Investigation of the Dynamic Evolution Mechanism of Bed Separation in Karst Aquifers and Risk Assessment of Water Inrush

ABSTRACT Coalfields in northern Guizhou have complex hydrogeology and are impacted by frequent roof karst water disruptions resulting from roof separation fractures. This study aims to characterize the dynamic evolution of roof bed separation beneath karst aquifers, focusing on the Longfeng Coal Mine as a case study. Numerical simulation using Universal distinct element code and a novel combined weighting method integrating Fuzzy Analytic Hierarchy Process, Entropy Weight Method, and Criteria Importance Through Intercriteria Correlation were applied to compare the importance of six key indicators, including aquifer thickness and mining height. The risk of water inrush from bed separation was visualized in a geographic information system. Mining‐induced bed separation fissures showed a staged development, with maximum lateral and vertical extension of the separation zone reaching 25.6 and 1.1 m, respectively, and with water accumulation in these zones increasing water inrush risk. Spatial analysis identified the highest risk of water inrush in the central‐eastern region, which, along with areas of lower risk, represents around 42.8% of the study area. The model results were validated using borehole experiments. The study results emphasize the need for mining safety precautions in the identified high‐risk zones and can guide the practical management of water‐related hazards in karst mining environments.