煤矿褶皱构造区冲击矿压震源机制

为实现对褶皱构造区冲击矿压震源机制的有效分析,基于震源机制矩张量反演方法,在优化震动波远场位移及破裂面产状求解方法的基础上,对甘肃华亭矿区砚北煤矿250204工作面回采期间冲击矿压震源破裂类型、破裂面产状及视应力等地震学参量进行系统分析,揭示了砚北煤矿褶皱构造区冲击矿压震源机制。研究结果表明:工作面回采扰动影响下,褶皱构造区冲击矿压震源破裂类型以拉张破裂为主,其矩张量以非双力偶部分占主导,表现为水平挤压构造应力、超前支承压力共同作用下煤岩体的应力释放;震源破裂面产状有明显分化趋势,小倾角(35°)震源破裂面走向多垂直工作面推进方向,而大倾角(35°)震源破裂面走向多平行于工作面推进方向且倾向实体煤一侧;褶皱构造区冲击矿压震源辐射能量和地震矩基本分布在一包络线内,随震源辐射能量增大,其地震矩大小分布更加集中;通过震源视应力计算,得到了回采扰动下工作面及其周边应力演化情况,与冲击矿压震源时空分布及巷道冲击显现结果基本吻合。     

煤矿冲击地压的推采速度效应及其动态调控

针对采煤工作面冲击地压存在推采速度效应问题,通过案例与微震监测数据分析,探讨了采场推采模式及速度与冲击地压的关系,揭示了采场推采速度效应产生机制,并通过对类似工作面微震特征的分析,建立了采场推采速度效应动态调控的方法。研究表明:回采工作面冲击地压危险性与采场推采模式及速度具有相关性,其中高速推采、非匀速推采易诱发冲击地压;高速推采造成多顶板势能转化和多煤层应变能均衡释放,非匀速推采导致煤层应变能集中释放;基于微震响应特征构建的采场推采速度效应动态调控方法具有良好的实用性。     

深井大规模矿床开采岩爆控制策略研究(2015-6增刊)

随着大规模矿床的开采,在高应力作用下,不断的产生破坏性岩爆等灾害,严重制约着这些矿床的正常生产。针对国内矿山即将进入1500m深度的千万吨级生产规模,本文对深井大规模矿山的采矿战略进行了研究,制定了深埋大规模硬岩矿床采矿的工作程序。设计阶段要遵守原则,如井下工程布置,采矿方法选择,实时监测系统布置等;生产阶段主要致力于日常矿山微震风险的管理工作,建立微震监测系统,调查破坏事件,分析应力场变化规律与预测风险区域,最终采取针对性的支护技术,合理安排出矿计划和特定工作环境下作业人员技能的培训等应对策略。     

固体潮汐应力与矿震触发之间的相关性及其作用机理分析

矿震的发生与地球固体潮汐活动存在一定相关性,为进一步探明固体潮汐应力对矿震的触发作用,本文以国内典型冲击灾害频发的华亭煤田矿区为研究背景,采用Schuster检验方法对发生在顶板中的矿震进行了固体潮日潮变化的统计分析。结果显示:1)固体潮汐应力对矿震的发生存在显著触发作用,矿震发生的频次与潮汐应力垂直、东西、南北和水平剪应力分量的相位角之间都有显著的相关性,Schuster检验P值均小于触发阈值0.05;2)潮汐应力对不同级别矿震触发作用存在差异,随着震级的增大,矿震的发生由重力控制转为构造应力控制;3)对不同类型矿震的触发力学作用不同,对于重力控制的中小型矿震,潮汐应力垂直分量最大(受压)、水平分量最小(受拉)时矿震较易发生,而构造应力控制的大级别矿震则与之相反;4)矿震活动也会造成相关区域地层中的钻孔应变时序形态产生畸变。     

大红山铁矿深井大规模开采岩爆综合评价

大红山铁矿是特大型深埋矿床,在深井开采时遇到的一个技术难题就是岩爆。为评价岩爆倾向性烈度,对该矿深部5种岩样进行室内岩爆倾向性试验,并采用声发射方法确定岩石接近峰值强度时的卸载点;通过地应力现场实测和三维有限元数值模拟,获得深部最大主应力和巷道开挖后最大切向应力;采用最大主应力判别法、切向应力准则、强度脆性系数法、变形脆性系数法、弹性应变能储存指数法这5种评价方法,对岩样的岩爆倾向性进行单项指标评价,分别得到各矿岩岩爆倾向性烈度。然后采用模糊数学法,对各单项指标评价结果进行综合评价。结果表明:深部主要矿岩体总体上具有发生中等岩爆和强烈岩爆的倾向性。最后,通过评价结果,在岩层图上绘制典型水平岩爆倾向性分布区域,可为深部开采和岩爆防治提供参考依据。     

