基于分形-脆弱性指数法的煤矿底板突水预测——以王行庄煤矿为例

针对脆弱性指数法在煤矿底板突水预测中主控指标选择和权重确定具有较大主观性的问题,提出了分形-脆弱性指数法,即以单位涌水量、含水层渗透系数、含水层水压及隔水层有效厚度4个主控因素量化含水层和隔水层的性质,以断层分维量化断层的综合性质,利用层次分析法确定以上5个主控因素权重,利用GIS进行权重叠加。并用该法对王行庄矿二_1煤层底板太原组L_(1-4)灰岩含水层突水危险性进行了预测。结果显示,王行庄矿二_1煤层底板脆弱区位于矿山西北部,占全区面积的10.38%,且实测突水点位于预测分区图的脆弱区。分形-脆弱性指数法减少了主控因素的数量(以往研究对断层的量化至少需要3个指标),提高了模型预测精度,可以更好地指导煤矿安全生产。     

煤层底板灰岩含水层突水危险性评价

在对某矿含水层富水性、地质构造、隔水层等影响底板突水因素综合分析的基础上,采用突水系数法和安全水头压力值对4号煤层底板主要灰岩含水层突水危险性进行了评价,分析结果表明,伏青灰岩水对-550m标高以下4号煤层的开采具有突水危险性,而对其他含水层均不构成突水威胁,这为矿井防治水和安全生产奠定了理论基础．     

基于可拓物元模型的煤层底板突水危险性评价

针对深部煤炭资源开采受底板奥陶系灰岩高水压的威胁问题,基于可拓学理论将9个因素作为物元模型的事物特征,利用层次分析法确定影响底板突水各因素的权重,建立了底板突水四级危险性物元评价模型,确定合适经典域和节域,并对盘道煤业3210工作面进行了底板突水危险性评价。结果表明物元模型能够定量化反映突水危险性程度。根据该模型,3210工作面突水危险性等级为较安全,突水系数为0.024 5~0.026 0 MPa/m,远远小于构造破坏块段突水系数临界值。2种方法均表明煤层底板能有效阻隔奥陶系灰岩水,可以实现安全带压开采。     

米村矿一_1煤底板奥灰水突水危险性分析

带压开采过程中,防止底板突水是安全生产的关键.为了解突水原因,通过对生产现场地质资料进行疏理,并运用地质理论和矿山压力理论,对拟开采的一1煤层突水危险性进行了分析,认为煤层直接底板本溪组铝土质泥岩隔水层厚度过薄,井田内小断层比较发育,间接底板奥陶系灰岩的富水条件是矿井突水的主要因素.分析结果可为今后预测一1煤底板突水危险性提供理论依据.     

米村矿一1煤底板奥灰水突水危险性分析

带压开采过程中,防止底板突水是安全生产的关键.为了解突水原因,通过对生产现场地质资料进行疏理,并运用地质理论和矿山压力理论,对拟开采的一1煤层突水危险性进行了分析,认为煤层直接底板本溪组铝土质泥岩隔水层厚度过薄,井田内小断层比较发育,间接底板奥陶系灰岩的富水条件是矿井突水的主要因素.分析结果可为今后预测一1煤底板突水危险性提供理论依据.     

基于岩体极限平衡理论的煤层底板突水危险性预测

基于岩体极限平衡理论,研究了完整近水平煤层底板突水力学机制。综合考虑底板隔水层厚度、工作面斜长及隔水层岩性组合特征,推导出了底板突水极限水压值计算公式。以保德煤矿为例,将突水极限水压值法运用到保德煤矿13＃煤底板突水危险性预测中。通过与传统突水系数法对比分析,阐明了突水极限水压值法的优越性:突水极限水压值法改进了传统突水系数法,可更有效地进行工作面斜长较大时的底板突水危险性预测。     

多煤层底板单一含水层矿区突水变权脆弱性评价与应用

针对煤层底板突水脆弱性常权评价中存在的不能反映各主控因素在不同组合变化状态下对底板突水的控制与影响作用,以及我国大范围多煤层底板单一含水层矿区突水的统一规范评价技术难题,以大屯矿区为例,采用基于变权的脆弱性指数法分别对7^#,8^#和21^#煤层底板奥灰突水进行了脆弱性评价和分区研究.通过采用对各主采煤层底板突水主控因素的统一归一化,构建相同变权状态向量,划分统一的各主控因素变权区间,确定统一的变权脆弱性指数分区阈值等关键技术,实现了大屯矿区7^#,8^#和21^#煤层底板奥灰突水脆弱性的统一评价与分区,首次对多煤层底板单一含水层类型矿井采用变权理论开展了突水脆弱性评价.本文还从区域大尺度范围,采用基于变权理论的底板突水脆弱性指数法对同一水文地质单元内的大屯矿区进行了统一评价和分区,并与常权脆弱性评价进行了对比.结果表明:基于变权的脆弱性评价能够更真实地反映各主控因素在不同组合状态下对底板突水的动态控制作用和煤层底板突水的复杂非线性动力作用过程.     

