New evaluation and prediction method to determine the risk of water inrush from mining coal seam floor

The aim of this study is to remedy the existing problems in the prediction methods of water inrush from the mining coal seam floor. This paper analyzes a large number of water inrush cases and proposes that there are four main factors, namely water pressure and water abundance of the confined karst aquifer in the mine floor, the lithological thickness and characteristics of different structures of aquiclude in the mine floor, the geotectonic characteristics of the aquifer and aquiclude, and mining ground pressure, which affect water inrush from the mining coal seam floor. Based on structural and damage mechanics, a mechanical model of homogeneously fractured weak rock stratum is established for the water-impermeable layer of the floor, 354 points of water inrush are used to investigate and analyze, critical curve equation of P vs. M of mine floor is determined and the primary factor that affects water inrush from the mine floor is obtained. Combined with the geological structure characteristics, the three-grade evaluation and prediction model is established for water inrush from mining coal seam floor. The results can be used toward a new evaluation and prediction method of water inrush from the mine floor.