Analysis of Rock Burst Risk of Roadway in Lower Seam “Knife Handle” Type Isolated Working Face

Abstract

In order to determine the influence degree of the main factors in the rock burst risk of the lower seam of the “Knife handle” type isolated coal face rail roadway. In this text, the methods of theoretical analysis, numerical simulation and field measurement are mainly used to study the stress distribution laws during the working face is extending, front abutment pressure and plastic zone of isolated coal pillar, variation of surrounding rock pressure and roadway deformation laws of ore pillar under the isolated coal pillar before and during mining of working face. The results show that two stress concentration areas are formed at the edge of the isolated coal pillar when the working face is not retreating mining, and the stress concentration degree of the upper seam goafs near the 1304 working face is greater. As far as the change of vertical displacement during mining is concerned, the convergence of the rail haulage gateway that its side is much larger than the roof-to-floor, and the deformation near the coal pillar side is larger than that on the side of the isolated pillar, and the maximum displacement deformation is 11 m in front of the coal wall; the rock movement during the advancing of working face is very irregular, and the distance is within 20–40 m front and back the variable face, and the abutment pressure and displacement deformation of the rail haulage gateway change a lot. The value change is obvious and the pressure is intense. Therefore, the distance of advance support is at least 40 m. It is necessary to strengthen the support in the range of 20 m.