冲击地压分类防治体系研究与应用

针对煤矿冲击地压类型复杂、治理技术缺乏针对性等问题,提出了以"分类治理"为核心思想的冲击地压"分类-评价-解危-预警-检验-支护-管理""七模块"治理技术体系。通过对矿井采深、地层条件、煤层条件、构造条件、开采方法和边界条件进行分析,提出了以8种不同的外部力源类型和10种典型巷道围岩结构形式两两组合的"深井冲击地压综合分类方法";在分类基础上对冲击地压的评价、解危、预警、检验、支护和管理技术进行了分析和优选。"七模块"冲击地压治理技术体系在山东能源集团新巨龙煤矿等矿井的成功应用,可为冲击地压矿井的安全开采提供借鉴。     

某深井矿山岩爆特征及形成机理研究

地应力、构造发育。对矿山地质条件进行了阐述,通过现场调查,描述了岩芯饼化和围岩剥落现象,分析了岩爆特征,总结了发生岩爆的基本规律,对8#矿体进行了岩爆类型和岩爆烈度分级划分,得出了该矿体围岩从1 451 m中段至1 261 m中段具有中等至强烈岩爆倾向性,从原岩应力、地质构造及开采深度等岩爆影响因素分析了岩爆发生的成因和形成机理,为选择合理的采矿方法和岩爆控制技术措施提供了重要依据。     

基于支承压力估算的合理开切眼位置确定方法

针对开切眼附近冲击地压事故,通过理论研究和现场勘查,探索了开切眼附近冲击地压发生的原因,提出了基于支承压力估算的合理开切眼平面位置确定方法。研究结果表明：开切眼布置在上覆岩层自重应力、采空区传递应力、构造应力等叠加区域内,叠加应力超过煤岩体冲击临界值是导致发生冲击的主要原因。基于现场微地震实测数据剖面分析,估算了关键岩层的断裂角。结合覆岩空间结构,建立了支承压力估算模型,估算了叠加总应力,并绘制了支承压力分布曲线。以动应力比d=σ/σc为冲击危险性判断标准,根据经验d值,在支承压力影响范围内划分冲击危险区,指导合理开切眼平面位置或现场防冲强度的确定。研究成果经河南某矿现场应用,效果良好。     

冬瓜山铜矿微震监测系统及其应用研究

冬瓜山铜矿是千米深井开采有岩爆倾向的金属矿山,建立了微震监测系统以实现岩层活动的连续监测和岩爆的实时预报。综合实际工程条件和拟定传感器空间网络方案的地震事件定位精度和系统灵敏度计算结果,实现了微震监测网络的优化。建立的数字化多通道微震监测系统具有先进和丰富的地震学定量分析和可视化解释功能,可以完成多重聚类和时间序列分析。在冬瓜山铜矿已记录的监测数据的基础上,开展了矿山地震信号识别、矿山地震活动分析方法和冬瓜山地震活动规律等研究,取得到了初步成果。     

华亭煤矿强矿压力学机制与防治对策

为从机理上认识和防治华亭煤矿强矿压,应用震源机制解答方法反演强矿压岩体破裂机制,结合现场地应力测量、微震监测、现场调查、采矿活动分析和理论分析等技术途径,验证震源机制解答方法的可靠性,分析强矿压成因,制定强矿压防治策略。研究得出如下认识：震源机制解答方法反演煤矿采动岩体破裂机制的应用效果较好;华亭煤矿强矿压频发的主要原因是水平应力强度高、最大主应力方向与巷道走向大角度相交、厚层砂岩大面积悬顶、底煤厚度大且冲击倾向性强;防治此类强矿压发生的主要途径是工作面设计应避开最大主应力方向与巷道走向大角度相交、先开采底板抗冲击性能较好的下分层、顶板预裂卸掉垂向采动应力和巷道钻孔、切槽断底。     

