软顶软底开采工艺探讨

煤层顶底板岩性影响着煤炭的安全开采,软顶软底条件下开采,破碎顶板极易冒落,安全生产和煤质难以保证,通过工艺改进,解决了同类条件下煤层开采安全问题,创造了很好的经济效益。     

软顶软底开采工艺探讨

煤层顶底板岩性影响着煤炭的安全开采,软顶软底条件下开采,破碎顶板极易冒落,安全生产和煤质难以保证,通过工艺改进,解决了同类条件下煤层开采安全问题,创造了很好的经济效益。     

鑫都煤业首采工作面矿压特征的探索与研究

不同地区的煤层赋存条件往往存在着很大的差异,由此而造成的综合机械化开采过程中的矿压显现特征也会有很大程度的不同,因此,针对不同矿区具体的煤层开采主、客观条件,对采场矿压显现特征进行有针对性的研究,运用数值计算方法对采场周围应力场分布、顶底板岩层稳定性、支架对围岩的支护效果等进行了研究,掌握老顶的初次断裂步距,对采场来压进行预测预报,并据此制定有针对性的矿压控制技术措施,来保证矿井安全高效生产。     

针对孤岛综放面煤层自燃防治方案研究

综放开采煤层都是特厚煤层,平巷沿底板掘进,留有顶煤。由于受采动影响,使得顶煤破碎离层;有些煤层煤质松软,掘进时,时常冒落形成空洞区;有的上分层已采,下分层采用综采放顶煤技术,由于煤层起伏变化,中间煤层破碎等原因,使综放平巷与顶采空区连通;无煤柱开采留小煤皮的沿空巷道与临近层采空区连通。由于上述种种因素,使综放无煤柱开采平巷自然火灾增多,且火源沿巷道顶板及沿空侧（或顶部）采空区发展迅速。     

高瓦斯煤层放顶煤安全开采

介绍我国放顶煤开采技术的发展过程,阐明放顶煤采煤法是一种既高产又安全的采煤方法。对于高瓦斯煤层进行放顶煤开采,在硬顶煤和硬顶板特殊的地质条件下,必须采取特殊的措施才能安全开采。     

关于对煤矿顶板及复合型顶板事故预防分析

顶板事故是煤矿生产的主要灾害之一,本文就煤层的顶底板及复合型顶板的概念、复合型顶板大面积冒落特点及复合型顶板推垮型冒顶的防治技术进行了探讨。     

中深孔爆破强制放顶

前言 龙煤集团双鸭山分公司新安煤矿在回采东翼三采区十上层煤时,由于此层煤顶板发育完整,坚硬,厚度大,（顶、底板岩性见表）,在回采过程中悬顶面积均超过10000平方米（最高达到14600平方米）老顶才开始初次来压,给安全生产造成极大危害.     

巷道底鼓的预防与治理

巷道受掘进或回采影响，常使顶底板和两帮岩体产生变形并向巷道内产生位移。巷道底板向上隆起的现象称为底鼓。目前巷道顶板下沉和两帮内移能控制在某种程度内，而防治底鼓仍缺乏经济有效的办法。在底板不支护的情况下，巷道顶底板移近量中约2／3—3／4是由底鼓造成的。强烈的巷道底鼓不仅增加大量维修工作，增大维护费用，而且还影响矿井安全生产。因此，研究巷道底鼓机理及其防治措施一直是软岩巷道支护的重要内容。     

阳煤五矿褶皱和挠曲构造对煤层开采的影响

矿井构造是控制煤系形态、位态和体态的首要地质因素，褶皱和挠曲构造通过改变煤层瓦斯、矿井涌水、煤层顶底板等地质条件，从而间接地影响着煤矿正常生产。本文以阳煤集团五矿15#煤层为目的层，总结研究了15#煤层的褶皱和挠曲构造形态展布和分布规律．进一步探讨了褶皱和挠曲构造对矿井15#煤屡开采的影响。研究结果表明：（1）采区内共揭露发育有褶曲26条，挠曲12个。褶曲在整个研究区均有分布。井田内地层形态变化较大，广泛发育有短轴褶皱以及挠曲和少量紧密槽皱。（2）褶曲构造的发育给主要运输巷和采区上山等岩石巷道的布置带来很大困难，影响井巷施工进度，增大煤层开采的难度，并绘顶板管理带来很大困难．同时．在带压区附近开采时应预防突水事故的可能性。向斜、背斜轴部及其附近有利于瓦斯聚集易于发生瓦斯事故。本文研究结果对于阳煤集团五矿的矿井安全生产具有指导性的作用。     

