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1.
跨采软岩巷道锚注支护试验研究 总被引：3，自引：1，他引：3
通过对鲍店煤矿北翼跨采软岩巷道的调查与分析，说明了巷道的破坏机理，并根据跨采软岩巷道的特点提出了各类巷道的支护技术方案。通过巷道数值模拟、相似材料模拟及井下试验应用，取得了较好的技术经济效果。 相似文献
2.
为预测煤巷冲击地压灾害,将强冲击倾向煤视作理想弹脆性材料,建立圆形煤巷力学模型,分析煤巷围岩的应力和变形能密度分布特征,进而建立煤巷冲击地压预测模型,利用该模型预测冲击地压灾害风险。研究结果表明：弹脆性煤巷围岩的切向应力和变形能密度在弹性区与破坏区界面处发生跃升;煤体强度损伤度和地应力增大,煤巷破坏区半径增大,煤巷围岩切向应力和变形能密度跃升高度增大;切向应力跃升为煤巷失稳破坏提供了力源,变形能密度跃升为冲击地压发生提供了能量源;切向应力和变形能密度跃升高度越大,煤巷越容易失稳和冲击;基于切向应力和变形能密度跃升,建立了煤巷冲击地压解析预测模型,预测结果与现场冲击地压实际情况一致,从而为脆性煤巷冲击地压预测提供了一种新的方法。 相似文献
3.
高地应力破碎软岩巷道底臌特性及综合控制对策研究 总被引：1，自引：0，他引：1
高地应力破碎软岩巷道底臌问题,由于其地质条件的复杂性,是煤矿开采的技术难题之一。通过总结分析高地应力破碎软岩巷道底臌的变形破坏特性,研究了底臌治理对策。研究结果表明,底板围岩呈现出挤压剪切流变特性,在支护对策上应将支护体系视为完整体系,在加强修复固结、应力转移和扩大承载圈的同时强调调动帮、顶部的间接控制作用。提出了以底板超挖、高强度预应力锚索、深孔注浆、底脚、拱角锚杆和回填为技术支撑的综合治理对策,通过FLAC3D建立的三维数值分析模型,分析了在综合治理对策下围岩位移场及塑性区的变化,验证了该方法的有效性。将综合治理对策应用到淮南潘二煤矿东二采区主要大巷,取得了良好的支护效果。 相似文献
4.
针对澄合矿区王村矿井部分巷道及硐室围岩变形破坏严重的现状,以围岩抗压强度、围岩泊松比、侧压力系数、围岩弹性模量、巷道埋深、巷道跨度、最大应力集中系数及围岩平均移动速率作为围岩稳定性因子,通过对8条典型巷道及硐室围岩稳定性因子的现场实测,并对所得数据进行模糊等价聚类分析的基础上,将围岩稳定性划分为极不稳定、不稳定、基本稳定、稳定及非常稳定等5类。在此基础上,将围岩稳定性影响因子分为最主要因素、主要因素及一般因素3大类,进而确定各监测巷道及硐室的围岩稳定性类别。结果表明,模糊等价聚类分析具有较强的工程适用性,是解决矿井围岩稳定性分析的一种有效方法,基于该方法得到的围岩稳定性影响因子分类和围岩类别可以为合理设计围岩支护方案及其参数提供理论依据。 相似文献
5.
煤岩强度离散性及三轴压缩试验研究 总被引：3，自引：0，他引：3
简述了煤的强度离散性原因。采用超声脉冲穿透法测量煤样波速并进行岩石力学试验,回归分析得出了煤岩试件声速与其力学参数之间的关系式,为尽可能避免因煤样离散性而带来的盲目试验提供了一条技术途径。采用MTS815岩石伺服试验系统进行了煤样三轴压缩试验。结果表明,与花岗岩等高强度岩石不同,由于煤的孔隙裂隙发育在围压作用下孔隙裂隙被压密闭合,煤的弹性模量随围压增大而增大,但并非线性关系;煤的轴向破坏应力及残余强度均随围压增大而增大。研究结论对于在破碎煤体中掘进的巷道的锚固机理研究有重要指导意义。 相似文献
6.
