冲击性顶板运动阻尼效应数值模拟及混沌动力学分析.pdfVIP

第24 卷 第11 期 岩石力学与工程学报 Vol.24 No.11 2005 年6 月 Chinese Journal of Rock Mechanics and Engineering June ，2005 冲击性顶板运动阻尼效应的数值模拟及 混沌动力学分析 刘传孝 山东科技大学 资源与环境工程学院，山东 青岛 266510 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。 关键词：岩石力学；冲击；顶板运动；阻尼效应；三维离散元；混沌动力学 中图分类号：TU 45 ；O 231 文献标识码：A 文章编号：1000 –6915 2005 11 –1875 –06 NUMERICAL SIMULATION ON DAMPING EFFECT OF IMPACTED ROOF AND ITS ANALYSIS WITH CHAOTIC DYNAMICS THEORY LIU Chuan-xiao Institute of Resources and Environment Engineering ，Shandong University of Science and Technology ，Qingdao 266510 ，China 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