煤矿安全2025，Vol.56Issue(5)：121-130,10.DOI:10.13347/j.cnki.mkaq.20241080
弱胶结含砾岩层覆岩断裂及应力变化特征研究
Study on fracture and stress variation characteristics of overlying rock with weakly consolidated gravel layer
张闯 1许良珂 2杜盼 1陈建崇 1姚新宇 1王博 1杨雨默 1李瞻领 1马耀荣 1常震坤1
作者信息
- 1. 鄂尔多斯市昊华红庆梁矿业有限公司,内蒙古 鄂尔多斯 014300
- 2. 山东科技大学 能源与矿业工程学院,山东 青岛 266590
- 折叠
摘要
Abstract
The western Inner Mongolia region is characterized by widespread weakly cemented soft rock strata,where the presence of thick overlying gravel layers exerts a significant influence on roof failure and stress distribution.Understanding the fracture beha-vior and stress distribution characteristics of weakly cemented gravel-bearing layers is critical for assessing roof stability and determ-ining the extent of pressure release zones in this region.Using Hongqingliang Coal Mine as a case study,this research integrates the-oretical analysis,laboratory experiments,numerical simulations,and field monitoring,focuses on the lithological and spatial distribu-tion features of 3-1 coal overburden,and the study investigates the fracture mechanisms and modes of the overlying roof in weakly cemented gravel-bearing strata.The evolution of roof fractures and associated stress variations are analyzed with engineering valida-tion through micro-seismic monitoring.The findings reveal that the roof fracture process in weakly cemented gravel-bearing strata occurs in four distinct stages:caving zone subsidence,stratified fracture of the gravel,overall roof failure,and roof bending-sagging.The strain response in the gravel layer follows a distinct"slow increase-rapid increase-sharp decrease-stabilization"pattern,with failure progressing of"stratified fracture,rotation,and compression into hinged rock blocks".The gravel layer plays a pivotal role in controlling roof failure,with the overlying strata bending and sinking in a coordinated manner,exhibiting relatively low damage and maintaining overall continuity.Tensile failure is predominant in the gravel layer,and after fracture,roof fissures and the pres-sure release zone stabilize vertically,with the fissure development height reaching approximately 52.8 meters.The pressure release zone extends to about 79 meters,as indicated by the distribution of roof stress concentration factors.During the micro-seismic monit-oring period,the fracture degree of the gravel layer was large,and the single energy release was high,with a maximum of 8 723.36 J,which occurred 249 times;the upper rock layer was relatively low but dense,and the microseismic events occurred more frequently,with a total of 658 times,and the maximum energy release was 7 432.52 J.关键词
弱胶结软岩/覆岩断裂/裂隙发育/应力变化/微震监测Key words
weakly consolidated soft rock/overburden fracture/fissure development/stress change/microseismic monitoring分类
矿山工程引用本文复制引用
张闯,许良珂,杜盼,陈建崇,姚新宇,王博,杨雨默,李瞻领,马耀荣,常震坤..弱胶结含砾岩层覆岩断裂及应力变化特征研究[J].煤矿安全,2025,56(5):121-130,10.
