| According to the numerious studies on the geological structure, depth of the mining face, properties of the coal seam and coal mining technology, the incentive of coal bump in island mining face is analysed. The strength theory, energy theory and liability theory is applied to research the mechanism of coal bump which is triggered on the island mining face. Meanwhile, the different depth of mining face, groundstress and anistropic of the coal and rock are considered in the FLAC3D numerical modeling to study the factor of coal bump. The distribution of stress field and energy field is also analysed in the numerical study according the geology of T2193A mining face of Tangshan coal mine. The dynamic mechanical process of coal pillar located on the beside of island mining face is anther objective of this study. For the purpose of dynamical forecasting the coal bump of coal pillar, the abutment pressure, plastic state and energy field during the mining process is investigated. In satisfying this objective of estimate of the burst risk in island longwall mining face, T2193A mining face of Tangshan coal mine is chosen to conduct a field experiment. In this experiment, roof displacement and electromagnetic radiations in roadway are investigated to determinate the region where the deformation of the roadway roof is most intense. Numerical model is established to further verify the results of field experiment and to divide burst-prone region of island mining face and coal pillar. According to these researches, the technology of stress pre-releasing by borehole is investigated by numerical method. The effect of different length and interval of boreholes to released stress is estimated. Modeling results suggest that the abutment pressure could be released by all kinds of boreholes with different length and interval parameter. The research of this study has important academic and engineering significances to keep miner safety and efficient production of coal mines. |
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