A New Method for Evaluating Floor Spatial Failure Characteristics and Water Inrush Risk Based on Microseismic Monitoring

Microseismic monitoring technology has developed rapidly in recent years, and effectively evaluating the risk of water inrush from coal seam floor using microseismic monitoring is a research method with development potential, which is of great significance for ensuring the safe and efficient mining of coal resources. Based on the research background of the threat of Ordovician limestone water inrush during the mining process of the 9212 working face in Dongpang Coal Mine, this paper proposes a new method for evaluating floor spatial failure characteristics and water inrush risk based on microseismic monitoring. First, three research stages are established according to theoretical analysis and comprehensive geophysical exploration, and the response characteristics and temporal and spatial distribution of the microseismic events in the different stages are analysed. Second, the weighted coefficient of variation ( \({\mathrm{CV}}_{\mathrm{W}}\) ${\mathrm{CV}}_{\mathrm{W}}$ ) and three floor factors (S, \(e\) $e$ , and \(\uptheta\) $\mathrm{\theta }$ ) are introduced as new risk evaluation indices for the risk of floor water inrush in the vertical direction. The comprehensive weight is determined based on the analytic hierarchy process (AHP) and the entropy weight method, and then the water inrush evaluation model is established by the vulnerability index method. For the water inrush risk of the floor in the horizontal direction, the stratified cumulative kernel density estimation method is employed to determine the degree of water inrush risk and distribution location of different layers from the perspective of microseismic frequency and microseismic energy. Finally, the potential location of the water-conducting channel in the three-dimensional space of the floor is successfully predicted in the analysed working face, and targeted grouting reinforcement and other treatment measures are effectively implemented to ensure the safe mining of the working face.