Instability failure mechanism of coal pillar in deep mine under dynamic disturbance
XING Chuangchuang;WANG Jun;NING Jianguo;SHEN Zhen
深部矿井护巷煤柱常处于“三高一扰动”的复杂环境,护巷煤柱稳定性对煤矿通风、运输与行人起着关键作用。针对动载扰动下深井护巷煤柱已发生突变失稳的问题,以新河煤矿-980 m水平3煤层6302工作面南部集中大巷保护煤柱为工程背景,基于FLAC3D模拟软件研究了动载扰动下深部护巷煤柱破坏失稳演化过程,分析了动载强度、煤柱尺度对煤柱动力破坏演化的影响规律,进而建立了护巷煤柱动力失稳尖点突变失稳模型和判别式,揭示了动载作用下深井护巷煤柱破坏特征及突变失稳机理。研究表明:(1)增大护巷煤柱尺寸能够提高稳定性,减小其失稳破坏的几率;(2)外部动载冲击强度越大,护巷煤柱易发生整体失稳破坏;(3)基于护巷煤柱承载力学模型,利用尖点突变模型和弹性薄板理论推演了与外部动载强度、煤柱尺寸等因素有关的煤柱稳定性判别式,提出了动载扰动下深井护巷煤柱失稳破坏判别方法,并进行了工程验证。研究成果丰富了煤柱失稳类冲击地压的预防和控制理论体系,为现场工作面回采护巷煤柱的留设及维护提供可靠的理论指导。
The coal pillar of roadway protection in deep mine is often in the complex environment of three high and one disturbance, thestability of coal pillar plays a key role in coal mine ventilation, transportation and pedestrians. Aiming at the problem of sudden instabilityof coal pillar in deep roadway protection under dynamic load disturbance, based on the engineering background of the southern concentratedroadway protection coal pillar in 6302 working face of No.3 coal seam in −980 m level of Xinhe Coal Mine, the failure and instabilityevolution process of coal pillar in deep roadway protection under dynamic load disturbance is studied based on FLAC3D simulationsoftware. The influence of dynamic load intensity and coal pillar scale on the dynamic failure evolution of coal pillar is analyzed, and thenthe dynamic instability cusp catastrophe instability model and discriminant of coal pillar in deep roadway protection are established. Thefailure characteristics and catastrophe instability mechanism of coal pillar in deep roadway protection under dynamic load are revealed.The results show that:①Increasing the size of coal pillar can improve the stability and reduce the probability of instability failure;②Thegreater the impact strength of external dynamic load, the overall instability of coal pillar is easy to occur;③Based on the bearing capacitymodel of coal pillar, the discriminant of coal pillar stability related to external dynamic load strength and coal pillar size is deduced by usingcusp catastrophe model and elastic thin plate theory, the discriminant method of instability failure of coal pillar in deep mine under dynamicload disturbance is put forward and verified by engineering. The research results enrich the theoretical system of prevention andcontrol of rock burst caused by coal pillar instability, provide reliable theoretical guidance for the retention and maintenance of coal pillars in the field working face, and provide theoretical basis for the safe and efficient mining of deep working face.
protective coal pillar; numerical simulation; dynamic load impact; theoretical model; instability discriminant
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会