沿空留巷底鼓力学模型及控制技术研究

发布时间：2018-05-13 09:21

本文选题：沿空留巷 + 底鼓　；参考：《中国矿业大学》2017年硕士论文

【摘要】：沿空留巷具有缓解采掘接替、实现“Y”型通风、提高煤炭采出率的优势得到快速发展,但沿空留巷严重底鼓现象成为制约其发展的瓶颈之一。本文综合应用理论分析、数值模拟、相似模拟实验及现场试验等方法,系统研究了沿空留巷底板变形规律及特征,建立沿空留巷底鼓力学模型,并分析底板应力及破坏范围变化规律,提出合理的底鼓控制技术等,主要研究成果如下:(1)沿空留巷底板变形规律及特征:底板变形主要发生在一次回采工作面前方40m至工作面后方80m范围内,二次回采工作面前方80m范围内;一次回采工作面前方工作面侧底板变形及破坏程度大于实煤体侧,沿空留巷阶段实煤体侧底板变形大于巷旁支护体侧。(2)采用复变函数理论,分析沿空留巷底板应力分布规律及影响因素:底角应力集中程度较大;随着巷道宽高比的增大,底角和底板应力减小;随着侧压系数的增大,底角应力增大,底板应力减小;随着埋深的增大,底角和底板应力均增大。(3)通过分析沿空留巷顶板破坏规律及两帮围岩不对称承载特性,建立沿空留巷底鼓力学模型,结合半无限平面体理论,推导出底板应力表达式,采用D-P准则计算底板破坏范围。(4)根据沿空留巷底板应力等值线和破坏范围曲线,揭示沿空留巷底鼓机理:随着底板应力和破坏范围的增大,一部分底鼓量由新增大破坏范围内岩体变形产生,另一部分底鼓量由原破坏范围内岩体在更高应力作用下失稳变形产生。随着底板应力和破坏范围的减小,只有原破坏范围内岩体在较小的应力作用下产生变形,底鼓量减小。由于底板应力和破坏范围的不对称性,造成不对称性底鼓。(5)加强顶板、两帮支护能够降低底板应力和破坏范围,有效控制底鼓;增加底角锚杆不仅能提高底板岩体弱面的抗剪强度,同时可提高围岩的残余强度,通过合理的安装角度能够发挥最大的加固作用,有效控制沿空留巷底鼓。工业性试验结果表明,研究成果有效指导了新元煤矿3107辅助进风巷底鼓控制,为工作面安全生产提供了有利条件。
[Abstract]:The roadway along the gob has the advantage of relieving the excavation, realizing "Y" ventilation and increasing the coal mining rate, but the serious bottom bulging phenomenon along the gob has become one of the bottlenecks that restrict the development of the roadway. Based on theoretical analysis, numerical simulation, similar simulation experiment and field test, the deformation law and characteristics of bottom plate along gob are studied systematically in this paper, and the mechanical model of bottom heave along goaf is established. At the same time, the variation law of stress and failure range of bottom plate is analyzed, and reasonable bottom drum control technology is put forward. The main research results are as follows: (1) the deformation law and characteristics of the floor along the gob: the deformation of the floor mainly occurs in the range of 40m from the front of the first stoping face to 80m behind the working face, and 80m from the front of the secondary mining face; The deformation and damage degree of the side floor in the front face of the primary mining face is greater than that of the solid coal side, and the deformation of the solid coal side floor is greater than that of the side support side of the roadway side in the stage of gob retaining roadway.) the theory of complex variable function is adopted. The stress distribution law and influencing factors along the goaf roadway are analyzed: the stress concentration degree of bottom angle is great, the bottom angle and floor stress decrease with the increase of the ratio of roadway width to height, the bottom angle stress increases with the increase of lateral pressure coefficient, and the bottom stress decreases with the increase of side pressure coefficient. With the increase of buried depth, the bottom angle and floor stress increase. 3) by analyzing the failure law of roof along goaf and the asymmetric bearing characteristics of surrounding rock of two sides, the mechanical model of bottom heave along goaf is established, which is combined with the theory of semi-infinite plane body. The stress expression of bottom plate is deduced, and the failure range of floor plate is calculated by using D-P criterion.) according to the isoline of stress and the curve of failure range, the mechanism of bottom bulging along goaf is revealed: with the increase of floor stress and failure range, One part of the bottom drum is produced by rock mass deformation in the new large failure range, and the other part is caused by the instability deformation of the rock mass under higher stress in the original failure range. With the decrease of floor stress and failure range, only the rock mass in the original failure range is deformed under the action of small stress, and the floor heave decreases. Because of the asymmetry of the stress and the failure range of the bottom plate, the asymmetric floor drum. 5) strengthen the roof, the two supports can reduce the stress and the failure range of the floor plate, and effectively control the floor drum. Increasing the bottom angle anchor can not only improve the shear strength of the weak surface of the floor rock, but also increase the residual strength of the surrounding rock. Through the reasonable installation angle, it can play the greatest reinforcement role and effectively control the bottom heave along the goaf. The industrial test results show that the research results can effectively guide the 3107 auxiliary air entry roadway floor drum control in Xinyuan Coal Mine and provide favorable conditions for the safe production of the working face.
【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】：TD353

【参考文献】