Experimental study on characteristics of strain and acoustic emission in the process of coal rock expansion and fracture
-
摘要: 针对目标对煤岩膨胀破裂过程中的声发射特征研究较少的问题，开展了煤岩膨胀破裂实验，分析了煤岩膨胀破裂全过程应变与声发射信号的变化规律。结果表明：① 煤岩膨胀破裂过程可划分为微破裂阶段(Ⅰ)、宏观裂纹生成及扩展阶段(Ⅱ)和劈裂阶段(Ⅲ)。② 煤、岩试样膨胀过程应变演化具有一致性，均呈现“缓变→加速→极值”变化趋势，但两者各阶段声发射信号差异较大。③ 煤样在第Ⅰ、Ⅱ阶段声发射振铃计数较为丰富，在临近第Ⅲ阶段累计振铃计数呈指数型递增；而砂岩在第Ⅰ、Ⅱ阶段声发射振铃计数较少，在临近第Ⅲ阶段累计振铃计数表现出 “突增→平静”趋势。④ 煤岩膨胀破裂过程均存在变形局部化现象，应变变异系数的突变和声发射峰值频率段增多现象可作为煤岩胀裂失稳破坏的前兆特征。研究结果可为煤岩致裂等工程的监测预警提供依据。Abstract: In order to solve the problem that there are few researches on the acoustic emission characteristics in the process of coal rock expansion and fracture, experiments on coal rock expansion and fracture are carried out to analyze the change law of strain and acoustic emission signals during the whole process of coal rock expansion and fracture. The results show that: ① the coal-rock expansion and fracture process can be divided into micro-fracture stage (Ⅰ), macro-fracture generation and expansion stage (Ⅱ) and splitting stage (Ⅲ). ② the strain evolution of coal and rock samples in the expansion process is consistent, showing the trend of 'slow change→acceleration→extreme value'. However, the acoustic emission signals of the two samples at each stage are quite different. ③ the acoustic emission ringing counts are more abundant in the coal samples at stages Ⅰ and Ⅱ, and the cumulative ringing counts increase exponentially near stage Ⅲ; while the acoustic emission ringing counts are less in the rock samples at stages Ⅰ and Ⅱ, and the cumulative ringing counts show a 'sudden increase - calm' trend near stage Ⅲ. ④ there is deformation localization in the process of both coal and rock expansion and fracture. The sudden change of strain variation coefficient and the increase of acoustic emission peak frequency range can be used as the precursor characteristics of coal rock expansion,fracture and instability. The research results can provide a basis for monitoring and early warning of coal rock fractures and other projects.
-
-
期刊类型引用(7)
1. 蔡敏博，李帅. 近距离煤层群保护层开采卸压瓦斯治理技术研究. 煤炭科技. 2023(04): 162-166 . 
百度学术
2. 黄兴. 近距离煤层群保护层开采底板卸压及效果考察. 中国矿山工程. 2022(04): 45-50 . 百度学术
3. 秦汝祥，杨珂，程健. 上保护层开采卸压保护范围研究. 工矿自动化. 2021(11): 81-87 . 本站查看
4. 谢小平，刘晓宁，梁敏富. 基于UDEC数值模拟实验的保护层无煤柱全面卸压开采分析. 煤矿安全. 2020(02): 208-212 . 百度学术
5. 韩飞林，郑春山，薛生，王志根，王永. 首采煤层开采诱发底板应力场分布特征研究. 煤矿安全. 2020(12): 263-269 . 百度学术
6. 聂凤祥，郭海峰. 潘西煤矿低瓦斯煤层喷孔动力显现规律研究. 工矿自动化. 2019(03): 12-17 . 本站查看
7. 韩泉胜，丁江海，李思乾. 远距离煤层开采保护范围确定及效果分析. 能源技术与管理. 2019(04): 86-88 . 百度学术
其他类型引用(6)
计量
- 文章访问数: 186
- HTML全文浏览量: 66
- PDF下载量: 11
- 被引次数: 13
下载:
