Study on influence of characteristics of air-supply jet on draincontamination efficiency and air quality in heading

Based on the theory of air-supply jet, the conception and theory of the air quality and the drain-contamination efficiency, the results achieved by comparing the circular cross-section wall jet with the plane wall jet were following: firstly, within the limitation of the ventilation distance at the tunnel heading in a coal mine, there were a better air quality and a higher efficiency of drain-contamination with application of the plane wall jet ventilation. Secondly, there was a advantage to improve the air quality of the workers‘ breathing area with mounting the air-supply outlet on the top but not on the side of the tunnel heading.     

NEW THEORY IN TUNNEL STABLILITY CONTROL OF SOFT ROCK ——MECHANICS OF SOFT ROCK ENGINEERING

Tunnel stability control is a world-wide difficult problem. For the sake of solving it,the new theory of soft rock engineering mechanics has been estabilished. Some key points,such as the definition and classification of soft rock, mechanical deformation mechanism of a soft rock tunnel, the critical support technique of soft rock tunnel and the new theory of the soft rock tunnel stability control are proposed in this paper.     

Study and application of plasticity plaster-slurry for preventing coal spontaneous combustion

Introduced the modulation scheme, function and mechanism of plasticity plaster-slurry preventing coal spontaneous combustion. The applications show that the plasticity plaster-slurry has good hygroscopicity and adsorptivity. To spray it on the coal wall of tunnel can shut off leakage wind fast and effectively. To press it into the coal body can absorb the heat and descend the temperature, surround the coal pieces, eliminate the possibility of the fiery distdct resuming combustion.     

Study on mechanism of reinforcing sides to control floor heave of extraction opening

Roadway surrounding rock is a compound structure consisted of roof, floor and sides. The sides of extraction opening is the weak coal mass, which affect immediately the stability of floor. It was simulated by numerical calculation for the strength of sides coal to affect the floor heave, the higher strength of sides coal is, the lower degree of floor heave was. So it was put forward reinforcing sides to control floor heave of extraction opening,and it was proved by engineering practice that the floor heave of deep extraction opening can be controlled to a certain degree by reinforcing sides of roadway.     

MODELING OF OVERBURDEN FAILURE UNDER THE CONDITION OF MINING TWO CLOSE-RANGESEAMS USING ROOM-AND-PILLAR ANDLONGWALL MINING

In,this paper the effect of the rnmaining coal pillars in a room-and-pillar,section on the long wall face in the lower coal bed are testde by using equivalent material models.The failure laws of the overburden under coal pillars are discussed.A phenomenon of sub-weighting has been observed when long-wall face is in process under the remaining pillars in room-and-pillar mining section.It is concluded that,because coal pillars underwent a course of the stress increasing before they were fully destroyde,the existence of the coal pillars would shorten the distance of periodical weighting of the main roof in the long-wall face.based on this,the characteristic equations of the overburden moyement under coal pillars are presented.     

Stress state and caving danger of the roof in bolt supporting roadway

The start point of this text is the bottleneck problem of bolt supporting coal entry that is security problem of bolt supporting roof, we divide one entry into some sections with different stress, simulate stress field of wall rock and rockbolt solidified at different sections used umbrella disperse soft UDEC（universal distinct element code）, we educe that the stress level of wallrock and bolt solidified is higher in roof fall risk section, and roof rockbolt load can reflect this rule clearly, that offer an important guideline in monitoring entry roof fall risk.     

Study of coal and gas outbursts by numerical modeling approach

Abstract During mining or road-way development, the distribution of stress and coal pore pressure in the coal face and rib around the new opening will change, under certain conditions, dynamic failure of coal in the form of an outburst can occur. In the modeling studies presented in this paper, an outburst was considered to consist of three distinct stages： preinitiation, initiation and post-initiation, which takes into account the major processes and mechanisms that can influence both outburst-proneness and post-initiation outburst behavior. The model has been applied to simulate the effects of mechanisms in the coal matrix, coal strength, coal damage, geological structures on outbursts. The model constructed using the FLAC software, which were undertaken to research the effects on outbursts of coal strength pressure gradient, and other factors.     

