Ground stability evaluation of a coal-mining area: a case study of Yingshouyingzi mining area, China

Ground subsidence is a very common phenomenon in mining areas, especially for those with a long mining period. After nearly half a century of mining activity, the concomitant disasters of Yingshouyingzi mining area gradually accumulated and have frequently occurred in recent years. In this work, the ground disaster situation and ground subsidence range appearing in the survey area were determined using field investigation and D-InSAR monitoring technology. Geophysical exploration technology (seismic prospecting and transient electromagnetic methods) and geological drilling exploration was adopted to ascertain the distribution of the underground goaf. The results show that the No. 4 and No. 6 coal seam goafs and second mining affected area were developed in the study area. Additionally, ten influencing factors were selected to evaluate the ground stability. According to the grading of each evaluation factor, the survey area was divided into four regions: unstable region, basic unstable region, basic stable region and stable region, based on a fuzzy comprehensive assessment method, which respectively occupy 15.57%, 60.28%, 15.17% and 8.98% of the total survey area. Through a comprehensive field investigation, the size and number of ground fissures and the housing damage rate decrease from the unstable region, basic unstable region, basic stable region to stable region, which indicates to us that the division result is consistent with the actual ground disaster situation. This, in turn, verified the rationality and validity of this evaluation method. Therefore, this study will provide help in forecasting and controlling the ground surface subsidence disasters caused by underground mining in the Yingshouyingzi mining area or other analogous areas.