【作者】 黄金香；

【导师】 张建华；

【作者基本信息】 武汉理工大学 ， 安全技术及工程， 2012， 硕士

【摘要】 东川河引水隧洞距离JDC露天采场较近,且其围岩节理、断层构造极为发育,围岩的稳定性极差,矿山生产爆破振动对隧洞的安全有不利影响。因此,降低生产爆破振动成为亟待解决的问题。微差爆破是控制爆破振动有害效应最有效的手段之一,合理选择微差时间是提高微差爆破降振效果的技术关键。在进行东川河隧洞围岩地质结构分析的基础上,借鉴国内外微差爆破降振效应研究成果,通过数值模拟研究了爆破荷载作用下隧洞的动态响应规律,并利用数值模拟、爆破地震波频带能量分析和现场试验的方法对不同微差时间的降振作用进行了深入探讨,取得的主要成果如下：(1)采用动态测试系统,对东川河引水隧洞衬砌在爆破振动作用下的振速等进行测试；整理分析测试数据,找出不同条件下隧洞衬砌的振速和动态变形规律,并进行了安全评估。(2)以JDC南露天矿台阶爆破参数为基础,运用LS-DYNA显式非线性动力分析有限元程序分别建立了微差时间0ms,25ms,42ms和65ms的双孔微差爆破有限元模型,通过模拟所得的各节点峰值振速在相同孔网参数和爆心距、不同微差时间下的对比可知42ms微差时间下各节点处的峰值振速总体偏小,从而说明42ms微差间隔时间下的降振作用最大。(3)基于爆破地震波频带能量分析观点,分析得出了相同孔网参数和爆心距、不同微差时间质点的总能量,得出不同微差时间的爆破总能量衰减率,进而通过不同微差时间爆破总能量的衰减率对比,进一步证明42ms的最佳减振效果。(4)通过现场试验,对比分析了相同爆心距和孔网参数的双孔微差爆破和齐发爆破的峰值振速,得出双孔微差爆破的峰值振速降振率,进一步说明微差爆破降振率分析的正确性。现场实践表明,论文成果对矿山爆破设计合理选择微差时间、有效降低爆破振动提供了参考依据,对临近隧洞爆破振动控制有重要的指导意义,可供类似矿山或工程借鉴。更多还原

【Abstract】 Dong chuan river diversion tunnel is under JDC open-pit mine, whose wall rock joint and fault structure are well developed, and it is badly stable, so the diversion tunnel’s safety is greatly influenced by blasting vibration in the mine area. Therefore, blasting vibration reduction becomes an urgent problem in the mine. Millisecond blasting is one of the main methods to control harm of blasting vibration, so how to choose the reasonable millisecond delay time is the key technology to improve the effect of blasting vibration reduction.Based on analysis the geological structure of Dong chuan river diversion tunnel, by consulting researches home and abroad on vibration reduction of millisecond blasting, in the paper, the dynamic response relationship under the blasting load is studied by numerical simulation. Besides, it is deeply discussed on decreasing vibration of different millisecond delay time using the method of numerical simulation, energy analysis in frequency bands of blasting seismic wave and field test, the main achievements are as follows:(1) Using dynamic measuring system, measure the velocity and any other data of the diversion tunnel’s lining under the blasting vibration. Arrange and analyze the data abtained, and find the law of the velocity and dynamic deformation of the tunnel in different situation, then do the safty assessment.(2) Using LS-DYNA, and based on the bench blasting parameters of JDC open-pit mine, establish a finite element model of millisecond blasting of double-hole whose millisecond delay times are Oms,25ms,42ms and65ms respectively. Compared the peak particle velocity of each points in the situation of same hole pattern parameters, blast center distance, and different delay time, it can be known that peak particle velocity in each points of42ms delay time are smaller overall, which illustrates that effect of vibration reduction in42ms delay time is the best.(3) Based on viewpoints of the energy analysis in frequency bands of blasting seismic wave, get the total energy of particles when it has the same hole pattern parameter, blast center distance and different millisecond delay intervals. Then attenuation rate in each delay time is known, comparing which could proof the best delay time is42ms. (4) According the field test, comparatively analyze the peak particle velocity of the double-hole millisecond blasting and simultaneous blasting in the situation of the same blast center distance and hole pattern parameters, moreover prove the correction of vibration reduction rate of millisecond blasting.The practice shows that the achievement of the paper provide a reference for blasting design in mine on the reasonable millisecond delay time and the effect of reducing blasting vibration. Additionally it has a guiding significance for controlling blasting vibration nearby the tunnel, in order to supply reference for the same mine.更多还原