In order to improve rib stability, failure criteria and instability mode of a thick coal seam with inter-band rock layer are analysed in this study. A three-dimensional mechanical model is established for the rib by considering the rock layer. A safety factor is defined foy the rib, and it is observed that the safety factor exhibits a positive correlation with the thickness and strength of the inter-band rock. A calculation method for determining critical parameters of the rock layer is presented to ensure the rib stability. It is revealed that incomplete propagation of the fracture at the hard rock constitutes a fundamental prerequisite for ensuring the rib stability. The influence of the position of the inter-band rock in the coal seam on failure mechanism of the rib was thoroughly investigated by developing a series of physical models for the rib at the face area. The best position for the inter-band rock in the coal seam is at a height of 1.5 m away from the roof line, which tends to provide a good stability state for the rib. For different inter-band rock positions, two ways of controlling rib by increasing supports stiffness and flexible grouting reinforcement are proposed.

中文翻译：

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带间岩石对大采高长壁面板肋板剥落的影响


为了提高肋的稳定性，本文对带间岩层厚煤层的破坏准则和失稳模式进行了分析。考虑岩层，建立了肋骨的三维力学模型。定义了肋骨的安全系数，发现安全系数与带间岩石的厚度和强度呈正相关。提出了一种确定岩层关键参数的计算方法，以确保肋的稳定性。结果表明，硬岩处裂缝的不完全扩展是保证肋稳定的基本前提。通过建立工作面区域肋的一系列物理模型，深入研究了煤层带间岩石位置对肋破坏机制的影响。煤层带间岩石的最佳位置是距顶板线1.5m的高度，这往往为肋提供良好的稳定状态。针对不同带间岩石位置，提出了增加支护刚度和柔性注浆加固两种控制肋的方法。