Roadway rock pressure appearance law of roof-cutting and pressure-relieving retaining roadway in medium thick seam

Through long-term monitoring of the displacement of the roof and the pressure changes of various supporting methods along the retaining section of No. 9 coal seam in the Dianping coal mine, the mechanical characteristics of the displacement of the roof and various supporting methods were analyzed. It has been found that the top layer of the roadway section has a longer aging effect and a lower value than the roof subsidence. The maximum pressure and average pressure of the side support side of the roadway are slightly lower than the pressure of the left side of the upper roadway. The initial pressure and cycle of the roadway side are slightly higher than the roadway side of the upper roadway. The constant resistance large deformation anchorage is more adaptable to the fluctuation of the roof pressure in a wide range than the door bracket.