Excavation-and-support induced disturbances are likely to make water-enriched roofs to become weathered and fractured.The development and connection of cracks provide new water channels which may result in water loss,...Excavation-and-support induced disturbances are likely to make water-enriched roofs to become weathered and fractured.The development and connection of cracks provide new water channels which may result in water loss,seriously affecting the in-tegrity and stability of roofs,leading to incidents of roof fall.Control of water-enriched rocks surrounding coal drifts is quite diffi-cult in China.Based on the practical situation of a water-enriched roof of a coal drift in working face 112201 of the Meihuajing coal mine,we studied the deformation features of surrounding rocks and the development of fractured areas and analyzed the major reasons for the decrease in load-carrying capacity,indicating that the key to maintain roof stability of this kind of coal drift is water retention.In addition,we proposed a staged control technology consisting of:1) surface grouting;2) cable anchor strengthening and 3) roof grouting,which has proven to be successful in this practical application.Our study indicates that,after the problem of water loss from the water-enriched roof had been effectively solved,a combined support system with high performance bolts can maintain the stability of the bearing structure,resulting in the control of roof stability in this kind of coal drift.展开更多
基金Projects 50674085 supported by the Qing Lan Project of Jiangsu Provicne50774077 by the National Natural Science Foundation of China
文摘Excavation-and-support induced disturbances are likely to make water-enriched roofs to become weathered and fractured.The development and connection of cracks provide new water channels which may result in water loss,seriously affecting the in-tegrity and stability of roofs,leading to incidents of roof fall.Control of water-enriched rocks surrounding coal drifts is quite diffi-cult in China.Based on the practical situation of a water-enriched roof of a coal drift in working face 112201 of the Meihuajing coal mine,we studied the deformation features of surrounding rocks and the development of fractured areas and analyzed the major reasons for the decrease in load-carrying capacity,indicating that the key to maintain roof stability of this kind of coal drift is water retention.In addition,we proposed a staged control technology consisting of:1) surface grouting;2) cable anchor strengthening and 3) roof grouting,which has proven to be successful in this practical application.Our study indicates that,after the problem of water loss from the water-enriched roof had been effectively solved,a combined support system with high performance bolts can maintain the stability of the bearing structure,resulting in the control of roof stability in this kind of coal drift.