“三软”煤层、复合顶板下沿空掘巷锚索网支护技术应用

“三软”煤层在煤矿企业开采过程中时常遇到,由于煤层属裂隙发育,地理构造复杂,顶板岩层、软的主煤层以及底板岩层都是软弱煤层,在沿空掘巷施工过程中操作十分谨慎,锚网梯＋锚索槽钢梁＋点锚索补强联合支护方式,有效地保持了巷道掘进期间的稳定性,改变了沿空掘巷难以支护的被动局面。本文将对具体的支护施工工艺展开探讨。     

煤矿采空区强制放顶爆破技术

为了研究采空区上方突发大面积的顶板垮落现象,结合昊达煤矿采空区顶板不能自然垮落且不具备良好作业条件的情况,提出了一种新的采空区顶板强制放顶方法——地表钻孔预留采空区顶板强制放顶爆破方法,包括采用3项关键技术:从地表向下垂直钻孔,不扩孔进行强制放顶爆破;采空区顶板预留的安全厚度由集中药包爆炸后内部作用裂隙区半径的计算公式算出;炮孔底部装填燃烧过的蜂窝煤碎渣且孔内分3段起爆,减少对炮孔底部岩石的破坏。工程实践证明,地表钻孔预留采空区顶板强制放顶爆破方法可有效预防采空区顶板大面积垮落,降低了人员作业风险,实现了煤矿安全生产。     

煤矿采空区强制放顶爆破技术

为了研究采空区上方突发大面积的顶板垮落现象,结合昊达煤矿采空区顶板不能自然垮落且不具备良好作业条件的情况,提出了一种新的采空区顶板强制放顶方法——地表钻孔预留采空区顶板强制放顶爆破方法,包括采用3项关键技术:从地表向下垂直钻孔,不扩孔进行强制放顶爆破;采空区顶板预留的安全厚度由集中药包爆炸后内部作用裂隙区半径的计算公式算出;炮孔底部装填燃烧过的蜂窝煤碎渣且孔内分3段起爆,减少对炮孔底部岩石的破坏。工程实践证明,地表钻孔预留采空区顶板强制放顶爆破方法可有效预防采空区顶板大面积垮落,降低了人员作业风险,实现了煤矿安全生产。     

浅埋深两硬条件下特厚煤层综放开采技术

针对平朔矿区4号煤层条件,采用理论分析方法研究了浅埋深两硬条件下4号煤层顶煤的冒放性及合理采煤方法。以提高顶煤冒放性为目标,采用数值模拟的方法进行了综放工作面参数及设备选型配套研究。实践表明,浅埋深两硬煤层条件下通过加大综放工作面长度与割煤高度,可以实现安全、高效、高回收率开采。     

Fracture failure analysis of hard–thick sandstone roof and its controlling effect on gas emission in underground ultra-thick coal extraction

In underground coal extraction of fully mechanized caving, the overlying hard–thick sandstone main roof could control the failure extent and the movement evolution of the entire overburden strata. The instantaneous failure of the hard–thick sandstone main roof possibly causes strata pressure behaviors, rock-bursts and abnormal gas emissions, which may result in equipment damages and casualties. Tashan coalmine was chosen as a field case study base because of its super great mining height (SGMH) and the overlying hard–thick sandstone roof (HTSR). This mine has experienced a great deal of damaging hydraulic support and abnormal gas emission accidents caused by strata pressure behavior. The fracture failure analysis was analyzed based on “Key Strata Theory” and numerical simulation results. The hard–thick sandstone main roof could perform as a very large double-sided embedded rock beam in the primary fracture and as a cantilever-articulated rock beam in periodic fracture, simultaneously generates a huge hanging space in the gob. The fracture failure of the hard–thick sandstone main roof causes a permeability enhancement in the adjacent rock-coal strata and near face coal seam. The substantial amounts of gas stored in the remaining coal, surrounding rock strata and adjacent coal seams rush out and aggregate in the caved and fissure zone of the gob, thereby forming a huge gas cloud. The disasters due to coupled strata pressure behavior and abnormal gas emissions, which primarily occurred after primary and periodic fracture failure, are predominantly caused by the instantly fracture of main roof. When the main roof reached the ultimate broken span and underwent, rotation and collapse, substantial amounts of gas accumulating in the gob escaped to the working face under the extrusion and impaction of the caving rock strata, which easily produced abnormal gas emissions, some of which exceeded the statutory limit. Shortening the length of the HTSR failure span using hydraulic presplitting and decreasing the gas content of the coal seam using gas drainage technology are recognized as two effective approaches to solve this issue.     

