Abstract:For open-pit to underground mining projects, the protective pillar is a key connecting part of the shallow to deep underground mining. The thickness of the protective pillar not only affects the safety of underground mining, but also affects the economic benefits of the mine. The rationality of its size is extremely important for the stability of the project and the safety of deep mining. An iron mine is a large deep open pit mine, and after the completion of surface mine mining, it will be transferred to underground mining. In this paper, FLAC3D software is used to establish a three-dimensional numerical model in combination with the engineering geological conditions of the iron mine, mining process plan, etc., to simulate and analyze the stability of roof pillars with different thicknesses. The results indicate that the setting of isolation pillars can effectively control the deformation of surrounding rock and the destruction of the goaf, ensure the safe mining of the ore body under the goaf, and determine the optimal thickness of artificial isolation pillars. It has certain reference and reference significance for recycling and safety production of similar mines.
