煤的电导率随地应力变化关系的研究

从理论上对煤的导电性及其影响因素进行分析,研究得出了煤的电导率随地应力变化的函数关系;在实验室利用专门研制的实验装置通过测定不同煤在承受不同的应力时的电导率值,得出了煤的电导率与地应力之间的变化关系.实验与理论研究的结果相吻合,从而为利用电磁波透视法预测煤层突出危险性技术的研究奠定了基础.     

中国煤炭苯提取液中多环芳烃赋存规律研究

利用高效液相色谱法对我国不同变质程度原煤的苯提取液中多环芳烃进行了测定．分别对不同煤种苯提取液中多环芳烃含量与煤的挥发份和碳氢比的关系进行了细致的研究．得出了煤苯提取液中多环芳烃赋存规律与煤变质程度的相关性．为煤的合理加工利用和多环芳烃污染的防治提供了基础资料．     

煤材料变形力学特性分析

在简单压缩实验条件下获得了煤的应力－应变（δ－ε）关系曲线．较好地再现了煤的应变强化和应变软化特性．实验表明煤材料具有典型的弹塑性性质；煤和地壳中其他岩石相比具有一定的特殊性．煤的应力、应变及破坏规律与煤的力学性质有关．     

铸铁构件固有频率与其残余应力关系的研究

铸铁构件残余应力的评价过程一直相当繁琐．为找到一种简便无损的铸件残余应力评价新方法,以梁形铸件为研究对象,从理论计算和实际测试2个角度对铸件固有频率与其残余应力的关系进行了研究,得出了反映二者之间关系的数学模型．由这一模型可知,梁形铸铁构件残余应力与其固有频率的函数关系为抛物线,即铸件残余应力与其固有频率的平方成比例．利用其数学模型对一组梁形铸铁试件的残余应力和固有频率进行了理论计算,同时采用X射线应力测定法和实验模态分析方法测试它们的残余应力和固有频率,得出结果基本吻合．     

掘进工作面前方电磁辐射分布规律研究

为了研究煤矿掘进工作面前方煤体内不同深度的煤岩电磁辐射分布规律，利用KBD5电磁辐射监测仪对工作面前方煤体电磁辐射进行了现场测试，基于煤岩电磁辐射力电耦合规律，对煤岩变形破裂过程与电磁辐射强度的相关性进行了理论分析．结果表明：电磁辐射变化与煤体应力状态有较好的对应关系，工作面煤体内部具有多种应力状态和变形破裂状态．文中给出了比较典型的4种电磁辐射分布类型：煤体长期暴露的电磁辐射分布、防突措施后电磁辐射分布、新揭露煤体电磁辐射分布、有构造煤层的电磁辐射分布．     

CeO2 的加入对(ZrO2)0.86(MgO)0.14陶瓷电导率的影响

对（ＺｒＯ２）０．８６ＭｇＯ０．１４外加２～１２ｍｏｌ％ＣｅＯ２陶瓷材料的电导率进行了研究,对此类材料的电导率、活化能与强度、结构的关系进行了分析。实验发现,当外加ＣｅＯ２含量在６～８ｍｏｌ％时,电导率、活化能发生反常变化,此变化可能与点缺陷行为有关;随热处理时间的增加,电导率下降,电导活化能出现极小值,而弯曲强度出现极大值,出现极值的区域具有较好的对应关系。     

煤材料变形力学特殊分析

在简单压缩实验上获得了煤的应力－应变关系曲线，较好地再了煤的应变强化和应变化软化特性。实验表明煤材料具有典型的弹塑性性质；煤和地壳中其他岩石相比具有一定的特殊性，煤的应力，应变及破坏规律及煤的力学性质有关。     

平面状态下的力磁关系及实验分析

从磁性、弹性基本理论出发,根据最小能原理推导出应力张量磁化率关系表达式,提出张量磁化率Molar圆概念,得出主磁化率表达式以及主磁化率方向夹角,进一步得出应力σ-磁化率△xnσ变化量的关系表达式。设计出磁化率检测装置,测量了受单向应力状态下的机械钢板不同取向上的磁化率。实验结果表明理论值与实验值符合的很好。从而为改善磁测技术提供了理论依据和潜在方法。     

注氮惰化窒息燃烧煤炭氧浓度的实验研究

利用煤炭自燃实验系统,对龙固煤矿7煤煤样的自燃过程进行了模拟实验.实验研究了注氮情况下的煤氧化煤温、自燃状态与氧含量的变化关系,确定了龙固煤矿7煤煤样窒息的最低氧浓度,研究结果对使用注氮防治煤炭自燃技术的应用具有重要的现实指导意义.     

