Predicting deformation kinetics and fractures propagation in coal-rock masses using acoustic emission testing
Majid Khan1
Xueqiu He1
Dazhao Song1
Zhenlei Li1
Xianghui Tian2
1.School of Resources and Safety Engineering,University of Science and Technology Beijing,Beijing 100083,China;Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mine,University of Science and Technology Beijing,Beijing 100083,China;Research Institute of Macro-Safety Science,University of Science & Technology Beijing,Beijing 100083,China2.School of Engineering and Technology,China University of Geosciences(Beijing),Beijing 100083,China
摘要：The formation of coalesced fractures critically alters the mechanical properties of the surrounding virgin material,signifi-cantly changing the stress distribution and deformation behavior of the rock mass.However,understanding the generation mechanism and accurate prediction of rock fracture growth remain challenging in many engineering projects.Despite,wide range of conventional approaches including field investigations,laboratory-scale tests,and numerical modeling,the complex geological conditions hinder their accurate determination.This study introduces a new robust and cost-effective holistic geophysical approach to determine fractures propagation and predict failure in coal-rock masses at laboratory scale applicable across scales.The proposed approach combines rock mechanics and Acoustic Emission(AE)testing systems to make useful correlation between AE source parameters and deformation kinetics.This correlation analyzes the spatiotemporal distribution of AE events to elucidate the evolution of fracture patterns in coal-rock specimens from a complex mining project.Results showed dense and complex fracturing networks within coal specimens due to higher density,compaction,and mechanical strength compared to rock samples.This is indicated by peak acoustic events at 80％-100％load versus minimal events at 0-15％load.Simulated fracture patterns closely matched observed acoustic events,identifying key lineaments(macro-cracks)representing the transition from microcracks to macro-fractures.The convergence of these lineaments indicated intensely deformed zones prone to failure,consistent with previous field investigations.Acoustic parameters describing critical dam-age revealed an inverse relationship between stress and AE event magnitude.At roughly 70％σmax,a dramatic fall is seen in acoustic parameters indicated the shift from small-scale to large-scale microfractures,ultimately leading to catastrophic failure of the samples.Furthermore,Single Link Cluster(SLC)analysis demonstrated strong correlation among AE events,spatial correlation length(ξ)and information entropy(H).Both increased significantly at the onset of loading and fluctu-ated in proximity to ultimate failure.Using the micro-crack density criterion and 3D-crack growth theory,changes in above parameters verified the cracks transformation process.These findings showed that,the proposed approach compared with the conventional approaches,can improve disaster control and management plans,predict critical failures,and save lives in global mining projects when applied to field-scale studies.
机标关键词：acousticemissionkineticscoal-rockdeformationfracturesmassespredicting
论文发表日期：2025-04-30
在线出版日期：2025-10-15（本平台首次上网日期，不代表文献的发表时间）
页数：18( 202-219 )
英文信息