工作面顶板周期来压灾变预测和拓扑预测

工作面顶板周期来压是矿井灾害之一.本文用灰色系统理论的灾变预测和拓扑预测对工作面顶板周期来压进行了研究,并利用义马跃进煤矿支柱载荷的观测数据和工作面顶板周期来压的关系对工作面顶板周期来压进行预测,得出了精度较高的预测结果,为工作面顶板周期来压的预测提供了新的思路.     

工作面顶板周期来压火灾预测和拓扑预测

工作面顶板周期来压是矿井灾害之一,本文用灰色系统理论的灾变预测和拓扑预测对工作面顶板周期来压进行了研究,并利用义马跃进煤矿支柱载荷的观测数据和工作面顶板周期来压的关系对工作面顶板周期来压进行预测,得出了精度较高的预测结果,为工作面顶板周为压的预测提供了新的思路。     

基于BP神经网络的工作面周期来压预测

针对现有工作面周期来压预测方法在算法结构复杂、计算量较大等问题,探索一种高效、准确、易于使用的工作面周期来压预测方法。以淮南潘集矿区20个已采工作面作为工程研究背景,采用BP神经网络预测原理,在分析工作面周期来压的影响因素基础之上,设计出一种基于BP神经网络的工作面周期来压预测方法,通过MATLAB编程实验表明BP神经网络在工作面周期来压的预测中具有较高的精度。     

大采深条带开采坚硬顶板工作面冲击矿压治理研究

为了解决大采深条带开采坚硬顶板工作面的冲击矿压问题,以古城煤矿2106工作面为例,采用现场分析、实验室试验、数值模拟的方法对其发生机理进行了研究.结果表明在此条件下开采时发生的冲击矿压与煤岩性质、采深、坚硬顶板厚度及顶板的周期来压有密切关系.当冲击矿压发生的煤层具有强冲击倾向性,煤层硬度系数大于3、采深900 m以上、顶板岩层坚硬且厚度大于20 m时,冲击矿压发生具有突然性和猛烈性;主要发生在顶板周期来压期间、超前支护50m范围内,此时工作面的CH4和CO气体含量同时升高.对此提出了钻屑法等预测预报的方法和煤体爆破卸压与柔性支护等治理措施.     

耿村煤矿综放开采覆岩移动和矿压显现规律研究

厚煤层综放开采矿山压力和围岩控制一直是综放开采研究的重点问题。基于义马矿区耿村煤矿特厚煤层综放工作面的地质采矿条件,采用数值模拟和现场矿压观测的方法,对综放工作面覆岩移动和矿压显现规律进行研究。结果表明:(1)综放工作面上方老顶形成"三铰拱"形砌体结构,该结构初次失稳和周期性失稳造成工作面初次来压和周期来压。老顶来压后,工作面前方支承压力趋于稳定,主要表现在最大应力集中系数和塑性区范围基本保持不变。(2)综放工作面顶板周期来压步距14.4~17.5 m,平均16.2 m,顶板来压动载系数1.81~2.04,平均1.92,顶板来压明显但较缓和。顶板来压期间支架时间加权平均工作阻力为其额定工作阻力的72.2%,选用ZF8600/18/35D型放顶煤液压支架合理。研究结果可为义马矿区综放开采围岩控制提供技术支撑。     

综放开采煤层倾角对周期来压特征的影响

为深入研究煤层倾角对周期来压特征的影响,以越南河林煤矿为研究对象,通过理论分析和现场实测就煤层倾角对综放开采工作面顶板周期来压特征的影响规律进行研究.理论分析和现场实测的研究.结果表明:当煤层倾角为-15°~15°时,随着煤层倾角的增大周期来压步距逐渐减小,周期来压峰值逐渐增大.进一步分析得出不同煤层倾角对周期来压特征的影响系数.由于仰斜开采时层向分力指向采空区方向,在弯矩和层向分力的作用下使得周期来压步距偏小,来压峰值偏大;由于俯斜开采时层向分力向着工作面推进方向,使得周期来压步距偏大,来压峰值偏小.     

