Research On Anchorage And Coupling Support Technology Of Coal Roadway In 3110 Working Face Of Laomupo Mine

In recent years,with the gradual exploitation of domestic shallow coal resources,the overall mining depth of coal mines is increasing.At the same time,due to the unfavorable conditions such as the increase of ground stress and the poor surrounding rock conditions,the roadway support problem has become a prominent and complicated problem,especially in deep soft rock or broken rock stratum,often with poor roadway support effect and deformation.Large amount and so on.Most of these problems occur because of the insufficient effect of roadway protection.The simple anchor and cable joint support commonly used before is often not enough to provide good protection ability.As a result,many roadway support failures and the overall stability of the support members are reduced due to insufficient effect of the watch.Many seniors and scholars have studied the above situation,and believe that the strength and coupling between the anchor and the anchor net are not achieved,and the strength of the bolt support is often insufficient,but the strength of the watch metal mesh is insufficient,so that the coal mine In the roadway support,it takes a lot of manpower and material resources,but it can’t significantly improve the support effect of the roadway.On the basis of theoretical discussion and numerical simulation,the paper studies the strength coupling conditions of anchor bolt and anchor net by industrial test and other methods,and achieves the following results:（1）After comparing the four rock classification methods or indicators,it is determined that the surrounding rock classification of the 3#coal seam roadway in Laomupo Mine is carried out by the Q system classification method.It is concluded that the surrounding rock of the 3#coal seam roadway of Laomupo Mine belongs to relatively broken soft rock,and the Q system is mostly grade IV,which requires higher support strength.（2）Classification of commonly used mesh sheets for engineering guards or slope protection.By comparison,it is concluded that the performance of the Gebin net,which is widely used in bridges,dams and other geotechnical engineering,is better than that of the rhombic metal mesh commonly used in coal mines.The cost is lower than that of the steel warp and weft,but the support strength is higher than that of the rhombic metal mesh.For the underground roadway support,not only can provide good support effect,but also can produce good economic benefits.（3）The anchor network coupling support mechanism is summarized.It is concluded that the strength of the protection of the net needs to be greater than the load applied by the broken surrounding rock in the anchorage area of the anchor,that is,the weight of the broken surrounding rock,so that the bolt and the anchor net can reach the strength coupling state,and the mechanical analysis of the force of the metal mesh is carried out.To verify the rationality of the above anchorage strength coupling conditions.（4）FLAC^3D numerical simulation was carried out on the working face of 3110coal seam 3110 in Laomupo Mine.The vertical stress distribution of the roadway surrounding rock in the unsupported state,the anchor rod+the diamond metal mesh,the anchor rod+the gemnet support state,and the displacement of the roadway are compared.The bolt parameters are:the specificationΦ20×2200mm left-handed Longitudinal threaded anchor,material HRB335,spacing between 900×1000mm.Diamond-shaped metal mesh parameters:wire diameterΦ4mm,mesh size 1000×1200,mesh size is 60×80mm.Gebin net specifications:Φ6mm gaben net,size 1000×1200,mesh size is 60×60mm.The results show that the two metal meshes can play the role of dispersing the surrounding rock stress.However,when the gabnet mesh support is used,the deformation of the roadway is obviously reduced,which indicates that the protective effect of the gabnet is stronger than that of the diamond mesh.（5）Conduct industrial tests on the 3110 coal seam 3110 working face of Laomupo.Through checking and verifying,it is proved that the original anchor rod and anchor cable of the coal mine have reached the strength requirement,and the spacing between the rows is reasonable.Therefore,the metal mesh of the watch metal was re-selected and designed.Finally,the Gebin network was selected for support,and the deformation of the roadway was observed after the start of mining.According to the analysis and analysis of the observation data,it can be seen that after the support of the Gebin network,the roadway support effect is significantly improved,and the maintenance cost is saved.