Study on width optimization of gangue filling working face in Tangshan Mine

The problem of coal pressure in Tangshan Mine is prominent, and the gangue discharge has certain pollution to the environment.In order to liberate the “three lower” pressed coal resources, reduce surface subsidence and control gangue discharge, it is necessary to limit the settlement of the roof plate of the working face F5001, and the relationship between the width of the working face and the settlement of the roof plate is studied considering the important influence of the width of the working face on the settlement of the roof plate.The coal seam roof is simplified into a combined solid support beam, and the relationship between roof settlement and working face width is deduced and verified by the available monitored roof settlement data.It is found that the working face width is arranged around 124 m, the roof plate in the mining area reaches the ultimate tensile strength of 4.63 MPa.When the working face width is arranged less than or equal to 103 m, the settlement of the roof plate above the working face is at low level.When the working face width exceeds 103 m, the sinking of the roof plate is at high settlement level.Considering the slanting length of coal seam, the final working face width is 66 m.At this time, the monitored roof settlement is 0.538 m, which is in low settlement level and close to the calculation result of 0.519 m.The accuracy of the theoretical calculation is high, but more examples are needed to verify its applicability.The research results show that there is an exponential relationship between the working face width and the roof settlement, and the control requirement of roof settlement needs to be considered when determining the working face width.