Application of Integrated Geophysical Prospecting Method in Steep Seam Goaf: A Case Study of The Closed Coal Mine in Xishan Area, Urumqi

A large number of goafs left behind by the closed coal mines at the edge of cities seriously threaten the safety of production and life. Finding out the distribution of goafs is the premise and basis for governance. This paper takes the goaf of steep coal seam in Xishan area of Urumqi as the research target, comprehensively analyzes the geological characteristics and interference background of the goaf and surrounding rock, the anti-interference, applicability and limitations of common geophysical methods, and selects four methods for integrated geophysical exploration: multi-electrode resistivity method, microtremor survey(MS), opposing coils transient electromagnetic(OCTE) and gravity exploration. Two goaf zones were found in the area, extending 50-450 m to the depth, both in a water filled state and proved reliable by drilling. The corresponding relationship between the parameter combinations of "low resistance low speed", "high resistance low speed", "low weight low speed" and different occurrence conditions of goaf is summarized. It shows that the method and technology combination proposed in this paper can play a role in similar goaf detection.