新疆雨田煤矿3-3号特厚煤层综采放顶煤条件下坚硬顶板处理技术

新疆托克逊县雨田煤矿含煤地层为侏罗系下统八道湾组,3-3号煤层厚度大、结构简单,为该矿的主采煤层。由于受坚硬顶板条件的制约,一直沿用"刀柱式采煤法",不仅回采率低,同时存在重大的安全隐患。根据煤层顶板物理力学性质测定结果,结合矿井3-3号煤层的赋存条件,确定工作面的顶板管理采用"超前工作面深孔预爆破控制坚硬顶板"的方式。该技术有效的提高了回采的安全性,顶板基本随采随冒,工作面无明显冲击来压现象,支架载荷变化平缓,资源回收率大幅提高。     

Research on Roof Fracture Characteristics of Gob-Side Entry Retaining with Roof Cutting and Non-pillar Mining in Thick Coal Seam,China

Geotechnical and Geological Engineering - Based on the S1201-2 large height mining in the 2–2 coal seam of Ningtiaota colliery with on-site microseismic measurement, physical simulation and...     

坚硬顶板煤层一次采全高顶板支护管理研究

大采高综采技术是厚煤层开采工艺的重要发展方向,越来越多地被采用,顶板事故在矿山生产安全事故中占有较大比例,有效控制顶板,合理对顶板进行支护是采矿过程中必须认真考虑的问题。大采高综采工作面采场顶板跨度大、高度高,矿山压力复杂,管理难道大,本文针对某矿9、10号煤层大采高综采工作面顶板坚硬特性,通过理论计算出了不同工作条件下支架工作阻力和顶板支护强度参数,结合对本矿区所做的相似模拟实验结论,对顶板管理中支护强度进行了分析研究,就矿区特定顶板条件选定和提出了具体支护要求。     

厚砂砾含水层下特厚煤层综放开采防治水技术研究

水帘洞煤矿地表水系发育,煤系地层上覆的白垩系洛河组和宜君组巨厚层状砂砾岩含水层,含水丰富,对矿井的安全开采构成了威胁。在详细分析矿区顶板含水层特征、隔水层岩性组合特征及隔水性能基础上,采用比拟法计算了综放条件下顶板导水裂隙带发育高度,并用数值法研究了不同采宽条件下顶板导水裂缝带发育规律,预计了工作面涌水量,为评价煤矿综放条件下工作面安全回采可行性提供了科学的依据。     

推覆体下特厚煤层开采的特殊地质灾害问题

新集二矿13-1煤为新生界松散层、推覆体下第一开采的特厚煤层,存在着与推覆体发育有关的隐伏构造裂隙水、离层裂隙水(气)、F02断层活化导水、冲击地压造成导水裂隙扩展等特殊的地质灾害问题。针对这些安全隐患,提出了留设防水煤柱、对离层空间充填注浆、选择合理的开采方案、加强采前探测等措施。     

浅埋深、薄基岩、厚松散含水层下煤层综合机械化开采防治水技术应用

神东煤炭公司大柳塔矿12404工作面煤层埋深浅，上覆基岩薄、松散含水层厚，且地表有河流横过(工作面长度240m，推进度3900m，其中薄基岩富水段150m)，为了减少工作面搬家次数提高生产效益，采取了地面抽排水、井下泄放水及地面注浆固沙等有效的防治水措施，工作面安全通过了母河沟，该防治水方法的应用改变了以往类似情况进行留煤柱跳采的方法，取得了浅埋深薄基岩厚含水层下煤层综合机械化安全开采经验，比停产跳采节省搬家费用2400万元，获得了显著的经济效益。     

Analysis on the Regular of Underground Pressure in Large Dip Angle Coal Seam with Soft Roof and Floor

Geotechnical and Geological Engineering - The dip angle of coal seam in Guanyinshan coal mine is between 32° and 39° and the first mining area is X11 and X12. According to the caving...     

Analysis of Main Controlling Factors of Overburden Failure in Coal Mining Under Thick Coal Seam Geological Conditions

According to the theory of elastic mechanics half plane, the mechanical model of roof overburden failure is established. Based on the numerical simulation software FLAC^3D, the failure process of roof overburden in 1308 working face is numerically simulated according to the orthogonal experimental design scheme. Matrix analysis and variance analysis are used to analyze and calculate the simulation results to determine the sensitivity of the main control factors to the failure height of overlying rock of mining roof. The results show that: (1) with the increase of mining depth and the advancing distance of working face, the subsidence of roof overburden increases. (2) The order of influence of main controlling factors on roof overburden failure height is: mining depth > working face length > internal friction angle > mining thickness > coal seam dip angle > cohesion > tensile strength. (3) Variance analysis showed that the mining depth height was significant, the working face length and internal friction angle were significant, and the significance of working face length was slightly greater than that of internal friction angle, and other factors were not significant.

