夯实作用下散体充填物料力学响应研究

发布时间：2018-08-14 11:46

【摘要】：随着固体充填采煤技术的发展以及在全国范围内的推广应用,充填物料的种类呈现多样化趋势,风积沙、黄土、矸石、粉煤灰和露天矿渣等散体物料陆续被用作充填物料。通过对散体物料力学特性的研究,为今后进一步提高充填开采效果奠定理论基础。本文从散体物料的基本特性着手,根据其不连续的特性引入离散元法进行数值模拟来研究散体充填物料的力学响应。结合实验室实验、虚拟实验参数标定最终确定了数值模拟中的参数,通过EDEM软件模拟了夯实作用下散体物料的力学响应,取得了以下研究成果:(1)通过实验室试验测得散体充填物料的基本特性,再根据虚拟参数标定实验得出数值模拟过程中散体充填物料的基本参数。在钢桶压实虚拟标定试验中,得出矸石颗粒的本征参数:泊松比为0.19,密度为2670kg/m3,弹性模量为15GPa。在自然安息角虚拟标定试验中,得出矸石颗粒模型的恢复系数为0.15,静摩擦系数为0.44,动摩擦系数为0.05。(2)随着夯实机构的夯实角度不断增加,散体充填物料的欠接顶量呈现先减小后增加的变化趋势。夯实角度在22°和27°时散体物料的平均密实度较为接近且均大于夯实角度为32°时的密实度。因此在夯实过程中既要保证夯实机构的夯实板完全进入料堆,又要保证夯实角度不宜过大,以保证夯实效果提高夯实效率。(3)随着散体物料的粒径不断增大,散体物料的欠接顶量随之增大,散体物料的平均密实度不断减小。且当散体物料粒径分布为小粒径和中粒径时,平均密实度差距不大。因此在制备散体充填物料时,考虑到破碎成本,建议将其破碎至中粒径即可,从而既可以提高破碎速度又可以保证密实度。(4)随着夯实机构速度的不断增加,散体物料的欠接顶量呈现线性增加的趋势。夯实机构速度对夯实机构后方散体物料的平均密实度影响很小,因此可适当减小夯实机构夯实速度,从而降低泵站压力减小设备投入。
[Abstract]:With the development of solid filling coal mining technology and the popularization and application in the whole country, the types of filling materials show a diversified trend, such as aeolian sand, loess, gangue, fly ash and open pit slag, and other granular materials are used as filling materials one after another. Through the study of the mechanical properties of bulk materials, the theoretical foundation is laid for further improving the effect of filling mining in the future. In this paper, the discrete element method is introduced into the numerical simulation to study the mechanical response of the bulk filling material based on the basic characteristics of the bulk material. In combination with the laboratory experiment, the parameters of the virtual experiment are finally determined, and the mechanical response of the bulk material under tamping is simulated by EDEM software. The following research results are obtained: (1) the basic characteristics of the bulk filling material are measured by laboratory tests, and the basic parameters of the bulk filling material are obtained according to the virtual parameter calibration experiment. In the virtual calibration test of steel barrel compaction, the intrinsic parameters of gangue particles are obtained: Poisson's ratio is 0.19, density is 2670 kg / m ~ (3), elastic modulus is 15 GPA. In the virtual calibration test of natural rest angle, the recovery coefficient, static friction coefficient and dynamic friction coefficient of gangue particle model are 0.15, 0.44 and 0.05 respectively. (2) with the ramming angle of the compaction mechanism increasing, the static friction coefficient is 0.44 and the dynamic friction coefficient is 0.05. The amount of underconnected top of bulk filling material decreased first and then increased. When the compaction angle is 22 掳and 27 掳, the average compactness of the bulk material is close and larger than that of the ramming angle of 32 掳. Therefore, in the process of ramming, it is necessary to ensure that the tamping plate of the ramming mechanism enters the pile completely and the angle of the ramming should not be too large, so as to ensure the compaction effect and improve the compaction efficiency. (3) with the increasing of the particle size of the bulk material, The amount of underconnected top of bulk material increases and the average density of bulk material decreases continuously. When the particle size distribution is small and medium, the difference of average density is small. Therefore, in the preparation of bulk filling materials, considering the crushing cost, it is suggested that it should be broken to the medium particle size, which can not only increase the crushing speed but also ensure the compactness. (4) with the increasing of the speed of the ramming mechanism, The amount of underconnected top of bulk material shows a linear increasing trend. The speed of the ramming mechanism has little effect on the average compactness of the bulk material behind the ramming mechanism, so it can reduce the ramming speed of the ramming mechanism and reduce the pressure of the pump station and the input of the equipment.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD823.7

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