煤与瓦斯突出研究现状及分析

阐述了煤与瓦斯突出机理的研究现状和基本特征,分析了煤与瓦斯突出机理研究中存在的问题。研究表明,煤与瓦斯突出机理的影响因素已经从单因素向多因素发展,综合作用假说得到了普遍认可,这为防突工作提供了理论依据。煤与瓦斯突出特征、物理模型的近似定量化及数值模拟、现场防突测评等方面还需要进一步深入研究。     

BP神经网络在煤与瓦斯突出预测中的应用

煤与瓦斯突出是一种极其复杂的瓦斯动力灾害现象.采用煤与瓦斯突出预测常用的7项指标作为输入值,基于BP神经网络的非线性自主学习能力,智能化、定量化地识别煤与瓦斯突出的类型.该模型基于MATLAB的神经网络工具箱加以实现.实验结果证明,基于BP神经网络的煤与瓦斯突出预测模型结果可靠,效果良好,应用性比较强.     

煤岩自然释放氢气与瓦斯突出关系初探

从某采区井下煤岩钻屑的自然释放气体中检测出氢气 (H2 ) .其中 ,在高瓦斯矿井的平均浓度为 33 6× 10 - 6;在低瓦斯矿井的平均浓度为 16× 10 - 6.对某突出灾害现场的煤样研究发现 ,突出点附近的煤屑自然释放气体中的氢气浓度高达 5 8× 10 - 6;突出点的煤屑则降到 10 - 5以下 .结果显示 ,煤岩自然释放氢气的现象具有一定的普遍性 .结果还暗示 ,易突出煤岩释放氢气的浓度可能较高 ;并且 ,突出过程中煤岩释放氢气的潜力可能发生重要变化 .在理论上 ,这里的观测结果支持了作者早先提出的关于煤与瓦斯突出的“氢地球化学异化”机理 .在应用上 ,本文指出氢气可望作为现场监测和预报煤与瓦斯突出的新指标 .在工程上 ,提出了运用微型专用质谱或专用气相色谱在井下现场单机同时监测氢气 (H2 )、氦气 (He)和甲烷 (CH4 )的建议     

大型真三维煤与瓦斯突出定量物理模拟试验系统研发

采用物理模拟试验开展多种组合条件下煤与瓦斯突出定量化模拟是目前研究煤与瓦斯突出机理与规律的主要研究手段,以综合作用假说、CSIRO突出模型为理论依据,根据推导建立的煤与瓦斯突出相似准则,研发了可考虑不同地质条件、地应力、煤岩体强度、瓦斯压力和施工过程的大型真三维煤与瓦斯突出定量物理模拟试验系统;系统由模型反力与空间密封单元、高地应力梯度加载智能控制单元、大流量高压瓦斯气体充填加载单元、巷道微型掘进与高速记录单元和多元信息瞬态获取五大关键单元构成。可实现最大尺寸为1.5 m×1.5 m×3 m(长×宽×厚)的试验模型真三维梯度加载,系统最大加载能力60 MPa,模型厚度方向可按0.6 m倍数调节,系统最大充气压力3 MPa,最大气体充填速度360 L/min,微型光纤光栅传感器最大采集频率500 kHz,巷道最大掘进速度10 cm/min。各模块协同工作,可实现三维气固耦合条件下石门揭煤诱发煤与瓦斯突出试验模拟,为探索不同组合因素下煤与瓦斯突出发生条件,揭示突出机理提供了定量化模拟平台。     

Numerical modeling of rock failure

Numerical calculations for the magnitudes of stresses at the instant of failure and angles at which it occurs are presented on the basis of stiff- and elastoplastic body models for plane and axially symmetric strain. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 36–44, March–April, 2000.     

煤与瓦斯突出多物理场分布特征的数值模拟研究

为揭示煤与瓦斯突出过程煤体多物理场耦合灾变机制,在含瓦斯煤气固耦合方程基础上,利用COMSOL软件中的固体力学与PDE模块,模拟了突出前后煤体应力场、变形场、气体流动场分布规律。与前期开展的突出物理模拟试验结果进行对比验证,证实了数值分析方法的可行性。模拟结果表明：突出后孔洞壁附近煤体发生塑性变形,导致此处煤体渗透率增大,且随着应力增大,突出孔洞壁处煤体渗透率可比原始渗透率增加2～3个数量级;突出后气体压力从突出孔洞壁面到煤体深部呈现先急剧上升后降低至原始气压的变化趋势,在孔洞壁处形成较高压力梯度,是突出持续发生的必要条件。     

Numerical modeling of overburden rehandling with draglines

The numerical modeling techniques are exposed and some mathematical problems are formulated to determine final spatial positions of the technology components included in open cutting with direct dumping, such as a disintegration of broken rocks, a rock pile and a dragline. The discussed formulations were integrated in algorithms and programs designed for automated composition of operating procedures for blasted overburden rehandling by draglines.     