软岩巷道围岩松散破碎承载力低,在工程荷载作用下,具有明显的塑性变形和强流变性。传统单一的支护手段难以保证其安全和稳定。高家梁煤矿2-2上煤层巷道是典型的软岩巷道,其围岩遇水泥化、膨胀、崩解,进而造成巷道出现断面收缩、片帮、冒顶等失稳现象。针对高家梁煤矿2-2上煤层20110综采工作面回风顺槽的软岩问题,结合该巷道具体工程地质条件及围岩物理力学特性设计出锚网索联合支护的方案。通过FLAC3D数值模拟分析及现场巷道围岩表面位移监测,对该方案的支护效果进行了分析,其结果证明了该联合支护方案可以有效的控制膨胀型软岩巷道的稳定性,从而保证了煤矿的安全生产。 相似文献
7.
The basic objectives of mine roadways are to provide sufficient cross sections to accommodate equipment, transport, personnel travel and ventilation. However, many roadways become damaged to the extent of needing maintenance, generally dinting, and in some cases requiring re-ripping. Strata conditions play important effects on stability of roadways and other mining activities. Weak rocks cause excessive roadway closures, and water softens some rocks and worsens the closure problem. Therefore, study on effect of mine water on the stability of underground coal mine roadways is important for underground coal mine development. A scientific discussion on the effect of water on the stability of roadways is given on the basis of results obtained by means of field investigation and laboratory tests. Based on analysis, rock in saturated condition has only between 0.19 to 0.49 of its compressive strength and 0.17 to 0.59 of its tensile strength in dry condition. Among the coal measures rock in research area, water has the most obvious effect on the strength reduction of shale. The slaking behavior of shale has also been the worst among the other. Field investigation of roadway driven in shale shown vertical closure in the wet and dry condition area reached 40–60 and 5–15 cm respectively, in 30 days after the drivage. Among the measures, drainage is considered to be the most economical and simplest method to reduce the water content in the rocks or the rock masses. 相似文献
8.
Arka Jyoti Das Prabhat Kumar Mandal Satya Prakash Sahu Angad Kushwaha Rana Bhattacharjee Subhashish Tewari 《Journal of the Geological Society of India》2018,92(6):732-742
The rock mass around an excavation is generally traversed by different geological discontinuities such as faults, folds, slips, joints, etc. Fault is one of the major geological discontinuities which creates lot of difficulties during underground winning of coal. Entire stress regime and ground conditions in the formation are altered in and around the faults. Faults also impose detrimental effects by introducing impurities, including clay and various forms of mineral matter into the coal seams; opening of pathways for the influx of water and gas into the underground workings; displacing the coal seams upward/downwards making the coal seams difficult or sometimes impractical to mine. Appropriate evaluation of the effect of the fault on the stability of the underground workings is a requisite for safe design of the underground mining structures. In this paper, a study has been carried out to assess the effect of the fault on the stability of underground coal mines by numerical simulation with distinct element method (DEM). On the calibrated DEM model, parametric study has been performed by varying the selected parameters, the dip and the friction angles of the fault. The analysis of variance (ANOVA) shows that both the factors have statistically significant effect on the strength of the coal pillar. Similarly, the displacement of the immediate roof and the height of the disturbed strata are evaluated by the DEM modelling and statistical analysis when the fault passes through the middle of the gallery. The results of ANOVA for both cases indicate that the both factors have significant effect on the displacement of the immediate roof and the height of the disturbed strata. It is obtained from the study that the low angle fault causes high instability in the immediate roof. The paper has been supplemented with the field observations where instability in underground roadways of a coal mine in India is caused by the fault. It was observed in VK-7 incline mine of Singareni Collieries Company Limited, India that there was sudden failure of immediate roof of a roadway where a low angle fault crosses the middle of the roadway. The findings of the paper help to understand the behaviour of the coal pillar and the surrounding rock mass in the presence of the fault. The study would also help to take appropriate decisions about the unstable regions of the working safeguarding safety in underground coal mines. 相似文献
9.
通过采用均匀化方法,研究了圆形隧洞的锚杆支护特性,将高密度支护模式下的岩石和锚杆复合体考虑成均匀、连续、强度参数增强的等效材料,简化了岩石和锚杆间复杂的力学耦合问题。通过定义锚杆密度参数来反映不同支护模式的特性,建立锚杆密度参数与Mohr-Coulomb屈服准则中主要参数之间的关系,推导出等效弹性模量、等效黏聚力和等效内摩擦角的表达式,并分析比较了隧洞在支护前后的位移情况。结合可靠性理论,采用容许极限位移量作为失稳判据,分析了隧洞在支护前后的可靠性指标与破坏概率,结果表明,文中提出的方法简单可靠,锚杆支护对隧洞的位移限制效果明显,可显著提高隧洞的可靠性。 相似文献
10.
