煤巷卸压带对煤和瓦斯突出的作用机理

应用岩石力学、弹塑性力学等有关知识，探讨了煤巷卸压区对煤和瓦斯突出发生的作用机理，建立了煤层界面的应力分布状态方程以及煤巷卸压带和地应力、瓦斯压力、煤强度之间的关系式，分析了煤苍卸压区中煤体稳定性的条件，表明：煤和瓦斯突出与工作面前方卸压区的大小有关，突出危险性预测就是检测卸压区的大小，现行防突措施的有效性取决于采取措施后卸压区的长度是否足以防止突出的发生。     

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．     

掘进煤巷应力仿真和延时煤与瓦斯突出机理研究

掘进煤巷工作面应力“三带”分布对延时突出起着关键作用．采用岩石破裂过程RFPA^2D分析软件数字仿真了煤巷掘进工作面应力状态及“三带”分布范围，分析了渗透力对瓦斯突出的作用．结果表明：充分卸压带为2m，部分卸压带为2～6m，集中应力带为6～18m．由于掘进工作面煤层应变软化，卸压带宽度随时间延长而展宽；当煤体水平承载能力小于水平载荷时，煤体脱离，在重力作用下冒落、掉渣．此时水平载荷转移到深部煤体，使处于临界状态的深部煤层破坏．这是一个正反馈的加速过程，最后水平载荷形成应力破坏波，造成煤体的快速拉裂破坏，形成煤与瓦斯突出．     

水力卸压防止承压散体煤和瓦斯突出机理

从散体煤和瓦斯失控突出条件出发，分析了超前水力卸压防止散体煤和瓦斯突出作用原理，并通过检测水力卸压前后瓦斯涌出量变化、利用电磁辐射技术检测煤体破裂变形以及相关实际资料验证了该机理的正确性。结果表明，实施水力卸压防突措施时电磁辐射强度及脉冲数增大，有利于防止突出，其防突作用原理有3条：1）煤体增裂预释放瓦斯，增加切向应力和散体摩擦阻力，2）增加煤体位移，预降低高压侧径向有效地应力，减少散体突变运动径向应力差，3）注水湿润使散体间及相邻蝶岩体黏结，增大了散体摩擦阻力系数．     

深孔控制卸压爆破及其防突作用机理的实验研究

本文应用相似理论，爆破力学，岩体力学等知识，探讨了深孔控制卸压爆破及其防突作用机理，并进行了实验室的模拟试验：得出了爆破后煤体周围应力分布状态及其孔洞分布形式，研究工作表明：深孔控制卸压爆破能够防止煤和瓦斯突出的主要原因在于采取措施后能够形成较大范围的卸压区，卸压区的形成是防突措施有效性的必要条件。     

水力冲孔措施在深部低透气性煤层中的应用研究

针对鹤壁八矿无保护层可采、低透气性突出煤层的现状,采用水力冲孔增透措施,利用数值模拟软件对出煤量与卸压范围大小及卸压范围内煤体位移量的变化情况进行仿真.结果表明,在水射流有效靶距范围内,水力冲孔孔洞半径与卸压范围成正比关系;随着冲孔半径的增大,钻孔周围煤体位移逐渐增大.在应力和瓦斯压力的作用下,孔洞周围煤体发生位移,应力向深部转移.通过检测卸压区内的煤层瓦斯含量与压力,得出卸压范围内煤层瓦斯含量和压力大幅度降低,均降至临界值以下,与数值模拟结果基本相符,说明数值模拟结果是可信的.     

煤与瓦斯突出过程中地应力作用机理研究

为了进一步探究地应力在不同工况下对突出发生的参与控制机理,本文开展了变应力因素下的诱突实验研究,并基于含瓦斯煤流-固耦合数学模型对受载含瓦斯煤体卸压后的应力分布与演化规律进行了数值模拟研究.研究结果表明:内部应力状态的分布及演化行为受到瓦斯流场状态、地应力以及卸压情况等因素的共同控制;吸附瓦斯压力与卸压口径的增大都会对...     

基于不同结构形式的钢箱梁锚固区力学行为研究

为提高索梁锚固区数值分析的准确性,根据陕西汉中某斜拉自锚式悬索组合体系桥吊杆锚固区的结构特点,对两种锚固构造和不同锚固区节段长度,建立了8个单元模型.对不同模型中的应力、变形和结构整体屈曲特性进行对比分析.分析结果表明:采用相同锚固结构形式时,不同锚固区节段长度对锚固区应力分布情况影响较大;随着节段长度的增加,锚固区整体变位的变化趋于稳定;节段长度的选取对锚固区结构屈曲特性影响明显.无论采用哪种锚固构造设置,当锚固区节段长度选取远离锚固区2倍梁高时,能较准确反应结构的受力情况.所得结论可供锚固区数值模拟及模型试验节段选取时参考.     

