蒙陕地区强冲击煤层塑性小煤柱沿空回采期间破坏规律研究

Study on failure law of small coal pillar during gob side mining in strong rockburst coal seam of Inner Mongolia and Shaanxi region

为了揭示蒙陕地区超长大采高工作面塑性小煤柱沿空回采期间的破坏规律,以纳林河矿区某矿为例,通过在其煤体内部布置钻孔应力计进行监测,采用固定工作面法,得出塑性小煤柱在回采期间的变形破坏过程分为4个阶段,基于黑箱理论,对不同观测站同一阶段的应力值进行无差别对待,在此基础上建立小煤柱水平切面的单元模型(6.6 m×11 m),采用Surfer 15软件绘制4个阶段的应力等值线云图,分阶段揭示塑性小煤柱应力水平变化规律,并提出有效塑性支撑面积及变化规律。结果表明,塑性小煤柱整体承载能力逐步降低,呈现出塑性-弱支撑的性能,为类似条件下的临空小煤柱围岩控制和采空区治理提供依据。

In order to reveal the damage law of the super long and large mining height working face during gob-side mining of plastic small coal pillars in the Inner Mongolian and Shaanxi area region,taking a mine in Nalinhe mining area as an example,a borehole stress gauge is arranged inside the coal mass for monitoring,using the fixed working face method,it is concluded that the deformation and failure process of plastic small coal pillars during mining is divided into four stages.Based on the black box theory,the stress values of different observation stations at the same stage are treated indiscriminately,and the small coal pillar level element model of the section(6.6 m×11 m)is established on this basis,it is using the Surfer 15 software to draw the stress contour cloud map of four stages,revealing the changing law of the stress level of the plastic small coal pillar in stages,and proposing the effective plastic support area.The results show that the overall bearing capacity of the plastic small coal pillars gradually decreases,showing the performance of plasticity and weak support,which provides the basis for the control of surrounding rock and the governance of the goaf under similar conditions.