深部矿井动压回采巷道围岩大变形破坏机理

发布时间：2019-05-11 04:58

【摘要】：针对深部动压回采巷道的大变形失稳破坏及其控制难题,建立了深部动压环境下圆形巷道力学模型,导出了塑性区边界隐性方程式。在此基础上,对深部动压巷道塑性区形态演化规律进行深入分析,阐明了第I类及第II类蝶形塑性区形成的力学条件,界定了塑性区恶性扩展及其临界的定义,揭示了深部动压回采巷道的变形破坏机理。结果表明,开采动压影响比常规条下围岩更易产生蝶形塑性区,且蝶叶发育尺寸、塑性破坏范围更大。随着动压影响的增强,巷道区域应力场成为超常规的超高应力场,巷道顶底、两帮的塑性破坏进一步向深部扩展,变形加剧,致使塑性区恶性扩展,最终造成围岩大变形破坏。对于深部动压回采巷道的设计、支护应充分考虑如何避免或降低动压的影响,改善围岩应力环境,减小蝶叶塑性破坏深度,以便更好地维护巷道。
[Abstract]:In view of the large deformation and instability failure of deep dynamic pressure mining roadway and its control problems, the mechanical model of circular roadway under deep dynamic pressure environment is established, and the hidden equation of plastic zone boundary is derived. On this basis, the morphological evolution of plastic zone in deep dynamic pressure roadway is deeply analyzed, the mechanical conditions for the formation of butterfly plastic zone of type I and type II are expounded, and the definition of malignant expansion and criticality of plastic zone is defined. The deformation and failure mechanism of deep dynamic pressure mining roadway is revealed. The results show that the influence of mining dynamic pressure is more likely to produce butterfly plastic zone than that under conventional strip, and the development size of butterfly leaf is larger and the plastic failure range is larger. With the increase of dynamic pressure, the regional stress field of roadway becomes super-high stress field. At the top and bottom of roadway, the plastic damage of the two sides extends further to the deep and the deformation intensifies, which leads to the malignant extension of the plastic zone and finally to the large deformation of the surrounding rock. For the design of deep dynamic pressure mining roadway, the support should fully consider how to avoid or reduce the influence of dynamic pressure, improve the surrounding rock stress environment, reduce the plastic failure depth of butterfly leaf, so as to better maintain the roadway.
【作者单位】：南方煤矿瓦斯与顶板灾害预防控制安全生产重点实验室;煤矿安全开采技术湖南省重点实验室;湖南科技大学资源环境与安全工程学院;
【基金】：国家自然科学基金资助项目(51434006,51504091) 湖南省教育厅科研资助项目(15C0551)
【分类号】：TD322

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