深部沿空掘巷主应力差分布规律及煤柱宽度优化

Distribution of principal stress difference and optimization of coal pillar width in deep excavation roadway driving along goaf

以与围岩剪切破坏密切相关的主应力差为研究切入点,利用理论计算及数值模拟等研究方法,以赵固二矿11030运输巷沿空掘巷为工程背景,研究了深部回采工作面侧向采动应力场主应力差分布特征和不同煤柱宽度下沿空掘巷围岩主应力差分布规律,并提出了以主应力差分布规律为依据的深部沿空掘巷煤柱设计思路。研究结果发现:11030运输巷沿空掘巷前围岩可以分为主应力差降低区、主应力差升高区和主应力差稳定区;不同煤柱宽度下,深部沿空掘巷顶板、底板和煤壁帮围岩的主应力差呈单峰值曲线分布;而煤柱帮围岩主应力差,在煤柱宽度≤8 m时,主应力差呈单峰值曲线分布;而当煤柱宽度>8 m时,主应力差呈双峰值曲线分布,且位于浅部围岩的峰值点大小明显小于位于围岩深部围岩的峰值点大小。在此基础之上,结合理论计算确定了11030运输巷沿空掘巷合理煤柱宽度应为8 m,并进行了现场工业性试验。

Taking the main stress difference closely related to the shear failure of surrounding rock as the research entry point,and using theoretical calculation and numerical simulation and other research methods,the distribution characteristics of the principal stress difference in the side mining stress field of the deep mining face and the distribution laws of the principal stress difference of the surrounding rock at the god-side entry of 11030 haulage roadway in Zhaogu No 2 under different coal pillar width were explored.The design approaches were proposed of coal pillar in deep gob side driving with the distribution law of force difference as the core.According to the distribution characteristics of the principal stress difference,the surrounding rock of 11030 haulage roadway before driving along goaf could be divided into three zones,i.e.,decreasing,increasing and stable zones.The results show that the principal stress differences of the deep surrounding rock on the roof,floor,and coal wall rib at the gob-side entry present a single-peak curve distribution under different coal pillar width.However,the principal stress difference of the surrounding rock on the coal pillar rib displays a single-peak curve when the coal pillar width is less than or equal to 8 m,while a double-peak curve appears when the coal pillar width is greater than 8 m.The peak value of the shallow surrounding rock is obviously smaller than that of the deep surrounding rock.On this basis,combined with theoretical calculation,it is determined that the reasonable width of coal pillar for driving along the goaf of 11030 haulage roadway should be 8 m,with the field industrial test carried out.