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Influence of the Coal Seam Strength on the Boundary of a Top Coal Limit Equilibrium Zone in a Fully Mechanized Top Coal Caving Stope
- Source :
- Mining, Metallurgy & Exploration. 38:2375-2392
- Publication Year :
- 2021
- Publisher :
- Springer Science and Business Media LLC, 2021.
-
Abstract
- In a fully mechanized top coal caving mining process, the mechanical properties of the top coal deteriorate constantly, and the stability of the support is determined by the boundary position of the top coal entering the limit equilibrium state. Top coal flaking occurs more easily along the advancing direction owing to an increase in the distance of the boundary from the wall. Moreover, the strength of the coal seam is an important factor that determines the boundary position. The equation of the top coal limit equilibrium zone boundary, used in fully mechanized top coal caving mining, was determined based on the limit equilibrium theory, continuum damage mechanics, and the Hoek–Brown rock empirical strength criterion. Using the RFPA3D and UDEC numerical analysis methods, the effect of top coal strength on the mechanical behavior during the mining process was determined; and the space–time relationship between the top coal deformation failure, damage evolution, and boundary of the limit equilibrium zone was established. The results revealed that when the coal mass entered the limit equilibrium zone, accelerated crack development, accelerated damage, and axial unloading occurred. Moreover, an increase in the coal seam strength caused the boundary of the top coal limit equilibrium zone to be closer to the wall. By comparing the numerical results with the theoretical results, the overall trend was found to be consistent, allowing the verification of the rationality and reliability of the determination equation of the boundary position of the limit equilibrium zone.
- Subjects :
- Deformation (mechanics)
General equilibrium theory
business.industry
Thermodynamic equilibrium
Mechanical Engineering
Numerical analysis
technology, industry, and agriculture
Metals and Alloys
Coal mining
Boundary (topology)
General Chemistry
respiratory system
Geotechnical Engineering and Engineering Geology
complex mixtures
respiratory tract diseases
Mining engineering
Control and Systems Engineering
otorhinolaryngologic diseases
Materials Chemistry
Coal
Limit (mathematics)
business
Subjects
Details
- ISSN :
- 25243470 and 25243462
- Volume :
- 38
- Database :
- OpenAIRE
- Journal :
- Mining, Metallurgy & Exploration
- Accession number :
- edsair.doi...........5adea2d1de5a45894b9a3bc710cfe563