Failure mechanism and prevention technology of air return gateway incoal mining face of Hongshiyan Mine

According to serious failure problems of the air return gateway in a coal mining face of Hongshiyan Mine, a site investigation, lab experiment, theoretical analysis and other methods were applied to analyze the failure influence factor and failure mechanism. The paper provided a prevention and control technology mainly with the floor pressure released slot to release the pressure and analyzed the pressure released mechanism of the pressure released slot. The results showed that the main cause of the failure occurred in the gateway were the support pressure of the coal mining face nearby. The second cause was the geological structure, the failure mechanism was that the plastic yield of the seam floor could cause the shearing failures of the two sidewalls, the two sidewall failure would make the floor lost a bracket and the floor heave degree would be increased until the floor pressure balanced. The pressure released slot would cut the direct floor and would change the floor stressed structure and the transmission path and method of the support pressure on the floor of the coal mining face. Therefore,the stressed status of the surrounding rock was changed, the pressure released slot could absorb the floor deformation and would be favorable to the stability of the mine roadway. The control technology mainly with the pressure released slot to release the pressure could effectively control the deformation failure of the mine roadway and could meet the requirements of the safety production.