基于微震时空信息的近直立煤层致冲因素研究

    Research on contributing factors of steeply inclined coal seam rock burst based on microseismic spatio-temporal information

    • 摘要: 为掌握近直立煤层冲击地压致灾因素,基于矿井开采布局及现场微震监测数据,从时间和空间多维度对矿井微震事件的分布及历次冲击地压事件进行了深入分析,研究了不同开采深度下的致灾因素的演变规律。结果表明:近直立煤层的冲击地压主要由悬空顶板和中间岩柱对工作面产生的应力集中以及煤岩体破裂产生的动载扰动诱发,日推进度、开采深度及遗留煤柱与冲击地压事件的发生也具有强相关关系,是矿井冲击主要致灾因素;矿井浅部开采时中间岩柱受水平构造应力和自重应力对煤岩体产生的“撬动”作用是导致煤岩体失稳破坏的主控因素,进入深部开采后叠加了悬空顶板的“挤压”作用,冲击致灾因素转变为顶板和岩柱的“压+撬”共同作用,而遗留煤柱等因素影响程度减弱。

       

      Abstract: In order to understand the factors leading to rock burst in steeply-inclined coal seams, based on the mining layout and on-site microseismic monitoring data, the distribution of mine microseismic events and previous rock burst events are deeply analyzed from time and space, and the evolution law of disaster factors under different mining depths is studied. The study shows that the rock burst in steeply-inclined coal seams is mainly caused by stress concentration on the working face due to the hanging roof and intermediate rock pillars, as well as the dynamic disturbance induced by the fracture of the coal and rock mass. The daily advance rate, mining depth, and remaining coal pillars are strongly correlated with the occurrence of rock burst events, and are the main factors leading to rock burst in the mine. During shallow mining, the “prying force” effect of the intermediate rock pillars caused by the horizontal tectonic stress and the self-weight stress on the coal-rock mass is the main factor causing instability and failure of the coal-rock mass. After entering deep mining, the “extrusion” effect of the hanging roof is superimposed on the “prying force” effect of the intermediate rock pillars, and the factors leading to rock burst change to the combined “extrusion + prying force” effect of the roof and pillars.

       

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