基于五图双系数法的煤层底板突水危险性评价

为准确预测煤层底板突水的危险性,以平煤八矿为例,利用五图双系数法对二1煤层底板寒武系灰岩水发生突水的危险性进行了预测评估。通过分析隔水层与水压的关系,计算了带压系数和突水系数;利用Surfer绘图软件,绘制了底板水压、水头分布、突水系数的等值线图和突水危险性分区图。该方法比突水系数法更为全面;与脆弱性指数法相比,不需要太多的相关资料。结果显示,突水危险性较大的区域分布在矿区的西北和东北部,面积较小;南部和中部有2个小的区域属于基本安全区;其他区域属于突水危险性较小的区域。整体而言,平煤八矿二1煤层底板寒武系灰岩水发生突水的危险性小。     

王河煤矿矿井突水特征与防治水对策

王河煤矿位于荥巩矿区中部,单一开采太原组一1煤层,属带压开采,为荥巩矿区矿井水害最为严重的矿井之一.该矿自投产以来累计发生突水事故达50余次,并造成淹井2次.本文通过对王河井田地质、水文地质条件、突水点分布规律和突水强度特征的分析研究,阐明了矿井突水事故频发的原因,论述了地质构造条件、一1煤层底板隔水层厚度、含水层富水性、矿山压力、水压与突水的关系.在此基础上,提出了矿井防治水害的方法和措施,为今后该矿的安全生产指明了方向.     

王河煤矿矿井突水特征与防治水对策

王河煤矿位于荥巩矿区中部,单一开采太原组一1煤层,属带压开采,为荥巩矿区矿井水害最为严重的矿井之一.该矿自投产以来累计发生突水事故达50余次,并造成淹井2次.本文通过对王河井田地质、水文地质条件、突水点分布规律和突水强度特征的分析研究,阐明了矿井突水事故频发的原因,论述了地质构造条件、一1煤层底板隔水层厚度、含水层富水性、矿山压力、水压与突水的关系.在此基础上,提出了矿井防治水害的方法和措施,为今后该矿的安全生产指明了方向.     

超细煤粉粒度对煤质分析特性的影响

对不同粒度的超细煤粉进行了粒度粉细和煤质分析测定,研究了超细煤粉的煤质分析特性随粒度的变化规律。对超细煤粉的工业分析表明,水分含量基本不随煤粉粒度的变化而变化;随着煤粉颗粒粒度的减小,灰分含量增大,挥发分含量减小。对超细煤粉的元素分析表明,由于煤粉偏析,随着煤粉颗粒粒度的减小,C,H 和 N 含量降低,O 和 S 含量增大。     

Application of coal mine roof rating in Chinese coal mines

The coal mine roof rating(CMRR) is a measure of roof quality or structure competency for bedded roof types typically of underground coal mines. The CMRR has been used widely in the US, South Africa,Canada and Australia. In order to investigate the application of the CMRR system in Chinese coal mines,two coal mines in China located in Panjiang Coal Field in Guizhou Province were investigated. Field data were collected which is required to calculate the CMRR value based on underground exposure. The CMRR values of 11 locations in two coal mines were calculated. The investigations demonstrated that the chance of mine roof failure is very low if the CMRR value is more than 50, given adequate support is installed in mine. It was found that the CMRR guideline are useful to preliminarily investigate stability in Panjiang Coal Field mines.     

Rockburst mechanism in soft coal seam within deep coal mines

A number of rockburst accidents occurring in soft coal seams have shown that the rockburst mechanism involved in soft coal seams is significantly different from that involved in hard coal seams. Therefore, the method used to evaluate rockburst in hard coal seams is not applicable to soft coal seams. This paper established an energy integral model for the rockburst-inducing area and a friction work calculation model for the plastic area. If the remaining energy after the coal seam is broken in the rockburstinducing area is greater than the friction work required for the coal to burst out, then a rockburst accident will occur. Mechanisms of ‘‘quaking without bursting" and ‘‘quaking and bursting" are clarified for soft coal seams and corresponding control measures are proposed as the optimization of roadway layouts and use of ‘‘three strong systems"(strong de-stressing, strong supporting, and strong monitoring).     

