【作者】 魏风清；

【导师】 张铁岗；

【作者基本信息】 河南理工大学 ， 安全技术及工程， 2010， 博士

【摘要】 煤与瓦斯突出是由地应力、瓦斯压力、煤体结构综合作用的、严重威胁煤矿安全生产的矿井瓦斯动力现象。煤与瓦斯突出机理及预测指标研究是制定突出危险性预测和防突措施效果检验指标体系的重要理论和技术依据。论文综合采用理论分析、实验室实验、现场实测验证的方法,对煤与瓦斯突出机理、预测指标及临界值确定方法、测试仪表、工程应用进行了系统研究,形成了一套从机理——预测指标——临界值——预测仪表——工程应用的理论技术体系,提高了煤与瓦斯突出预测的可靠性和准确性。(1)在充分分析煤与瓦斯突出要素及其作用的基础上,讨论了煤与瓦斯突出的动力来源和能量转化,在煤与瓦斯突出过程中,破坏煤体的主要动力是地应力,而煤与瓦斯突出发生的主要能量来源于瓦斯膨胀能,提出了一定量的瓦斯膨胀能是煤与瓦斯突出发生、发展的必要条件。(2)煤与瓦斯突出的准备、发生、发展划分为3个连续过程:①受工作面附近地应力的作用,煤层卸压破坏;②积聚在煤体空隙中的瓦斯急速解吸涌出,煤体爆炸破碎;③瓦斯大量涌出,产生瓦斯煤混合流,搬运煤体,形成空气冲击波;根据弹塑性力学、空气动力学理论,详细研究了煤层卸压破坏、煤体爆炸破碎、瓦斯煤混合流运移的力学和能量条件,提出了煤与瓦斯突出的物理爆炸模型。(3)根据煤与瓦斯突出物理爆炸模型,分析了煤与瓦斯突出的影响因素:①煤体卸压是煤与瓦斯发生的激发因素,地应力越大、煤层强度越低,卸压波速度越大,煤层容易越形成大面积快速卸压破坏,有利于瓦斯突出的发生;②煤体裂缝形成的速度越快,越有利于瓦斯气泡的破裂,形成瓦斯煤混合流;煤体强度降低,有利于瓦斯气泡的破裂,有利于突出的发生;提出了瓦斯膨胀能大于煤体移动功是瓦斯煤混合流运移的必要条件,瓦斯膨胀能应大于小型煤与瓦斯突出的煤体移动功,瓦斯膨胀能临界值为76.96 kJ/t,为煤与瓦斯突出预测指标临界值的确定提供了理论依据。(4)根据煤与瓦斯突出的物理爆炸模型,对预测指标与瓦斯膨胀能的关系进行了分析,选取了区域突出危险性预测指标和工作面突出危险性预测指标;结合实验室试验,提出了预测指标临界值确定方法的技术路线、步骤以及可靠性评价方法,为煤与瓦斯突出预测指标及临界值研究提供了理论依据和技术方法。(5)根据煤层瓦斯流动的达西定律,研究了钻孔瓦斯涌出速度与瓦斯压力、测试时间等因素的关系,提出了测试仪表应满足的技术条件;分析了钻孔瓦斯涌出初速度q测试仪表存在的不足,研制了WY-Ⅰ型瓦斯q值测定仪,提高了钻孔瓦斯涌出初速度q的测试精度。(6)根据瓦斯膨胀能与预测指标的关系,提出了瓦斯解吸指标Q3 ,采用实验室试验和现场测定的方法,研究了瓦斯解吸指标Q3与瓦斯初始解吸量V1、瓦斯压力P、瓦斯含量X的关系,具有很好的相关性,可以采用瓦斯解吸指标Q3进行突出危险性预测。(7)通过新安煤田二1煤层瓦斯地质规律及实验室实验研究,提出了区域预测方法和指标,对新安煤田二1煤层进行了区域突出危险性预测,预测结果与生产实际基本一致。(8)通过实验室实验研究和现场专项测试,分析了工作面预测指标与瓦斯含量的关系,对预测指标的影响因素及其敏感性进行了分析,通过现场工业性试验和可靠性评价,确定了告成煤矿掘进工作面、回采工作面、孟津煤矿石门揭煤工作面突出危险性预测指标及其临界值,提高了突出危险性预测的可靠性。更多还原

