深部构造区冲击地压巷道合理掘进错距研究

Study on the reasonable distance of rock burst excavation roadway in deep structured area

针对深部构造区冲击地压矿井地应力分布不均匀的实际条件,利用数值模拟、微震监测和现场试验对比的方法,研究了深部冲击地压矿井在构造区和非构造区掘进时掘进错距对巷道围岩的应力分布的影响规律。结果表明,在掘进工作面附近及前方应力分布变化剧烈,而且与矿井最大水平主应力方向一致的应力变化最为明显,掘进工作面后方围岩应力分布则相对稳定;在无构造区域,平行掘进巷道错距在50m范围以内后两巷道围岩均会出现显著的应力集中、塑性区增加等;在构造区内随着两巷错距减小,扰动区微震能量频次变化整体可分为"高频低能"、"高能低频"、"冲击孕育"三个阶段,并得出构造区内掘进错距不应低于250m。

Aiming at the unstable distribution of deep structured rock burst coal mines,the impact of roadway distance on the stress distribution of surrounding rock in structured and non-structured area was analyzed comparatively by numerical analysis,seismic monitoring and field work.The results showed that the situation of stress distribution varied severely in the front of driving face especially when the stress was paralleled with the maximum principal stress and conversely,the stress stays rather stable at the back of excavating face.The stress concentration occurred obviously when the distance was lower than 50 min non-structured area.According to the seismic monitoring,the energy and frequency of microseismic activity can be divided into 3 stages namely high frequency while low energy,high energy while low frequency,preparation of rock burst in the disturbing zone and based on the research the safe distance of excavation faces was concluded to be no more than 250 m.