Fracture features of brittle coal under uniaxial and cyclic compression loads
Shikang Song1
Ting Ren2
Linming Dou3
Jian Sun4
Xiaohan Yang5
Lihai Tan6
1.Shaanxi Zhengtong Coal Industry Co.,Ltd.,Xianyang 713600,China2.School of Civil,Mining and Environmental Engineering,University of Wollongong,Wollongong 2522,Australia3.State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology,Xuzhou 221116,China4.School of Energy and Safety Engineering,Anhui University of Science and Technology,Huainan 232001,China5.School of Civil Engineering,The University of Queensland,Brisbane 4072,Australia6.School of Civil,Mining and Environmental Engineering,University of Wollongong,Wollongong 2522,Australia;State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology,Xuzhou 221116,China
摘要：Under the effects of complex geological and stress environments,burst hazards continue to be a major challenge for under-ground space utilization and deep resources exploration as its occurrence can lead to personnel causalities,equipment damage and structural collapse.Considering the stress path experienced by in-situ coal body,cyclic loading appears in quite vari-ous forms for instance shearer cutting,overlying strata breakage,hydro-fracturing and blasting,during tunnel,mining and underground space utilizing process.The stability of the underground coal body subject to periodic loading/unloading stress is extremely important for maintain the function of designed engineering structure for waste storage,safe mining,roadway development,gas recovery,carbon sequestration and so on.The mechanical properties of hard rock subject to cyclic fatigue loads has been intensively investigated by many researchers as the rock burst induced by supercritical loads has long been a safety risk and engineering problems for civil and tunneling engineering under deep overburden.More recently,the mechani-cal properties of coal samples under cyclic fatigue loads is investigated from the aspect of hysteresis,energy dissipation and irreversible damage as the burst hazards of brittle coal is rising in many countries.However,the crack propagation and fracture pattern of brittle coal need more research to understand the micro mechanism of burst incubation subject to cyclic fatigue loads as brittle coal can store more elastic strain energy and rapidly release the energy when its ultimate strength once reached.This research studied the internal crack status corresponding to different cyclic fatigue loading stage of brittle coal samples.The AE monitoring was applied during the uniaxial and cyclic loading process of brittle coal samples to record the crack intensity of samples at different loading stages.The damage evolution curve corresponding to loading status was then determined.The fracture pattern of coal samples determined by micro-CT scan was observed and discussed.It has been found by this paper that brittle coal of uniaxial compression tests demonstrated sudden failure caused by major splitting fracture while that of cyclic fatigue tests experienced progressive failure with mixture fracture network.
机标关键词：brittlecoalcompressioncyclicfeaturesfractureloadsunder
论文发表日期：2023-02-28
在线出版日期：2025-08-15（本平台首次上网日期，不代表文献的发表时间）
页数：13( 60-72 )
英文信息