CFRP加固RC梁弯曲裂缝引起的剥离分析

为研究CFRP加固钢筋混凝土粱弯曲裂缝引起的界面粘结失效即剥离破坏机理,采用钢筋混凝土梁的受力原理,分析了加固梁截面的弯矩一曲率关系,结合截面应力应变的变化特性求得纤维布应力;根据滑移量角度与弯曲裂缝引起的剥离机理的关系,建立纤维布的拉力增量滑移模型,得出了相对滑移量表达式;利用非线性界面本构关系,对剥离破坏进行预测．...     

不同温度应力条件下煤体渗透率实验研究

为了深入研究渗透率与温度和应力的关系,分别采用吸附性气体甲烷和非吸附气体氦气,进行了不同应力条件,不同温度条件下的煤体渗流实验.结果表明,不同有效应力条件下煤体渗透率与温度的关系,并非单调递增或单调递减,而是存在一个转折区,转折区的位置取决于有效应力与热应力的大小对比关系,低有效应力条件下,热应力大于有效应力,煤体外膨胀,渗透率随温度的升高而增大,呈正指数关系;高有效应力条件下,热应力小于有效应力,煤体内膨胀,渗透率随温度的增加而减小,呈负指数关系.这一发现将以往的矛盾结果统一了起来.     

晋城无烟煤煤中CH4和CO2运移规律研究

基于三轴应力条件下,煤岩有效应力、吸附膨胀量和渗透率的一体测试,研究了晋城无烟煤吸附甲烷和二氧化碳后,渗透性随有效应力改变和煤岩吸附膨胀效应的变化规律.认为煤岩吸附膨胀量和孔隙压力的关系可用兰氏方程描述;煤岩渗透性同有效应力、吸附膨胀量均呈负指数函数关系,同时结果表明:甲烷和二氧化碳在晋城无烟煤中的扩散方式不同,煤岩对甲烷的吸附膨胀符合单孔气体扩散模型,而对二氧化碳的吸附膨胀符合双孔气体扩散模型,且甲烷的吸附膨胀速率小于二氧化碳的吸附膨胀速率;煤岩饱和吸附后,各孔隙压力条件下的初始渗透率与孔隙压力呈幂函数关系减小.针对晋城无烟煤,同等条件下煤岩吸附甲烷后的渗透率为吸附二氧化碳后渗透率的1.14～1.51倍,大部分在1.30倍左右.     

煤层底板音频电透视探测 成果反映的底板阻水条件

应用音频电透视技术,分析了杨村煤矿2702工作面底板30m和50m深度界面的探测成果, 并与井下水文钻孔揭露的煤层底板岩层结构及探水结果对比研究,发现音频电透视探测的煤层底板综 合视电导率高异常与岩层的裂隙性及其充水程度具有很强的关联性;岩层裂隙与含水层连通性良好部 位明显显现视电导率高值异常,结果表明,音频电透视探测成果能够综合反映底板岩层的阻水条件。     

基于微震成像的采煤工作面应力异常监测

为了实现对深井采煤工作面的冲击地压灾害预防,采用微震走时成像技术,监测采煤工作面的应力异常.根据系统要求布置传感器台网,实现工作面全覆盖;采用层状模型分析地震波传播路径,计算地震波传播速度,利用子空间分阶段求解的方法进行反演,实现对监测区域的地震波走时层析成像;结合地震波速度和岩石所受应力的关系,达到研究采煤工作面应力异常的动态分布及变化特征的目的.试验结果表明：工作面推进时,煤层顶板高应力异常达到最大,工作面前方的高应力异常区动态变化范围较大,工作面后方存在较稳定的地震波低速异常,利用微震成像技术可以有效地监测地震波速度异常区域的范围及变化特征.     