大埋深坚硬顶板厚煤层冲击地压微震监测及防治措施

针对深部矿井冲击地压形成机理复杂造成其监测预警困难的现状,本文介绍了一种适用于大埋深坚硬顶板厚煤层冲击地压的多因素耦合监测及防治方法。首先通过数值模拟分析临空面超前区域应力分布时空演化特征;其次,分析了冲击前兆发生时微震监测、声发射电磁辐射监测以及支架阻力监测曲线的变化规律,判断超前区域存在冲击危险性后,现场采取大直径钻孔进行卸压。以巴彦高勒煤矿311305工作面为工程背景开展了该方法的现场实践,通过数值模拟计算临空工作面回采至300m附近时超前应力大小和应力集中系数远超正常值,结合回采过程中工作面超前区域微震监测、声电辐射强度强度曲线的变化特征和现场超前区域30m内的钻检结果,判定311305工作面回采至300m附近时具有强冲击危险性,现场采用110mm大直径钻孔进行卸压,有效降低了311305临空回采面"初次见方"时冲击地压的发生几率。     

基于“协同开采”理念的深部磷矿岩爆防控研究

随着浅层磷资源的逐步枯竭,磷矿山企业逐步转向深部开采,然而深部磷矿开采中的岩爆灾害突出,对井下人员和设备造成了严重的安全隐患。以某磷矿深部开采中呈现的岩爆现象为例,结合工程开挖环 境与开挖工况,引入“协同开采”理念,从应力转移、应力防控和岩性改善的角度对深部磷矿岩爆防控进行了研究。结果表明,①井下岩爆主要表现为开拓巷道掌子面附近的即时型岩爆和巷道交叉处及采区矿柱中上 部的滞后型岩爆;②对采场切割巷道掌子面附近采取“品”字形错位布置和泄压挂网的主动防护方式,可有效降低岩爆产生烈度和岩爆发生次数,并对岩爆瞬间飞溅碎屑进行阻拦;③通过优化矿区尺寸,采用间隔错 位开采方式优化回采工艺,并进行采区充填,可有效降低开挖引起的采区应力集中程度,从而在控制工程成本的同时降低作业现场安全隐患程度。基于“协同开采”理念的深部磷矿岩爆防控思路的提出,对于确保磷 矿深部安全高效开采具有一定的借鉴意义。     

用采矿诱发微震法判别岩体性态特性

本文介绍在加拿大矿山应用微震技术描绘活性裂隙、评估应力变化以及判断大规模震动和发生岩爆条件的研究。该研究表明：可利用微震法判断活性裂隙的方位、确定异常应力区范围以及可能发生岩爆的区域、掌握局部应力对剪切破坏所起的作用，并且可确定与远距离诱发岩爆相关的应力变化路径。岩爆可能发生的特征是沿断层面方向微震显著增加并伴随有效应力增高。因此，微震分析法可作为远距离监测采矿引起的岩体性态变化的方法。     

冲击地压矿井综采工作面同时相向回采可行性分析

受矿井采掘布局影响,耿村煤矿13230工作面和13200工作面在一定回采时期会出现同时回采,两工作面同时回采期间存在应力集中叠加,增加工作面发生冲击地压危险性的可能性.为确定两工作面同时回采的可行性,通过FLAC3D软件建立2个工作面不同回采阶段的回采模型进行数值模拟和理论分析.结果表明,两工作面同时回采期间相互影响很...     

深部开采诱发的岩爆及其防治策略的研究进展

深部开采诱发了严重的岩爆。在南非的深部金矿，67％的死亡和30％的受伤者与岩爆和岩崩有关。本文给出了目前岩爆机理和风险估计研究的主要进展、现场监测矿震的主要手段和防治岩爆的几种主要的有效措施。     

金属矿深部开采岩爆危险预测的GA-ELM模型研究

为对金属矿山深部开采时岩爆的危险性进行预测,在总结深部开采岩爆发生机理的基础上,综合选取影响岩爆发生的3个重要因素作为岩爆预测的判别因子。搜集国内外金属矿深部开采岩爆的实例作为训练样本,引入极限学习机算法(ELM),针对该算法的不足,采用遗传算法(GA)对其相关参数进行优化,建立了岩爆预测的GA-ELM模型,并与单一ELM模型进行对比。利用该岩爆预测模型对一典型金属矿深部开采进行岩爆预测,结果与实际情况相吻合。研究结果表明,岩爆预测的GA-ELM模型训练效果及泛化能力均优于单一ELM模型、SVM模型及传统的BP模型,且该模型能够对金属矿深部开采的岩爆进行准确有效地预测,具有一定的工程应用价值。     

