陷落柱突水机制的数值模拟研究

NUMERICAL SIMULATION STUDY ON WATER INRUSH MECHANISM FROM COLLAPSE COLUMN

在理论分析基础上,将固流耦合方程转化为热分析问题,利用有限元软件ANSYS模拟,系统研究陷落柱突水的力学机制及突水规律,并以潞安矿务局五阳煤矿地质为背景,通过对工作面远离陷落柱、接近陷落柱时底板应力、应变与水压分布规律的对比分析,结果显示:围岩的应力、位移及渗流场在工作面远离陷落柱时,互不影响;而随工作面推进至接近陷落柱时,围岩的应力-应变曲线形态发生改变,含水构造带渗流场水头压力亦发生改变,其界线约50m。应力在工作面远离陷落柱时变化幅度较慢,接近陷落柱时应力集中程度变化稳定,但分布范围扩大,并迅速扩散到陷落柱。渗流突水的最大水头位于工作面后方15～20m,表明隐伏陷落柱突水多为滞后突水。

Based on the study of water inrush mechanism from coal floor in coal mining above confined aquifer, the water inrush mechanism and law were studied by using ANSYS through translating solid-fluid coupling equations into thermal analysis problem. Taking the Wuyang mine of Lu′an coal mining administration geology as an example,the comparison of coal seam floor′s stress,strain and water pressure distribution rules of working face is studied when the working faces keep away from or are close to collapse column. The results show that stress, displacement and seepage field of surrounding rock mass do not influence each other when working faces keep away from collapse column. With working face being pushed close to working face,alteration of the stress-strain curve,water level pressure of water-bearing structural zone in seepage field all will take place,and the approximate boundary distance is about 50 m. It is found that alteration of stress is small as working faces keep away from collapse column,and the degree of stress concentration remains stable. However,the distribution range expands and diffuses speedily to collapse column. The highest water level of water inrush from solid seepage is located at the 15-20 m backside of working face,so water inrush from concealed collapse column is commonly the water inrush lagged.