     

Investigation into the Behaviour of a Support System and Roof Strata During Sublevel Caving of a Thick Coal Seam

Monitoring of strata control parameters and behaviour of a powered support was carried out during an experimental trial of a mechanized longwall sublevel caving face for exploitation of a 7.5m thick coal seam. Field observations indicated that the requirement of support density for underwinning of top coal by sublevel caving under intact strata is different from that for underwinning under broken and fractured rock mass. Analysis of the leg closure observations and support resistance variations during different mining cycles showed rapid increase of the setting load density of the support in relation to the yield load density. This resulted in a large amount of leg closure during mining cycles of the sub level caving face under broken rock strata. Due to operational constraints, the field observations could not provide enough information to visualize the behaviour of the overlying rock strata. Simulation of the field conditions was therefore performed on a physical model to bridge this gap of information. Results of laboratory investigations on the physical model are combined with those of the field to explain the critical behaviour of the support system during sublevel caving under broken rock strata.     

Influence Mechanism of Mine Pressure on Coal Seam Gas Emission During Mining

Geotechnical and Geological Engineering - Gas is one of the main factors causing coal mine accidents in China. Understanding the mechanism of the influence of mine pressure on coal seam gas...     

Determination and Engineering Practice of Unsupported Roof Distance for Rapid Excavation of Roadway with Thick and Hard Basic Roof

Geotechnical and Geological Engineering - In order to determine the reasonable empty roof distance during roadway excavation, a mechanical model of the direct roof rock beam was established, and...     

大直径高位钻孔瓦斯抽放技术在特厚煤层矿区的应用

针对郭家河煤矿1303工作面瓦斯涌出量大、上隅角及回风流瓦斯超限的问题,通过对高位钻孔瓦斯抽放原理及参数进行分析计算,并结合工作面生产情况,应用实践了常规高位钻孔及大直径高位钻孔瓦斯抽放技术。实践结果表明,大直径高位钻孔抽放效果远胜于常规高位钻孔,并有效地解决了瓦斯超限问题,改善了工作面的安全生产状况。     

浅埋近水平煤层采动地面变形规律研究

以神府矿区大柳塔煤矿１２０３综采工作面为例,探讨了浅埋煤层开采过程中,地面下沉变形孤过程及有关参数,为地面建筑物的安全煤柱留设提供了依据。『     

带压开采煤层底板的承压能力研究

通过实测资料揭示了煤层底板保护层在一定条件下存在导水和贮水的性能,并剖析了这种性能的水理性质和规律,阐明了起始水力梯度、消压强度、抗水压强度、临界突水系数在概念上的统一性;在此基础上,分析了煤矿突水的机理与模式;并指明了探测研究保护层这一特性在确定开采煤层底板抗水压能力和带压开采安全性等方面的重要意义。     

太平煤矿煤层开采覆岩压分布与裂隙带预测

运用求解非线性大变形问题有限差分法(FLAC),对攀枝花宝鼎矿区太平煤矿第二水平1#、3#和5#急倾斜多煤层开采采场围岩压分布、裂隙带特征进行了究研。结果表明:1在进行三个煤层回采工作过程中,采空区附近的围岩应力不断变化;2保护煤柱附近的煤层回采时,在煤柱附近会形成应力集中区域,当回采工作继续向下进行时,采空区又对保护煤柱产生类似于"解放"的效果,煤柱附近的应力集中现象得到缓解;3在煤层回采完后,上部保护煤柱发生塑性破坏,形成了导水通道。     

江仓矿区巨厚煤层煤种结构与煤种储量计算方法

江仓矿区煤炭资源丰富。主采煤层属巨厚煤层,其煤层结构和煤种结构一般都很复杂,按不同煤种进行分层开采,有利于煤炭资源合理利用。江仓矿区20煤煤种结构变化大,且无规律可循,探讨了分煤种计算储量的几种方法,对未来煤矿的设计与开采有一定的指导意义。     

The Hazard Analysis of Water Inrush of Mining of Thick Coal Seam Under Reservoir Based on Entropy Weight Evaluation Method

The water inrush of roof induced by mining was related to the height of water flowing fractured zone under large-scale water bodies. Based on the drilling revealed stratum, the thickness of different overlying layers was obtained within the scope of Santaizi reservoir. The height of water flowing fractured zone of different workface on the outside of reservoir under the condition of fully mechanized level mining area was the prediction sample, the generalized analysis of sensitive factors that affected the development of water flowing fractured zone was carried on. The mining depth, dip angle of coal seam, mudstone ratio, compressive strength, mining thickness and the inclined length of the goaf were selected as the influence factors to predict the height of water flowing fractured zone. The height of water flowing fractured zone of unmined working face within the scope of Santaizi reservoir was obtained by objective entropy method. The index weight value of each influence factor was determined. The thickness of the different overlying rock layers above water flowing fractured zone was obtained. And the safety evaluation of water-inrush of unmined working face within the scope of Santaizi reservoir was studied. The important parameter and technical support were provided for the rational design and mining of the working faces under the reservoir.