3D Modeling of Water Inrush in Coal Mines: Understanding the Causes to Enhance Safety in Mining Operations

Water-sand mixture inrush disaster in coal underground mining activities refers to the disruption of the original equilibrium state in the source area. This leads to the sudden inflow of water-sand (or water-solid) mixture under its own gravity or pressure into the underground, seeking a new equilibrium. This process often results in significant economic losses and casualties. The present work refers to a disaster happened in China in 2018; during a tunnel excavation of a coal mine, an instantaneous water solid mixture inrush of around 15,000 m3/h flooded the work site. By collecting all the available information about the geology and hydrogeology of the area, a 3D geological model was created, from the surface to beyond the depth of the mine. Afterwards, the inrush was numerically simulated and the results were compared with the hydraulic head variations in the area, measured by the nearest piezometer. The results can be used to better understand the water inrush phenomenon, in order to enhance safety of mining operations in similar geological conditions.