煤巷卸压带及其在煤和瓦斯突出危险性预测中的应用

本文应用岩体力学,弹塑性力学等有关知识,探讨了煤巷卸压带对煤和瓦斯突出的作用机理,建立了煤层界面的应力分布状态方程以及煤巷卸压带和地应力,瓦斯压力,煤强度之间的关系式,并分析了煤巷卸压带中煤体稳定性的条件。研究工作表明:煤巷卸压带中的瓦斯压力,煤体透气性值可以作为突出危险性预测指标和防突措施效果检验的敏感指标。最后,利用自行设计的泡沫封孔测压仪对现场进行了突出危险性预测和防突措施效果检验,得到了十分满意的结果。     

超长"孤岛"综放面大煤柱护巷的数值模拟

基于兖矿集团兴隆庄4324超长“孤岛”综放工作面开采条件，采用离散元数值计算程序UDEC3．0，模拟研究了不同宽度煤柱护巷条件下巷道围岩的应力分布和变形特征，分析了不同宽度煤柱的承载状况和应力峰值区的位置．研究表明，采用20m大煤柱维护巷道，可以改善巷道围岩应力环境；煤柱的承载能力适应超长“孤岛”综放工作面顶板的活动规律；围岩变形量小；能够保障巷道的整体稳定性和有效断面．通过现场实测，讨论了大煤柱维护巷道的矿压显现规律和对巷道的良好维护效果．     

Application of high-pressure water jet technology and the theory of rock burst control in roadway

This paper puts forward using high-pressure water jet technology to control rock burst in roadway, and analyzes the theory of controlling rock burst in roadway by the weak structure zone model. The weak structure zone is formed by using high-pressure water jet to cut the coal wall in a continuous and rotational way. In order to study the influence law of weak structure zone in surrounding rock, this paper numerically analyzed the influence law of weak structure zone, and the disturbance law of coal wall and floor under dynamic and static combined load. The results show that when the distance between high-pressure water jet drillings is 3 m and the diameter of drilling is 300 mm, continuous stress superposition zone can be formed. The weak structure zone can transfer and reduce the concentrated static load in surrounding rock, and then form distressed zone. The longer the high-pressure water jet drilling is, the larger the distressed zone is. The stress change and displacement change of non-distressed zone in coal wall and floor are significantly greater than that of distressed zone under dynamic and static combined load. And it shows that the distressed zone can effectively control rock burst in roadway under dynamic and static combined load. High-pressure water jet technology was applied in the haulage gate of 250203 working face in Yanbei Coal Mine, and had gained good effect. The study conclusions provide theoretical foundation and a new guidance for controlling rock burst in roadway.     

Effects of coal seam dip angle on the outburst in coal roadway excavation

The prevention and forecast of coal and gas outburst has always been one of the key issues in coal mining safety. By simulating the process of tunneling in coal seam with different dip angle through FLAC3D software, the dangerous zone in which outburst may occur and the probability of outburst near the working face were predicted through the distribution of stress, displacement and plastic zone. Then we discussed the size of unstable area in the surrounding rock through the distribution of stress and the variation curve of the displacement on the roadway wall. The results show that, with an increase of the coal seam dip angle, the risk of outburst in the working face rises gradually. And the dangerous areas in which may outburst occur moves to the upper part of coal seam. The size of unstable area in the surrounding rock increases with the increase of coal seam dip angle.     

利民煤矿煤与瓦斯突出的地质构造条件研究

在对湖南利民煤矿煤与瓦斯弱突出区域、强突出区域和未突出区域的地质构造特征作详细分析后 ,发现煤层顶底板断 褶构造发育不协调、边界条件不一样 ,引起Ⅰ、Ⅱ、Ⅲ、Ⅳ各区的应力分布不均匀 ,构造复杂程度具一定的差异性 ;同时探讨了构造应力场和煤与瓦斯突出的关系 ,认为构造应力决定着突出强度的大小 ,进而控制煤与瓦斯突出的区域、密度、强度的差异性 .所得结论为矿区煤与瓦斯突出预测防治提供了理论依据 .     