急倾斜放顶煤矿压显现规律的观测与研究

通过对宜洛煤矿李沟井伪俯料放顶煤回采工作面的矿压观测,从4个方面研究了急倾斜伪俯斜放顶煤工作面矿压显现规律;（1）工作面的初次来压、周期来压步距和来压强度;（2）沿工作面走向控制区内的顶板压力状况,以及生产工序对控制区内支柱载荷的影响;（3）研究了沿倾斜方向矿压显现特点,分析了与近水平煤层矿压显现不同的原因;（4）观测了上下巷矿压显现规律,并分析了上下巷压力不同的原因．用统计法对伪俯斜放顶煤采煤法和分层开采上下巷矿压显现作了对比。     

坚硬顶板型冲击矿压灾害防治研究

针对兖州矿区济三煤矿6303工作面的冲击矿压问题，分析了冲击矿压发生的主要原因及影响因素．根据现场条件和数值模拟分析，提出了采用顶板爆破解除冲击矿压危险的技术措施，并确定了爆破参数．采用矿用钻孔窥视仪并配合电磁辐射法和钻屑法对爆破进行了效果检验．结果表明，通过顶板爆破措施可以破坏工作面上方坚硬厚层砂岩顶板的完整性，提前释放顶板聚集的弹性能，减弱和消除了工作面的冲击矿压危险，胜，保证了工作面的安全生产．现场实践证明，该项技术对具有坚硬顶板型冲击矿压的防治效果明显．     

基于在线监测的三软煤层综采工作面矿压显现规律研究

针对郑州矿区三软煤层出现的煤巷锚杆被剪断、工作面两巷表面位移大和综采工作面矿压显现规律不清晰等情况,以芦沟煤矿32081综采工作面为工程背景,应用KJ21煤矿顶板灾害监测预警系统对该工作面及两巷矿压进行在线监测,分析研究芦沟煤矿综采工作面周期来压步距、巷道围岩显现规律和超前支承应力分布规律。研究得出如下结论:芦沟煤矿选用ZF3000/17/27型液压支架能满足支护要求,综采工作面平均周期来压步距为11.16 m,沿空掘巷煤柱最佳宽度为3 m,综采工作面两巷超前加固距离不应少于50 m,为矿井综采工作面支架选型和煤巷锚网支护设计提供了科学依据,有效保障了矿井安全生产。     

宝雨山矿放顶煤工作面矿山压力显现规律研究与分析

通过利用GSJ-1型矿压仪、DZ—WCI型单体液压支柱工作阻力检验仪及钢卷尺对宝雨山煤矿11103放顶煤工作面进行了全面矿压观测和研究，掌握了顶板运动规律、工作面矿压显现特征和顶板控制特征．对11103采煤面所使用的支护设备的可靠性和适应性进行了评价，为工作面设备的改进与更新提供了参考；确定了采动影响范围及支承压力分布规律，为合理选择工作面支护方式提供了依据．     

Influence of Lithological Characters of Coal Bearing Formation on Stability of Roof of Coal Seams

Lithology is one of the important factors influencing the stability of roof of coal seams. In order to investigate this, the phenomenon of underground pressure and distribution of pressure were studied by using the local observation and simulation test with similar materials. The observation results show that the distance of initial weighting and periodic weighting of the mudstone roof is shorter than that of sandstone roofs. The sandstone roof with a high strength has a longer distance of initial weighting and periodic weighting, the abutment stress on the working face is big and the height of caving and fracture zone is high. The peak point of abutment stress in the sandstone roof is near to the working face and the pressure bump is inclined to occur. The result is contrary to that in case of the mudstone roof with a low strength. While in the transition zone of nipped sandstone, roof rock-mass is broken and is poor in stability, therefore, it is difficult to hold the roof.     

浅埋综采面高速推进对周期来压特征的影响

以活鸡兔井为工程背景,通过实测和理论分析就浅埋综采面高速推进对周期来压特征的影响规律进行了深入研究.结果表明:在高速推进情况下(推进速度一般大于10m/d),工作面周期来压持续长度显著增加,而周期来压步距、支架载荷和动载系数的变化相对较小.推进速度差异引起周期来压特征发生变化的实质是围岩变形破坏特征时间效应的体现.工作面高速推进时,直接顶由于推进速度较快垮落不充分,老顶在破断回转过程中需要更大的回转量才能触矸稳定,这是导致来压持续长度明显增加的重要原因.将推进速度对周期来压特征的影响规律运用到了神东矿区双回撤通道综采面末采段的让压开采实践中,指导了活鸡兔井21306综采面的安全回撤.     