Developing coal burst propensity index method for Australian coal mines

Coal burst is the violent failure of overstressed coal, and it is often accompanied by sound, coal ejection and seismic events. It is subsequently recognized as a serious safety risk of Australia after double fatalities coal burst happened at Austar Coal Mine. Considering the increasing trend of coal burst severity and frequency with mining depth, it is an urgent task to develop the coal burst risk assessment methods for Australia underground coal mines. Coal burst propensity index method is a widely used method of burst risk evaluation of coal as it is summed up from the coal burst research and practice of many countries.This paper presents the experimental and theoretical research of coal burst propensity index method for coal burst risk assessment in Australia. The definition of four indexes including elastic strain energy index(W_(ET)), bursting energy index(K_E), dynamic failure time(DT) and uniaxial compression strength(RC)is introduced in the first part. Then, the standard laboratory test process and test parameter of coal burst propensity index is presented. DT test is conducted with 0.3 mm/min displacement control loading rate while other test is with 0.5 mm/min. Besides, modified data processing and risk classification method of test are proposed. Differentiate analysis of stress-strain curve is adopted in the data processing of DT and KEindex. A four level risk classification form of burst risk is recommended for Australian underground coal mines. Finally, two likely improvement methods of W_(ET) test, including volumetric strain indicator method and theoretical calculation method, are discussed.     

不同煤体结构煤的f值分布特征

以淮南煤田C13-1煤层不同煤体结构类型煤的118个坚固性系数(f值)测定资料为基础,分析了不同煤体结构煤的f值分布特征和统计规律,说明了煤体破坏与f值的相互关系,并提出将f值作为硬煤和构造软煤的分类指标.     

不同煤体结构煤的f值分布特征

以淮南煤田C13-1煤层不同煤体结构类型煤的118个坚固性系数(f值)测定资料为基础,分析了不同煤体结构煤的f值分布特征和统计规律,说明了煤体破坏与f值的相互关系,并提出将f值作为硬煤和构造软煤的分类指标.     

改善平沟煤矿16~#煤层润湿性的研究

煤层注水现已成为矿井预防重大事故的综合性安全技术措施.煤层注水是以解决采煤工作面煤尘问题而发展起来的,后来又逐渐应用于预防冲击地压,提高瓦斯抽放效等方面.煤体注水的好处很多,但是不同煤质会对注水造成不同的影响.针对平沟16#煤润湿性差的现象进行了研究,并提出了添加尼诺尔、十二烷基苯磺酸钠和2种表面活性剂改善其煤体的润湿性,以提高煤体注水的效果.     

电厂燃用神华煤和大同煤经济性分析

结合目前煤炭市场情况,对锅炉燃用神华煤、大同煤的实际效果进行了对比分析,从而为燃煤电厂实现节能降耗和降低成本提供了参考依据．通过试验发现,用神华煤比大同煤锅炉效率低0．37％,并且储存损失较大;然而神华煤比大同煤SO2排放量小,同时神华煤市场价格较低,按照目前市场价格,燃用神华煤标煤单价比大同煤只要低9．5元／t,燃煤电厂的综合效益就会提高．     

Review of coal and gas outburst in Australian underground coal mines

Outburst of coal and gas represents a significant risk to the health and safety of mine personnel working in development and longwall production face areas. There have been over 878 outburst events recorded in twenty-two Australian underground coal mines. Most outburst incidents have been associated with abnormal geological conditions.Details of Australian outburst incidents and mining experience in conditions where gas content was above current threshold levels are presented and discussed. Mining experience suggests that for gas content below 9.0 m³/t, mining in carbon dioxide (CO₂) rich seam gas conditions does not pose a greater risk of outburst than mining in CH₄ rich seam gas conditions. Mining experience also suggests that where no abnormal geological structures are present that mining in areas with gas content greater than the current accepted threshold levels can be undertaken with no discernible increase in outburst risk. The current approach to determining gas content threshold limits in Australian mines has been effective in preventing injury from outburst, however operational experience suggests the current method is overly conservative and in some cases the threshold limits are low to the point that they provide no significant reduction in outburst risk. Other factors that affect outburst risk, such as gas pressure, coal toughness and stress and geological structures are presently not incorporated into outburst threshold limits adopted in Australian mines. These factors and the development of an outburst risk index applicable to Australian underground coal mining conditions are the subject of ongoing research.