摘要
针对预掘双回撤通道贯通时围岩失稳问题,通过理论分析和数值模拟方法,研究了预掘双回撤通道围岩破坏机理、回撤通道间合理煤柱尺寸、末采期间的围岩破坏特征和区域应力场矢量分布规律.结果表明:末采期间回撤通道处于非等压动态叠加应力场,围岩塑性区趋于蝶形失稳;理论计算主、辅回撤通道的合理煤柱尺寸为20 m,此时煤柱内应力分布呈现双峰状态,辅回撤通道区域应力场极值较小,有利于巷道的稳定;末采期间主回撤通道围岩逐渐塑性失稳,但20 m煤柱保证了辅回撤通道围岩塑性区的有限扩展.基于此,提出回撤通道合理煤柱尺寸留设配合加强支护的围岩稳定性控制技术,现场应用后主回撤通道最大帮部变形为173 mm,最大活柱下缩量为246 mm,围岩稳定性得到了有效控制.
Aiming at the problem of surrounding rock instability of pre-excavated double equipment withdrawal channel(EWC),the failure mechanism of surrounding rock around EWCs,the reasonable coal pillar size between EWC,the failure characteristics of surrounding rock and the vector distribution of regional stress field during final mining were studied by employing theoretical analysis and numerical simulation. Results show that during the final mining period, the EWC is in a non-isobaric dynamic superposition stress field,and the plastic zone of surrounding rock tends to butterfly instability.The theoretical calculation shows that the rational coal pillar size between the main EWC and auxiliary EWC is 20 m,and the stress distribution inside the coal pillar presents a double peak state. The stress around the auxiliary EWC is smaller,which is beneficial to the stability of roadway.During the final mining period,the surrounding rock of the main EWC gradually becomes plastic unstable,but the 20 m coal pillar makes the plastic zone expansion of the auxiliary EWC limited.Based on this,the stability control technology of EWC surrounding rock with reasonable coal pillar size design and reinforced support was put forward.After field application, the maximum side deformation of the main EWC is 173 mm, the maximum shrinkage of the hydraulic support is 246 mm, and the stability of surrounding rocks is effectively controlled.
作者
李臣
郭晓菲
霍天宏
刘润
LI Chen;GUO Xiaofei;HUO Tianhong;LIU Run(School of Energy and Mining Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Rescarch Center of Roadway Support and Disaster Prevention Engineering in Coal lndustry,China University of Mining and Technology(Beijing),Beijing 100083,China;Wanli No.1 Mine,Shenhua Baotou Encrgy Co.Ltd.,Ordos 017000,Inner Mongolian China)
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2021年第4期20-25,31,共7页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(52004289)
中央高校基本科研业务费专项资金资助项目(2020YJSNY09)。
关键词
煤柱尺寸
回撤通道
应力演化
塑性区
围岩控制
coal pillar size
equipment withdrawal channel
stress evolution
plastic zone
surrounding rock control