Impact of geo technical factors on strata behavior in longwall panels of Godavari Valley coal field-a case study

Understanding the cantilevers formed by thick, massive beds in the near-seam overburden above longwall panels and the associated loads and strata fracturing effects developed during caving(main and periodic weightings) are key elements for the successful implementation of longwalls. Such caving mechanisms rely on the geotechnical conditions within the panel. In India, the majority of longwall downtime and/or roof failures were caused by a lack of knowledge on overburden caveability, in particular when the main and periodic weightings will impact the face and longwall support selection to effectively mitigate such weightings. Godavari Valley Coal Fields is no exception as longwall faces were adversely affected due to the presence of thick, massive beds in the near-seam overburden at both Godavarikhani(GDK) 7 and 9 Incline mines. In contrast, overburden weightings were negotiated successfully in GDK10 A and Adriyala Longwall Project(ALP) mines by detailed geotechnical studies, the use of adequate longwall support capacities, and effective operational practices. Thirteen longwall panels with varying face width, at different depths have been extracted under massive sandstone beds of 18 m to28 m thickness at GDK 10 A and ALP mines. This study elucidates that the main roof weighting interval decreases with an increase in face width and attains a constant value with further increases in face width under the same geo-mining conditions. In addition, this study also concludes that with increases in face width, the periodic roof weighting interval decreases and shield loads increase. Similarly with increasing panel width to depth ratio, the main and periodic roof weighting intervals decrease but shield loads again increase. Lastly, the strata behaviour of the longwall face retreated along up-dip direction is demonstrated. The results of this paper improves the mechanistic understanding of the impact of face width,depth and main roof thickness on periodic weighting and associated roof control problems on the longwall face.     

单体支柱工作面顶板动态的监报

本文提出顶板动态监报应包括回采工作面局部冒顶的监报及顶板来压的预报这两个方面的观点。初步给出了局部冒顶监报指标的确定方法;重点探索了采用回采工作面来压综合判断指标来预报顶板来压的可能性。文中所给的回采工作面局部冒顶的监报指标及顶板来压预报指标所采用的系数,基于现场统计资料,或现场经验的数学处理结果。     

复杂条件下上提蹬空工作面矿压显现特征研究

为了解决蹬空对巷道围岩变形影响严重等问题,针对张集矿1410（1）工作面复杂的地质条件,采用计算机数值模拟（UEDC）系统和现场工程实践相结合的方法,对工作面推进不同距离时上覆岩层垮落形态、初次来压步距、周期来压步距、液压支架受力以及巷道围岩的变形特征进行研究。研究表明：工作面老顶初次来压步距约为32 m左右,周期来压步距约为16 m左右。工作面液压支架所需支撑的最大岩层高度约为25m。在工作面每天正常推进8m的情况下,工作面压架的危险性较小。     

下分层综放工作面上覆岩层结构特征

我国综放开采技术是在分层综采技术的基础上发展起来的,对于一直采用分层综采的一些大型厚煤层生产矿井,面临着顶分层采后下分层综放开采技术问题,这个问题与一次采全厚整层综放开采矿压显现有所不同.下分层综放开采时,二次垮落的直接顶岩层碎胀系数较小,垮落带高度与采高的比值将增加,造成顶分层开采时下位老顶岩层垮落后转化为规则垮落带,成为下分层综放工作面的上位直接顶,促使下分层综放工作面的老顶“砌体梁”式平衡结构向更高层位岩层发展.上位直接顶岩块强度较高、块度较大,容易形成“岩-矸”半拱式平衡结构.该结构的周期性失稳和垮落,造成采场出现小的周期来压现象;而“砌体梁”平衡结构的周期性失稳和垮落,将导致采场出现大的周期来压现象.     

Roof pre-blasting to prevent support crushing and water inrush accidents

Support crushing and water inrush when mining under an unconsolidated confined aquifer in the Qidong Coal Mine was prevented by roof pre-blasting. The mechanism and applicable conditions for this method have been studied. The results show that when an overburden structure that may cause support crushing and a water inrush accident exists the weakening of the primary key stratum, which thereby reduces its weighting step, roof pre-blasting is both feasible and effective. If the position of the primary key stratum can be moved upward to exceed 10 times the mining height the possibility of support crushing and water inrush disaster caused by key stratum compound breakage will be lowered. The overburden structure of the number 7121 working face was considered during the design of a technical proposal involving roof pre-blasting. After comprehensively analyzing the applicability of roof pre-blasting the resulting design prevented support crushing and water inrush disasters from happening at the number 7121 working face and laid a solid foundation for mining safely.