深部厚顶煤巷道围岩稳定性相似模型试验研究

针对深部厚顶煤巷道围岩控制难题,采用相似模型试验方法,分析了埋深、构造应力等因素对厚顶煤巷道围岩变形、围岩应力及支护结构的影响,揭示了厚顶煤巷道围岩稳定性规律:随着埋深增大,两帮及顶煤内应力峰值增大,围岩变形破坏程度增大;随着构造应力增大,围岩变形破坏程度增大,构造应力对顶煤稳定性影响显著,顶煤水平应力呈现出"两端低、中部高"分布形态,且应力峰值位置随构造应力增大向深部转移,下位顶煤、煤层与顶板交界面附近的顶煤破坏严重,最终发生"尖顶型"垮冒;顶板锚杆和穿过煤岩层交界面的锚索易被剪断。对于深部构造应力作用下的厚顶煤巷道,认为提高顶煤锚固体的抗剪能力尤为重要,提出采用"高强高预紧力锚杆及斜拉锚索梁"支护技术,以此增强厚顶煤锚固体的抗剪能力、提高两帮承载能力,顶煤和两帮稳定性的提高则有助于减小底臌量。研究成果成功应用于工程实践。

Experimental study on similar simulation for surrounding rock stability of deep roadway with thick top coal

In order to solve the difficult problem of surrounding rock control for deep roadway with thick top coal，the similarity model was established to analyze the influence of buried depth and tectonic stress to deformation and stress of surrounding rock，and support structure.Stability law of surrounding rock for roadway with thick top coal was discovered.With the increase of buried depth，the deformation and failure of surrounding rock increases.With the increase of tectonic stress，the deformation and failure of surrounding rock increases，and tectonic stress affects the stability of top coal significantly：there is a “low in the two ends，high in the middle” distribution of stress in the top coal，and the peak stress depth transfer to the deep with the increase of tectonic stress.The damage of the shallow top coal and the coal near the interface of seam and roof is serious，appearing “fastigium” shape collapse finally.Roof bolts and cable through the interface between the top coal and rock roof are broken under shear force easily.For the deep roadway with thick top coal under high tectonic stress，improving the shear resistance of roof bolt and cable is particularly important.“High strength and high pre-stress bolt and diagonal cable and beam structure” support technology was put forward，in order to enhance the shear capability of thick top coal anchorage body and the bearing capacity of two sides.And the improvement of top coal and two sides stability is helpful to reduce the floor heave amount.The research results were successfully applied to engineering practice.