| Autor: |
Ma, Hongfa, Song, Yanqi, Yang, Jiangkun, Zheng, Junjie, Shen, Fuxin, Shao, Zhixin, Xia, Zhiguo |
| Předmět: |
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| Zdroj: |
Natural Resources Research; Apr2023, Vol. 32 Issue 2, p543-566, 24p |
| Abstrakt: |
Seasonal freeze–thaw (F–T) cycles in cold regions may affect the stability of the slope rock mass in open-pit coal mines and even induce engineering geological disasters, such as landslide. In this paper, the moisture-control and water-immersion F–T tests of lignite obtained from the slope in an open-pit mine were carried out, respectively, and the uniaxial compression tests of lignite subjected to the F–T effect were conducted with the acoustic emission monitoring in the whole test. The results showed that the quality, height and porosity of lignite samples increased with the F–T cycles, accompanied by increase in the development degree of macro- and micro-horizontal cracks, and the cracks appeared earlier and larger for the water-immersed rock samples. Mechanical parameters such as uniaxial compressive strength presented a decreasing trend with increase in F–T cycles, accompanied by decline of strain energy, which was significant for the water-immersed samples. In addition, the acoustic emission activity was gradually significant with increase in F–T cycles, which also caused the intensification of microstructure responses. The interior of lignite had significant horizontal bedding structure and banded areas of water, which contributed to the rapid development of horizontal cracks caused by the F–T effect, resulting in the gradual deterioration of lignite; meanwhile, the deterioration degree was more prominent for water-immersed lignite due to continuous water supply and response of free water. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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