近距离煤层煤巷掘进底板防突岩柱厚度数值分析

以平煤股份五矿己-1532020掘进工作面为研究对象,针对该掘进工作面处于近距离煤层上保护层内、掘进巷道底板与被保护层的间距过小、掘进过程中可能发生下部突出煤层冲破底板岩柱而导致煤与瓦斯突出的情况,运用FLAC3D对底板防突岩柱厚度进行模拟研究,结果表明,在围岩均质完整情况下,煤巷掘进的最小预留防突岩柱厚度不应小于2.5 m,结合现场实际,安全岩柱厚度应不小于3 m.     

基于突出强度对突出煤层分级问题的探讨

通过对2000—2019年较大及以上突出事故、大量瓦斯基本参数实验室测试,以及以往研究成果的分析,对突出煤层分级的方法、依据和判定规则、指标临界值等相关问题进行了深入探讨。提出将突出煤层划分为“一般突出煤层”和“严重突出煤层”两级,并以突出强度作为分级指标依据的突出煤层分级方法,建立了严重突出煤层的判定规则并确定了判定指标的临界值。研究结果可为突出矿井确定开采程序、防突规划、采掘接替规划等提供重要依据。     

Numerical modeling of hydraulic fracture initiation and development

Studying initiation and propagation of hydraulic fractures is carried out based on the hypersingular boundary element method. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 45–63, January–February, 2007.     

红菱煤矿石门揭煤突出过程模拟研究

运用Ansys、Flac3D有限元分析软件,在实测地应力、煤岩体力学性质和瓦斯压力的基础上,以红菱煤矿‘6.20'特大煤与瓦斯突出事故为背景,对煤与瓦斯突出中地应力、瓦斯压力、煤岩体力学性质等综合作用下的复杂力学过程进行了数值模拟;并对揭煤前的应力集中、揭煤后应力诱发煤岩破裂和瓦斯压力驱动下的煤体抛出三个阶段进行了阐述.模拟结果,较好地再现了含瓦斯煤岩由萌生裂隙、发生破坏、大量突出直至突出孔洞达到稳定、突出停止的过程,并与事故现场调查结果进行了对比,两者具有较好的一致性.红菱煤矿石门揭煤突出过程的机理研究,对该矿后期的深部开采具有一定意义.     

含瓦斯"试样”突出现象的RFPA2D数值模拟

运用新近开发的岩石破坏过程分析ＲＦＰＡ＾２Ｄ（Ｒｏｃｋ Ｆａｉｌｕｒｅ ＰｒｏｃｅｓｓＡｎａｌｙｓｉｓ）系统,以含瓦斯煤岩的破坏过程分析为例,通过对含瓦斯煤岩突出孕育机制及其声发射的数值模拟,说明了数值模拟方法给含瓦斯煤岩空出机制及其预测理论的发展所带来的新契机,数值模拟再现了含瓦斯煤岩突出的发生、发展过程,模拟结果表明,复杂的瓦斯煤岩断裂,突出现象可能是一些简单机理的演化结果。     

Outburst control in soft and outburst prone coal seam using the waterjet slotting technique from modeling to field work

The paper discussed a comprehensive numerical simulation and field work by the usage of waterjet slotting technique to prevent the occurrence of outbursts in soft and outburst prone coal seams. This was based on the geological and geomechanical conditions of Jinjiachong Colliery, Guizhou Province, associated with varied waterjet slotting parameters such as slotting penetration, slotting thickness and slotting distance along the length of borehole. Also, to understand the variation of internal stress of coal seams after waterjet slotting application, the internal stress levels were compared with and without slotting application, and the results indicate that the internal effective stress levels can be reduced to 70% and 45% for the vertical and horizontal stresses, respectively, and the gas concentration can be increased up to 5 times when the waterjet slotting is applied.     

