| Autor: |
Jia, Jinhe, Wang, Zhichao, Zhang, Zhen |
| Zdroj: |
International Journal of Mining and Mineral Engineering; 2024, Vol. 15 Issue: 1 p49-70, 22p |
| Abstrakt: |
The geological feature of sandstone strata directly overlying coal seams is common in the Shendong shallow buried coal field, and causes delayed roof caving and the risk of windblasts in the initial longwall mining stage. To mitigate windblasts, preconditioning measures, such as hydraulic fracturing operations and temporary blasting operations, are employed to improve the roof caving performance. Site observations show that the thicker the overburden, the more difficult the roof caving becomes, and the conditioning measures do not produce very good roof caving performance as expected when the overburden thickness approaches 200 m. Numerical simulations are employed to investigate the roof-caving mechanism associated with the geological conditions of the Shendong coal field. The numerical results show that structurally controlled instability is the main mechanism of the roof caving; the gravitationally-loaded horizontal stress can lead to worse roof caving performance in the case of greater overburden thickness. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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