Study on application and numerical simulation of the airflow temperature distribution rule in drifting tunnel

According to the law of conservation in the state of turbulent flow, the differential equation describing the airflow temperature distribution in drifting tunnel is derived, By theo-retical analysis and field measurement of the airflow and thermal process in mine, theoretical analysis and systematic flow are developed. By PHONENICS program, the numerical simula-tion is processed, and the changing rule of airflow temperature with various parameters in drifting tunnel is derived. The airflow temperature in drifting tunnel decreases as the airflow velocity increases in a way of negative power exponent, and elevates lineady as the tempera-ture of the incoming airflow elevates.     

Applied on bolting－cable anchor support of full－seam roadway in weaker thick coal seam

The designing method and the supporting mechanism of both bolt and small cable anchor for full-seam roadway in the weaker thick coal seam are systematically analyzed, and the construction technology and the supporting results are briefly summarized.     

Propagation simulation and attenuation law analysis of seismic wave in elastoplastic tunnel rock medium

The energy caused by the dynamic impact in mining engineering forth release and spread by the way of seismic waves, monitoring is an effective way for forecasting mine dynamical disasters, such as rockburst and coal and gas outburst. Three-dimensional dynamic model was built to simulate the propagating progress of seismic waves in the elastoplastic tunnel rock and analyzed the propagating law of perturbation acceleration around tunnel, based on the finite element dynamic analysis software ANSYS/L S-DYNA. The simulation results indicate that： （1） The propagation attenuation of seismic wave is a negative index relationship; （2） The acceleration amplitude of seismic wave decays rapidly in near-field and decays slowly in far-field; （3） When the perturbation is generated in the dead ahead of tunnel, the acceleration of seismic wave become smaller and smaller away from the roadway-rib;（4） The elastic and plastic stress state of tunnel rock is also an important factor for propagation process of wave, the energy of seismic wave is mainly consumed for geometric spreading and plastic deformation in propagation in the elastoplastic medium model.     

黄陵二号煤矿107综采工作面顺槽支护探讨

通过对黄陵二号煤矿井田地质及煤层、煤层顶、底板、分布规律、巷道断面形状、支护方式的介绍,提出了107综采工作面顺槽断面形状及支护方式,通过方案比较,提出107综采工作面顺槽采用半圆拱形断面,U形钢可伸缩支架支护的建议。     

人工隔离墙置换采煤工作面间小煤柱的工艺研究

煤炭开采中,综采工作面在受瓦斯威胁等复杂条件下往往采用留设工作面煤柱的方法,形成了煤炭资源的浪费。为了减少这部分损失,研究了一种在巷道掘进时或采煤前多层喷射锚网混凝土,建立强度高、密封好的支柱隔离墙的工艺,用隔离墙代替煤柱,有效提高煤炭资源回收率。     

厚煤层高效截流“钻墙”边掘边抽的试验研究

煤巷掘进巷道的瓦斯来源于暴露煤壁和掘进落煤,其中,暴露煤壁的瓦斯涌出量约占80%以上,高瓦斯矿井在煤巷掘进时经常出现瓦斯超限的情况,"钻墙"就是针对高瓦斯巷道掘进时截流煤壁瓦斯向巷道涌出的一种边掘边抽布孔方式,此方式在铜川矿务局陈家山煤矿421运输巷进行了试验研究,实践表明,"钻墙"能够非常有效截流煤壁瓦斯涌出、避免巷道瓦斯超限。     

厚煤层高效截流“钻墙”边掘边抽的试验研究

煤巷掘进巷道的瓦斯来源于暴露煤壁和掘进落煤,其中,暴露煤壁的瓦斯涌出量约占80%以上,高瓦斯矿井在煤巷掘进时经常出现瓦斯超限的情况,"钻墙"就是针对高瓦斯巷道掘进时截流煤壁瓦斯向巷道涌出的一种边掘边抽布孔方式,此方式在铜川矿物局陈家山煤矿421运顺进行了试验研究,实践表明"钻墙"能够非常有效截流煤壁瓦斯涌出、避免巷道瓦斯超限。     

