Research on characteristics of surrounding rock failure in floor roadway under the influence of stress con-centration in upper coal pillars
ZHENG Zheng
ZHANG Yu
WANG Junqing
CHEN Xiaofei
LIU Lin
HU Shilei
YANG Zengqiang
WEN Lei
Abstract：In order to determine the range of the stress concentration area in the bottom roadway under the influence of the upper coal pillar and to reveal the pressure-bearing behavior and failure characteristics of the surrounding rock,taking the close distance coal seams 15#and 16#in Lingxin Mine as the research objects,the"principal stress difference"was introduced instead of the tradi-tional"vertical stress"as the evaluation index for the pressure-bearing characteristics of the coal and rock mass.This research was carried out using methods such as the"half-plane body theory"and FLAC3D numerical simulation.The results show that the differ-ence curves of the principal stresses at different burial depths of the 15#coal seam bottom plate have a unique envelope line,based on the"mutation point"of the principal stress difference curve of the 16#coal seam roof,it is inferred that the range of this stress con-centration area is approximately 45 meters;after the 15#coal was mined,the distribution of the principal stress difference in the shal-low surrounding rock of the 35 m boundary coal pillar floor showed a"double-peak"pattern,as the burial depth increased,the prin-cipal stress difference began to change from a"double-peak"pattern to a"single-peak"pattern;based on the distribution of the main stress difference of the surrounding rock in the roadway under different widths of the coal pillar,combined with the particular-ity of the roadway section,the analysis indicated that although an elastic core zone of a certain width can be formed under the 20-meter coal pillar support condition,the roof rock still shows significant asymmetric stress and failure characteristics.
Keywords：close distance coal seamsprincipal stress differencestress concentration zonesurrounding rock controlasymmetric destruction
Publication Date：2026-02-20
Online Publishing Date：2026-03-19(First online date of this platform, not the publication date of the document)
Pages：9( 145-153 )