【Abstract】 Coal and gas outburst is a gas dynamics phenomenon which is affected synthetically by stress,gas pressure and the coal structure. It has a serious threat to coal mine safety production. coal and gas outburst mechanism and outburst prediction indexes research are important theoretical and technical basis of setting out outburst risk forecast and prevention measures of coal and gas outburst effect test indexes system. The article uses synthetically methods of theoretical analysis, laboratory experiment, and on-site measurement and verification to study systematically the mechanism of coal and gas outburst, fixing method of prediction indexes and critical value, testing instrumentation and engineering application, then a technical system theory from the mechanism - forecast indexes- critical value - prediction instrument– to application of project system is formed, which improves the reliability and accuracy of coal and gas outburst prediction.Basing on the full analysis of coal and gas outburst factors and its function, the article discussed the power sources and energy conversion of coal and gas outburst. in the process of coal and gas outburst, stress is the main force to destroy the coal , while the main energy of coal and gas outburst comes from gas expansion energy, so a certain amount of gas expansion energy is the necessary condition which coal and gas outburst happen and develop.The preparation occur and development of coal and gas outburst can be divided into three continuous processes:①Coal is pressure relief destructed by the aiction of stress nearly the work face;②The gas that accumulated in the coal gap poured out Sharply and coal explosion shattered;③a large amount of gas poured out and coal and gas mixed flow was produced, which transits coal and formats air Shockwave;according to plastic and elastic mechanics, aerodynamics theory, the article studied the coal seam pressure relief destruction, coal explosive fragmentation, the mechanical and energy conditions of gas and coal mixture flow in details, and put forward the physical explosion model of coal and gas outburst.According to the physical explosion model of coal and gas outburst, analyzed the impact factors of coal and gas outburst;①C oal pressure relief is the motivating factor of coal and gas outburst occur, the greater the stress, the lower seam strength, the relief wave velocity is greater,and large-scale fast relief destruction become easier for coal. it’s favorable for the occurrence of gas outburst;②t he faster Coal cracks formed, the more favorable breakdown of gas bubbles and forming coal and mixed flow;the strength of coal reduces that is propitious to gas bubble break and the occurrence of outburst;it proposed that gas expansion energy greater than coal moving power is a necessary condition of moving mixture of coal gas flow. Gas expansion energy should be greater than small-sized coal and gas outburst moving power. the gas expansion energy critical value is 76.96 kJ/t, it provided a theoretical basis for determination the critical value of coal and gas outburst prediction indexs.According to outburst physical explosion model of coal and gas outburst, analyzed the relationship between prediction indexs and gas expand energy,selected region risk prediction indexes and work face outburst prediction indexes. combined with laboratory testing, technical route, process of prediction index critical value determination methods and reliability evaluation method is proposed. and provided a theoretical basis and technical approach for coal and gas outburst prediction indexs and the critical value research.According to Darcy’s law of gas flow, studied the relationship of initial rate of gas emission in drilling hole q, gas pressure, test time and other factors, and put forward the technical requirements which test instrument should meet with. analyzed the shortage of test instrument of initial rate of gas emission in drilling hole q, developed WY-Ⅰtype gas q value test meter, which improves the test accuracy of initial rate of gas emission in drilling hole q.According to the relationship of gas expansion energy and prediction indexes, put forward gas desorption index Q3 ,using laboratory tests and filed measurement methods, studied the relationships of gas desorption index Q3 ,gas initial desorption quantity V1, gas pressure P and gas content X,which are good correlation.gas desorption index Q3 can be used to predict outburst rick.Through Xin‘an coal filedⅡ1 coal seam gas Geological rule and laboratory studying, proposed regional prediction methods and indexes,and took a regional outburst of prediction of Xi’anⅡ1 coal seam. The result is consistent with the actual production.Through laboratory research and on-sit testing, analyzed the relationship between work face outburst prediction indexes and gas content. and also analyzed the impact factors and sensitivity of prediction indexes. Through field industrial experiment and reliability assessment, determined the Coal and gas outburst forecast prediction indexes and their critical value of Gaocheng Coal mine advancing work face, coal face and Mengjin exposing outburst seam by crosscut. and the reliability of Outburst Prediction is improved.更多还原