下位煤层开采切眼合理布置方式与支护技术

Reasonable arrangement and support technology for lower coal seam mining

为了研究下位煤层大断面切眼的控制理论及技术,选取铁新煤矿2901切眼为研究对象,采用理论分析和数值分析,确定2901切眼应错开煤柱15m以上,处于主应力降低区。模拟研究了切眼宽度在3.5~7m过程中,围岩拉、剪塑性区的扩展趋势。认为该类型切眼支护的关键部位是顶板,以肩角稳定区作为加强支护锚固基础,以保证围岩稳定的设计思路,并确定了桁架锚索与锚杆联合支护技术参数。结果表明,该大断面切眼掘出7d后可实现自稳,无明显矿压显现,为类似条件下大断面切眼支护提供借鉴。

In order to study the control theory and technology of large-section cut-out of the lower coal seam, the 2901 cut-eye of Tiexin Mine was selected as the research object. The theoretical analysis and numerical analysis were used to determine that the 2901 cut-eye should be staggered more than 15 m, and the principal stress was reduced. The simulation showed the extension trend of the surrounding rock pulling and shearing plastic zone during the process of cutting eye width was from 3.5 to 7 m. It was believed that the key part of this type of eye-cutting support was the roof plate, and the shoulder-stable stability zone was used as the anchoring foundation for strengthening the support to ensure the stability of the surrounding rock. The technical parameters of the truss anchor cable and bolt joint support were determined. The results showed that the large-section cut-out could achieve self-stability after 7 d, and no obvious mine pressure appeared, which provided a reference for large-section cut-eye support under similar conditions.