Numerical simulation and engineering verification of mining-induced fault water inrush disaster

In order to study the stress transfer law of fault zone and the dynamic evolution characteristics of pore water pressure under the influence of mining, this paper takes a mine in Shandong as the research background, comprehensively uses the method of combining theoretical analysis, numerical simulation and engineering verification, and combines the classical Biot seepage mechanics coupling equation. The dynamic evolution law and prevention and control technology of mining fault slip are studied in depth, and a numerical model conforming to the geological conditions of the mining area is constructed. FLAC 3D is used to simulate the stress changes in the process of roadway passing through faults and mining and mining, and to verify the difference of stress transfer between the upper and lower plates of faults under mining. The results show that : (1) When the hanging wall is mined, the roof forms an articulated structure, part of the load is transmitted through the fault, and the transmission amount is related to the coefficient ; the footwall mining cannot form a stable structure, the load is difficult to transfer, and the stress concentration of the coal pillar is more significant. When the coal pillar of the same width is reduced, the footwall load increases more, which easily leads to the destruction of the coal pillar. (2) With the advance of the working face, the stress value near the fault increases sharply, the plastic zone presents the stage expansion characteristics, the pore water pressure rises continuously along the fault, and the water channel is easy to form at the fault. After the mining of working face A, the mining of working face B is affected by the early stage, the damage range is wider, the pore water pressure is prone to sudden increase, and even the phenomenon of water gushing is caused. The research results of this paper reveal the dynamic evolution law of water inrush from mining faults, and provide theoretical support for the prevention and control of water inrush from faults.