高级检索

煤样力学行为的结构敏感特性及干预机制试验研究

Experimental study on structural sensitivity and intervention mechanism of mechanical behavior of coal samples

  • 摘要: 冲击地压的形成过程极为复杂,但本质是弹性能的大量积聚和剧烈释放。明确影响能量演化过程的客观要素和干预机制,将为指导实际防控工作提供基础认知。通过CT扫描重构了具有真实分布特征的煤样数值模型,并基于力学行为和加载环境密切相关的事实,开展了不同加载速率模拟试验。研究结果表明,应力环境变化时,相较于强度较小的煤基质,强度较大的夹杂质对于屈服、应力集中等响应表现出了更为显著的吸引作用,而屈服较晚的单元体在积聚弹性变形能的同时,整体逐渐形成了具有承载能力的空间骨架,并指出夹杂质、承载骨架或其他能够破坏介质均匀性的结构性要素,其空间分布模式对于能量或应力分布具有潜在控制作用。基于含人造结构面试样开展的不同加载速率力学试验验证了该结论,并提出有目的的人工形成特定的结构模式可实现对于煤岩宏观力学行为的选择性控制,进而为冲击地压的量化防控提供参考。

     

    Abstract: The formation process of rock burst is extremely complex,and the essence is the accumulation and violent release of elastic energy. Clarifying the objective elements and intervention mechanisms that influence the energy evolution process will provide basic knowledge to guide practical prevention and control efforts. In this paper,a numerical model of coal sample with real distribution characteristics was reconstructed by CT scanning. Based on the fact that the mechanical behavior is closely related to the loading environment,a multi-loading rate simulation test was carried out. The research shows that when the stress environment changes,the impurity inclusion with higher strength has more significant attraction to the response of yield and stress concentration compared with the coal matrix with smaller strength,and the late yielding element gradually forms a spatial skeleton with load-bearing capacity while accumulating elastic deformation energy. It is pointed out that the spatial distribution pattern of impurities,load-bearing skeleton or other structural elements that can destroy the medium uniformity and has a potential control effect on the energy or stress distribution. The multi-loading rate mechanical test based on the sample with artificial structure verified the conclusion,and proposes that the selective control of macro mechanical behavior of medium can be realized by purposeful artificial formation of specific structure mode,which provides a clear research direction for quantitative prevention and control of rock burst.

     

/

返回文章
返回