厚复合层顶板沿空掘巷支护研究
Study on Gateway Driving Along Goaf with Thick Compound Roof
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摘要: 以铜川矿区复合顶板条件为例,基于沿空掘巷围岩大、小结构的稳定性原理,结合覆岩破断的弧形三角块模型,根据理论分析初步确定了沿空掘巷小煤柱留宽方案;进而采用锚杆组合梁加固理论与锚索悬吊补强理论进行支护断面的初步设计。采用FLAC3D模拟软件对各方案分别进行了掘巷阶段与采动影响阶段的支护效果考察,最终确定小煤柱留宽5 m,巷道支护采用左旋无纵筋高强度螺纹钢锚杆,排距800 mm。沿空掘巷与采动影响阶段的支护效果表明,采用该支护方案巷道围岩应力分布合理,锚杆支护系统适应性良好。Abstract: Taking complex roof condition in Tongchuan Mining Area as an example, based on the stability principle of large and small structures in surrounding rock of the gateway driving along goaf, in combination with the broken arch delta model of the overburden strata, the small pillar width plan of the gateway driving along goaf was preliminarily set up from the view of the theoretical analysis.Thus the bolt combined beam reinforcement theory and the anchor suspension reinforcement theory W as applied to the preliminary design of the support cross section.The FLAC3D simulation software was applied to the support effect investigation of the gateway driving stage and the coal mining influence stage for each plan.Finally the width of the coal pillar was determined as 5 m.A left rotary no longitudinal rib high strength deformed steel bar bolt was applied for the support of the gateway with a row distance of 800 mm.The support effect of the gateway driving along the goaf and the mining influenc e stage showed that with the support plan applied, the stress distribution of the surrounding rock along the gateway was rational and the suitability of the bolt support s ystem was excellent.