【作者】 高魁；

【导师】 刘泽功；

【作者基本信息】 安徽理工大学 ， 安全技术及工程， 2013， 博士

【摘要】 大多数煤与瓦斯突出的发生和复杂的地质构造有关,这些区域的煤层被构造运动破坏成了碎裂煤、碎粒煤或糜棱煤,构造软煤发育。而石门揭煤突出又是煤与瓦斯突出事故中强度最高和危险性最大的一种矿井瓦斯动力现象。因此,研究地质构造影响下石门揭构造软煤的突出特性,采取相应的防治措施对煤矿安全高效生产具有十分重要的现实意义和实用价值。本文首先对构造软煤的物理力学特性进行研究,然后建立石门揭构造软煤的物理模型,并在实验室搭建石门揭构造软煤的试验平台进行相似模拟试验,结合数值模拟取得了以下主要研究成果：综合分析了构造软煤的物理力学特性及其对煤与瓦斯突出的影响。微孔隙发育、比表面积大、吸附能力强和渗透性低使构造软煤能够保存较多的瓦斯；力学强度低使构造软煤抵御外力作用的能力降低。构造软煤的物理力学特性是导致构造软煤带容易发生煤与瓦斯突出的重要原因。在地质构造和煤与瓦斯突出关系的研究成果基础上,构建了压性断层带石门揭构造软煤突出的试验模型。模型中有一落差大于煤层厚度的逆断层,在断层上盘发育有褶曲,使煤层厚度发生了变化,总结了该试验模型的基本特征并进行了力学分析。基于相似模拟试验思想和地质力学模型试验思路,针对淮南矿区11-2突出煤层的顶底板岩性及力学参数,在实验室进行了压性断层带石门揭构造软煤的相似模拟试验。试验研究了石门揭构造软煤过程中煤岩的应力和位移的变化规律,突出过程中煤层内瓦斯压力变化规律,充气和突出过程中温度和声发射的变化规律。利用数值模拟软件COMSOL Multiphysics建立了压性断层带石门揭构造软煤的数值模型并进行了求解,研究了石门揭构造软煤过程中的应力演化、裂隙发展和瓦斯运移规律。发现断层附近存在异常的构造应力场,并与由开挖导致的集中应力相互叠加；瓦斯在突出的启动和发展过程中发挥了重要作用。最后,通过对相似模拟试验和数值模拟的结果分析得出：压性断层带石门揭构造软煤突出是一个由开挖导致的集中应力和异常的构造应力首先使构造软煤内的弹性潜能增加,为瓦斯撕裂煤体发生突出创造条件；然后,瓦斯使破碎的煤体失稳,在较高的瓦斯压力梯度下携带碎煤抛出的一个过程。更多还原

【Abstract】 Coal and gas outburst always occurs in the strongly varied geological structure region, such as fault, fold and coal seam thickness and so on, forming the development of tectonic soft coal. Moreover, tectonic soft coal uncovering by cross-cut outburst is the most strong and dangerous coal and gas outburst. Therefore, the study of tectonic soft coal uncovering by cross-cut induced outburst mechanism and corresponding prevention measures have a practical significance and practical value for the safety production in coal mines. This paper studied the physical mechanic properties of tectonic soft coal, and then established the physical model of tectonic soft coal during the uncovering tectonic soft coal by cross-cut, and built up a test platform to test the outburst properties during the uncovering tectonic soft coal in the laboratory. The main research results are as follows:Regards of different coal and rock ingredients, we chose a typical sample from native structure of coal and tectonic soft coal, and made research on the physical and mechanical characteristics of the two kinds of coal, with microscope, pressure mercury, IS-100type isothermal adsorption and desorption meter, MYS-I type of test equipment on coal and rock sample seepage rate, gas coal and rock mass gas-solid coupled parameter tester. Based on the experiment, we analyzed the effect of physical and mechanical characteristics of tectonic soft coal on coal and gas outburst. The physical and mechanical characteristic of tectonic soft coal increases the danger of coal and gas outburst.Based on the research results of relationship between geological structure and coal and gas outburst, the physical model for the tectonic soft coal outburst was established. There is a reverse fault that the throw is greater than the thickness of the coal seam in the model; fole developing in the hanging wall of the fault makes the coal seam thickness changes. The basic characteristics of the physical model were summarized and mechanics analysis of the physical model was done. The outburst occurs in tectonic soft coal seam was influenced by coupling effect of physical mechanical properties, gas pressure and tectonic stress.Based on ideas of the similar material simulation test and geomechanical model test and according to the lithological and mechanical parameters of11-2outburst coal seam in Huainan mining area, similar simulation test of tectonic soft coal uncovering by cross-cut was done in the laboratory. The change laws of coal and rock stress and displacement in the process of tectonic soft coal uncovering by cross-cut were studied. The gas pressure, temperature and acoustic emissionwere in the process of gas injection and outburst were studied too.The tectonic soft coal uncovering by cross-cut of numerical model was established by simulation software of COMSOL Multiphysics to study on the evolution of stress, crack development and the law of gas migration. The results showed that there was obvious tectonic stress concentration area in the geological structures vicinity; Tectonic stress and excavation stress concentration due to the tectonic soft coal further broken and deep extended large outburst; Gas pressure played an important role in the process of coal and gas outburst start and sustained development.Finally, based on the similar simulation test results and the numerical simulation analysis of tectonic soft coal uncovering by cross-cut, it obtained the reason for the outburst during the uncovering tectonic soft coal. First, ground stress makes the coal body crusher and the elastic potential of coal body increase to create the conditions for gas to tear coal body induced gas outburst; then, the destructioned coal instability and powdered coal are carried by gas pressure.更多还原