국내 폐광산의 광산재해에 대한 물리탐사 적용사례 분석

Abstract

Currently, about 63 percent of two thousand mines have been left in Korea. Such abandoned mines have caused serious mine hazards such as ground subsidence due to old mine workings, and acid mine drainage problem originated from tailings and waste rocks. The government and local autonomous entities have endeavored to prevent and restore these mine hazards. This review briefly analyzes case histories of geophysical investigations for mine hazard problems in Korea during past decade and summarizes the applicability and limitation of geophysical techniques for mine hazard problem. Most geophysical approaches to mine hazard problem have put their focuses on verifying the spatial distribution of ground subsidence, the extent of tailings or waste rock, and the estimation of acid mine drainage distribution and flow path. In the case of ground subsidence, seismic survey has been successful, while both seismic and resistivity survey has been effective for the investigation of the spatial distribution of tailings or waste rock. Spontaneous potential (SP) as well as resistivity and seismic method has been reported to be also effective for the delineation of the extent and the flow-path of acid mine drainage. Geophysical methods can play key roles in the detection of abandoned underground mine workings, adjacent faults and fractures, and the distribution and the flow path of acid mine drainage and others. However, to achieve the purpose of investigations, of consequence is appropriate selection of methods, and integrated application based on careful consideration and understanding on the site condition and characteristics. Furthermore, multi-disciplinary co-works with geochemistry and rock engineering are essential for further quantitative analysis and reinforcement or reclamation design.