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．     

淮北矿区煤层底板突水的岩体结构控制研究

淮北矿区位于华北聚煤区南部,其水文工程地质环境具有华北煤田的基本特征,水文地质条件复杂,山西组煤层开采普遍受到底板灰岩水的严重威胁,曾发生多次底板突水事故。本文介绍了淮北矿区煤系水文地质与工程地质特征,并对研究区底板突水典型案例进行了系统分析,揭示了不同的底板地质构造条件和突水通道所导致的突水特征的差异性,对于认识底板突水的岩体结构控制具有典型意义。     

白庙矿二_1煤层底板防治水研究

为解决白庙矿二1煤层底板防治水问题,分析了底板含水层赋水特征和矿井历年突水情况,基于渗流转换机理预算了主要断层突水量.结果表明,太原组下部石灰岩含水层和寒武系石灰岩含水层是底板突水的重要水源,云盖山正断层和下白峪正断层是潜在的底板突水通道,一旦发生底板突水,断层突水量将达1000 m3/h以上.提出了以疏水降压为主、预注浆堵水为辅的底板综合防治水措施,寒武系石灰岩含水层的疏放效果证明了此措施是可行的.     

基于板壳理论的隐伏陷落柱突水煤层底板破断机理研究

为揭示陷落柱突水时煤层底板的破断机理,基于板壳理论和断裂力学理论,建立隐伏陷落柱突水煤层底板的破断力学模型,研究陷落柱突水时煤层底板裂纹的扩展机理,得到底板内应力分布情况和裂纹应力强度因子。结果表明:横向荷载作用下,煤层底板内的应力与煤层底板厚度呈负相关,与距离中面的位置、半径和水压呈正相关;在含有裂纹的煤层底板中,随着底板厚度增加、裂纹增长和底板半径减小,裂纹越难扩展。利用理论结果分析淮南矿业(集团)有限责任公司张集煤矿"2·18"特大突水事故煤层底板破断机理,分析结果与现场实际情况相符。     

用突水概率指数法预测采场底板突水

介绍了采场底板突水预测的新方法－突水概率指数法,以肥城煤田为例,阐述了该方法在预测煤矿底板突水中的应用。该方法的基本思想为：基于大量的采场底板突水案例分析,找出导致煤矿底板突水的主要因素;根据各种因素在底板突水中所起的作用大小,利用概率统计法及专家经验法确定各种因素在底板突水中所占的权重,建立计算突水概率指数的数学模型;将模型应用到已有的突水案例中,计算出各个突水案例的突水概率指数;再用概率统计的     

煤层底板“下三带”突水防治措施探析

根据煤层底板"下三带"理论,对煤层底板突水实质及影响因素进行分析,并在此基础上提出相应的煤层底板突水防治措施。探讨了采用注浆改造技术对煤层底板进行改造的施工工艺。     

矿井直流电法及在煤层底板突水探测中的应用

阐述了矿井直流电法及其在探测煤层底板突水中的应用．由于受全空间效应和巷道空间影响，井下稳恒电流场的分布有其特殊性．文中重点叙述了不同矿井直流电法的全空间效应和巷道影响特征，给出了拟一维层状介质模型的巷道影响校正系数公式．结合应用实例，对巷道底板电测深法、矿井电剖面法和高密度电阻率法资料的处理与解释方法分别进行了讨论．     

刘庄煤矿11-2煤层顶、底板砂岩水特征与防治技术

初步探讨了刘庄煤矿11-2煤层顶、底板砂岩裂隙水的特征及其综合防治技术,为其它煤层及相邻矿井煤层顶、底板砂岩水的防治提供参考。     

Switching mechanism and optimisation research on a pressure-attitude adaptive adjusting coal seam water jet slotter

To investigate the attitude-switching mechanisms of existing jet slotters, which integrate drilling, punching and slotting operations, and to improve its fracture ability, we used the power bond diagram theory to analyse the dynamic flow pressure, and force of slotters. A mathematical model was developed for the dynamic characteristics of slotter systems. Furthermore, to study the effect of the main characteristic parameters on the ability of the nozzle to erode sandstone, multi-orthogonal experiments were carried out. And the optimised slots were applied in later practical operations. The research results show that the inlet fluid passed through the time-varying orifice to generate pressure differential thrust, which overcame the spring force, pushed the valve core to open the side nozzle, and closed the rear cavity channel thereby realising the switch of the slotter attitude. An optimal plan was established to balance the diameter, depth, and volume of punching, and a rock-breaking plan was developed for the slotter. Subsequently, the optimised water jet slotter was practically used in coal seam gas drainage. Compared with conventional dense drilling, water jet slotting technology significantly improves the ability, efficiency, and effect of increasing the permeability of the coal seam.     

