Analysis and control of water inrush under high-pressure and complex karstic water-filling conditions

Karstic water damage is one of the main disasters that threatens safe production in coal mines. As coal mining in China moves toward deeper strata, deep karst water disasters caused by mining are increasingly common. This paper studies the Jiyang coal mine in Shandong Province, China; conducts an in-depth analysis of the water charging conditions of the Ordovician limestone karst aquifer; determines four evaluation indices of the Ordovician limestone water inrush risk (water yield, water pressure, geological structure complexity and effective aquifuge thickness); and establishes a multifactor model to evaluate the water inrush risk of the Ordovician limestone using multisource information fusion, the water resistance coefficient and the equivalent coefficient. In addition, the floor water inrush risk of the Ordovician limestone during caving mining, strip mining and backfilling mining of the No. 13 coal seam is evaluated in the study area, which is then divided into different zones: a safe zone, a relatively safe zone and a danger zone. According to the evaluation results, the full backfilling mining method with the minimum risk range of water inrush is selected for future mining. Using this method, most of the research area is classified as a safe zone or relatively safe zone, and only a very small area in the south is classified as a danger zone. The threat of Ordovician limestone inrush caused by coal mining is low. The evaluation results of the water inrush risk and optimization of the mining method provide a reference for the prevention and control of mine water damage and can provide guidance for safe coal mining.