Baotang Shen 《Rock Mechanics and Rock Engineering》2014,47(6):2225-2238
Roadway instability has always been a major concern in deep underground coal mines where the surrounding rock strata and coal seams are weak and the in situ stresses are high. Under the high overburden and tectonic stresses, roadways could collapse or experience excessive deformation, which not only endangers mining personnel but could also reduce the functionality of the roadway and halt production. This paper describes a case study on the stability of roadways in an underground coal mine in Shanxi Province, China. The mine was using a longwall method to extract coal at a depth of approximately 350 m. Both the coal seam and surrounding rock strata were extremely weak and vulnerable to weathering. Large roadway deformation and severe roadway instabilities had been experienced in the past, hence, an investigation of the roadway failure mechanism and new support designs were needed. This study started with an in situ stress measurement programme to determine the stress orientation and magnitude in the mine. It was found that the major horizontal stress was more than twice the vertical stress in the East–West direction, perpendicular to the gateroads of the longwall panel. The high horizontal stresses and low strength of coal and surrounding rock strata were the main causes of roadway instabilities. Detailed numerical modeling was conducted to evaluate the roadway stability and deformation under different roof support scenarios. Based on the modeling results, a new roadway support design was proposed, which included an optimal cable/bolt arrangement, full length grouting, and high pre-tensioning of bolts and cables. It was expected the new design could reduce the roadway deformation by 50 %. A field experiment using the new support design was carried out by the mine in a 100 m long roadway section. Detailed extensometry and stress monitorings were conducted in the experimental roadway section as well as sections using the old support design. The experimental section produced a much better roadway profile than the previous roadway sections. The monitoring data indicated that the roadway deformation in the experimental section was at least 40–50 % less than the previous sections. This case study demonstrated that through careful investigation and optimal support design, roadway stability in soft rock conditions can be significantly improved. 相似文献
11.
高应力大断面煤巷锚杆索桁架系统试验研究 总被引：2，自引：0，他引：2
高应力构造区大断面煤巷围岩控制技术是煤矿巷道工程中亟需研究的问题之一。以峰峰集团新三矿废矸充填复杂困难煤巷为典型研究对象,综合现场调研和数值模拟分析结果得出高应力作用下大断面煤巷变形破坏特征,提出一种基于“索-拱”结构为核心的高应力煤巷围岩控制系统-锚杆索桁架,分析该支护系统基本结构,设计流程及支护预应力场分布特征,在新三矿某一置换煤巷开展工业性试验,研究结果表明,新型支护系统结构稳定,巷道围岩控制效果良好,对类似困难巷道支护具有一定的理论和实用参考价值。 相似文献
12.
13.
针对红庆梁煤矿回采巷道变形严重问题,采用空心包体地应力测量方法对红庆梁煤矿3-1煤的地应力进行了实测,获得地应力场分布特征。应用地质动力区划法划分红庆梁井田Ⅰ—Ⅴ级断裂构造,应用“岩体应力状态分析系统”,进行应力区划分和巷道稳定性分析。研究表明:红庆梁煤矿地应力场属于以水平压应力为主导的水平构造应力场,地应力场方向对巷道稳定性影响较小;井田范围内共划分4个应力区:低应力区、正常应力区、应力梯度区、高应力区,分别占井田面积的5.9%、55.7%、27.0%、11.4%;应力大小是影响巷道稳定性的主要原因,致使处于应力梯度区和高应力区内的巷道变形严重。地应力场的分布特征分析和应力区的划分对红庆梁煤矿及类似条件矿井的采掘部署和支护设计具有重要作用。移动阅读 相似文献
14.
