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1.
本文结合我国滑移顶梁液压支架放顶煤开采的实践,对滑移支架放顶煤工作面顶煤的破碎和放出规律进行了研究,指出工作面长度,煤层强度、开采深度及煤层结构等是影响顶煤破碎和放出效果的主要因素,同时指出顶煤的破碎是顶煤与上覆岩层相互作用的结果,而支架仅起辅助破煤的作用。  相似文献   

2.
本文结合我国放顶煤开采的实践,对放顶煤工作面顶煤的破碎和移动规律及上覆岩层的活动规律进行了研究,指出了开采深度、煤层强度、支架支护强度及煤层厚度等是影响顶煤破碎和放顶煤效果的主要因素。同时指出了顶煤的破碎是顶煤与上覆岩层相互作用的结果,而支架仅起辅助破煤的作用。并在此提出了顶煤破碎分区。  相似文献   

3.
综放开采是我国特厚煤层高产工作面最主要的采煤方法,其中放煤方式是影响顶煤回收率的重要因素.为了提高特厚煤层综放开采顶煤回收率,基于综放开采顶煤放出散体介质流运移规律和特征,针对现有放顶煤试验平台工作面方向放煤试验较少、相似比例小、支架个数少、放煤口大小无法控制等问题,研制特厚煤层综放开采倾向大比例试验平台,相似比1:1...  相似文献   

4.
本文介绍了七五煤矿悬移支架放顶煤工作面顶煤破碎冒落规律,叙述了顶煤爆破和松动方法及参数优化,此法是煤质硬煤层放顶煤面控制块度,提高回收率的一种有效方法。  相似文献   

5.
结构复杂厚煤层综放开采相似模拟研究   总被引:3,自引:3,他引:0  
以现场实测资料为基础,通过实验室相似模拟试验对含厚夹矸结构复杂厚煤层的综放开采对工作面含厚夹矸顶煤的冒放性、放煤工艺及放出规律、夹矸层极限厚度的确定等问题进行了研究,并指出了含夹矸顶煤活动规律对放顶煤开采的影响.  相似文献   

6.
以现场实测资料为基础,通过实验室相似模拟试验对含厚夹矸结构复杂厚煤层的综放开采对工作面含厚夹矸顶煤的冒放性、放煤工艺及放出规律、夹矸层极限厚度的确定等问题进行了研究,并指出了含夹矸顶煤活动规律对放顶煤开采的影响.  相似文献   

7.
"三软"煤层炮采放顶煤工作面矿压规律研究   总被引:7,自引:2,他引:5  
通过对红旗井中厚煤层炮采放顶煤工作面矿压观测分析,得出“三软”中厚煤层炮采放顶煤工作面的矿压显现特征,综合评价其支架的适应性与工作状态,为工作面支架选型提供依据,对同类条件下放顶煤工作面开采具有指导意义.  相似文献   

8.
通过对红旗井中厚煤层炮采放顶煤工作面矿压观测分析,得出“三软”中厚煤层炮采放顶煤工作面的矿压显现特征,综合评价其支架的适应性与工作状态,为工作面支架选型提供依据,对同类条件下放顶煤工作面开采具有指导意义.  相似文献   

9.
通过对单体支柱、π型梁放顶煤一次采全高技术的开采试验 ,研究了在“三软”极不稳定煤层条件下 ,普通放顶煤开采工作面的矿压显现规律 ,试验研究了合理的支护方式及支护参数。实践和研究证明在“三软”极不稳定煤层中 ,单体支柱放顶煤一次采全高是一种与之相适应的高产高效开采技术 .  相似文献   

10.
通过对单体支柱、π型梁放顶煤一次采全高技术的开采试验,研究了在"三软"极不稳定煤层条件下,普通放顶煤开采工作面的矿压显现规律,试验研究了合理的支护方式及支护参数.实践和研究证明在"三软"极不稳定煤层中,单体支柱放顶煤一次采全高是一种与之相适应的高产高效开采技术.  相似文献   

11.
顶煤冒放性及其预测分类研究   总被引:5,自引:0,他引:5  
运用相似材料模型试验,提出了顶煤冒放的桥拱式、半拱式和柱式3种结构特征;分析了影响顶煤冒放性的主要因素;运用数值方法得出了各因素的影响规律、主次排序和权重;基于模糊数学理论,提出了预测顶煤冒放性的分类方案.并运用全国29个主采煤层的分类结果验证了分类方案的正确性和实用性.  相似文献   

