Khademian Zoheir, Sears Morgan
Pittsburgh Mining Research Division, CDC NIOSH, Pittsburgh, PA, USA.
Min Metall Explor. 2024;41(2):695-705. doi: 10.1007/s42461-024-00925-3.
According to the 2010-2019 Mine Safety and Health Administration (MSHA) accident report database, 91% of reported ground control accidents in US longwall mines were caused by roof instability. Gateroads are subjected to significant changes in loading conditions from the development to the longwall abutment loading phases. When combined with thinly bedded shale roof, found in many US longwall coal mines, the design of efficient roof support becomes challenging. In previous work, the bonded block modeling (BBM) of roof by UDEC was validated against field extensometer measurements in a longwall entry roof at a 180-m depth of cover. The BBM was shown capable of capturing delamination and buckling of shale roof, one of the main roof instability mechanisms in longwall mines. This paper presents the recent findings on the roof-support interaction using BBM models of the same longwall entry. The effects of cable bolts, roof bolt density, and strap support on potential roof instability are studied. Results demonstrate the potential for BBM numerical models to help understand the complex roof and support system interactions and to assist with optimizing gateroad support systems.
根据2010 - 2019年矿山安全与健康管理局（MSHA）事故报告数据库，美国长壁式煤矿中91%的上报的地压控制事故是由顶板失稳引起的。从开拓阶段到长壁式工作面支承压力加载阶段，顺槽承受的载荷条件会发生显著变化。再加上美国许多长壁式煤矿中存在的薄层页岩顶板，高效顶板支护的设计变得具有挑战性。在之前的工作中，通过通用离散单元法（UDEC）对顶板进行的粘结块体建模（BBM），已针对埋深180米的长壁式巷道顶板中的现场引伸计测量结果进行了验证。结果表明，粘结块体建模能够捕捉页岩顶板的分层和屈曲现象，这是长壁式煤矿中主要的顶板失稳机制之一。本文介绍了使用同一长壁式巷道的粘结块体建模（BBM）模型对顶板 - 支护相互作用的最新研究结果。研究了锚索、顶板锚杆密度和钢带支护对潜在顶板失稳的影响。结果表明，粘结块体建模数值模型有助于理解复杂的顶板与支护系统相互作用，并有助于优化顺槽支护系统。
