浅部隔离煤柱对覆岩运移的控制及其合理留设

为了揭示西部浅埋工作面沿倾向方向开采时隔离煤柱对覆岩运移的控制作用，以大柳塔煤矿为工程背景，采用相似材料模拟试验方法，分析工作面开采中隔离煤柱对覆岩垮落、移动变形的控制作用及其应力变化特征，并确定煤柱的合理留设。研究结果表明，采区倾向方向上，由于工作面间存在隔离煤柱，各工作面开采会形成彼此独立的垮落带，隔离煤柱有效地分隔了相邻工作面垮落空间的横向贯通和纵向扩展，隔开了相邻工作面上覆岩层沉降曲线；覆岩垮落高度与工作面倾向开采长度密切关系，非充分采动较充分采动时覆岩垮落高度明显降低。在煤层开采过程中，留设30 m宽的1^#~4^#煤柱处于稳定状态，但3^#、4^#煤柱安全性较低。理论计算出了2^-2煤和5^-2煤合理煤柱宽度分别为18.6 m、24.5 m，得出了避开煤柱集中应力与控制地表均匀沉降的上下煤层煤柱最佳错距为95.5 m。

Control of overlying strata migration by shallow isolated coal pillars and their reasonable setting-up

In order to reveal the control effect of overlying strata movement by isolated coal pillars during mining along inclined direction in western shallow working face, Daliuta coal mine is taken as engineering background, the control effect of overlying strata collapse, movement and deformation by isolated coal pillars and the characteristics of stress change in mining face are analyzed by using similar material simulation test method, and the rational setting of coal pillars is determined. The results show that in the direction of mining area inclination, each working face will form an independent caving zone with isolated coal pillars between them, which effectively separates the lateral penetration and vertical expansion of the caving space in adjacent working faces and divides off the settlement curve of overlying strata on adjacent working faces; the caving height of overlying strata is closely related to the mining length of working face inclination not filled with coal pillars. The collapse height of overburden rock decreases when sublevel mining is more fully exploited. In the process of coal seam mining, the No.1^# to No.4^# pillar with a width of 30 m is in a stable state, but the safety of No.3^# and No.4^# pillars is low. The reasonable pillar widths of No. 2^-2 and 5^-2 coal seam are 18.6 m and 24.5 m, respectively. The optimum offset of upper and lower coal pillars is 95.5 m to avoid the concentrated stress of pillars and control the uniform settlement of the surface.