煤巷掘进突出预测指标研究

针对煤巷掘进煤与瓦斯突出严重,预测指标不可靠等问题,对新密矿区大平煤矿16121下巷掘进工作面预测指标进行了试验研究.通过现场连续测定瓦斯涌出初速度q,钻屑量S值,钻屑解吸量△h2和煤体温度T等指标,对比分析指标间关联、指标数值区间分布特征、预测可靠敏感程度等,得出了该矿区煤巷掘进突出预测敏感指标及其临界值,并提出了影响突出危险预测指标可靠性的几点认识.     

上社煤矿突出预测敏感指标及其临界值确定

为提高上社煤矿突出危险性预测的准确性,根据上社矿15#煤层的特点,在实验室试验的基础上,应用"四率法"对掘进工作面敏感指标及其临界值进行分析研究。研究结果:瓦斯解吸K1值和钻屑量S指标均具有敏感性,其临界值分别为0.55 m L/(g.min1/2)、6kg/m,可在瓦斯放散初速度大、瓦斯解吸指标随瓦斯压力变化明显的掘进工作面中应用。     

瓦斯隧道穿越突出煤层安全技术研究

随着我国交通基础路网的快速发展,瓦斯隧道越来越多,隧道施工风险高,保障隧道穿越煤层的安全可靠性,准确预测穿越煤层风险等级、对突出煤层进行防突措施选择及搭建风险评价体系是实现隧道安全揭煤的保障。本文以坪上隧道为例,通过测定煤层瓦斯含量及钻屑瓦斯解吸指标参数,实施消突措施,实现安全揭穿突出煤层。实测结果表明:瓦斯隧道穿越突出煤层采用煤层瓦斯含量及钻屑瓦斯解吸指标可实现准确预测穿越煤层风险等级,通过措施效果评价,可研判是否消除突出危险性,对类似条件下隧道施工具有很好的推广应用价值。     

煤层高压注水防治煤与瓦斯突出效果考察及机理分析

为了深入探讨煤层高压注水的防突出机理,采用地应力分布、瓦斯解吸速度和钻屑瓦斯解吸指标K1值作为研究指标,考察了阳泉煤业集团新景矿煤层高压注水后的防突效果,结合实测数据对煤层高压注水的防突机理进行了分析.研究表明,煤层高压注水具有如下2种效应:一是高压水破裂煤体,使煤体塑性增加,导致集中应力带前移;二是注水后残留的水分对煤体瓦斯解吸有抑制效应,可避免煤体瓦斯快速解吸.2种效应同生共存,共同对煤与瓦斯突出产生防治作用.     

鹤壁四矿煤巷掘进工作面效检指标的敏感性分析

为了确定适合鹤壁四矿瓦斯地质特点的煤巷掘进工作面的突出危险性预测敏感指标及其临界值,通过对大量资料的收集、整理及现场参数的测定,分析得出鹤壁四矿煤巷掘进煤与瓦斯突出危险性预测敏感指标为瓦斯解吸指标Δh_2,并确定其临界值为380 Pa,为该矿煤巷快速掘进提供理论上合理的数据和参数,并在实践中证明其是可靠的、合理的.     

钻屑解吸指标临界值的确定

通过测定北票、焦作和抚顺矿区突出预测参数，建立了钻屑解吸指标同瓦斯压力、瓦斯放散初速度指标、煤的坚固性系数和煤的挥发份之间的关系，提出了确定钻屑解吸指标临界值的方法，得出煤钻屑解吸指标临界值无烟煤为３９２Ｐａ，烟煤为１６０Ｐａ．     

含水煤体钻屑瓦斯解吸指标K_1值的临界值研究

研究采取水力压裂措施后含水煤体钻屑瓦斯解吸指标K_1值随水分的变化规律,得出不同水分下K_1值的临界值。在实验室采用模拟测试的方法对新景矿3号煤层不同水分煤样的瓦斯解吸规律和K_1-p关系进行实验测试。试验结果表明,水能够抑制煤样瓦斯的解吸,钻屑瓦斯解吸指标K_1值随瓦斯压力增大呈幂函数关系增大,随煤样水分增大呈负指数函数关系减小。研究表明,采用实验模拟得出临界压力下K_1值与水分的关系函数,可对采取水力化措施后煤层钻屑瓦斯解吸指标K_1值的临界值进行修正。     

