综放采场J型通风系统治理高瓦斯涌出的研究

根据潞安王庄煤矿5201综放工作面实际条件，在成功实施沿空小断面留巷的基础上，提出了综放采场J型通风系统治理高瓦斯涌出的方法及其调控技术．J型通风系统本质上是以通风方法按工作面瓦斯来源分别治理高瓦斯涌出的一种新型“一进两回(排)”通风系统，现场应用表明，利用该系统能从根本上消除工作面和上隅角局部瓦斯积聚，实现高产高效综放开采．     

综放巷内充填沿空留巷工业试验

针对常村煤矿S2-6综放工作面采用传统技术沿空留巷的难点，进行了巷内充填沿空留巷工业试验．试验分三步进行：第一步，对原巷采用锚梁网索联合支护实施加固，撤掉梯形架棚；第二步，在已加固巷道下一工作面侧煤壁，实施扩帮锚网支护；第三步，在原巷位置实施巷内充填，并加固充填体．结合高水速凝充填材料的性能，通过建立合理的综放沿空留巷的围岩结构力学模型和充填工艺设计，井下工业试验达到了预期效果，留巷断面稳定后超过10m^2．证明了在巷内基本支护为梯形金属支架的巷道中进行综放沿空留巷的可行性，并作了经济效益评价．在此基础上提出了综放巷内充填沿空留巷新技术．     

设置顶板道解决综放工作面瓦斯超限问题的局限性

针对通过设置顶板道来解决综放工作面瓦斯超限技术的广泛应用问题,分别较深入地探讨了顶板道和回风巷风量变化与其排放瓦斯量之间的关系。研究表明,一般情况下设置顶板道可以较好地解决综放工作面的瓦斯超限问题,但瓦斯严重超限时,顶板道的排放瓦斯能力难以满足需要,在满足回风巷风速及瓦斯浓度均不超限的条件下,可通过增大其风量来提高综放工作面总的排放瓦斯能力．     

漳村煤矿设瓦斯巷综放面瓦斯分布及涌出特征

由于综放工作面开采强度大,引起瓦斯涌出量成倍增加,严重制约着工作面的安全生产．针对瓦斯涌出强度大的问题,通过在山西潞安矿务局漳村煤矿综放工作面布置测点、测线,进行现场观测和研究,分析论述了工作面设置排放瓦斯巷解决瓦斯严重超限问题时,综放工作面的瓦斯分布状况及涌出特征．     

设置顶板道解决综放工作面瓦斯超限问题的局限性

针对通过设置顶板道来解决综放工作面瓦斯超限技术的广泛应用问题 ,分别较深入地探讨了顶板道和回风巷风量变化与其排放瓦斯量之间的关系。研究表明 ,一般情况下设置顶板道可以较好地解决综放工作面的瓦斯超限问题 ,但瓦斯严重超限时 ,顶板道的排放瓦斯能力难以满足需要 ,在满足回风巷风速及瓦斯浓度均不超限的条件下 ,可通过增大其风量来提高综放工作面总的排放瓦斯能力 .     

“三软”煤层综放开采避开动压沿空留巷方法及应用

为实施"三软"煤层综放面沿空留巷,掌握留巷围岩结构和矿压变化规律,以新登煤矿31061综放面为研究对象,研究采空区侧向覆岩结构和应力分布,综放面后方沿空留巷变形和顶板压力分阶段变化规律,提出了避开动压沿空留巷方法,并在现场进行了工业试验。研究表明:(1)31061采空区侧向煤壁变形量大,应力降低区范围大,应力集中影响范围达到煤体内部30 m。(2)留巷矿压显现分为3个阶段。工作面后方30~40 m为巷道加速变形阶段,从工作面后方5 m留巷变形速度持续增加,但顶板压力升高较慢;工作面后方40~70 m为变形持续阶段,此阶段巷道变形速度保持稳定,顶板压力快速升高,临时支架产生变形破坏;工作面后方70 m以后为变形稳定阶段,此阶段变形速度明显降低,顶板压力趋于稳定。(3)避开动压沿空留巷方法是利用临时支护使留巷度过动压影响阶段,允许巷道有较大变形量,在工作面后方一定距离处对留巷进行扩修和加固。实践表明,该方法具有成本低、工艺简单、留巷后期稳定性好、留巷施工与采面生产互不干扰等优点,在条件适合的矿区值得推广。     