回采三角煤在新立煤矿的应用

采煤回采至停采线之前,上下巷经常不同步。为了减少煤炭损失,提高回采率,采取新的回采方式,即伪倾斜开采和上巷前进式、下巷前进式回采,使煤炭损失量降低到最小程度,提高了经济效益。     

厚煤层一次采全高煤壁失稳原因及控制技术

针对成庄煤矿四盘区层一次采全高煤壁失稳问题,对观测统计数据进行分析,发现片帮主要表现形式分五种:顶部、腰部、顶底部、底部以及斜切片帮,据此采用对顶板超前预爆破和煤壁超前预加固技术来控制大采高煤壁稳定性,不仅对煤壁失稳的控制取得了良好的效果,而且经济效益显著。可为相似条件下的厚煤层一次采全高煤壁失稳控制提供借鉴。     

“隔离水墙+泄放钻孔”技术在治理煤壁内煤炭自燃中的应用研究

矿井巷道煤壁内煤炭氧化自燃事故的处理,常规方法是采取挖出着火点煤炭、向煤壁内注水等措施,但某矿井出现巷道煤壁内煤炭氧化自燃事故后,常规方法不仅未能有效处理,反而出现随着灭火钻孔注水范围扩大。煤炭氧化范围顺巷道向着火点两侧扩大的异常现象。针对此种异常现象,研究分析了煤炭氧化范围自着火点向两侧扩大的原因,创新地采用“隔离水墙+泄放钻孔”技术,即在着火点两侧施工注水钻孔构建“隔离水墙”,阻止着火点高温气体向周围扩散,同时在着火点范围两侧、“隔离水墙”之内,施工开口不封闭的“泄放钻孔”,构建高温气体“泄放通道”,使着火点内的高温气体从“泄放钻孔”泄出。采用“隔离水墙+泄放钻孔”技术,成功治理了煤壁内煤炭氧化自燃事故。该研究成果对类似事故的处理具有借鉴意义。     

松软煤层片帮漏顶防治技术研究

金黄庄矿业公司是新建矿井,属于煤与瓦斯突出矿井,地质条件极其复杂,首采面B102工作面开采期间断层较多,松软煤层的形态均呈层状,煤层中沿顶位置煤体松软,煤层厚度不稳定变化较大,开采过程中出现了严重的片帮、漏顶等情况。根据工作面煤岩层特点和水分对煤岩改良作用的原理,采用煤壁浅孔注水和超前加固综合治理技术,实现了工作面煤壁的稳定,保证了矿井安全、正常生产。     

云盖山一矿治理边界小煤矿越界排水技术应用

云盖山一矿630 m轨道下山西翼采空区突然涌水,经综合分析及实地调查判定,突水水源为边界小煤矿越界排水。矿井通过物探与钻探相结合精确判定小煤矿越界巷道位置、标高,设计施工堵水巷道、挡水墙,井下墙体连续浇筑,墙体前后围岩岩体注浆加固封闭,墙体设导管实现小煤矿积水水位观测与水源利用相结合。小煤矿水患治理工程成功实施,降低矿井排水量近80m3/h。     

割煤高度对大采高综放工作面煤壁稳定性影响

采用FLAC3D模拟分析了割煤高度对大采高综放工作面煤壁稳定性的影响.模拟结果表明,增大割煤高度,首先是增大了煤壁无水平约束空间,加剧煤壁的变形和破坏,导致煤壁片帮,而煤壁片帮又加大了支架与煤壁间的无支护面积,使端面顶煤的变形加剧,从而诱发架前冒顶,割煤高度对煤壁片帮的影响更为明显,现场观测也同样验证了以上结论.