【摘要】 根据现场验证的冲击性顶板4个阶段运动特征的数值模拟结论,采用三维离散单元法研究冲击阶段顶板运动的阻尼效应,并进行相应的混沌动力学分析。研究结果表明:随系统阻尼水平的提高,坚硬顶板运动系统的冲击性呈明显降低趋势,存在冲击性显著降低的拐点;系统的状态由混沌态演化到有序的定常态又演化到了混沌态;混沌度表明阻尼水平的提高起到了促使系统朝向有序稳定状态转化的作用,甚至可促使冲击性顶板系统的运动状态由原始的主动模式转向被动模式。冲击性顶板悬露到一定范围时,实施防冲击措施可提高系统的阻尼,促使坚硬顶板从整体大范围冲击性运动向周期性分段运动转化。更多还原

【Abstract】 Based on numerical results of impacted roof movement at four stages which have been verified in-situ, the damping effects of roof movement at the impacted stage with three-dimensional distinct element code and chaotic dynamics theory are studied. With the increase of damping degree,the impact of roof movement decreases obviously and its damping inflection is at the point of 0.8. Meanwhile,the states of the system evolve from chaos to ordered steady state and then to chaos again. Index of chaotic degree shows that the system will develop towards the ordered and stable states with improvement of damping level,which can even change movement of impacted roof from initial active mode to passive mode. If the area of hanging impacted roof is large enough,measures to prevent rock burst may improve damping level of the system and change movement of the hard roof from impacted mode to periodic mode.更多还原