摘要
针对双巷布置工作面留巷受重复采动影响围岩变形破坏严重、支护难度大、存在冒顶隐患等问题,以神东布尔台矿22205回风巷道为工程背景,采用理论分析、数值模拟及现场实测方法,分析了重复采动巷道围岩塑性区及应力时空演化规律,获得巷道围岩从掘进稳定到废弃的整个动态破坏过程,以及不同位置围岩破坏状态的静态空间展现,阐明重复采动巷道塑性区变化的动-静组合机制。研究结果表明:①采动过程中塑性区扩展时间阶段与空间区域存在对应关系并根据现场实测得到空间区域具体范围,是分析巷道变形机理及提出分次支护方案的重要基础。②获得塑性区非对称扩展机理:其范围由偏应力大小决定,方位则由主应力方向主导,偏应力大小及角度共同作用造成塑性区非对称扩展,进而产生非对称变形,并以此揭示了重复采动巷道塑性区随时空扩展力学机制。③根据塑性区扩展形态,得出一次采动过程中塑性区深度及范围扩展显著且顶、底板明显大于两帮;2次采动过程中塑性区深度变化较小,而范围明显增加,主要发生在煤壁帮顶角位置及煤柱帮底角位置。④基于重复采动过程中塑性区扩展时空关系,提出分次补强支护方法,解决重复采动巷道围岩稳定控制;根据塑性区扩展形态及现场实测明确具体补强时间、地点及参数,并进行顶板补强支护,节省工期同时保障了回采期间安全生产。
In view of the serious deformation and destruction of surrounding rock,the difficulty of support and the hidden roof fall hazard affected by repetitive mining in the retained roadway,the temporal-spatial evolution laws of stress and surrounding rock plastic zone were studied in the 22205 air return roadway in Buertai Colliery by the comprehensive analysis methods including theoretical analysis,numerical simulation and field test.The whole dynamic failure process of roadway surrounding rock from excavation stability to abandonment and the static spatial expression of surrounding rock failure state at different positions are obtained.The dynamic-static combination mechanism of plastic zone variation in repeated mining roadway is expounded.The results show that①there is a corresponding relationship between the time and the spatial zone of the plastic zone expansion in the mining process and the specific range of the spatial zone is obtained according to the field measurement,which are important foundations in analyzing the mechanism of roadway deformation and putting forward the support plan in different stages.②The asymmetric expansion mechanism of the plastic zone is obtained.Its range is determined by the magnitude of deviatoric stress,and its orientation is dominated by the direction of principal stress.The combined action of the magnitude of deviatoric stress and angle causes the asymmetric expansion of plastic zone,and then generates asymmetric deformation,so the mechanical mechanism of temporal-spatial expansion in the plastic zone of repetitive mining roadway is revealed.③According to the expansion form of plastic zone,the depth and range of plastic zone expand significantly in the primary mining process,and the roof and floor are obviously larger than the two sides.In the process of secondary mining,the plastic zone depth changes little but the range increases obviously,which mainly occurs at the top angle of coal wall and the bottom angle of coal pillar.④Based on the temporal-spatial relationship of plastic zone expansion during repeated mining,a method of fractional reinforcement support is proposed to solve the stability control of surrounding rock in repeated mining roadway.According to the expansion form of plastic zone and field test,it should clearly determine the reinforcing time,position and parameters,and provide a reinforcing roof bolting to save work time and guarantee the mining safety in production.
作者
吴祥业
刘洪涛
李建伟
郭晓菲
吕坤
王婧雅
WU Xiangye;LIU Hongtao;LI Jianwei;GUO Xiaofei;LÜKun;WANG Jingya(Institute of Mining Engineering,Inner Mongolia University of Science and Technology,Baotou 014010,China;School of Energy and Mining Engineering,China University of Mining & Technology (Beijing),Beijing 100083,China;Mine Safety Technology Branch,China Coal Research Institute,Beijing 100013,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2020年第10期3389-3400,共12页
Journal of China Coal Society
基金
国家自然科学基金资助项目(51964036,51774288,51864036)。
关键词
采动影响
保留巷道
塑性区
偏应力
围岩控制
mining impact
retained roadway
plastic zone
deviatoric stress
surrounding rock control
