煤田地质与勘探2024，Vol.52Issue(5)：46-55,10.DOI:10.12363/issn.1001-1986.23.10.0649
基于BOTDR的区段煤柱水平变形监测
BOTDR-based horizontal deformation monitoring of section coal pillars
摘要
Abstract
To address potential safety hazards like microcrack initiation,deformation,and failure inside coal pillars,this study monitored the horizontal deformations of coal pillars using the Brillouin optical time-domain reflectometry(BOT-DR)-a distributed optical fiber sensing technology.Firstly,this study established a method for converting the axial strain of optical fibers into horizontal deformations based on a theoretical analysis of the failure and bulking characterist-ics of coal pillars.Secondly,it determined the axial tensile response of metal-based cord-shaped sensing optical fibers by conducting laboratory tests.Then,it corrected the strain coefficient based on the deformation and failure patterns of coal pillars.Finally,against the engineering background of the Huojitu well of the Daliuta coal mine in Shaanxi Province,this study implemented on-site monitoring of the horizontal deformations of section coal pillars in mining face 22206.The key results are as follows:(1)Significant differences in horizontal deformations were observed between the mining and non-mining sides of section coal pillars.Specifically,the mining sides exhibited the largest horizontal deformation,about five times that of the non-mining sides.However,coal pillars manifested minor overall horizontal deformation character-ized by only elastic deformation,suggesting relatively stable coal pillars.(2)Coal pillars displayed significant deforma-tion zones,presenting an elastic core zone in the central part but plastic failure zones on both sides.(3)As the mining face advances from 20 m in front of the measurement ponit to 40 m behind the messurement point,the horizontal strain of coal pillars increased exponentially,and after moving away from survey points,the deformations tended to stabilize,reflecting a dynamic link between coal pillar deformations and mining-induced stress disturbance.(4)A analysis on the horizontal strain and vertical stress of coal pillars revealed an exponential relationship between both,forming a quantitat-ive relationship between both.The result indicates that the deformations and failure of coal pillars largely depend on the distribution and evolution of mining-induced stress.Overall,the BOTDR-based monitoring of the deformations inside section coal pillars can yield accurate information on microdeformations inside section coal pillars,serving as an import-ant guide for determining coal pillar sizes,controlling surrounding rocks,and evaluating pressure in goaves.关键词
分布式光纤/区段煤柱/水平变形/煤柱稳定性Key words
optical time domain reflectometer/section coal pillar/horizontal deformation/coal pillar stability分类
矿业与冶金引用本文复制引用
柴敬,郝鸿儒,杨健锋,高登彦,高奎英,陈建华,杨磊,刘泽宇..基于BOTDR的区段煤柱水平变形监测[J].煤田地质与勘探,2024,52(5):46-55,10.基金项目
国家自然科学基金青年科学基金项目(52004203) （52004203）
