Failure mechanism of gob-side roadway in deep coal mining in the Xinjie mining area: Theoretical analysis and numerical simulation

Abstract

In deep coal mining, complex stress and mining conditions often cause large deformation and roof falling of roadway, which seriously threatens the production safety of coal mines. This study investigated the stress characteristics, failure mechanism, and control methods of gob-side roadway (GSR) at Hongqinghe Coal Mine in the Xinjie deep mining area, Inner Mongolia, China. The long and short arm F-shaped roof structure models during the different mining stages for the first working face were established. The stress calculation methods for GSR surrounding rock were proposed based on foundation static load (FSL), mining-induced additional static load (MIASL), and disturbance dynamic load (DDL). Moreover, the stability of GSR was analyzed. The failure mechanism of GSR was revealed. It was concluded that the GSR failure may occur due to the high stress and energy induced by the additive effects of the FSL, the MIASL, and the DDL. The coal pillar width of 5–10 m can provide a low stress environment for GSR, conducive to reducing the risk of GSR failure. The suitable control methods for GSR were proposed, which included selecting reasonable coal pillar widths, cutting off the dynamic load sources, reducing the static load stress concentration, and application of energy-absorbing bolts. The findings may provide valuable insights for controlling roadway surrounding rock in similar conditions.

Keywords

deep coal mining / gob-side roadway / roof structure / dynamic and static loads / numerical simulation

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