1. School of Energy Engineering,Xi’an University of Science and Technology,Xi’an　 710054,China; 2. Key Laboratory of Western Mines and Hazard Pre- vention,Ministry of Education,Xi’an　 710054,China; 3. Chongqing Energy (Guizhou) Coal Co. ,Ltd. ,Bijie　 551700,China

为了实现大范围岩层控制技术,提高大倾角煤层长壁工作面“R-S-F”系统稳定性,在分析区段采空区围岩失稳机制的基础上,建立区段间围岩失稳模型,研究了区段煤柱的应力分布规律和失稳破坏准则,确定了区段煤柱的合理尺寸。结果表明:大倾角煤层区段围岩联通运移可总结为“挤压-弯垮”与“压垮-倾倒”两种模式。而要实现大范围岩层控制技术,应使区段采空区围岩以“压垮-倾倒”模式进行失稳联通。覆岩结构以“梁-拱组合梁”形式存在时,区段煤柱强度决定了区段采空区的联通运移模式,以“双拱连续梁”形式存在时,区段煤柱尺寸决定了“压垮-倾倒”联通运移模式的矿压显现特征及变形破坏后的采空区三维空间形态。因而大范围岩层控制技术的关键在于区段煤柱的设计。结合区段煤柱自身强度及失稳破坏准则,确定其宽度k须在满足k>kZH条件的同时尽量满足k<kSK。最后以甘肃东峡煤矿大倾角煤层多区段开采为例,进行理论计算判定与相似模拟实验对比分析,从而对提出的区段煤柱失稳机理进行了验证。

In order to achieve the technology for a large-scale ground control between sections and improve the stability of steeply dipping seam longwall face “ Roof-Support-Floor” system,based on the analysis on the section of gob sur-rounding rock instability mechanism, this paper established an inter section rock instability model, researched the stress distribution law and instability criterion of the section coal pillar,and determined the rea-sonable size of the sec-tion coal pillar. The results show that the steeply dipping seam section of surrounding rock movement can be summa-rized as two modes of “extrusion-bend down” and “crush-dumping”. In order to realize this technology,the surround-ing rock of the gob will lose stability in a “crush-dumping” mode. When the overburden structure exists in the form of “ beam arch combined beam”,the strength of the section coal pillar determines the movement mode of the surrounding rock in the gob section. When the overburden structure is in the form of “ double arch continuous beam”,the size of section pillar determines the pressure behavior characteristics of the “crush-dumping” mode and the gob’ s three-di-mensional spatial form after the deformation and failure. Thus the key of this technology lies in the design of the section coal pillar. According to the strength and instability criterion of the section coal pillar,it is determined that the width of k must satisfy the k>kZH condition and meet the k>kSK condition as much as possible. In a case study at the multi-sec-tion mining of steeply dipping seam in Gansu DONGXIA coal mine,the comparative analysis of the theoretical calcula-tion and similar simulation experiment was carried out,and the mechanism of the pillar instability was verified.

WU Yongping,HUANGFU Jingyu,XIE Panshi,et al. Mechanism of instability of section coal pillar in steeply dipping seam based on large-scale strata control technology[J]. Journal of China Coal Society,2018,43(11):3062-3071.