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旺格维利式开采采硐间煤柱合理宽度留设研究

Research on reasonable width of coal pillars between caverns of Wongawilli mining

  • 摘要: 为解决条带式旺格维利式开采(简称“旺采”)特有采硐间煤柱在回采过程中影响顶板稳定性,制约连采设备高效回采、安全退出,降低煤炭资源采出率的难题,以盛平煤矿为研究对象,采用FLAC3D数值模拟研究方法,分析了1.00、1.25、1.50、1.75 m不同采硐间煤柱宽度方案下的煤柱受力情况、煤柱塑性区分布、直接顶塑性区受力、基本顶塑性区受力、巷道顶板下沉量、支架受力状态,得出了条带式“旺采”采硐间煤柱影响回采的有关规律。研究结果表明:采硐间煤柱在常规尺寸范围内,无法通过增加煤柱宽度来阻止其全部进入塑性区;随着采硐间煤柱宽度增大,承载能力增加,更好地保证采硐间煤柱后侧采硐的安全回采且巷道超前段采空区侧煤体塑性区减小;随着采硐间煤柱宽度增加,巷道顶板下沉量逐渐减小,但宽度在1.25~1.75 m的控制效果不会再显著增强,无法通过增加煤柱宽度改变直接顶的总体运移规律;随着采硐间煤柱宽度的增加,基本顶发生破坏的面积会大幅减小,基本顶底部塑性区变化规律未见显著差异,仅区域大小有所不同,表明较宽的采硐间煤柱有着更高的承载能力,但难以改变采场“大结构”的演化规律。采硐间煤柱宽度增大,行走液压支架立柱工作阻力近似线性减小,且对相邻支巷采硐间四边形不规则煤柱的应力峰值没有影响。

     

    Abstract: In order to solve the problem that the unique coal pillar between the mining tunnels of the strip-type "Wongawilli mining" affects the stability of the roof during mining, restrictsthe efficient mining and safe withdrawal of continuous mining equipment, and reduces the recovery rate of coal resources, the Shengping coal mine was used as a research case. FLAC3D numerical simulation research method was used to analyze the stress of the coal pillar, the distribution of the plastic zone of the coal pillar, the stress of the plastic zone of the direct top, the stress of the coal pillar under the scheme of the coal pillar with different widths of 1 m, 1.25 m, 1.5 m and 1.75 m were analyzed. The relevant laws of the influence of coal pillars between the strip-type “Wongawilli mining” mining tunnels on the recovery were obtained. The research results show that the coal pillars between the tunnels are within the conventional size range and cannot be prevented from entering the plastic zone by increasing the width of the coal pillars. With the increase of the width of the coal pillar between the tunnels, the bearing capacity increases, which better ensures the safe mining of the tunnel behind the coal pillar between the tunnels and the reduction of the plastic zone of the coal body on the side of the gob in the leading section of the roadway.. With the increase of pillar width, the subsidence of roadway roof decreases gradually, but the control effect of the width within the range of 1.25 m to 1.75 m will not be significantly enhanced, and the overall movement law of direct roof can not be changed by increasing pillar width. With the increase of pillar width, the area of damage of basic roof will be greatly reduced. There is no significant difference in the change law of plastic zone between the basic roof and the bottom, but the size of the zone is different, which indicates that the wider coal pillar between the mining pits has a higher bearing capacity, but it is difficult to change the evolution rule of the “large structure”of the stope. When the width of the coal pillar between the mining tunnels increases, the working resistance of hydraulic support pillar decreases approximately linearly, and it has no effect on the stress peak of the quadrangular irregular coal pillar in the adjacent branch roadway.

     

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