Hazards of Environmental Disruption in Mine Goafs and Stability Evaluation in Gaofeng Mining Area

Abstract

China is rich in mineral resources with many points and broad faces in metal and nonmetal mines. However, numerous goafs are formed due to backward mining technology, low intensification degree, incomplete safety precautions, and the excessive exploitation of mineral resources, thus leading to severe environmental disruption. Accidents, like goaf collapse, are major geological disasters in mine production, and goaf stability evaluation is of great importance for reducing natural disasters in goafs and implementing environmental protection. The hazard types of environmental disruption caused by mine goafs were first analyzed in this study. Then, an influence factor index system of goaf stability was established, and a case study of a mine goaf in Henan Province was conducted using an analytic hierarchy process (AHP)-based fuzzy comprehensive evaluation model. Results show that the hazards of environmental disruption in mine goafs are manifested in the structural failure of surrounding buildings, massive water and soil loss, the exhaustion of water resources, the degradation of soil quality, and the remarkable reduction of overlying animals and plants. Technical factors exert the maximum influence on underground goaf stability with the total weight value reaching 72.42%, and the influence weight of goaf span on goaf stability reaches 21.43%, followed by goaf area and pillar distribution with influence weights of 18.58% and 11.17%, respectively. Through fuzzy AHP-based comprehensive evaluation and calculation, the goaf stability of the Henan Sandaozhuang open-pit mine in the case study belongs to grade (ordinary), that is, the goaf stability is in the ordinary state, and the evaluation result reflects the reality. The study results have improved the reasonable stability and safety management scheme for complex multi-layer goaf and solved complex goaf hazards faced by Gaofeng mining area, so they will be of general significance for the environmental governance of other underground mine goafs.

Keywords

• mine goafs, environmental damage, stability evaluation, gaofeng mining area,