| The technology of gob side entry retaining,known as the technology of no pillar mining,has the direct value effect of saving coal resources,prolonging the service life of mine and improving the investment benefit of wells.Based on previous studies,this paper systematically studied the working face of 8101 in a coal mine by means of theoretical analysis,numerical simulation and field monitoring.The main achievements of this paper are as follows:(1)The general rule of overlying rock movement and the condition of gob side entry retaining are analyzed.The bearing principle of the gob side entry retaining and the retaining wall under the one or two impact dynamic pressure is expounded.(2)The mechanical model of "stacked laminates" in the surrounding rock of the goaf is established,and the theoretical formula of support resistance,the strength of support and the width of the retaining wall are determined.In order to increase the surrounding rock’s binding force and improve the strength and elongation of the anchor,the supporting form and specific parameters of the roadway are designed,and a new combined mechanism of the anchor bolt is put forward.At the same time a new technology for building walls in bags.(3)FLAC3D simulation software is used to simulate the vertical stress and roof subsidence of the side supporting body under different widths,and the optimum width of the support body is determined.At the same time,the plastic distribution,vertical stress,horizontal stress and roof displacement of surrounding rock under specific width are simulated,and the stability of surrounding rock is better.(4)The industrial test of new technology of bagged softball was carried out on the working face.The load of single pillar,the amount of roof separation layer,the stress of bolt,the amount of deformation on two sides and the change of the amount of roof and floor movement are monitored and analyzed. |
