Deformation analysis and control of expanding brush of haulage roadway ofNo.3 mining district in Hexi coal mine

Based on the control problems of surrounding rock of large-section roadway after the expansion, the expansion and construction of the haulage roadway in the third mining district of the No.4 coal seam of Hexi coal mine is taken as the research background.The difficulty in controlling the surrounding rock of the large-section roadway after the expansion is theoretically analyzed.The distribution and evolution characteristics of vertical stress and plastic zone of surrounding rock before and after the expansion of haulage roadway are simulated by FLAC^3D software.The results show that the distribution range of the vertical stress concentration zone and the plastic zone of the roadway after the expansion are obviously increased.There is a continuous and evenly distributed plastic ring of the thickness of 3.5 m in the surrounding rock of shallow roadway.Accordingly, the joint support technology of anchor cable+grouting+U-shaped steel shed is proposed.After the support of bolt, a prestressed arch-shaped bearing structure with a thickness of 1.6 m is formed in the surrounding rock of the shallow roadway.The tests show that the maximum displacement of the top and bottom of the roadway is 218 mm, while two gangs is 165 mm, and the deformation of the roadway after the expansion is effectively controlled.