石门揭构造软煤诱发煤与瓦斯突出模拟试验研究

发布时间：2018-11-19 07:22

【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。
[Abstract]:Most of the coal is related to the occurrence of gas outburst and complicated geological structure. The coal seams in these areas have been destroyed by tectonic movement into broken coal, broken coal or minced coal, and developed structural soft coal. The coal outburst in Shimen is the most powerful and dangerous gas dynamic phenomenon in coal and gas outburst accidents. Therefore, it is of great practical significance and practical value to study the outburst characteristics of soft coal in Shimen structure under the influence of geological structure and to take corresponding preventive measures for the safe and efficient production of coal mines. In this paper, the physical and mechanical properties of structural soft coal are studied, and then the physical model of structural soft coal is established, and the similar simulation test is carried out on the test platform of Shimen structure soft coal in laboratory. The main research results are as follows: the physical and mechanical properties of structural soft coal and its influence on coal and gas outburst are comprehensively analyzed. Micropore, large specific surface area, strong adsorption ability and low permeability can preserve more gas in structural soft coal, and low mechanical strength can reduce the ability of structural soft coal to resist external force. The physical and mechanical properties of structural soft coal are the important reasons for the easy occurrence of coal and gas outburst in the structural soft coal zone. Based on the research results of geological structure and the relationship between coal and gas outburst, a test model of soft coal outburst in Shimen structure of compressional fault zone is established. In the model, there is a reverse fault with a drop greater than the thickness of the coal seam, and a fold is developed in the upper face of the fault, which changes the thickness of the coal seam. The basic characteristics of the test model are summarized and the mechanical analysis is carried out. Based on the idea of similarity simulation test and the train of thought of geomechanical model test, a similar simulation test of soft coal in Shimen exposed structure of compressible fault zone was carried out in the laboratory, aiming at the roof and floor rock properties and mechanical parameters of outburst seam 11-2 in Huainan mining area. The variation law of stress and displacement of coal and rock during the process of shimen uncovering soft coal structure, the variation law of gas pressure in coal seam during outburst, and the variation of temperature and acoustic emission during aeration and outburst are studied experimentally. Using the numerical simulation software COMSOL Multiphysics, a numerical model of soft coal in Shimenjie structure of compressive fault zone is established and solved. The stress evolution, fracture development and gas migration during the process of shimenjie structural soft coal are studied. It is found that there is an abnormal tectonic stress field near the fault, which is superimposed with the concentrated stress caused by excavation, and gas plays an important role in the start-up and development of the outburst. Finally, by analyzing the results of similar simulation tests and numerical simulations, it is concluded that the outburst of the structural soft coal in the compressive fault zone is a concentrated stress caused by excavation and abnormal tectonic stress, which firstly increases the elastic potential of the structural soft coal. Creating conditions for gas tearing coal body outburst; Then, the gas destabilizes the broken coal and carries the broken coal out at a higher gas pressure gradient.
【学位授予单位】：安徽理工大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TD713

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