Abstract: Due to the longterm influence of surrounding rock,water and pressure,the concrete bearing structure of coal feeder chamber of No.214 coal bunker in Xiashijie coal mine is seriously deformed and damaged,which can not meet the normal production demand of the mine.Combined with theoretical analysis and numerical simulation,the reasons for the instability and failure of the coal feeder chamber of 214 coal bunker and the influence of high stress in coal pillar and water on the stability of the feed chamber are analyzed.The results show that under the action of high stress,the concrete bearing structure and surrounding rock of the chamber are in a large range of shear yield state,and the bearing structure surface is damaged by the strong extrusion of surrounding rock; the expansion and weakening of the carbonaceous mudstone and root soil rock of the chamber floor when encountering water will lead to the strong swelling of the surrounding rock of the floor,and the bearing beam of the concrete floor will be squeezed by the surrounding rock of the floor.It is almost in the state of tensile failure,and the column is also in the state of tensile failure due to compression,which leads to the overall instability of the concrete bearing structure.

Key words: coal feeder chamber,bearing structure,instability failure,numerical simulation