露天矿边坡动载响应特性的数值模拟研究

发布时间：2018-04-17 18:39

  本文选题：震动载荷 + 动力响应　； 参考：《内蒙古科技大学》2015年硕士论文

【摘要】：随着我国工业的改革，，能源产业低消耗、高利用的战略思想深入到每个资源领域，特别是采矿行业。全面协调可持续的发展理念要求采矿行业克服种种困难，对一切可用可不用的矿业资源必须实行科学高效的利用。同时对自然环境的保护和人身安全的注重，更加重了采矿技术者的“负担”，凸显了安全开采的重要性。 以露天矿开采为例，由于经济利益的驱使，露天开采边坡逐渐趋于高陡化。在最小的范围内获取最大的矿业资源，迫使采矿技术不断革新，开采难度不断加大，而边坡的不稳定系数也一并得到了提高。加上现代爆破开采技术的应用以及自然地震等动载荷的作用，更加大了高陡化边坡的失稳系数，研究动载下边坡的响应规律日趋重要。传统的边坡稳定性分析方法仅选取两个静止状态进行分析，没有真正实现对动力加载过程的研究，虽对实际生产有一定借鉴意义，但始终存在纰漏。基于三维显式有限差分计算的FLAC3D数值分析软件，为分析动载荷作用提供了一种全新手段。 论文首先对动载荷作用进行分析，了解动力载荷的产生过程和作用机理。发现动载荷的实质是地震、人工爆破等震动引起的震动波作用在边坡上，引起边坡内外质点的振动的现象。研究了不同震动波的传播特征和动力作用特征的同时，结合FLAC3D的动力分析功能，给出了数值模拟的原理和求解方法。 其次，以双利露天矿边坡为对象建立数值模型，按照震动波频率与计算要求划分模型网格。并从动载荷的选取与输入方法、边界的设定、内部阻尼的选取等方面讨论了影响数值模拟的因素，选取了较为合理的参数，分工况对实测震动波信号进行了FLAC3D数值模拟，获取了最佳模拟效果。 最后通过实时监测、记录坡体不同部位震动响应值，对动载条件下边坡的动载响应规律进行总结。发现动载作用下边坡的应力应变受动力作用的强弱、岩体力学参数大小影响显著；不同持时、幅值、频率下，边坡的动力响应加速度、速度及位移等表现出不同程度的变化，呈现一定的规律。为了进一步验证这些规律的正确性，结合实际工程应用，对比不同分析方法下的边坡稳定系数，证明了利用FLAC3D数值模拟分析动力问题的可靠性，同时也为预裂爆破的优化提供了理论依据。
[Abstract]:With the reform of industry in China, the low consumption of energy industry and the strategic thought of high utilization have penetrated into every field of resources, especially in mining industry.The idea of comprehensive and sustainable development requires the mining industry to overcome all kinds of difficulties and to make scientific and efficient use of all available mining resources.At the same time, the emphasis on the protection of natural environment and personal safety has increased the burden of mining technologists and highlighted the importance of safe mining.Taking open pit mining as an example, the slope of opencast mining tends to be steep because of economic benefits.To obtain the largest mining resources in the minimum range, the mining technology is constantly innovated, the mining difficulty is increasing, and the instability coefficient of the slope is also increased.Combined with the application of modern blasting mining technology and the action of natural earthquake and other dynamic loads, the instability coefficient of high steepening slope is increased, and it is increasingly important to study the response law of slope under dynamic load.The traditional slope stability analysis method only selects two static states to analyze, and does not really realize the study of dynamic loading process. Although it has some reference significance for practical production, there are always flaws.FLAC3D numerical analysis software based on 3D explicit finite difference calculation provides a new method for dynamic load analysis.In this paper, the process and mechanism of dynamic load are analyzed.It is found that the essence of the dynamic load is the phenomenon that the vibration waves caused by earthquake and artificial blasting are acting on the slope and causing the vibration of the particles inside and outside the slope.The propagation and dynamic characteristics of different vibration waves are studied, and the principle and solution of numerical simulation are given in combination with the dynamic analysis function of FLAC3D.Secondly, the numerical model of the slope of Shuangli opencast mine is established, and the model grid is divided according to the frequency of vibration wave and the requirement of calculation.The factors influencing the numerical simulation are discussed from the aspects of the selection and input method of dynamic load, the setting of boundary and the selection of internal damping, and the reasonable parameters are selected. The FLAC3D numerical simulation of the measured vibration wave signal is carried out under different working conditions.The best simulation effect is obtained.Finally, the dynamic response of slope under dynamic load is summarized by recording the vibration response of different parts of slope through real-time monitoring.It is found that the stress and strain of the slope under dynamic load are affected by the dynamic action and the mechanical parameters of the rock mass are significantly affected, and the dynamic response acceleration, velocity and displacement of the slope show varying degrees under different durations, amplitudes and frequencies.Show a certain regularity.In order to further verify the correctness of these laws, combined with practical engineering applications, the slope stability coefficients under different analysis methods are compared, and the reliability of dynamic problem analysis using FLAC3D numerical simulation is proved.It also provides a theoretical basis for the optimization of pre-splitting blasting.
【学位授予单位】：内蒙古科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD804

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