泥化弱胶结软岩地层中矩形巷道的变形破坏过程分析 总被引：2，自引：0，他引：2
在西部地区,一定数量的矿区处于泥化弱胶结软岩地层,此类软岩胶结性差、强度低、遇水泥化。矩形是采区巷道的常用型式,但其断面受力不均、稳定性差。在上述软岩地层中的矩形巷道承载力低、变形量大、变形持续时间长,给煤矿的安全生产带来极大困难。以内蒙古新上海一号煤矿皮带顺槽矩形巷道为背景,运用FLAC3D软件中的Cvisc黏弹塑性模型,对矩形巷道的变形破坏进行了数值模拟,并将模拟结果与现场监测结果对比分析。结果表明:巷道开挖支护后,受断面形状影响,矩形巷道四角出现压应力集中和顶板受拉区,巷道顶板下沉量大,底板底臌严重,两帮向巷道挤出;受围岩岩性影响,围岩进入塑性的时间快短、范围大,塑性区超出了支护体的作用范围,造成锚杆(索)的锚固效果难以完全发挥,围岩出现整体滑动的现象;巷道变形呈现出流变变形的特性,变形量随时间持续增加,持续的蠕变变形超出了支护体的可控范围,最终引起巷道的失稳破坏。 相似文献
15.
煤矿开采岩体稳定性研究 总被引：1，自引：0，他引：1
煤矿开采岩体稳定性研究一直是人们普遍关注的课题。本文对影响岩体稳定性的因素进行了分析,提出了岩体稳定性的研究方法,并以协庄矿为例,对顶板稳定性进行了预测,为煤矿开采岩体稳定性预测提供了一条途径。 相似文献
16.
鉴于岩石碎胀特性对于煤矿地下水库储水能力及地表沉陷的重要影响,选取神东矿区某矿22615面为工程背景,利用相似材料模型试验探究采空区垮落岩体应力及碎胀系数分布规律,明确垮落岩体应力-碎胀系数关系,并通过岩石压实试验进行验证,揭示饱水岩石压实特性。研究结果表明：沿采空区走向,边界附近老顶悬臂梁结构限制覆岩下沉,垮落岩体应力最低仅为0.32 MPa,碎胀系数最大达1.48;中间区域老顶结构失稳覆岩完全下沉,垮落岩体应力趋于1.5 MPa,碎胀系数降至1.09。沿采空区垂向,垮落岩体应力随高度负相关改变,而碎胀系数成正相关变化。无论沿采空区走向或垂向,垮落岩体碎胀系数与应力均满足负对数关系。与自然岩石相比,受载饱水岩石碎胀系数减幅更为明显,两者相差8.514%,为煤矿地下水库储水量和地表沉降量预测提供了基础理论依据。 相似文献
17.
融化作用下含冰裂隙冻岩强度特性及寒区边坡失稳研究现状 总被引：1，自引：1，他引：0
如何科学评价裂隙冻岩质边坡稳定性、如何采用有效措施保证冻岩边坡工程的安全建设和运营,已是目前岩石力学研究领域的一个重要课题.首先对青海木里地区含冰裂隙冻岩地层煤矿露采过程中的大规模边坡工程问题开展现场勘察和试验研究,分析了高寒地区冰体赋存特征、含冰地层消融特征及含冰地层融水出流特征;结合前人研究,较为全面地总结了含冰裂隙冻岩强度特性及冻岩边坡普遍性的变形失稳特点,提出寒区冻岩边坡失稳机理为冰-岩系统在热侵蚀和荷载共生作用下的热力耦合结果;对消融作用下含冰裂隙冻岩的物理力学、热力耦合特性及裂隙冻岩质边坡稳定性评价等方面的国内外研究现状进行了综述和讨论;认为开展融化作用下含冰裂隙冻岩体强度特性及边坡失稳研究将是与冻融损伤并重的一个新的研究方向. 相似文献
18.
《Geomechanics and Geoengineering》2013,8(1):71-77
Rock bolt is a major reinforcement technique for roadways in coal mines in China. Generally, separation of the bonding interface between the rock mass and the bolt may lead to collapse of the bolted rock mass due to stress concentration. In order to establish the stress concentration mechanism on the bonding interface, the distribution functions for shear stress and longitudinal force on the interface are derived using Mindlin's model, and a failure criterion for the interface is proposed. In addition, influencing factors for the stress distribution mode are identified. Both analytical study and numerical simulations by ANSYS have shown that, as the elastic modulus of rock increases, both shear stress and the longitudinal force-concentrating zone move towards the outer end of bolt and decrease gradually from the free surface to the rock mass body. Also, there is an optimizing cement thickness which results in relatively uniform distributions of shear stress and longitudinal force on the interface. It is valuable to investigate the bolt invalidity mechanism as well as reinforcement safety estimation in underground rock engineering design. 相似文献
19.