Fractal analysis of thermal conduction of loose coal

For deep mining engineering,heat transfer of coal mass is a vital factor in the thermal environment of coal mines.In order to study the thermal conduction mechanism,we obtained gray images of coal mass microstructure by scanning samples with a digital microscope.With the use of Matlab,these gray images were transformed into binary images,which were then transformed into a corresponding matrix consisting only of the values 0 and 1.According to the calculation method of box-counting dimension,we calculated the fractal dimension of the loose coal to be approximately 1.86.The thermal conductivity expressions of loose coal were derived based on the simulation method of thermal resistance.We calculated the thermal conductivity of loose coal by using a fractal model and compared the calculated values with our experimental data.The results show that the test data show an encouraging agreement with the calculated values.Hence fractal theory is a feasible method for studying thermal conductivity of loose coal.     

Test studies of gas flow in rock and coal surrounding a mined coal seam

An analysis of the variation rule of abutment pressure at the mining working face in a single coal seam and the mechanical behavior of surrounding rock during stoping is presented. Consideration of the elastic and plastic deformation zones that develop during the mining process allowed the determination of a relationship between horizontal stress and vertical stress. Based on this, a confined pressure unloading test was conducted by the use of the “gas-containing coal thermo-fluid-solid coupling 3-axis servo seepage” experimental apparatus. Thus, gas flow patterns in the elastic and plastic zones were derived from an experimental point of view. Darcy’s law and the Klinkenberg effect were used to derive a gas flow equation for the elastic and plastic stress fields. The study of gas flow phenomena at the working face during coal mining is of great importance for the study of gas migration and enrichment patterns.     

Response characteristics of gas pressure under simultaneous static and dynamic load: Implication for coal and gas outburst mechanism

Coal and gas outbursts are dynamic disasters in which a large mass of gas and coal suddenly emerges in a mining space within a split second. The interaction between the gas pressure and stress environment is one of the key factors that induce coal and gas outbursts. In this study, first, the coupling relationship between the gas pressure in the coal body ahead of the working face and the dynamic load was investigated using experimental observations, numerical simulations, and mine-site investiga...     

Correlation of electromagnetic radiation emitted from coal or rock to supporting resistance

More accurate forecasting of rock burst might be possible from observations of electromagnetic radiation emitted in the mine. We analyzed experimental observations and field data from the Muchengjian coal mine to study the relationship between electromagnetic radiation signal intensity and stress during the fracturing of coal, or rock, and samples under load. The results show that the signal intensity is positively correlated with stress. In addition, we investigated the change in the electromagnetic radiation intensity, the supporting resistance in a real coal mine environment, and the coal or rock stress in the mining area. The data analysis indicates that: 1) electromagnetic radiation intensity can accurately reflect the distribution of stress in the mining area; and, 2) there is a correlation between electromagnetic radiation intensity and supporting resistance. The research has some practical guiding significance for rock burst forecasting and for the prevention of accidents in coal mines.     

A method of determining the permeability coefficient of coal seam based on the permeability of loaded coal

This study developed the equipment for thermo-fluid–solid coupling of methane-containing coal, and investigated the seepage character of loaded coal under different working conditions. Regarding the effective pressure as a variable, the variation characteristics of the gas permeability of loaded methane-containing coal has been studied under the conditions of different confining pressures and pore pressures. The qualitative and quantitative relationship between effective stress and permeability of loaded methane-containing coal has been established, considering the adsorption of deformation, amount of pore gas compression and temperature variation. The results show that the permeability of coal samples decreases along with the increasing effective stress. Based on the Darcy law, the correlation equation between the effective stress and permeability coefficient of coal seam has been established by combining the permeability coefficient of loaded coal and effective stress. On the basis of experimental data, this equation is used for calculation, and the results are in accordance with the measured gas permeability coefficient of coal seam. In conclusion, this method can be accurate and convenient to determine the gas permeability coefficient of coal seam, and provide evidence for forecasting that of the deep coal seam.