放顶煤开采沿空留巷围岩移动规律及变形特征

运用适于分析岩层断裂和垮落的数值模拟软件UDEC建立了相应的模型，分析了综放沿空留巷围岩应力和位移的演变过程、围岩移动的特征，阐述了巷道和充填体上方顶煤的位移及其与上覆岩层破断之间的关系，为沿空留巷充填体参数选择提供科学依据．     

综放沿空留巷围岩变形影响因素的分析

从技术因素和地质因素两个方面重点论述了综放巷内充填沿空留巷围岩变形和应力分布的基本特征．通过计算机数值模拟，优化了充填工艺参数，得出了合理的留巷技术方案．在此基础上，系统分析了煤层硬度、采高、直接顶厚度和硬度、老顶岩层硬度及关键层复合效应等因素对留巷围岩变形与垂直应力分布的影响规律．并采用多元分析方法，得到了各因素对围岩最大应力的回归方程．研究结果可对综放巷内充填沿空留巷的应用提供理论依据和设计指导．     

阳泉三矿大采长综放工作面瓦斯涌出特征分析

大采长综放工作面单位时间内瓦斯涌出量增大,经常造成工作面回风隅角和回风巷瓦斯质量浓度超限.通过分析综放工作面瓦斯涌出源,可以了解其瓦斯涌出特征.对阳泉三矿大采长K8206综放工作面初采期和回采期的瓦斯涌出规律的分析可知,初采期瓦斯涌出量具有大幅度波动性,其原因主要为采空区瓦斯不断地、周期性地涌入.正常回采期,只要高抽巷的抽放负压足够大,邻近层瓦斯涌入工作面的问题就能解决;而大采长综放工作面本煤层瓦斯涌出量增大,则需要增加通风量或者采用新的通风方式.     

阳泉三矿大采长综放工作面瓦斯涌出特征分析

大采长综放工作面单位时间内瓦斯涌出量增大,经常造成工作面回风隅角和回风巷瓦斯质量浓度超限.通过分析综放工作面瓦斯涌出源,可以了解其瓦斯涌出特征.对阳泉三矿大采长K8206综放工作面初采期和回采期的瓦斯涌出规律的分析可知,初采期瓦斯涌出量具有大幅度波动性,其原因主要为采空区瓦斯不断地、周期性地涌入.正常回采期,只要高抽巷的抽放负压足够大,邻近层瓦斯涌入工作面的问题就能解决;而大采长综放工作面本煤层瓦斯涌出量增大,则需要增加通风量或者采用新的通风方式.     

Critical Value of CO of Forecasting Coal Spontaneous Combustion

CO has been used widely in the production process of colliery as an index gas to predict spontaneous combustion of coal. But in some collieries there are CO gas in the upper corner of the face all the times, sometime CO gas even exceeds the regulated critical index. This phenomenon is much more obvious in the fully-mechanized longwall face and fully-mechanized long, wall and top-coal caving face. Ahhough many measures of fire-proof and fire-extinguishing have been adopted, the flowing amount of CO gas can be only decreasd, but can not be eliminated completely. Using the different kinds of coal, the experiment of coal oxidation was made at the low temperature. The experiment indicates that some kinds of coal can produce CO under the condition of normal temperature oxidation, sometime the CO consistency is very high, and the intension of CO can be decreased with oxidation time prolonging. Selecting rational critical value of CO is the kev to predicting spontaneous combustion of coal correctly and reliably. The problem of selecting retional critical value of CO was studied. Finally, the amount of CO gas released by different kinds of coal was obtained under normal temperature condition.     

预报煤炭自燃的CO指标气体临界值研究

CO气体作为预报煤炭自燃的指标气体在煤矿中已被广泛使用,但有些矿井回采面上隅角始终存在CO气体,甚至超出矿业安全规定的临界指标,特别是在综采或综放工作面这一现象更明显,尽管采取多种防灭火措施,只能使CO气体涌出量减少而不能消除CO的产生,为了解其原因,在实验室做了不同煤种低温氧化实验,通过实验发现有些煤种在常温氧化条件下就会出现CO气体,甚至出现的CO量还很大,且随着煤的氧化时间的延长,产生CO气体强度在降低。为了及时准确、可靠预报煤炭自然发火,合理选择CO指标气体临界值是关键。利用多阀气相色谱仪检测常温条件下不同煤种氧化放出的CO气体量,对合理的CO指标气体的临界值进行了研究,确定不同情况下CO的临界值。     

