Macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force in deep coal and gas outburst
Abstract With the increase of mining depth and intensity, coal and gas outburst dynamic disasters occur frequently. In order to deeply study the macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force, taking the outburst coal seam of Pingmei No. 11 Coal Mi...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2023-09-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-023-43100-2 |
| _version_ | 1797453255057342464 |
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| author | Lingran Ren Jupeng Tang Yishan Pan Xin Zhang Honghao Yu |
| author_facet | Lingran Ren Jupeng Tang Yishan Pan Xin Zhang Honghao Yu |
| author_sort | Lingran Ren |
| collection | DOAJ |
| description | Abstract With the increase of mining depth and intensity, coal and gas outburst dynamic disasters occur frequently. In order to deeply study the macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force, taking the outburst coal seam of Pingmei No. 11 Coal Mine and Sunjiawan coal seam of Hengda Coal Mine as the research objects, the simulation roadway test system of self-developed true triaxial coal and gas outburst is applied to carry out the simulation test of deep coal and gas outburst with buried depths of 1000 m, 1200 m, 1400 m and 1600 m. During the test, the overlying strata stress is simulated by axial compression, the surrounding rock stress is simulated by confining pressure, the gas pressure is simulated by pore pressure, the impact force and acoustic emission monitoring technology are introduced, and the coal seam gas pressure is simulated by mixture pressure of 45% CO2 and 55% N2. From the viewpoint of fracture mechanics, the crack propagation mechanism of coal in the outburst launching area is discussed, the evolution characteristics of impact force and gas pressure are analyzed, and the influence law between acoustic emission signal and impact force is revealed. From the viewpoint of energy conversion, the transformation character of gas internal energy to impact kinetic energy (gas pressure to impact force) are analyzed. The results show that the generation of I-type crack is a prerequisite for outburst catastrophe. With the crack propagation, I-type and II-type cracks intersect and penetrate, resulting in internal structural damage and skeleton instability of coal. Gas wrapped fragmentized coal body thrown, outburst occurs. There is obvious negative pressure in the roadway after outburst. The occurrence of negative pressure is greatly affected by the physical and mechanical properties of coal, ground stress and gas pressure. Impact kinetic energy is mainly provided by gas internal energy. Part of the gas pressure is converted into impact force. The strength and duration of the impact force are determined by the gas pressure. Under the condition of deep working conditions (high ground stress and low gas pressure), the propagation of impact force in the roadway is more hindered. Both impact force and acoustic emission signals can monitor the occurrence of outburst. The peak point of acoustic emission ringing count is earlier than the impact force. The acoustic emission signal can monitor the outburst hazard earlier. The impact force can more specifically reflect the coal fracture. |
| first_indexed | 2024-03-09T15:20:10Z |
| format | Article |
| id | doaj.art-10bb4d07b6f04671bfdc91ccccd75b60 |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-03-09T15:20:10Z |
| publishDate | 2023-09-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-10bb4d07b6f04671bfdc91ccccd75b602023-11-26T12:50:09ZengNature PortfolioScientific Reports2045-23222023-09-0113111510.1038/s41598-023-43100-2Macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force in deep coal and gas outburstLingran Ren0Jupeng Tang1Yishan Pan2Xin Zhang3Honghao Yu4School of Mechanics and Engineering, Liaoning Technical UniversitySchool of Mechanics and Engineering, Liaoning Technical UniversitySchool of Physics, Liaoning UniversitySchool of Mechanics and Engineering, Liaoning Technical UniversitySchool of Mechanics and Engineering, Liaoning Technical UniversityAbstract With the increase of mining depth and intensity, coal and gas outburst dynamic disasters occur frequently. In order to deeply study the macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force, taking the outburst coal seam of Pingmei No. 11 Coal Mine and Sunjiawan coal seam of Hengda Coal Mine as the research objects, the simulation roadway test system of self-developed true triaxial coal and gas outburst is applied to carry out the simulation test of deep coal and gas outburst with buried depths of 1000 m, 1200 m, 1400 m and 1600 m. During the test, the overlying strata stress is simulated by axial compression, the surrounding rock stress is simulated by confining pressure, the gas pressure is simulated by pore pressure, the impact force and acoustic emission monitoring technology are introduced, and the coal seam gas pressure is simulated by mixture pressure of 45% CO2 and 55% N2. From the viewpoint of fracture mechanics, the crack propagation mechanism of coal in the outburst launching area is discussed, the evolution characteristics of impact force and gas pressure are analyzed, and the influence law between acoustic emission signal and impact force is revealed. From the viewpoint of energy conversion, the transformation character of gas internal energy to impact kinetic energy (gas pressure to impact force) are analyzed. The results show that the generation of I-type crack is a prerequisite for outburst catastrophe. With the crack propagation, I-type and II-type cracks intersect and penetrate, resulting in internal structural damage and skeleton instability of coal. Gas wrapped fragmentized coal body thrown, outburst occurs. There is obvious negative pressure in the roadway after outburst. The occurrence of negative pressure is greatly affected by the physical and mechanical properties of coal, ground stress and gas pressure. Impact kinetic energy is mainly provided by gas internal energy. Part of the gas pressure is converted into impact force. The strength and duration of the impact force are determined by the gas pressure. Under the condition of deep working conditions (high ground stress and low gas pressure), the propagation of impact force in the roadway is more hindered. Both impact force and acoustic emission signals can monitor the occurrence of outburst. The peak point of acoustic emission ringing count is earlier than the impact force. The acoustic emission signal can monitor the outburst hazard earlier. The impact force can more specifically reflect the coal fracture.https://doi.org/10.1038/s41598-023-43100-2 |
| spellingShingle | Lingran Ren Jupeng Tang Yishan Pan Xin Zhang Honghao Yu Macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force in deep coal and gas outburst Scientific Reports |
| title | Macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force in deep coal and gas outburst |
| title_full | Macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force in deep coal and gas outburst |
| title_fullStr | Macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force in deep coal and gas outburst |
| title_full_unstemmed | Macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force in deep coal and gas outburst |
| title_short | Macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force in deep coal and gas outburst |
| title_sort | macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force in deep coal and gas outburst |
| url | https://doi.org/10.1038/s41598-023-43100-2 |
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