Affiliation:
1. School of Environment and Resource, Southwest University of Science and Technology, Mianyang 621010, China
2. School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China
3. State Collaborative Innovation Center of Coal Work Safety and Clean-Efficiency Utilization, Jiaozuo 454000, China
Abstract
The deformation and re-crushing characteristics of different lithological caving crushed gangues in mine goaf directly affect the overburden strata movement, which significantly affects the surface subsidence of mining goaf. The effect of particle size on the re-crushing characteristics of different lithological caving crushed gangues in mine goaf is investigated in this study based on an innovative compression–AE (acoustic emission) measuring method. The results showed the following: (1) The compression deformation was divided into three stages: rapid, slow, and stable compaction. With the increase in axial pressure, the large particle skeletons were destroyed, medium particles were displaced and slid, and small particles filled the pores. (2) For singular lithologies, stress was positively correlated with pressure, and porosity was negatively correlated with stress. The composite sample was between the singular gangue samples. (3) The fractal dimension of crushed gangue samples was exponentially related to the proportion of gangue in singular and combined lithologies. (4) The cumulative AE count and energy of the combined lithological gangue samples were between those of the singular samples. The research results provide a theoretical foundation for further research into the characteristics of the overlying strata, surface movement, and safety management of the goaf.
Funder
Key Project of the National Natural Science Foundation of China
National Natural Science Foundation of China
Henan Science and Technology Research Project
Project of Science and Technology Innovation Leading Talent in Central Plains
Henan Excellent Youth Science Foundation
Program for Science & Technology Innovation Talents in Universities of Henan Province
scientific and technological innovation research team of Henan Polytechnic University
Key Scientific Research Projects of Colleges and Universities in Henan Province
Research fund of Henan Key Laboratory for Green and Efficient Mining & Comprehensive Utilization of Mineral Resources
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