method, and the dispersion curve was extracted by ESPAC method. Through the comprehensive detection of multiple methods, the apparent resistivity mutation area and wave velocity change area are the mined-out range. The acceptance of goaf has been carried out by several borehole verification, and good practical results have been obtained. The research results show that the high density resistivity method, transient electromagnetic method, microtremor detection and other comprehensive geophysical exploration methods can be used to identify the goaf abnormal area, which can be efficient, economical and accurate detection of goaf.