大断面巷式全采充填覆岩移动规律研究

发布时间：2018-05-06 18:02

本文选题：大断面巷式充填 + 覆岩移动　；参考：《中国矿业大学》2017年硕士论文

【摘要】：论文针对传统开采方法所引起的地表沉陷和井下突水灾害,以王台铺煤矿为工程研究背景,提出一种新式的采煤方法—大断面巷式全采充填开采,综合运用理论分析、物理相似模拟、数值模拟等研究方法,对该种采煤方法的覆岩移动规律和导水裂隙发育特征进行初步探讨和研究,研究成果可为其以后的工程应用提供参考。主要得出的结论如下:(1)通过理论分析研究发现该采煤法跟常规采煤法类似,充填前顶板移近量、充填体压缩量和未接顶量是覆岩移动的主要影响因素。并且通过理论分析发现,在四个开采阶段中,第一、第二阶段覆岩基本不跨落只发育裂隙和弯曲下沉,在后面的两个阶段中裂隙迅速发育,但是顶板的下沉还是在可控范围内。以弹性地基理论为基础建立了两类情况下的顶板移动模型,并根据挠度跟转角、曲率之间的关系,又分别建立了两类顶板的转角和曲率模型。在忽略顶板提前下称量和充填体压缩量前提下,将充实率乘以采高近似于煤层的采高,提出了如何理论预测导水裂隙发育高度的方法。(2)通过物理相似模拟研究了三个开采阶段的方案下的覆岩移动规律。可以发现在巷道开采的前期顶板位移量非常小,但是在第三阶段开采过程中,顶板下沉量急剧增加。因此可以说明最后开采阶段是控制覆岩移动变形的“关键阶段”。第三阶段开采完毕后,覆岩结构基本完整没有出现垮落带,只在煤层上方的小部分范围内有裂隙发育,覆岩中只出现三带中的两带裂隙带和弯曲下沉带。(3)通过数值模拟研究了四个开采阶段方案条件下的覆岩移动特征,进一步证实了最后开采阶段是控制覆岩移动的“关键阶段”主要表现在地表最大下沉系数、顶板最大下沉量、最大支承压力以及导水裂隙发育高度随着巷道的推进而增加,其中在最后一阶段的开采过程中的增加量要远远大于前三阶段的增值;覆岩参数地表最大下沉系数、直接顶最大下沉量、支承压力、导水裂隙发育在前三个开采阶段基本不随着充填率的改变而发生变化,但是在第四阶段不同充填率的四类覆岩参数发生了变化,在最后一个阶段充填率成为了控制覆岩移动的主导因素,直接顶的最大下沉量跟充填率呈近似负相关的关系,其中最大支承压力的位置由第三阶段的采场中央的第四阶段煤柱转移到了采场两侧的煤壁中。(4)因此可以得出结论“关键阶段”以及充填率是大断面巷式充填覆岩移动变形的主要控制因素,在某些地质条件非常复杂,生态系统脆弱的地区可以选择保留下“关键阶段”不开采以及尽量提高充填率等措施。
[Abstract]:Aiming at the surface subsidence and underground water inrush disaster caused by traditional mining method, taking Wangtaipu coal mine as the engineering research background, this paper puts forward a new kind of coal mining method-large-section roadway type full mining and filling mining, and synthetically applies the theory analysis. Physical similarity simulation, numerical simulation and other research methods are used to study the overburden movement law and the characteristics of water-conducting fracture development of this kind of mining method. The research results can provide a reference for its engineering application in the future. The main conclusions are as follows: (1) through theoretical analysis and research, it is found that the coal mining method is similar to the conventional mining method, and the front roof movement of the filling, the amount of compression of the filling body and the amount of unconnected roof are the main influencing factors of the overburden movement. Through theoretical analysis, it is found that in the first and second stages, the overburden only develops fissures and bending subsidence in the first and second stages, and the cracks develop rapidly in the latter two stages, but the roof subsidence is still within the controllable range. Based on the theory of elastic foundation, two kinds of roof moving models are established. According to the relationship between deflection, rotation angle and curvature, the two kinds of roof rotation angle and curvature model are established respectively. On the premise of neglecting the weight of the roof in advance and the compression of the filling body, the enrichment rate multiplied by the mining height is similar to the mining height of the coal seam. A theoretical method of predicting the height of water-conducting fractures is put forward. The overlying rock movement under three mining stages is studied by means of physical similarity simulation. It can be found that in the early stage of roadway mining, the roof displacement is very small, but in the third stage, the roof subsidence increases sharply. Therefore, it can be concluded that the final mining stage is a critical stage for controlling the movement and deformation of overburden. After the third stage of mining, the overburden structure basically did not appear collapse zone, only in a small part of the area above the coal seam developed cracks, The characteristics of overburden movement under four mining stages are studied by numerical simulation. It is further proved that the final mining stage is the "critical stage" for controlling the movement of overburden rock, which is mainly manifested in the maximum subsidence coefficient of the surface, the maximum roof subsidence, the maximum supporting pressure and the development height of the water-conducting fissure with the advance of the roadway. The increment in the last stage of mining is much larger than the increment of the first three stages, the maximum subsidence coefficient of overburden parameters, the maximum subsidence of the direct top, and the supporting pressure, In the first three mining stages, the development of water-conducting fractures does not change with the change of filling rate, but in the fourth stage, four types of overburden parameters with different filling rates change. In the last stage, the filling rate becomes the dominant factor to control the overburden movement, and the maximum subsidence of the direct roof has an approximate negative correlation with the filling rate. The position of the maximum supporting pressure is transferred from the fourth stage pillar in the middle of the third stage of the stope to the coal wall on both sides of the stope. Therefore, the conclusion can be drawn that the "critical stage" and the filling rate are large section roadway filling overburden. The main controlling factors of movement and deformation, In some areas where the geological conditions are very complex and the ecosystem is fragile, we can choose to keep the "critical stage" from mining and to increase the filling rate as far as possible.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD325

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