Geophysical criterion of pre-outburst coal outsqueezing from the face space into the working

The initial process of coal and gas sudden outburst is studied in the article when under the influence of rock and gas pressure the part of a coal seam layer(a coal section) is squeezed out from the mouth of the future outburst cavity in a jump-like manner into the working. Geo-mechanical criterion for a part of a coal seam layer outsqueezing in the form of the relation of active(squeezing out) and passive(preventing the outsqueezing) forces is defined in the article. Based on it, the geophysical criterion is defined by expressing basic physical parameters through geo-physical ones: the current stress is defined by spectral-acoustic method through the ratio of high frequency and low-frequency components of an acoustic signal, which is generated into a face working space by the mining equipment operating in the face; in-situ gas pressure is defined by gas analytical method by the concentration of methane in the atmosphere of the working; the strength of the most broken coal layer is defined by a strength measuring device(a device for measuring the depth of a steal cone punched into the coal by a spring mechanism). This paper studies the influence of acoustic, strength and filtrating and collecting properties of a face working space on the limit value of an obtained geophysical criterion of pre-outburst squeezing of a coal ‘‘plug" out of the mouth of the future outburst cavity into the working.     

无煤柱分阶段沿空留巷煤与瓦斯共采方法与应用

针对深井高瓦斯低透气性煤层群的典型赋存特征,结合淮南矿区千米深井无煤柱煤与瓦斯工程实践,提出了改进Y型通风模式,即分阶段沿空留巷方法,完善了对共采工程的维控预应力锚固技术.工程实践表明:预应力锚固技术可以实现深井强动压开采过程中对沿空留巷和回风巷道围岩稳定的有效维控,至第1阶段结束,留巷顶板下沉量为144mm,两帮移近量为351mm,分阶段沿空留巷对共采巷道的维护时间缩短了4/5.减少了留巷变形速度稳定后累计变形的不利影响.超前工作面布置的瓦斯抽采工程中,单孔抽采瓦斯浓度(体积分数)达到40%,实现了煤与瓦斯共采.     

人工神经网络在瓦斯涌出量预测中的应用

当采掘工作面遇有岩浆岩破坏煤系和煤层时,地质条件尤为复杂,采用常规的矿山统计法和瓦斯含量法预测瓦斯涌出量难以取得理想的结果.作者从矿井地质综合分析入手,采用BP神经网络的方法建立了适用于矿井未采区瓦斯涌出量的预测模型,分别用48个4-2煤层、40个7-2煤层钻孔点的煤层瓦斯质量体积、煤层埋藏深度、煤质、火成岩分布、顶底板砂泥岩比值等数据作为输入层,预测地质条件相对复杂矿井的瓦斯涌出量.经已采区实测值与预测值比较分析认为,预测结果可信.     

人工神经网络在瓦斯涌出量预测中的应用

当采掘工作面遇有岩浆岩破坏煤系和煤层时，地质条件尤为复杂，采用常规的矿山统计法和瓦斯含量法预测瓦斯涌出量难以取得理想的结果．作者从矿井地质综合分析入手，采用BP神经网络的方法建立了适用于矿井未采区瓦斯涌出量的预测模型，分别用48个4-2煤层、40个7-2煤层钻孔点的煤层瓦斯质量体积、煤层埋藏深度、煤质、火成岩分布、顶底板砂泥岩比值等数据作为输入层。预测地质条件相对复杂矿井的瓦斯涌出量．经已采区实测值与预测值比较分析认为．预测结果可信．     

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 investigations. It was observed that the impact rate of the dynamic load on the gas-bearing coal can significantly change the gas pressure. The faster the impact rate, the speedier the increase in gas pressure. Moreover, the gas pressure rise was faster closer to the impact interface. Subsequently, based on engineering background, we proposed three models of stress and gas pressure distribution in the coal body ahead of the working face: static load, stress disturbance, and dynamic load conditions. Finally, the gas pressure distribution and outburst mechanism were investigated. The high concentration of gas pressure appearing at the coal body ahead of the working face was caused by the dynamic load. The gas pressure first increased gradually to a peak value and then decreased with increasing distance from the working face. The increase in gas pressure plays a major role in outburst initiation by resulting in the ability to more easily reach the critical points needed for outburst initiation. Moreover, the stronger the dynamic load, the greater the outburst initiation risk. The results of this study provide practical guidance for the early warning and prevention of coal and gas outbursts.