爆破开采扰动对巷道围岩稳定性影响的模拟研究

以某金矿Ⅶ号矿体-498m水平开采工作面为研究对象,采用有限元数值仿真分析方法研究了该矿爆破开采扰动对巷道围岩稳定性的影响。研究结果表明:受开挖扰动的影响,巷道顶板的最大主应力减小较为明显。在工作面推进过程中,巷道周边岩体向开挖空间内移动,采掘横巷顶部的位移场沿工作面呈现心型分布,且在采掘横巷与水平沿脉巷交汇处出现的最大位移为6.31mm。随着工作面的推进,采掘横巷围岩的垂直位移呈现增大的趋势,当巷道掘进工作面推进3m以内时,其采掘横巷顶板的垂直位移变化较大,最大增大了60.13%;当巷道掘进工作面推进距离超过3m时,顶板的顶部垂直位移变化不明显,而水平沿脉巷道各监测断面的围岩垂直位移趋于稳定;当工作面推进20m后,可认为开挖对水平巷道围岩的垂直位移没有影响。巷道围岩主要表现为剪切破坏,且巷道临空位置顶板和底板主要表现为拉伸破坏和拉剪复合破坏。     

平朔井工开采煤层顶底板水文地质条件评价及防治水对策研究

针对平朔井工一矿所面临的煤层顶底板水害威胁,在分析矿井采矿、地质等条件的基础上,确定了与煤层顶底板水文地质条件相关的若干因素,分别运用"三图法"和"脆弱性指数法"对该矿煤层顶板涌突水条件和底板突水脆弱性进行了评价,并制定了具体的防治水措施。     

Demonstration Project of Safe and Efficient Mining Operations in Extra-thick Coal Seam

Mineable coal reserves in thick and extra-thick seams account for 44% of the total deposit in China. Fully-mechanized top-coal caving technology is a new mining method of safe and efficient underground operations in extra-thick seams in China. The development of fully-mechanized top-coal caving technology in China, which was successfully applied in Face 8105 in Tashan Coal Mine, Datong, Shanxi, China, is analyzed in this paper. Studies on movement pattern of top-coal and roof from fully-mechanized top caving face in 14–20 m extra-thick seams have been carried out. A series of key technologies were successfully developed, including strata control technology, equipment for high-efficient and high-recovery top caving operations, and safety guarantee technology for low gas occurrence and high gas emission. As a result, the fully-mechanized top-coal caving Face 8105, with large mining height in Tashan Coal Mine, has achieved a recovery rate of 88.9% and an average equipment operation rate of 92.1%. With coal production of 10.84 Mt in 2011, the demonstration project is a technology and equipment breakthrough for fully-mechanized top-coal caving face in extra-thick coal seams with large mining height.     

地下开采引起地表沉陷预测的弹性薄板法

基于弹性力学中的薄板弯曲理论,在岩体移动领域建立了地表下沉预测分析的层状模型。通过单元开挖给出了地下工程开挖引起岩体移动变形分析的二维和三维问题理论计算公式,推导了山区地下采矿引起地表下沉的理论公式并用于贵州水城矿务局汪家寨煤矿地下开采引起地表下沉的预测分析。在分析过程中,采用Matlab软件进行数值积分计算和图形绘制。通过工程实例计算分析表明,理论计算结果与矿山现场实测资料二者吻合的很好。     

大倾角松软特厚易燃煤层综放安全高效开采实践

淮北矿业股份有限公司朱仙庄煤矿主采煤层8煤,平均9．98m厚,但开采条件复杂,煤层极松软,局部煤层倾角超过40°,通过加强顶煤管理、保证支架及前后刮板输送机稳定性、防止煤炭自燃发火等措施,最大限度提高回收率,实现了大倾角松软特厚易燃煤层综放安全高效开采。     

A Study on Dual-Load-Zone Model of Overlying Strata and Evolution Law of Mining Stress

The changeable structure and movement law of overlying strata are the main contributor to the change of mining stress. Starting from the relevant theory of key stratum and particularly based on the theory of mine ground pressure and strata control, this research proposed a new solution to mining stress problems by establishing a dual-load-zone stratum structural model. Elastic foundation beam theory was used to solve the stress of overlying strata of the dual-load-zones with superposition method, which revised the traditional calculation method of mining stress. The abnormal increase of lead abutment pressure in the mining area was explained effectively, through which the evolution law of mining stress in the case of hard rock was obtained. The results indicate that mining stress experiences a drastic change within the range of 50 m ahead of the coal wall due to the collapse of main roof; under the influence of main key stratum and inferior key strata, the influence range of lead abutment pressure is extended up to approximately 120 m in the working face; this remarkable increase can be attributed to the excessive length of sagging zone. Results from both the dual-load-zone model experiment and field measurement demonstrate high consistency. The model can predict the influence range of abutment pressure effectively and thus guide the safety production of mining.