厚煤层横跨煤柱复采工作面矿压显现特征研究

发布时间：2018-05-28 12:15

本文选题：理论分析 + 相似模拟　；参考：《太原理工大学》2017年硕士论文

【摘要】：本文在现有岩石力学和采场围岩控制理论以及大量前人实验研究的基础上,通过理论分析、相似模拟和工程类比等方法,对白沟煤矿三采区旧采长壁普采人工放顶煤工作面所形成的旧采区的复采工作面采场围岩控制做了如下研究:1、对复采工作面通过残采区时上覆岩层的垮落带、裂隙带和弯曲下沉带进行了分析。得知覆岩的“纵三带”高度均有所增加,尤其是垮落带和裂隙带的高度增量较为明显,并且裂隙带岩层受采动影响后稳定性变差,从而导致其工作面矿压现象发生变化。2、通过对煤柱应力特征的分析,得出煤柱在复采过程中要经历三个过程,依次为:(1)复采工作面前方支承压力和煤柱另一侧支承压力互不影响阶段。(2)复采工作面前方支承压力和煤柱另一侧支承压力相互影响阶段。(3)煤柱两侧压力相互叠加并导致煤柱失稳阶段。尤其需要注意第三阶段,煤柱失稳会严重的影响工作面的安全生产。3、通过相似模拟实验并分析岩层的受力情况得出:煤柱区的峰值压力表现为煤柱两侧应力集中程度大于煤柱中部应力集中程度。残采区内超前支承压力显现不明显,支承压力受煤柱结构性失稳影响较大,尤其是在煤柱发生完全垮落时,其上覆岩层完全垮塌对采空区内产生的附加载荷较为明显。煤柱区在复采前,其应力集中程度较明显,并且在复采工作面推进过程中,煤壁前方有明显的超前支承压力的存在,但在液压支架完全推过以后,其采空区内压力减小,甚至降低为零,产生这种现象的主要原因是由于煤柱上覆岩层在发生台阶垮落以后,煤柱两侧形成“倒梯形”结构,该结构体的梁板结构两侧受到较大的支撑作用,从而对下方空区产生的载荷减小。由相互作用力原理可知,在残采区和采空区对煤柱上方的梁板形成支撑结构的同时,上方的梁板给工作面前方残采区以作用力,同时煤柱垮塌导致上覆岩层整体垮塌,从而使得靠近煤柱一侧的残采区应力较煤柱另一侧采空区应力大。4、基于液压支架和围岩相互作用体系现有理论,分别分析了残采区和煤柱区液压支架所承受的载荷。当位于煤柱区时,液压支架在出煤柱时所承受的载荷最大,最大载荷达到液压支架初撑力的9倍,对复采工作面的安全生产影响较大。
[Abstract]:Based on the existing rock mechanics, stope surrounding rock control theory and a large number of previous experimental studies, this paper adopts theoretical analysis, similarity simulation and engineering analogy, etc. In this paper, the control of the surrounding rock of the old mining face formed by the old longwall common top coal caving face in the third mining area of Baigou coal mine is studied as follows: 1. The collapse zone of the overlying strata when the mining face passes through the remnant mining area is studied as follows. Fracture zone and bending subsidence zone are analyzed. It is known that the height of the "longitudinal third zone" of overburden rock increases, especially the increment of the height of the collapse zone and the fracture zone is obvious, and the stability of the rock layer in the fracture zone becomes worse after being affected by mining. As a result of the change of mine pressure phenomenon in the coal face, through the analysis of the stress characteristics of the coal pillar, it is concluded that the coal pillar has to go through three processes in the process of remining. In turn, the bearing pressure on the front and the other side of the pillar do not affect each other. (2) the support pressure in front of the coal pillar and the other side of the pillar affect each other in order. 3) the pressure on both sides of the pillar is superimposed on the other side of the coal pillar. And lead to instability stage of coal pillar. Particular attention needs to be paid to the third phase, The instability of coal pillar will seriously affect the safety production of coal face. Through similar simulation experiment and analysis of the stress situation of rock strata, it is concluded that the peak pressure of coal pillar area shows that the degree of stress concentration on both sides of coal pillar is greater than that on the middle part of coal pillar. The leading bearing pressure in the residual mining area is not obvious, and the bearing pressure is greatly affected by the structural instability of coal pillar, especially when the coal pillar completely collapses, the additional load generated by the complete collapse of the overlying strata on the goaf is obvious. In the coal pillar area, the stress concentration is obvious before the remining, and in the process of the remining face, there is obvious leading support pressure in front of the coal wall, but after the hydraulic support is pushed completely, the pressure in the goaf decreases. Even reduced to zero, the main reason for this phenomenon is that "inverted trapezoid" structure is formed on both sides of the coal pillar after the collapse of the coal pillar overburden, and the beam-plate structure of the structure is supported greatly on both sides of the structure. As a result, the load generated on the lower empty area is reduced. According to the principle of interaction force, while the residual mining area and goaf form the supporting structure to the beam and slab above the coal pillar, the upper beam and slab force the residual mining area in front of the working face, and the collapse of the coal pillar results in the collapse of the overlying rock layer as a whole. Therefore, the stress of residual mining area near one side of coal pillar is greater than that of goaf on the other side of coal pillar. Based on the existing theory of interaction system between hydraulic support and surrounding rock, the load of hydraulic support in residual mining area and coal pillar area is analyzed respectively. When it is located in the coal pillar area, the maximum load of the hydraulic support is 9 times of the initial supporting force of the hydraulic support, which has a great influence on the safety production of the working face.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD323

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