基于ANN方法的煤巷掘进前方小构造预报技术

利用煤巷掘进过程中所暴露出的大量的煤层信息，确定了与煤巷掘进前方小构造存在密切关系的影响因素，分析了煤层倾角、煤层厚度、涌水量、瓦斯等各个影响因子，选出主控因子，建立主控因子与煤巷掘进前方小构造预测危险性指数间的人工神经网络（ANN）分析模型，求取了各影响因素对前方小构造预测的权重系数，并建立了煤巷掘进前方小构造预测预报的ANN模型及其判据．对鹤壁十矿煤巷掘进前方小构造进行了预测，结果表明：ANN技术可用于煤矿巷道掘进前方小构造预测．     

九里山矿突出煤层巷道掘进防突技术

突出煤层煤巷掘进防突直接关系到煤矿的安全生产和采掘接替.在长期的生产实践中,煤矿科研工作者进行了深入地研究,试验了不同的防突技术措施和工艺,并在不同时期取得了较好的效果.通过焦作矿区九里山矿15011工作面巷道掘进期间的瓦斯防治技术实践,阐述了煤巷掘进防突技术在焦作矿区的应用与发展,并对焦作矿区的煤巷掘进防突技术进行浅要的分析与展望.     

煤巷掘进过程中煤层瓦斯流动的分析解

通过对煤巷掘进过程中煤层瓦斯流动及涌出规律的研究，提出了煤巷掘进时煤层瓦斯压力分布分析解，以及巷道煤壁瓦斯涌出量的解析式。给出了煤层中瓦斯近于单向流动时的煤巷已掘出长度的计算式。导出的结果是对煤巷掘进长度较短时瓦斯涌出规律研究的补充。     

安林煤矿煤与瓦斯突出区域危险性分布的探讨

通过分析安林煤矿煤与瓦斯突出特点及瓦斯赋存状况,研究和探讨了地质构造和岩浆岩侵入对煤质和瓦斯赋存的影响,测定了突出预测指标在煤层中的变化及其分布规律,对开采煤层进行了突出危险性区划.     

△P index with different gas compositions for instantaneous outburst prediction in coal mines

In this study we measured the △P(initial speed of gas emission)index with different gas concentrations of carbon dioxide(pure CO2,90% CO2+10% CH4,67% CO2+33% CH4,50% CO2+50% CH4,30% CO2+10% CH4 and pure CH4)of coal samples from the No.2 coal seam in the Yaojie Coal Mine,Gansu province,China.The effect of carbon dioxide concentration,gas composition,coal strength and particle size of coal samples on the △P index was investigated.The experimental results show that with gas of various compositions,the △P value of three samples were clearly different.The △P index of coal samples A,B and C(0.2～0.25 mm)were 4,6 and 7 with pure CH4 and 22,30 and 21 when pure CH4 was used.Carbon dioxide concentration affects the△P index markedly.The △P index increases with an increase in carbon dioxide concentration,especially for coal B.Hence,the△P index and K(another outburst index)values tested only with pure CH4 for prediction of the danger of outburst is not accurate.It is important to determine the initial speed of gas emission given the gas composition of the coal seam to be tested for exact outburst prediction.     

Coal and gas outburst dynamic system

Coal and gas outburst is an extremely complex dynamic disaster in coal mine production process which will damage casualties and equipment facilities, and disorder the ventilation system by suddenly ejecting a great amount of coal and gas into roadway or working face. This paper analyzed the interaction among the three essential elements of coal and gas outburst dynamic system. A stress-seepage-damage coupling model was established which can be used to simulate the evolution of the dynamical system, and then the size scale of coal and gas outburst dynamical system was investigated. Results show that the dynamical system is consisted of three essential elements, coal-gas medium(material basis), geology dynamic environment(internal motivation) and mining disturbance(external motivation). On the case of C13 coal seam in Panyi Mine, the dynamical system exists in the range of 8–12 m in front of advancing face. The size scale will be larger where there are large geologic structures. This research plays an important guiding role for developing measures of coal and gas outburst prediction and prevention.     

Pore characterization of different types of coal from coal and gas outburst disaster sites using low temperature nitrogen adsorption approach

To characterize the pore features of outburst coal samples and investigate whether outburst coal has some unique features or not, one of the authors, working as the member of the State Coal Mine Safety Committee of China, sampled nine outburst coal samples(coal powder and block) from outburst disaster sites in underground coal mines in China, and then analyzed the pore and surface features of these samples using low temperature nitrogen adsorption tests. Test data show that outburst powder and block coal samples have similar properties in both pore size distribution and surface area. With increasing coal rank, the proportion of micropores increases, which results in a higher surface area. The Jiulishan samples are rich in micropores, and other tested samples contain mainly mesopores, macropores and fewer micropores. Both the unclosed hysteresis loop and force closed desorption phenomena are observed in all tested samples. The former can be attributed to the instability of the meniscus condensation in pores,interconnected pore features of coal and the potential existence of ink-bottle pores, and the latter can be attributed to the non-rigid structure of coal and the gas affinity of coal.     

