DOI: 10.11799/ce202601017
Surrounding rock failure characteristics and stress transfer laws in combined mining of steeply pitching coal seams with horizontal sublevel
WU Yongping
RU Xiaohui
XIE Panshi
WANG Hongwei
WANG Liwei
DU Yuqian
YAN Zhuangzhuang
TIAN Chengyang
WANG Lechen
WANG Zhengfu
Abstract：During the horizontal sublevel mining of steeply pitching coal seam groups,multi-sublevel extraction leads to complex roof movement and stress evolution.To investigate the fracture characteristics and stress evolution mechanisms,based on the engineering background of Tianshun Mine in Xinjiang,we combined physical similarity simulation and numerical calculation to analyze the asymmetric failure characteristics of surrounding rock and the energy-stress synergy mechanism.The results indicate that the mining-induced stress field exhibits significant asymmetric deflection.Stress concentration zones form in the upper and lower parts of the goaf roof along the dip,with a stress relief zone in the middle.The third principal stress deflects reversely,forming an asymmetric stress envelope arch.The surrounding rock failure evolves in three stages:sublevel 1 and sublevel 2 represent the initial stable stage,with minor principal stress deflection and slight rock caving.Sublevel 3 is the critical instability stage,where principal stress deflection increases markedly,both microseismic energy and unloading volume peak,the bearing arch undergoes abrupt instability,and high-position strata experience intense caving.Sublevel 4 and sublevel 5 constitute the chain propagation stage,characterized by an expanding unloading scope and increased microseismic frequency,with the failure range extending as the mining deepens.The study reveals that roof stability is synergistically controlled by the mining technique and principal stress deflection.The roof becomes unstable in stages at a sublevel height of 25 m,with the third sublevel acting as the critical threshold.
Keywords：steeply pitching coal seamhorizontal sublevelsurrounding rock failurestress transfer pathstress deflection direction
Publication Date：2026-01-20
Online Publishing Date：2026-03-10(First online date of this platform, not the publication date of the document)
Pages：10( 133-142 )