两软一硬煤层突出控制因素与发生规律

针对两软一硬煤层特殊的瓦斯地质条件,以云盖山井田一矿二1煤层为例,探寻了两软一硬煤层煤与瓦斯突出的控制因素,分析了掘进工作面掘进期间突出预测指标的分布特征,总结归纳了"两软一硬"煤层煤与瓦斯突出发生规律.研究结果表明,由于地质构造变动,云盖山一矿二1煤层产状变化较大,煤层倾角发生急剧变化的地带,地应力集中;受层间滑动构造的影响,煤层厚度变化较大,具有突然增厚、变薄以至尖灭、挤灭现象;二1煤层构造软煤呈连续层状发育.因此,在煤层薄、厚交接处(煤层急剧变化带),小断层附近,应力集中,瓦斯积聚,煤体破坏严重,易发生突出.此项研究,可为地质条件类似矿井开展瓦斯地质研究和瓦斯灾害防治工作提供方法借鉴和理论指导.     

Forecast of Geological Gas Hazards for “Three-Soft” Coal Seams in Gliding Structural Areas

Gas outbursts from "three-soft" coal seams (soft roof, soft floor and soft coal) constitute a very serious problem in the Ludian gliding structure area in western Henan.By means of theories and methods of gas geology, structural geology, coal petrology and rock tests, we have discussed the effect of control of several physical properties of soft roof on gas preservation and proposed a new method of forecasting gas geological hazards under open structural conditions.The result shows that the areas with type Ⅲ or Ⅳ soft roofs are the most dangerous areas where gas outburst most likely can take place.Therefore, countermeasures should be taken in these areas to prevent gas outbursts.     

Comparing potentials for gas outburst in a Chinese anthracite and an Australian bituminous coal mine

Gas outbursts in underground mining occur under conditions of high gas desorption rate and gas content, combined with high stress regime, low coal strength and high Young’s modulus. This combination of gas and stress factors occurs more often in deep mining. Hence, as the depth of mining increases, the potential for outburst increases. This study proposes a conceptual model to evaluate outburst potential in terms of an outburst indicator. The model was used to evaluate the potential for gas outburst in two mines, by comparing numerical simulations of gas flow behavior under typical stress regimes in an Australian gassy mine extracting a medium-volatile bituminous coal, and a Chinese gassy coal mine in Qinshui Basin (Shanxi province) extracting anthracite coal. We coupled the stress simulation program (FLAC3D) with the gas simulation program (SIMED II) to compute the stress and gas pressure and gas content distribution following development of a roadway into the targeted coal seams. The data from gas content and stress distribution were then used to quantify the intensity of energy release in the event of an outburst.     

煤和瓦斯突出机理的流变假说

目前煤和瓦斯突出机理的假说,都是在弹性力学基础上建立的,缺少时间因素,难于完满地解释突出的发生发展过程。作者通过对含瓦斯煤样在三维受力状态下流变特性的研究,得出了含瓦斯煤样蠕变行为的数学模型,能够比较好地阐明突出的机理。实验表明,突出煤和非突出煤其流变行为并无本质区别,只要条件具备,各类煤层都有产生突出的可能。含瓦斯煤蠕变方程的导出为建立广义的突出危险综合指标提供了基础。     

煤与瓦斯突出在地质构造中的分布及其规律探讨

以华蓥山矿务局历年来发生的１８６次煤与瓦斯突出为例，从地质角度分析了突出与地质构造的关系及分布规律，得出在该矿区的突出矿井中，突出多发生在地质构造变化带及其附近，并分析了在这些区域容易发生突出的原因，为采取有针对性的防范性措施提供了依据。     

不等长工作面覆岩破坏规律的数值模拟分析

针对不等长工作面煤层开采日渐增多的现状,采用数值模拟与理论分析相结合的方法,对采场覆岩的破坏特征及支承压力的分布状态进行系统研究,并相应模拟出工作面前方应力场与位移场的演化规律。结果表明：工作面自开切眼开始向前推移,推进到工作面“见方”期或斜长的整数倍位置时,顶板活动剧烈,覆岩空间结构发生新旧更替,形成了“0”型破断区;不等长工作面推进过程中岩层运移极不规则,推进距离在衔接面前后20～30m的范围内,应力波动较大,数值变化明显;回采期间支承压力对覆岩活动产生了重要影响,其大小约为水平应力的1．5～2倍;就采动过程中竖向位移的变化而言,巷帮移近量远大于顶底板变形量,故工程实践中应特别注意对巷帮及顶板的加固和维护。