School of Mineral Engineering, Xi’an University of Science and Technology
Key Laboratory of Western Mine Exploitation and Hazard Prevention Ministry of Education

大倾角大采高工作面煤壁临空高度大，自由运移空间广，自稳平衡性差，煤壁在工作面内并非独体，其会与围岩及支架等介体组成承载结构，且采动行为间密切联动，倾角效应极易促使煤壁所处应力环境异化，诱使其响应行为复杂化，增加煤壁及围岩稳定性控制难度，制约工作面安全高效生产。为解决大倾角大采高工作面煤壁稳定性控制难题，综合采用理论分析、数值计算法进行研究。研究得出大倾角煤层大采高工作面塑性区内应力呈指数曲线状递增，煤壁邻域存在非对称拱状残余应力影响区，塑性区广度分区异化，广度由大到小依次为上部、中部、下部，分布形态呈梯级拱状，塑性区内煤体会重复性承压，并会随塑性区扩展增强；采高增大，煤壁邻域残余支承压力降低，煤壁前方煤体承压强度、位移幅度及受扰动范围均会增加；倾角效应下煤壁应力及运移分区式发展，其中，应力由大到小依次为下部、上部、中部，位移由大到小依次为中部、上部、下部，此外，伪斜布置下工作面倾角会诱使煤壁失稳模式转换，伪斜角大时，工作面倾角小，支承压力压缩分力作用增强，主要发生外凸片落式破坏，反之，则为采动应力及煤体自重倾向分力耦合性侧压下滑移失稳。综合分析可知，倾角及采高耦合作用下煤壁采动性状区域异化，且由于工作面中部、上部应力卸荷、运移量均较大，故此两域应为大倾角大采高工作面煤壁失稳重点防控区。

Coal wall of large mining height face in steeply dipping coal seam has large free height, wide free movement space and poor self-stabilization balance, coal wall is not an isolated body in the face, it can form a load-bearing structure with the surrounding rock, supports and other mediators, and the mining behavior is closely linked. The dip angle effect can easily promote the dissimilation of the coal wall bearing environment, complicate its response behavior, increase the difficulty of coal wall and surrounding rock stability control, and restrict the safe and efficient production of the face. In order to solve the problem of coal wall stability control of large mining height face in steeply dipping coal seam, theoretical analysis and numerical calculation are comprehensively used for research. The stress in the plastic zone of large mining height face in steeply dipping coal seam increases exponentially, there is an asymmetric arch residual stress influence zone in the vicinity of the coal wall, the plastic zone breadth is dissimilated in different regions, and the width from large to small is the upper, middle and lower part, and the distribution pattern is in the shape of stepped arch, coal in the plastic zone bears repeated pressure, and will be enhanced with the expansion of plastic zone. As the mining height increases, the residual abutment pressure near the coal wall decreases, the compressive strength, displacement value and disturbed range of the coal in front of the coal wall will increase. The stress and transport of the coal wall under the dip angle effect develop in a zonal manner, in which the stress distribution is lower> upper> middle, while for the displacement is middle> upper> lower. In addition, the working face inclination under the oblique angle will lead to the transformation of the coal wall instability mode, when the oblique angle is large, the dip angle of face is small, the compression component of abutment pressure is enhanced, and the external convex spalling mainly occurs. On the contrary, it’s the sliding instability under the coupling of mining stress and self weight. The comprehensive analysis shows that the coal wall mining behavior is regionally heterogeneous under the coupling effect of dip angle and mining height, and because the stress unloading and migration in the middle and upper part of the face are larger, therefore the two regions should be the key prevention and control areas for coal wall instability of large mining height face in steeply dipping panel.

国家自然科学基金资助项目（52104147，51774230）

张　浩，伍永平，解盘石. 大倾角大采高采场塑性区分布及主控因素分析[J]. 煤炭科学技术，2023，51（9）：55−64

ZHANG Hao，WU Yongping，XIE Panshi. Plastic zone distribution and main controlling factors analysis of large mining height face in steeply dipping coal seam[J]. Coal Science and Technology，2023，51（9）：55−64