Comprehensive exploration, safety evaluation and grouting of karst collapse columns in the Yangjian coalmine of the Shanxi province, China

摘要

Karst Collapse Columns (KCC) are special geologic structures in the Carboniferous-Permian coalfields of the northern China. It is easy to generate severe water inrush accidents during mining activities, which can cause many casualties and property losses. To evaluate the impact of the KCC on the coalmine during the excavation and exploration of the Panel 90102 at the Yangjian Coalmine, the Shanxi Province, five KCC were detected by combining geophysical exploration and drilling information and by considering the Ordovician limestone aquifer analyses of water pressure, aquifer thickness, water-content conditions, electric conductivity, and the physical properties of the rocks. The hydrogeological characteristics of the five collapse columns (CC) are determined, which helped evaluate the impact of each collapse column's water pressure on the Panel 90102. For the sake of solving the threat of water inrush from the five CC, two of them were grouted and consolidated to prevent the Ordovician aquifer water from flowing into the Panel 90102. The results have greatly improved the safety of the roadway advancing and mining activities in the Panel 90102.