【摘要】 基于三软煤层老采区留设煤柱中复采工作面无煤柱沿空掘巷采用工字钢梯形棚架支护条件下,针对煤矿巷道围岩稳定性差、底鼓变形严重影响生产的实际,采用理论分析和现场实践的方法,提出锚网索支护新方案,即通过锚索强大的预紧力,主动对巷道围岩进行加固,改变基本顶岩层深部的应力分布,使基本顶岩层在巷道两侧所形成的集中应力向两侧的深部转移,减轻对底板及两帮的压力,同时通过贴帮柱加强采空侧帮部对顶板的支撑,使底鼓及两帮的变形得到控制。经实际测定,巷道顶底板的变形总量为478mm,底鼓量为235mm,两帮总变形量为172mm。与工字钢梯形棚式支护相比,巷道的变形量大幅降低,不需要挖底扩帮进行多次返修,保证了生产。更多还原

【Abstract】 Based on the condition of the H type steel square supports in the pillarless gateway driven along goaf of the second mining face to excavate the coal pillars left in the goaf in seam with the soft roof,soft coal and soft floor,according to the poor stability of the gateway surrounding rock and the floor heave deformation seriously affected to the actual production in a mine the theoretical analysis and the site practical method was applied to propose the new bolt/steel mesh/anchor support plan.That was to say,with the powerful pre-stressed anchor actively to reinforce the gateway surrounding rock in order to change the deep stress distribution in the main roof strata.The concentrated stress at the two sides of the gateway caused by the main roof strata would transfer to the deep sections of the two side walls and the pressure to the floor and the two side walls would be reduced.Meanwhile the props set closely against with the side wall would reinforce the support to the roof at the side of the goaf in order to control the floor heave and the two side wall deformation.The actual measurements showed that the total deformation value of the roof and floor in the gateway would be 478 mm,the floor heave value would be 235 mm and the total deformation value of the two side walls would be 172 mm.In comparison with the H type steel bar supports,the deformation of the gateway could be highly reduced,no multi repair would be required for the floor heave and the mine production could be ensured.更多还原