Fluid-Solid coupling analysis of the safety of the waterproof coal pillar

The paper analyzes the stability and anti-water-inrush ability of the waterproof security coal pillar of a certain mine respectively considering fluid-solid coupling and without coupling through FLAC^3D. The comparison between both computation results shows that plastic zones in both cases take on a "saddle" shape which is high at both ends and low in the middle, but the plastic zone is larger in the coupling analysis. The stress state and deformation and failure law of the bottom floor can be simulated in the coupling analysis. It is necessary to consider fluid-solid coupling in the example and the computed minimum length of waterproof coal pillar shall not be shorter than 28 meters. The results indicate that fluid-solid coupling analysis of the waterproof coal pillar is more truthful and effective.