In order to determine the matching between the key parameters of roof cutting and the geological conditions of the site under the condition of leaving small coal pillars along the hollow roadway,the load distribution under different fracture states of the basic top rock layer was analyzed through the theory of masonry beams,and the theoretical selection ranges of different heights and angles of roof cutting were also determined,and the effects of different heights and angles on deformation of the roadway peripheral rock,lateral sup-port and pressure distribution,and damage of the coal pillar and the roadway peripheral rock were later compared through numerical cal-culations.Pressure distribution,coal pillar and roadway peripheral rock damage,the results show that:the top-cutting height mainly af-fects the stress distribution,the top-cutting angle mainly affects the peripheral rock damage;in the width of the coal pillar 10 m,the higher the top-cutting height,the lower the stability of the roadway peripheral rock and the peak of the support pressure,in which the top-cuttingheightof21.5m compared to the top-cutting height of 9.5 m of the peak of the lateral support pressure is reduced by 22%,and the deformation of top and bottom slabs and two gangs is reduced by 24 8%respectively.Meanwhile,the plastic damage of coal pillar and surrounding rock of the roadway is distributed in a"U"pattern with the increase of top-cutting angle,and it reaches the lowest when the top-cutting angle is 75°,and compared with the top-cutting angle of 60° and 90°(the larger value on both sides of the U-shape),the plastic damage of the coal pillar decreases by 7.9%and 16.6%separately,and the plastic damage of surrounding rock decreases 7.9%and 16.6%separately,and the plastic damage of coal pillar decreases 7.9%and 16.6%separately.Compared with 60° and 90°(the larger values on both sides of U-shape),the plastic damage of coal column decreased by 7.9%and 16.6%,and the plastic damage of surrounding rock decreased by 16.5%and 31.7%,respectively.As a result,when the height of the cut top was 21.5 m,and the angle of the cut top was 75° of the angle of elevation,the peak value of the lateral support pressure decreased,and the displacement of the surrounding rock was reduced,so that the stability of the surrounding rock of the roadway and the coal column was improved.
top-cutting parametertop-cutting decompressiontunneling along the airnumerical calculation
万方数据
维普