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).     

Water inrush evaluation of coal seam floor by integrating the water inrush coefficient and the information of water abundance

The method of singular coefficient of water inrush to achieve safety mining has limitation and one sidedness. Aiming at the problem above, large amounts of data about water inrush were collected. Then the data, including the maximum water inrush, water inrush coefficient and water abundance in aquifers of working face, were processed by the statistical analysis. The analysis results indicate that both water inrush coefficient and water abundance in aquifers should be taken into consideration when evaluating the danger of water inrush from coal seam floor. The prediction model of safe-mining evaluation grade was built by using the support vector machine, and the result shows that this model has high classification accuracy. A feasible classification system of water-inrush safety evaluation can be got by using the data visualization method which makes the implicit support vector machine models explicit.     

浅析峰峰矿区矿井突水原因及防治

峰峰矿区是华北大水矿区 ,水害严重威胁着下组煤层的开采。本文通过对该矿区典型突水事例的分析 ,探讨了造成突水的原因 ,并提出了防治的措施。     

松软煤体中锚杆支护锚固体形成机理分析

通过对松软煤体锚杆支护稳定性影响因素分析,利用数值模拟方法研究了松软煤体中锚杆作用机理,进而分析了松软煤体中锚固体形成条件.结果表明,高预紧力锚杆支护作用下,树脂端锚体与松软煤体间的错动、滑移及在应力重新分布过程的锚杆滑脱与护表构件失效是松软煤体中锚杆支护失效的主要原因;松软煤体进行单根预紧力锚杆锚固后,锚杆轴向应力、附加应力场及位移场随预紧力提高而增大,但附加应力场(锚固体)成型范围受预紧力限制,即随着预紧力(40 kN→60 kN→80 kN)增加,自由段两端附加应力场(锚固体)会出现"一定程度叠加→较大叠加范围→不能相互叠加"的过程,整体锚杆自由段轴向应力分布均匀;多根预紧力锚杆支护产生的附加应力场相互叠加形成锚固体,松软煤体强度特征是形成锚固体的首要条件,可控条件为松软煤体强度与锚杆(较小)预紧力的匹配、增加锚杆长度与支护密度.     

积水区下煤层的安全回采

介绍了积水区探放水设计的主要内容,讨论了下煤层开采的基本方法,提出了几点重要的安全措施.     

煤层瓦斯产出流态判识方法研究

针对目前评价瓦斯运移产出难易程度的方法均依据线性渗流理论,评价结果严重失真的问题,提出以雷诺理论为基础,通过实验室煤样地质强度因子(Geological Strength Index,GSI)的观测、启动压力梯度(λ)和渗透率测试方法,且初步建立了启动压力梯度法和GSI法用于判识瓦斯运移产出流态。指出当λ=0 Pa·m-1时为线性渗流;当λ≠0 Pa·m-1,瓦斯压力梯度大于λ时为低速非线性渗流,小于λ时为扩散。同时,以渗透率为桥梁建立了GSI与雷诺数的关系,通过煤心观测、煤壁观测和测井资料解释等途径获取GSI,即可判识煤的瓦斯流态。     

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.     

石灰在煤泥水混凝中的作用机理研究

石灰在煤泥水混凝中的作用机理：石灰对煤泥水的混凝作用不是补给了ＯＨ＾－，而是提供了大量的Ｃａ＾２，Ｃａ＾２＋通过压缩双电层，破坏了煤泥颗粒的稳定性，从而使煤泥颗粒发生凝聚。ＯＨ＾－和Ｃａ（ＯＨ）２对煤泥水的混凝不直接作用。