基于冲击地压-矿震协同控制的隔离煤柱合理宽度研究

Study on reasonable width of isolated coal pillar based on rock burst-mine earthquake coordinated control

针对陕蒙地区深部矿区工作面隔离煤柱宽度设计不合理导致冲击地压和矿震频发的现状,采用案例调研、理论分析和现场监测等方法,对隔离煤柱区冲击地压和矿震的发生机理及隔离煤柱合理宽度进行了研究。以近年来陕蒙深部矿区工作面在隔离煤柱区发生的3起典型冲击地压和矿震事件为工程背景,根据动力显现特征和诱发机理不同,将其分为煤柱局部破坏型冲击地压、煤柱整体失稳型冲击地压和煤柱区厚硬砂岩组破断型矿震3类。分别建立了采空区侧向支承压力估算模型、采空区转移应力估算模型、煤柱承载应力估算模型和关键层挠度弯曲变形力学模型,揭示了不同宽度隔离煤柱诱发局部冲击、整体冲击和矿震的机理。研究结果表明:2101工作面和2201工作面间隔离煤柱不发生局部冲击的宽度为5~6 m或不小于128 m;不发整体冲击失稳的宽度为不小于138 m;不发生矿震的宽度为498 m。在此基础上探讨了不同宽度隔离煤柱对冲击地压和矿震的影响,提出了基于冲击地压-矿震协同控制的合理隔离煤柱宽度设计方法,以期为陕蒙深部矿区相似条件工作面隔离煤柱宽度设计提供参考。

In view of the current situation that rockburst and mine earthquake frequently occur in the working face of Shaanxi and Inner Mongolia deep mining area due to unreasonable design of coal pillar width,by means of case study,theoretical analysis and field monito⁃ring,the mechanism of rock burst and mine earthquake in isolated coal pillar area and the reasonable width of isolated coal pillar are stud⁃ied.Three typical rock burst and mine earthquake events occurred in isolated coal pillar area in the working face of Shaanxi and Inner Mongolia deep mining area in recent years are taken as engineering background,according to the different dynamic characteristics and in⁃duced mechanisms,they can be divided into three types:rock burst caused by local failure of coal pillars,rock burst caused by overall in⁃stability of coal pillars,and mine earthquake induced by thick hard-strata breaking under the support of isolated coal pillars.The goaf lat⁃eral abutment pressure estimation model,the goaf transfer stress estimation model,the bearing stress estimation model of coal pillar and the deflection and bending deformation mechanical model of key stratum are established respectively,the mechanism of local rock burst,overall instability type rock burst and mine earthquake induced by different width isolated coal pillars are revealed.The results show that,the width of isolated coal pillar between No.2101 working face and No.2201 working face without local rock burst is 5~6 m or not less than 128 m;the width without overall instability type rock burst is not less than 138 m;the width of no mining earthquake is 498 m.On this basis,the influence of coal pillar width on rock burst instability and mine earthquake is discussed,and the reasonable design basis of coal pillar width based on the cooperative control of rock burst and mine earthquake is proposed,in order to provide reference for the design of coal pillar width in similar conditions.