煤巷复合顶板结构对其稳定性影响试验

Influence of composite roof structure on the stability of coal roadway

  • 摘要: 煤层巷道复合顶板结构较为复杂,其自身稳定性与岩性、岩层厚度、层数、岩层位置及层间黏结力等因素有关。基于简化的复合顶板组合梁结构力学理论,建立了简化的组合梁力学测试模型,通过不同试验分析复合顶板结构特征对其稳定性的影响,其目的是为复合顶板稳定性分类及控制提供科学依据。研究结果表明:煤巷复合顶板厚度不变时,其自身稳定性随岩层强度提高、硬岩层厚度增加、硬厚岩层到煤层距离的减小及层间黏结力的增大而提高,随分层数的增多而降低,当层数达到4层及以上时,顶板稳定性受其层数变化的影响变小。各因素的影响程度由大到小依次:岩性 > 岩层厚度 > 层数 > 岩层位置 > 层间黏结力;强度低、厚度小的软弱薄夹层较其他岩层更易产生应力集中,且破坏早于其他岩层。

     

    Abstract: The composite roof structure of coal roadway is rather complex. Its stability is related to lithology, thickness of strata, number of strata, location of strata and cohesive force between layers. Based on mechanics theory of simplified composite roof composite beams, a simplified mechanical test model of composite beams was established, and the effects of the structural characteristics of composite roof on the stability of composite beams were analyzed by experiments. The purpose is to provide a scientific basis for the classification and control of composite roof stability. The results show that the stability of the roof increases with the increase of the lithology, the increase of the thickness of the hard rock, the decrease of the distance between the hard and thick layers and the strengthening of the interlayer bonding force when the thickness of the composite roof of the coal roadway is certain, but it reduce with the manifold of the number of layers, until the number of layers is more than four layers, and the stability of roof is affected by the number of layers. The influence of variation is small, and the influence degree of its influence factors from large to small is:lithology > rock thickness > layer > rock location > interlayer cohesive force. Compared with other rock formations, the weak thin interlayer with lower strength and small thickness is more prone to produce stress concentration anterior to other damages of layers.

     

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