动力扰动下区段煤柱稳定机理和宽度设计研究

Stability Mechanism and Width Design of Section Coal Pillar under Dynamic Disturbance

区段煤柱宽度的确定应兼顾煤炭回收率和巷道稳定性。区段煤柱受2个工作面回采的影响,尤其第2个工作面回采时,顶板剧烈活动对煤柱产生动力扰动。利用FLAC^(3D)动力分析模块对动力扰动下煤柱稳定机理和围岩动力响应进行了数值分析。窄区段煤柱(10.5 m)受2个工作面回采影响,处于全塑性状态,但通过应力释放达到卸压作用,有效抵抗动力扰动,通过提高护表能力,可防止片帮和煤柱失稳,巷道围岩变形量明显减小,煤柱在动力扰动后承载能力仍达到5.98 MPa,满足承载需求。研究成果与现场实测相吻合。

The determine of section coal pillar width need to take into account the coal recovery rate and roadway stability.Section coal pillar is affected by two mining faces,especially during the second mining face,the violent activity of roof is able to generate dynamic disturbance on coal pillar.The dynamic analysis in FLAC3Dis used to study the stability mechanism and dynamic response of coal pillar.Narrow coal pillar(10.5 m)can play a role of pressure relief;although the whole coal pillar is in plastic state,it can endure the dynamic disturbance and keep stability;the rib spalling of coal pillar can be prevented by increasing the surface protecting ability.The deformation of roadway surrounding mass is much less;the bearing capacity of coal pillar increases with its width,the capacity can reach to5.98 MPa when the width is 10.5 m,and this is able to satisfy needs.The research results match well with the data monitoring in situ.