12.
Under fully mechanized, large mining height top coal caving conditions, the shield beam slope angle of the support increases due to the enlargement of the top coal breaking and caving space. This results in a change of the caving window location and dimensions and, therefore, the granular coal-gangue movement and flows provide new characteristics during top coal caving. The main inferences we draw are as follows. Firstly, after shifting the supports, the caved top coal layer line and the coal gangue boundary line become steeper and are clearly larger than those under common mining heights. Secondly, during the top coal caving procedure, the speed of the coal-gangue flow increases and at the same drawing interval, the distance between the coal-gangue boundary line and the top beam end is reduced. Thirdly, affected by the drawing ratio, the slope angle of the shield beam and the dimensions of the caving window, it is easy to mix the gangue. A rational drawing interval will cause the coal-gangue boundary line to be slightly behind the down tail boom lower boundary. This rational drawing interval under conditions of large mining heights has been analyzed and determined.  相似文献   

13.
The size distribution of the broken top coal blocks is an important factor, affecting the recovery ratio and the efficiency of drawing top coal in longwall top coal caving(LTCC) mining panel. The standard deviation of top coal block size(dt) is one of the main parameters to reflect the size distribution of top coal. To find the effect of dton the caving mechanism, this study simulates experiments with 9 different dtby using discrete element software PFC. The dtis divided into two stages: uniform distribution stage(UDS) whose dtis less than 0.1(Schemes 1–5), and nonuniform distribution stage(NDS) whose dtis more than 0.1(Schemes 6–9). This research mainly investigates the variation of recovery ratio, drawing body shape,boundary of top coal, and contact force between particles in the two stages, respectively. The results showed that with the increasing dt, the recovery ratio of the panel increases first and then decreases in UDS. It is the largest in Scheme 3, which mainly increases the drawing volume at the side of starting drawing end. However, the recovery ratio decreases first and then increases quickly in NDS, and it is the largest in Scheme 9, where the drawing volume at the side of finishing drawing end are relatively higher. In UDS, the major size of top coal is basically medium, while in NDS, the size varies from medium to small, and then to large, with a distinct difference in shape and volume of the drawing body. When the major size of top coal is medium and small, the cross-section width of the initial boundary of top coal at each height is relatively small. Conversely, when the top coal size is large, the initial boundary of top coal has a larger opening range, the rotating angle of lower boundary is relatively small in the normal drawing stage, which is conducive to the development of drawing body and reduces the residual top coal, and the maximum particle velocity and the particles movement angle are both larger. This study lays a foundation for the prediction of recovery ratio, and suggests that the uniform top coal is more manageable and has a larger recovery ratio.  相似文献   

14.
通过对放顶煤开采方法的实验室相似材料模拟研究和现场矿压实测资料的分析,文章提出了放顶煤采场上覆岩层移动规律和采场矿压显现特征,同时还建立了放顶煤采场矿压结构模型。  相似文献   

15.
通过对套迭梁的试验研究,得出了在开裂前套迭梁的刚度略小于整浇梁,开裂后两者刚度基本相同的结论。并给出了套迭梁的挠度验算式。  相似文献   

16.
本文用相似材料模拟试验法,对生产实践中无法确定的顶煤回收率问题进行了研究.获得了较有价值的研究结果:单轮顺序放煤优于单轮间隔放煤方式;含矸率越高,顶煤回收率越高,无矸回收率为80%.  相似文献   

17.
放顶煤综采采空区“三带”的理论计算与观测分析   总被引:10,自引:1,他引:10  
本文应用非线性渗流理论建立采空区流场二维平面非线性渗流流函数微分方程,利用有限元技术求得各结点上的流函数值和各单元上的流速v_x、v_y、v_o在此基础上,得到采空区风流流线和等速线。依据煤自燃所对应的风速上下限,得到放顶煤综采采空区不自燃带、可能自燃带和窒息带的形态和范围。对采空区矿压显现、采空区温度变化及氧浓度变化进行的观测表明,理论计算与实际观测所得结果基本一致。  相似文献   

18.
关于长壁放顶煤开采基础理论的研究   总被引:8,自引:2,他引:6  
对当前放顶煤开采基础理论研究的背景、研究内容、研究重点及其相互关系、研究工作的切入点等作了较全面的分析,阐述了研究的指导思想,希望对我国综采放顶煤开采基础理论研究有一定的推动作用.  相似文献   

19.
放顶煤无煤柱护巷机理的有限元分析   总被引:1,自引:0,他引:1  
根据有限元正交试验法,设计了有限元正交试验方案,建立了放顶煤无煤柱护巷的数值模型;通过对计算结果分析,得出放顶煤无煤柱开采沿空巷道的布置参数和支护形式,可为放顶煤无煤柱护巷提供理论依据  相似文献   

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