A novel coupled progressive corrosion–water hammer inrush model for deep coal seam floors

The mining industry is frequently subjected to various disasters, one of the major concerns is water-related disasters, particularly seam floor water inrush. These disasters pose significant threats to the safety and production of deep coal mines. The primary reason for this is that the fracturing of the rock mass induces the formation of a fluid (water) with both kinetic and potential energy. In this paper, a novel water inrush mechanism for deep floor failure due to water hammer effects is proposed based on the Xingdong coal mine in China. The water hammer pressure within rock pore channels has a different impact on the surrounding rock, leading to the degradation of the rock mass channel through repeated conduction and instantaneous cutoff. To further investigate this phenomenon, a progressive corrosion fracture mechanics (PCFM) model induced by a water hammer is established. The results show that the water hammer pressure caused by instantaneous channel truncation increases with increasing water flow velocity. The chemical damage factor (i.e., stress corrosion fracture) is also incorporated into the Dugdale–Barenblatt (D-B) model to analyze the factors influencing the PCFM. These findings indicate that the greater the degree of damage is, the more likely the concealed fault is to experience water inrush. Finally, methods for controlling water inrush caused by the water hammer effects of deep floors are proposed. The failure mechanisms of the water hammer and the PCFM provide theoretical and practical guidance for controlling water inrush from the deep floor.