Fracture features of brittle coal under uniaxial and cyclic compression loads
Abstract Under the effects of complex geological and stress environments, burst hazards continue to be a major challenge for underground space utilization and deep resources exploration as its occurrence can lead to personnel causalities, equipment damage and structural collapse. Considering the str...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2023-02-01
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| Series: | International Journal of Coal Science & Technology |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/s40789-023-00564-x |
| _version_ | 1827985439576817664 |
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| author | Shikang Song Ting Ren Linming Dou Jian Sun Xiaohan Yang Lihai Tan |
| author_facet | Shikang Song Ting Ren Linming Dou Jian Sun Xiaohan Yang Lihai Tan |
| author_sort | Shikang Song |
| collection | DOAJ |
| description | Abstract Under the effects of complex geological and stress environments, burst hazards continue to be a major challenge for underground 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 various 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 mechanical 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. |
| first_indexed | 2024-04-09T23:14:54Z |
| format | Article |
| id | doaj.art-12615b5f5c4f4782b5b974ecfe5d6d25 |
| institution | Directory Open Access Journal |
| issn | 2095-8293 2198-7823 |
| language | English |
| last_indexed | 2024-04-09T23:14:54Z |
| publishDate | 2023-02-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | International Journal of Coal Science & Technology |
| spelling | doaj.art-12615b5f5c4f4782b5b974ecfe5d6d252023-03-22T10:03:56ZengSpringerOpenInternational Journal of Coal Science & Technology2095-82932198-78232023-02-0110111310.1007/s40789-023-00564-xFracture features of brittle coal under uniaxial and cyclic compression loadsShikang Song0Ting Ren1Linming Dou2Jian Sun3Xiaohan Yang4Lihai Tan5Shaanxi Zhengtong Coal Industry Co., Ltd.School of Civil, Mining and Environmental Engineering, University of WollongongState Key Laboratory of Coal Resources and Safe Mining, China University of Mining and TechnologySchool of Energy and Safety Engineering, Anhui University of Science and TechnologySchool of Civil Engineering, The University of QueenslandSchool of Civil, Mining and Environmental Engineering, University of WollongongAbstract Under the effects of complex geological and stress environments, burst hazards continue to be a major challenge for underground 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 various 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 mechanical 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.https://doi.org/10.1007/s40789-023-00564-xFractureCrackCoal burstAcoustic emissionComputed tomography |
| spellingShingle | Shikang Song Ting Ren Linming Dou Jian Sun Xiaohan Yang Lihai Tan Fracture features of brittle coal under uniaxial and cyclic compression loads International Journal of Coal Science & Technology Fracture Crack Coal burst Acoustic emission Computed tomography |
| title | Fracture features of brittle coal under uniaxial and cyclic compression loads |
| title_full | Fracture features of brittle coal under uniaxial and cyclic compression loads |
| title_fullStr | Fracture features of brittle coal under uniaxial and cyclic compression loads |
| title_full_unstemmed | Fracture features of brittle coal under uniaxial and cyclic compression loads |
| title_short | Fracture features of brittle coal under uniaxial and cyclic compression loads |
| title_sort | fracture features of brittle coal under uniaxial and cyclic compression loads |
| topic | Fracture Crack Coal burst Acoustic emission Computed tomography |
| url | https://doi.org/10.1007/s40789-023-00564-x |
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