覆岩关键层破断对采空区压力变化规律影响的实验研究

发布时间：2018-05-29 03:20

本文选题：覆岩关键层 + 采空区压力　；参考：《中国矿业大学》2017年硕士论文

【摘要】：煤炭开采引起的一系列采动损害与环境问题都与覆岩的内部运动有关。而覆岩关键层破断后会对采空区压力产生最直接的影响。因此本文将结合关键层理论,研究采空区压力变化规律与覆岩关键层破断之间的对应关系,从而实现深入掌握覆岩内部运动规律的目标。论文综合运用理论分析、物理模拟、数值模拟以及现场实测等方法,首先通过物理模拟研究得到覆岩关键层破断对采空区压力变化规律影响的特征。运用数值模拟对影响采空区压力变化规律的各因素进行了分析。最后采用自行研制的采空区压力监测系统进行了现场实测,初步得出了覆岩关键层破断对采空区压力变化影响的基本规律。物理模拟实验表明,煤层开采后采空区的压力随着上覆关键层的破断呈阶梯状增长。初采期时采空区压力呈阶梯状增长直至最终稳定,且采空区最终压力值远小于其原岩应力值。正常回采期时测点上方不同层位关键层破断时采空区压力呈阶梯状增长,而当上方主关键层破断后,采空区压力以不同斜率曲线恢复原岩应力的稳定值。数值模拟实验表明,无关键层条件下采空区压力会以线性增长方式从零增加至最终稳定值。覆岩存在关键层时,当测点布置在切眼附近时,采空区压力始终随关键层破断呈阶梯状增长方式,压力最终值会小于原岩应力值。当测点布置在正常回采阶段时,采空区压力变化情况会受到关键层层位、关键层厚度、采高等各因素的综合影响。根据上述研究并结合采空区复杂的条件,运用自行研制的采空区压力监测系统及其工艺方法,在淄博王庄煤矿进行了现场实测,验证了监测系统的准确可行性以及采空区压力变化的基本规律。
[Abstract]:A series of mining damage and environmental problems caused by coal mining are related to the internal movement of overburden. The key strata of overburden have the most direct effect on the pressure of goaf after breaking. Therefore, combining with the theory of critical layer, this paper will study the corresponding relationship between the law of pressure variation in goaf and the breaking of key strata of overburden, so as to realize the goal of mastering the law of motion inside overburden. In this paper, theoretical analysis, physical simulation, numerical simulation and field measurement are used to study the characteristics of the influence of the breakage of the key strata of overburden on the pressure variation in the goaf. The factors influencing the variation of goaf pressure are analyzed by numerical simulation. Finally, the field measurement is carried out by using the self-developed goaf pressure monitoring system, and the basic law of the influence of the breakage of the key strata of overburden on the pressure variation of the goaf is preliminarily obtained. The physical simulation results show that the pressure of the goaf increases with the breaking of the overlying key layer. During the first mining period, the pressure of goaf increases step by step until it is finally stable, and the final pressure of goaf is much less than the stress value of the original rock. In normal mining period, the pressure of goaf increases step by step when the key strata above the measuring point break, and the pressure of goaf recovers the stable value of the original rock stress with different slope curves after the main key layer is broken. The numerical simulation results show that the goaf pressure increases from zero to final stability in a linear way without critical layer. When there is a critical layer in overburden, when the measuring points are arranged near the cutting hole, the pressure of goaf always increases in step with the breakage of the critical layer, and the final value of pressure will be less than the stress value of the original rock. When the measuring points are arranged in the normal mining stage, the pressure changes in the goaf will be affected by the key layers, the thickness of the critical layer, the mining height and other factors. According to the above research and combined with the complicated conditions of goaf, using the self-developed goaf pressure monitoring system and its technological method, the field measurement was carried out in Wangzhuang Coal Mine, Zibo. The accurate feasibility of the monitoring system and the basic law of the pressure variation in the goaf are verified.
【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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