School of Energy Science and Engineering, Henan Polytechnic University
Kuqa County Yushuling Coal Mine Co Ltd
State CollaborativeInnovation Center of Coal Work Safety and Clean-efficiency Utilization
School of Geology and Mining Engineering, Xinjiang University

煤岩破坏是能量驱动下的状态失稳现象,从能量角度描述煤岩破坏是评价工程稳定的有效方法之一。基于能量耗散有限差分算法,提出采用耗散能集中区定位煤岩破坏位置,采用耗散能密度评估煤岩破坏程度,描述煤岩峰后软化和变形破坏行为。将动压煤柱简化为平面应变模型,研究覆岩给定变形作用下煤柱耗散能演化规律,从能量角度揭示煤柱的变形失稳路径:煤柱能量耗散主要发生在峰后和残余阶段,峰后剪切面与角部能量耗散区贯通,并随加载程度增加发生内移,一旦弹性区消失,煤柱存在失稳风险。煤柱能量耗散及稳定状态与煤柱宽度、加载程度和加载方式有关。建立煤柱主动支护模型,研究锚杆(索)对能量耗散的调控效应,发现锚杆(索)可有效改善耗散能的传递和分布状态,支护强度增加有利于提高煤柱延性和抗变形能力,不同支护方式对耗散能的调控效果不同,锚索优于锚杆,对穿锚索优于常规锚索。以榆树岭矿小煤柱留巷为例,介绍小煤柱“锚杆+对穿锚索”支护的现场应用,取得良好的控制效果。

The failure of coal and rock masses is an instability phenomenon driven by energy, and de- scribing the failure behavior of coal rock from the perspective of energy dissipation is one of the effective methods to evaluate the stability and safety of engineering operation. Based on the finite difference me- thod for energy dissipation, it is proposed that the failure position and degree of coal rock can be charac-terized by high-concentration energy dissipation regions and the density of energy dissipation, respective- ly. Accordingly, the post-peak strain softening and deformation failure behavior of coal rock can be elu- cidated. In this study, by simplifying the coal pillar in gob-side entry under dynamic pressure into a plane strain model, the evolution law of dissipated energy of coal pillars during overburden deformation was investigated, and the deformation and instability paths of coal pillars were revealed from the per- spective of energy. The results demonstrate that energy dissipation of coal pillars mainly occurs in the post-peak and residual stages. The post-peak shear plane is connected with the corner energy dissipation region, and it shifts inward with the increase of loading degree. Once the elastic zone disappears, the coal pillar is prone to instability. The energy dissipation and stability of a coal pillar are related to its width, loading degree, and loading mode. Furthermore, an active support model of coal pillars was es- tablished, and the control effect of bolt (cable) support on energy dissipation was explored. It was found that bolt (cable) support can effectively improve the transfer and distribution of dissipated energy, and that an increase in support strength is conducive to enhancing the ductility and deformation resistance of coal pillars. Besides, different support patterns exert a control effect on energy dissipation to varying de- grees. Specifically, the control effect of cable support is better than that of bolt support, and bidirectional grouting cable support is superior to conventional cable support. Finally, by taking narrow coal pillars in a retained roadway in Yushuling Coal Mine as an example, the field application of “an- chor and bidirectional grouting cable” support on narrow coal pillars was introduced, which brought about a remarkable control effect.

国家自然科学基金项目(52174074,51704098);河南省自然科学基金项目(222300420048);河南省高校科技创新人才项目(23HASTIT012);河南理工大学杰出青年基金项目(J2021_4)