【作者】 王振；

【导师】 尹光志； 胡千庭；

【作者基本信息】 重庆大学 ， 安全技术及工程， 2010， 博士

【摘要】 生产实际表明,深部高瓦斯煤层发生的动力灾害往往表现出兼具煤与瓦斯突出和冲击地压两种灾害的特征。上述非典型动力灾害的出现,为其定性带来了难题,而灾害的定性将决定其相应的预防和治理措施。因此,有必要把冲击地压和煤与瓦斯突出统一起来进行研究,建立新的煤岩动力灾害分类体系,研究灾害间的诱发转化条件,从而为灾害的定性和预防治理提供理论指导。本论文依托国家重大基础研究发展计划(973计划)课题“煤岩瓦斯动力灾害的动力学演化机理”和国家自然基金重点项目“煤与瓦斯突出机理及探测预防基础研究”,以煤岩瓦斯动力灾害新的分类及诱发转化条件为中心,进行了如下几个方面的研究:(1)针对发生非典型动力灾害的煤的性质区别于一般的突出构造软煤和发生典型冲击的硬脆煤的特点,本文利用瓦斯气体密封系统,提出了测定含瓦斯煤体力学指标的类单轴实验方法;并通过实验研究,得到了有效围压为零条件下瓦斯对煤样力学性质和力学响应的影响规律。(2)针对深部条件下“三高”开采的生产实际,论文通过实验研究了不同围压、温度和瓦斯吸附压力条件下,煤样瓦斯的解吸特性及渗透率的变化规律,分析了不同条件下应力、瓦斯和温度对灾害发生的不同作用机制。(3)煤岩的破坏失稳是煤岩体损伤不断累积和断裂逐渐发展的结果。基于此,通过理论和模拟研究分析了煤岩裂隙的扩展演化规律和破坏特征,认为煤岩瓦斯动力灾害的失稳破坏主要可分为准静载作用下的流变剪切破坏和动载作用下的瞬时拉伸破坏两种形式,并建立了各自的力学分析模型。(4)能量转化是物质物理过程的本质特征,物质破坏是能量驱动下的一种失稳现象。煤岩动力灾害的发生过程实质上就是能量释放和能量耗散的综合结果。因此,论文在分析煤岩系统破坏失稳过程中能量来源的基础上,结合冲击地压和煤与瓦斯突出发生的能量本质,建立了煤岩动力灾害发生的统一能量方程,分析了煤岩系统破坏失稳过程中的能量传递过程,并提出了灾害发生的能量判据。(5)根据煤岩瓦斯动力灾害的统一能量方程和瓦斯在其中参与程度的不同,建立了煤岩瓦斯灾害新的分类体系——典型的煤岩瓦斯动力灾害(包括冲击地压和煤与瓦斯突出)和非典型的煤岩瓦斯动力灾害(包括煤岩瓦斯压出和煤岩瓦斯突出),并提出了区分非典型动力灾害即煤岩瓦斯压出和煤岩瓦斯冲击的实验方法。实验结果和实例证明了此鉴别方法的科学性、可行性。(6)论文结合高瓦斯煤层冲击地压和突出的异同点,以实验研究和理论分析为基础,提出了煤岩瓦斯动力灾害的统一理论,建立了两种灾害在孕育发生和发展等不同阶段的诱发转化条件,研究了不同应力分布对煤岩瓦斯动力灾害的控制作用,分析了采场和巷道发生动力灾害的各自特征。(7)研究及实践表明,钻屑量指标对预测以地应力为主导因素的动力灾害较为敏感,是深部高瓦斯煤层动力灾害预测的重要参考指标之一。常用的最大钻屑量指标仅仅反映了某一点的应力情况,而动力灾害的发生主要是由于应力状态的突然改变产生的,也就是应力变化梯度的大小是决定灾害发生的主要原因。因此,论文提出了考察应力变化情况的新的钻屑量指标,即钻屑增量变化指标。结合采掘工作面支承压力的分区特点,在整体把握钻屑增量指标的前提下,论文着重把握两个拐点处量值的变化。理论分析和实践证明,采用钻屑增量指标,再辅以最大钻屑量指标,则可更好的反映工作面的应力变化情况,从而能够更为准确的预测深部高瓦斯煤层灾害发生的可能性。更多还原

【Abstract】 Practical case show that dynamic disasters have mutual features of coal-gas outburst and shock burst in deep high methane mine. So how to define and prevent these disasters is a problem. In order to meet practical demand, a new classification will be built to substitute the dated system and induction and transforming conditions between disasterswill be studied based on the further studied on united the coal-gas outburst and shock burst. So relyed on the National Great Research Foundation of China(973 Programs)“Mechanism of coal and rock , gas dynamic disastrous evolution”and the National Natural Science Foundation of China“the fundamental study on Mechanism and Prediction & Prevention techniques of Coal-gas Outburst”, the thesis give a study on the a new classification and induction and transforming conditions about rockburst and coal-gas outburst in the following aspects:(1)Properties of coal fedding from the coal seam where happening atypical dynamic disasters are different from the coal fedding from the coal seam where happening typical dynamic disasters.So utilizeing the gas sealing system,analogic uniaxial experiment method was proposed.Mechanical Properties and Response of Coal treated with gas under effective confirming pressure=0 had been studied also.(2)In viewing the high temperature, pore-pressure, stress in deep mining conditongs, the variation has been studied of which instantaneous desorption characteristics and permeability of gas under different confining pressure, temperature and pore-pressure. Also the effect of stress,gas and temperature on disasters have been researed.(3)The failure of coal caused by accumulation of damage and development of fracture. So the evolution laws and failure characteristics of fracture have been studied.Two main forms of failure are completely analyzed by theoretical analysis and numerical simulation that are shearing rheological failure affected by quasi-static loading and tensile instantaneous failure for dynamic loading. The force analysis models are established respectively.(4)Energy transformation is the essential character of material’physical process. Material damage is one of failure phenomenon caused by energy. The essence of dynamic disasters is the result of energy dissipation and release. Unified energy equation has been built based on the analysis about energy source and occurring essence of disasters. Energy transfer process is analyzed and energy criteria is put forward in the paper.(5)A new classification has been built based on the unified energy equation and the amount of participation by gas which contains typical disasters (rock burst and coal-gas outburst) and atypical disasters( extrusion of coal-gas and impact of coal-gas), Distingish methed of Atypical dynamic disasters has been proposed. The experimental results show that this distingish methed is scientific and feasible .(6)Based on the analysis of the similarities and differences of coal-gas outburst and rockburst , unified theory and induced transformation mechanism has been proposed at different stages. Control action of stress affecting on disasters is analyzed and the resbectively characters of disasters occurring in stope and roadway is also studied.(7)The maximum drillings volume commonly used just reflects the stress of one point, but the stress gradient is the main causes of disasters occurred. So the Index of drillings incremental volume is put forward for completely reflect the change of stress. The stress change of inflection points are the key of study. Theory analysis and practice proved, the index of drillings incremental volume plus the maximum drillings volume can completely reflect the stress change in working face, so the occurrence of disaster can be predicted more accurately.更多还原