Numerical modeling of deformation and failure of sandstone specimens

The author has simulated behavior of geomaterials based on the modified models of Drucker-Prager-Nikolaevski and Rudnicki. It is shown how fractures extend under stresses applied on a section of a specimen surface. The characteristic patterns are obtained for deformation localization in low porosity and high porosity sandstone under biaxial compression, and the stress-to-strain curves are plotted. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 69–79, January–February, 2008.     

突出口径对煤与瓦斯突出强度影响研究

改进大型煤与瓦斯突出模拟试验装置,增加两个气体压力传感器和两个温度传感器,进行突出口径分别为10mm,30mm,50mm的煤与瓦斯突出模拟试验。试验结果表明:在0.75 MPa瓦斯压力条件下,突出口径为10mm时没有发生煤与瓦斯突出,突出口径为50mm和30mm时发生煤与瓦斯突出,突出煤体质量分别为25.40kg和15.05kg。随着突出口径的减小煤与瓦斯突出的煤量减少,突出强度降低。突出口径的大小影响煤体突出的状态,突出口径越大,煤体突出的距离越远,破坏性也越高。突出后煤样中粒径在1.6~5.0mm范围内的煤颗粒比例减小,而粒径小于0.75mm的煤颗粒比例增加,体现了突出过程中的破碎功,具有较强的粉碎性。突出口径越大,煤体越易于破裂失稳并发生煤与瓦斯突出,煤体中瓦斯的放散受突出口径的影响,使煤体中瓦斯压力梯度变化趋势不同。突出口径越大,瓦斯压力降低越快,瓦斯对煤体的粉碎性越明显,突出强度也越大,突出过程中煤体温度也发生变化,说明突出口径影响含瓦斯煤的破断失稳和突出特性。     

油气悬挂缸数学模型和仿真分析

根据油气悬挂缸的结构和工作原理 ,建立了数学模型 ,模型仿真结果和试验结果的一致性 ,证明了该模型的正确性。通过对油气悬挂缸进行计算机仿真和试验研究 ,分析了气腔初始充气压力和温度对悬挂缸性能的影响     

Numerical modeling of hydrofracturing in a multilayer coal seam

The mathematical model of the process for hydrodynamic fracturing in a multilayer coal seam is proposed. The model is based on the equation of continuity and Darcy’s law. The filtration — temperature analogy allows solving the obtained non-linear, non-stationary problem in an axisymmetric statement for the pressure function as the heat-conductivity problem, by the finite-element method. The calculation results yield estimation of the radius of degassing borehole influence zone. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 61–70, January–February, 2006.     

综采工作面水力超前卸压防突数值模拟与试验研究

基于张集煤矿7353综采工作面采矿条件，通过数值模拟，分析了采煤工作面水力超前卸压防突效应，提出了利用煤壁位移量指标对其防突效果进行检验的方法，试验确定了水力超前卸压防突关键技术参数.现场试验表明，采取水力超前卸压防突措施可使工作面前方集中应力带深移，卸压带长度增加，工作面煤壁产生挤出位移，卸压带内瓦斯大量涌出，突出危险性显著降低，在保证防突措施超前距条件下实现了安全回采.     

对非突出区域瓦斯突出预测敏感指标的探索

 对存在突出危险性升级的煤层和矿井,如何采用科学的方法,提前确定预测敏感指标,对于指导矿井防突具有重要的指导意义。本文以顾桥矿13-1煤为研究对象,根据对地质构造带瓦斯突出预兆的假设,利用“三率”分析法与模糊聚类分析法相互印证的方法,对非突出区域瓦斯突出预测敏感指标进行了探索。     

Numerical modeling of time-dependent closure of coal seam artificial fractures

In order to improve efficiency of coal seam gas drainage, many fracturing techniques, such as waterjet fracturing, hydraulic fracturing and explosive fracturing, etc, have been developed and widely used in China coal mining industry. However, during the engineering applications, it is observed that the efficiency of gas drainage initially improves, but reduces thereafter. Thus, it is speculated that the contrasts in coalbed methane drainage efficiency may reflect variation of the closure behavior of the artificial fracture created. Based on comprehensive gas drainage monitoring data in underground coal mines, the work presented herein uses numerical simulation to show the behavior of the time-dependent closure of coal seam fractures associated with various levels of waterjet fracturing parameters and geomechanical conditions.