矸石充填体宏细观力学特性及充填综采支架围岩关系研究

发布时间：2018-01-17 15:05

本文关键词：矸石充填体宏细观力学特性及充填综采支架围岩关系研究　出处：《中国矿业大学》2016年博士论文　论文类型：学位论文

【摘要】：液压支架-围岩-充填体之间的关系是综合机械化充填开采技术体系中最重要的问题之一,而充填体性质研究是解决该问题的基础和保证。本文运用实验测试、理论分析、数值模拟和相似材料物理模拟等方法,研究了矸石充填体的宏细观力学性质,并对综合机械化充填开采过程中的支架-围岩-充填体间的关系展开了系统的研究。论文的主要创新工作和研究成果包括以下几个方面:(1)通过侧限压实试验研究了多种矿渣混合料的应力-应变、压实度和变形模量特征,发现应力-应变满足对数关系,适当增大细小颗粒、石灰或水含量,都有利于提高体系的抗压缩性能。结合Singh-Mitchell蠕变模型对破碎矸石的侧限压实蠕变试验过程进行分析,得到了适合五种破碎矸石的压实蠕变方程。(2)建立了离散元计算模型,分别对矿渣混合料的侧限压缩和矸石充填体的双轴压缩进行数值模拟分析。发现用簇单元模拟的结果更加接近于实际。石颗粒粘结强度或含石率较大时,矸石充填体的双轴压缩峰值强度均较大,峰后软化与涨落的现象也较为明显。含石率大于50%以后,强力链的贯通性逐渐下降,力链也发生倾斜。力链形态会随加载过程不断变化。(3)创建了矸石充填体与充填采煤液压支架夯实机构的相互作用的颗粒流计算模型,研究发现引入振动机制,能减缓推压板的应力增加速度,保证在相同应力下,推压板行进距离更远;增大频率或振幅均能提高夯实效果。(4)建立了充填综采支架-顶板-充填体力学模型,计算顶板岩梁的下沉量和工作面超前应力分布。发现初始充填高度是控制顶板岩梁各部分的下沉和运移稳定性的决定性因素,对工作面超前应力分布也有很大影响。支架作用于充填体的推压作用力对顶板下沉及工作面超前应力的控制作用主要表现在2.0MPa以内;支架让压高度对工作面超前应力也有一定的影响。(5)建立充填采煤液压支架和采场数值模型,对充填开采过程进行计算,验证了顶板变形和工作面超前应力的理论计算结果。支架顶梁上的应力分布整体上前面小后面大,且前、后顶梁上应力都会随开采状态而变化;支架让压高度对支架顶梁的应力分布和数值都会产生极大的影响。(6)在合理确定充填体和支架相似模型后,利用相似模拟试验对充填综采过程进行研究。发现初始充填高度和支架让压高度对顶板下沉量和超前应力的影响规律与理论部分相同,试验测量值与理论计算值及数值计算结果也基本吻合。(7)成功地将充填开采支架-顶板-充填体力学模型应用于某矿工作面,计算顶板下沉和应力分布规律,并与现场实测结果比较,验证了模型的可靠性。
[Abstract]:The relationship between hydraulic support, surrounding rock and filling body is one of the most important problems in the comprehensive mechanized filling mining technology system, and the study of filling properties is the basis and guarantee to solve this problem. Theoretical analysis, numerical simulation and physical simulation of similar materials were used to study the macroscopic and meso-mechanical properties of gangue filling. The relationship between support, surrounding rock and filling body in the process of comprehensive mechanized filling mining is systematically studied. The main innovative work and research results in this paper include the following aspects: 1). The stress-strain of various slag mixtures was studied by lateral compaction test. According to the characteristics of compaction degree and deformation modulus, it is found that the stress-strain relationship is logarithmic, and the content of fine particles, lime or water is increased appropriately. Combined with the Singh-Mitchell creep model, the creep test process of the broken gangue was analyzed. The compaction creep equation for five kinds of broken gangue is obtained. (2) the discrete element calculation model is established. Numerical simulation analysis of the side limit compression of slag mixture and biaxial compression of gangue filling is carried out respectively. It is found that the results of cluster element simulation are closer to the reality. When the bond strength or rock content of stone particles is higher. The peak strength of biaxial compression of gangue filling is larger, and the phenomenon of softening and fluctuation after peak is also obvious. When the rock content ratio is more than 50%, the permeability of strong chain decreases gradually. The shape of the force chain will change with the loading process.) the particle flow calculation model of the interaction between the gangue filling body and the tamping mechanism of the filling coal mining hydraulic support is established. It is found that the vibration mechanism can slow down the increasing speed of the stress of the push plate and ensure that the pressure plate travels farther under the same stress. Increasing the frequency or amplitude can improve the compaction effect. It is found that the initial filling height is the decisive factor to control the stability of subsidence and migration of each part of roof slate beam. It also has a great influence on the distribution of the leading stress in the working face. The controlling effect of the pushing and pressing force acting on the filling body on the roof subsidence and the leading stress of the working face is mainly within 2.0 MPA. The hydraulic support and stope numerical model is established to calculate the filling mining process. The theoretical calculation results of roof deformation and working face advance stress are verified. The stress distribution on the top beam of the support is small and large on the whole, and the stress on the front and back top beam will all change with the mining state. The stress distribution and value of the top beam will be greatly affected by the pressure height of the support. (6) after the reasonable determination of the similar model of the filling body and the support. The similarity simulation test was used to study the filling process of fully mechanized coal mining. It was found that the influence of initial filling height and support pressure height on roof subsidence and lead stress was the same as that of theory. The experimental results are in good agreement with the theoretical values and the numerical results.) the steve-roof filling mechanics model is successfully applied to the mining face of a certain mine. The reliability of the model is verified by calculating the law of roof subsidence and stress distribution and comparing with the field measured results.
【学位授予单位】：中国矿业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TD823.7

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