临空留巷底板冲击地压启动区判定与分步防治技术

发布时间：2018-09-04 07:08

【摘要】：以山西余吾煤业N2105工作面回采过程中临空留巷底板冲击地压为工程背景,理论分析底板冲击地压可能的冲击启动区及主导应力源,采用数值模拟追踪煤层开挖后侧向煤柱及留巷围岩各向应力、位移的演化过程,建立采空区影响下留巷底板水平应力演化模型并进行验证。基于临空留巷底板冲击地压主导力源判定及能量传递过程分析,提出该类底板冲击地压分步防治关键技术,并进行现场应用。结果表明:煤层开挖后中,临空留巷底板在破坏深度范围内存在"卸压通道"机制,临空煤柱垂直应力不断增长的同时,留巷底板水平应力通过"卸压通道"释放,释放程度与该通道宽度呈正相关。临空煤柱帮内弹性核区为留巷底板冲击地压的冲击启动区,其不断增长的垂直应力为主导载荷源,而非留巷底板水平应力。为阻止该类底板冲击地压发生启动,关键在于削弱采空区侧向顶板压力传递作用及煤柱弹性能积聚水平,弱化留巷底板只能缓和冲击显现强度,非对称支护对留巷围岩变形破坏特征的适应性更强。
[Abstract]:Based on the engineering background of impact ground pressure of the floor plate in the mining process of N2105 working face in Yuwu Coal Industry of Shanxi Province, this paper theoretically analyzes the possible impact starting area and the leading stress source of the floor impact ground pressure. A numerical simulation was used to track the evolution process of stress and displacement in lateral pillar and surrounding rock of roadway after coal seam excavation, and the model of horizontal stress evolution of roadway floor under the influence of goaf was established and verified. Based on the determination of the dominant force sources and the analysis of energy transfer process, the key technologies for the prevention and control of the impact ground pressure of this kind of floor slab are put forward and applied in the field. The results show that during the coal seam excavation, there is a "pressure relief channel" mechanism in the depth of failure, and the vertical stress of the coal pillar is increasing, while the horizontal stress is released through the "pressure relief channel". The release degree was positively correlated with the width of the channel. The elastic core area of the coal pillar is the impact starting area of the roadway floor, and its increasing vertical stress is the main load source, not the horizontal stress of the retaining roadway floor. In order to prevent this kind of floor from starting up, the key lies in weakening the lateral roof pressure transfer in goaf and the accumulation level of elastic energy of coal pillar. Asymmetric support is more adaptable to deformation and failure characteristics of roadway surrounding rock.
【作者单位】：中国矿业大学(北京)资源与安全工程学院;煤炭科学研究总院开采研究分院;天地科技股份有限公司开采设计事业部;
【基金】：国家重点研发计划资助项目(2017YFC0804204,2016YFC0801401) 国家自然科学基金资助项目(51704155)
【分类号】：TD324

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