Study of the Influence of Damage Structures in Coal Seam Floors on the Damage of Small Hidden Faults

In order to study the catastrophe law of small hidden faults along the floors of deep quarries under the coupled conditions of high stress and strong seepage, this paper proposes a concept of damage structure that can replace the overall performance of a population of tiny fracture swarms within a non-homogeneous rock mass. Numerical simulation software is used to simulate and analyze the influence of damage structure on the evolution of surrounding rock, regarding its plastic zones, shear stress, and displacement, and the pore water pressure distribution in small hidden faults along coal seam floors. This study shows that under the influence of damage structure, the shear stress of the rock above the fault shows “N”-type change, the displacement of the surrounding area shows “S”-type change, and the shear stress of the rock below the fault and the pore water pressure above the fault show “M”-type change. The damage structure changes the performance of the coal seam floor’s water barrier by reducing the strength of the rock surrounding the fault, blocking the release rate of the shear stress of the surrounding rock, weakening the support pressure of the fault, reducing the degree of expansion of the surrounding rocks and shifting the direction of concentration of the pore water pressure. The results of this study can provide a reference for technology for water damage prevention and control of coal seam floors containing small hidden faults, under the influence of non-homogeneous rock bodies.