| During the mining of steeply dipping seams,roadway rib spalling,roof fall,big deformation and other issues during mining,seriously restricted the safe and effective product of mine.Therefore it has important theoretical significance to solve the deformation characters and support technology of steeply dipping seam abnormity reoadway.The thesis comprehensively uses three kinds of research methods:physical experiment,numerical simulation and theoretical analysis to study the law of deformation and failure of roadway in detail in order to solve the 25221 roadway rib spalling,roof fall,big deformation and other issues during mining in 2130 coal mine,provides a technical reference for the resolution of similar problems,and obtain the following main conclusions:(1)There were ten periodic weighting of main roof in similar experiments about coal seam mining with steeply dipping seam,supporting pressure peak between,the maximum abutment pressure is 5.71MPa-7.71MPa,and the increasing load modulus is 1.66-2.25,the abutment pressure is affected by the mining in front of the work surface about 50m.(2)The stress field in the roadway changes from the symmetrical state to the asymmetrical state with the increase of coal seam inclination,the vertical stress reduction zone gradually moves from the middle to the high-side direction in the roof,vertical stress concentration of high-side gradually disappeared,and vertical stress concentration of low-side gradually increased,roof sinking rapidly increased and surrounding rock destruction area increases gradually.(3)In different stress environments,the top and bottom of the roadway are mainly tensile failure,and other parts are mainly shear failure.But tensile damage area is 29.9%of the total destruction area in high-side of roadway not affected by mining stress,the proportion of tensile damage rapidly decreased,and the proportion of shear damage increased gradually with the increase of mining stress.And the depth of destruction of the low-top angle is the fastest.At the same time,surrounding rock surface displacements were linear or quadratic parabolic rise with the mining stress increases,roof displacement increase is the fastest,and low-side displacement increase is the fastest.(4)25221 Roadway service cycle is short,the roof tilt serious,deformation damage asymmetry,and most of the time and range under static action,in the roadway support design,should be based on different stages of different design,and verify the design of each stage,strong support and weak support combined to ultimately maximize efficiency.(5)Field measurements show that the displacements of roof,high-side and bottom are 48.1mm,28.5mm and 10.5mm during the mining process,when the roadway is supported with bolt,anchor,metal mesh,reinforced beams and channel steel under static action.coal mines can carry out normal safety production. |