深井中厚煤层突出预测敏感指标临界值研究

＂突出＂已成为我国煤矿安全生产的主要隐患之一,＂突出＂防治成为矿井安全工作的重中之重。采掘工作面突出危险性预测预报敏感指标的确定是矿井综合防突体系中重要的环节,为了有效预测及防治深部矿井工作面采掘过程中煤与瓦斯突出事故,采用理论分析、实验室分析和现场试验相结合的多种研究手段,获得了试验区13-1煤层突出预测敏感指标及其临界值,S0=6.0 kg/m,q〈4.0 L/m in.m,无突出危险;q≥8.0 L/m in.m,有突出危险;{4.0≤q〈8.0 L/m in.m}∩{Cq〉0.65}无突出危险;{4.0≤q〈8.0 L/m in.m}∩{Cq≤0.65}有突出危险。结果表明,确定的指标及其临界值合理有效,指导试验区安全掘进6 000m,并得到有效推广应用,技术经济效益显著。     

瓦斯地质编图在生产中的运用

通过矿井瓦斯地质编图，将井田划分为严重突出区、一般突出区、突出威胁区，按分区采取防突措施，指导了矿井的安全生产，获得了较好的社会效益和经济效益。     

演马庄煤矿突出煤层炮采放顶煤工作面防治煤与瓦斯突出的方法和措施

介绍了演马庄煤矿 2 70 2工作面突出煤层炮采放顶煤效果检验的方法和防止煤与瓦斯突出所采取的措施 ,提出突出煤层炮采放顶煤工作面瓦斯抽放是防止煤与瓦斯突出的有效手段 ,当工作面有煤与瓦斯突出危险时 ,采取恰当的防突措施 ,能够降低煤与瓦斯突出的危险程度 ,可供同类工作面回采时借鉴     

基于支持向量机的煤与瓦斯突出预测研究

煤与瓦斯突出已经成为影响煤矿生产最严重的安全问题和经济问题之一.在国内外有多种用于预测煤与瓦斯突出的方法,包括动态和静态预测,但是这些方法大多只考虑单一的参数,因此它们对煤与瓦斯突出的预测效果并不是很理想.对于近年来应用较为广泛的神经网络,由于其固有的缺陷,对于高维、小样本的情况具有不太理想的预测效果.作者综合考虑了多个因素,并将支持向量机(Support Vector Machine)这一方法应用到煤与瓦斯突出预测中.经过仿真试验,证明这种方法能够取得较好的预测效果.     

井田地质构造对煤与瓦斯突出影响的定量研究

通过对平顶山十二矿进行的煤与瓦斯突出区域预测研究 ,仔细分析了井田地质构造与突出的关系 .在该井田的构造复杂区 ,首次采用数学方法 ,将影响突出的构造因素定量化 ,并对构造复杂程度系数计算公式作了改进和简化 ;提出了确定复杂程度突出临界值的原则 ,并结合井田突出实际 ,划定了构造复杂程度系数的突出临界值 ,将其作为一项判断突出的依据 ,对十二矿进行了瓦斯地质区划 ,取得了良好的预测效果     

Investigations into the identification and control of outburst risk in Australian underground coal mines

Australian coal mines currently use gas content to assess outburst risk. The gas content threshold values for each mine are indirectly determined from measurement of gas volume liberated from 150 g coal samples during Q_3 residual gas content testing. It has been more than twenty years since this method, known as desorption rate index(DRI), was presented to the Australian coal industry, and in that time, there have been significant changes in mining conditions and the outburst threshold limits used at the benchmark Bulli seam mines. NSW Regulations list matters to be considered in developing control measures to manage the risk of gas outburst, and specifies that gas content, or DRI method, is used as the basis for determining outburst control zone. Whilst Queensland Regulations state that a coal or rock outburst is a high potential incident, there is no guidance provided to assist mine operators to define outburst prone conditions. A research project is planned at UOW to investigate the application of the DRI method and other potentially significant factors, such as gas pressure, coal toughness and permeability, which can be utilised by mine operators to assess outburst risk and determine appropriate outburst threshold limits and controls.