巨厚松散层下开采地表下沉的影响因素分析

Analysis of influence of different parameters of mining under super-thick loose layer on surface subsidence

巨厚松散层下煤层开采地表下沉较大,对生态环境的影响较大。为揭示不同参数对地表下沉的影响规律,采用数值模拟的方法分析松散层厚度与基岩厚度比、煤层埋深与煤层厚度比2个尺寸参数,以及基岩抗拉强度、黏聚力、内摩擦角3个力学参数在地表下沉中的作用。模拟分析表明:下沉系数呈现随着松散层厚度与基岩厚度比的增加迅速增大并逐渐趋于稳定的趋势,下沉系数呈现随着煤层埋深与煤层厚度比的增大线性降低的趋势,下沉系数呈现随着抗拉强度的增大逐渐降低的趋势;基岩厚度一定时,存在临界黏聚力数值和临界内摩擦角数值,在小于临界值的范围内提高黏聚力或内摩擦角,下沉系数逐渐降低,当超过该临界值时进一步提高黏聚力或内摩擦角,下沉系数基本无变化。

Based on the theoretical research and field practice of rock burst,this paper puts forward the stress control theory of rock burst,which is centered on stress control and characterized by unit stress gradient.the induction mechanism of rock burst caused by original rock stress,tectonic stress and mining stress is analyzed by similar simulation and numerical simulation,and the field practice of rock burst prevention and control is carried out from the point of view of stress control.The results show that the tectonic stress of the fault is the main cause of the rock burst,and the mining stress will also induce the rock burst of the driving roadway due to the influence of the residual stress in the adjacent mining area.The advanced deep-hole roof pre-splitting blasting and open-hole penetration dynamic stress control technology are applied to the anti-scour practice to verify the effectiveness of the stress control theory.