Numerical simulation of deep-level rockburst in Fuxin coalfield

On the basis of ANSYS finite element model(FEM) software, the deep-level rockburst in Fuxin coalfield was simulated numerically. Based on Haizhou Mine and Wulong Mine as two typical deep-level rockburst examples in Fuxin coalfield, the rules and characteristics of the deep-level rockburst were analyzed. And the models were established. For Haizhou mine, the relationship between mining distance and rockburst was presented when 100, 300, 600 m were mined in 3313 working face. When 300 m were mined, the rockburst began to emerge. When 600 m were mined, the rockburstwas the most possible to happen and the compression stress of the working face reached to the maximum value. The effect of tectonic stress on synclinal axis is also a key factor to rockburst occurrence. This was verified by the rockburst happened when 496 m were mined. For Wulong mine, based on the 311 working face as an example,the contours of Y stress in the roof and floor were obtained when the mining distance were 100, 200, 300 and 400 m. When 100 and 400 m were mined, the high stress concentration regions occurred in the front of working face. This shows the rockburst is easy to happen. It is confirmed by the rockburst when 91m were mined in 311 working plane.The above indicates that the numerical simulation has instructive rule to study the deep-Ievel rockburst in Fuxin coalfield.     

Application of acoustic measurement data to characterize initiation and development of disintegration focus in a rock mass

A new approach to local rockburst hazard problems and rockburst prediction is demonstrated in terms of acoustic measurements in two mine workings of Joint Kirov Mine, Apatit Co. The new approach is based on spectrum–correlation analysis of acoustic emission signals, on the one hand, and on the Griffith?Irwin fracture model, on the other hand. Acoustic emission signals are recorded using Prognoz-L new-generation portable system for local rockburst hazard monitoring. Prognoz-L provides digital recording and processing of a wide range of acoustic signal parameters. The analysis of spectrum parameters of the recorded signals confirms applicability of the innovative software/hardware system to predict dynamic events in rock masses.     

Simulation of microseismic emission during rock failure

In order to interpret the microseismic data proceeding rockbursts, it is important to understand the emission process of microseismic events. A numerical, phenomenological model has been developed to simulate seismic events and energy release during rock failure. This model consists of a 1-D multiple-mass-spring system and it is based on the stick-slip process using a slip-velocity-dependent friction law. Although no constitutive law of seismic emission was used, this model generates results that are of practical value. The simulated seismic events and energy release are very similar to those recorded during laboratory tests on rock specimens. Some important features obtained from these results can also be observed from the microseismic data monitored during some rockbursts. The effects of material properties and loading conditions on microseismic emission are examined using this model, which is otherwise not possible in the field. The effect of inhomogeneities is also assessed. For the case of a hard intercalation in the rock mass along a joint, the modelling results have showed excessive microseismic events and the event rate shows more than one peak value when compared with the case of a homogeneous rock mass. This may explain why periods of high seismic activity are sometimes not followed by rockbursts. With a soft intercalation, failure seems to follow the peak of microseismic emission very closely. There is little warning time for this case. This may be the reason of some rockbursts not showing seismic precursor.     

Applying a Maintenance Methodology for Excavation Reliability

Production management in mining needs to consider the performance reliability of not only the machine systems and workforce but also the excavations themselves. Excavations such as tunnels and shafts are critical components of an underground mine production system. Their operational reliability and capacity is dependent upon several factors, but primarily upon how the ground conditions can affect their structural stability over time. Much effort has been placed in the past towards developing the ability to characterize and analyze ground conditions and then design excavations and ground control practice to avoid ground-related problems. Unfortunately there has been only limited capacity in the past to manage the actual excavation performance and the impact of ground-related problems on production, in terms of productivity losses, costs and reliability. The economics of ground control and reliability analysis have not been fully integrated into traditional mine production management. This paper demonstrates how an approach using a maintenance methodology can be applied to assess the reliability of underground mining excavations. The approach is also applicable to surface mining excavations. Research indicates that the performance of the excavations, as well as the machines and workforce, should be tracked to manage the quality of mine production planning and control more effectively. This also should ensure the realization of the full potential of future automated mining systems.