Research on the Law of Top Coal Movement and Influence Factors of Coal Caving Ratio for Fully Mechanized Top Coal Caving Working Face
Abstract
1. Introduction
2. Top Coal Dispersoid Media Flow Law and Mobility Evaluation
2.1. Top Coal Dispersoid Flow Characteristics and Types of Top Coal Arching
2.2. Flow Model of Top Coal Dispersoid
2.2.1. Top Coal Flow Without Support Influence
2.2.2. Top Coal Flow Considering Bracket Influence
2.3. Mobility Analysis of Top Coal Dispersoid
3. Analysis of the Influence of Lumpiness on the Caving Rate of Top Coal and Arch Formation
3.1. Influence of Lumpiness on Top Coal Caving Rate
3.2. Judgment of Arch Formation of Top Coal Dispersoid
4. Discussion of Measures and Practices for Preventing Arching of Dispersoid Medium of Top Coal
4.1. Extra-Large-Height Fully Mechanized Top Coal Caving
4.2. Pre-Rupturing Top Coal by Multiple Alternating Loads
4.3. Limitations and Future Research Directions
5. Conclusions
- (1)
- Coal gangue arching is an important influencing factor on poor top coal mobility and low top coal recovery rate. Using dispersoid mechanics theory can provide the influencing factors of the top coal body sliding surface resistance and reduction measures; that is, increase the height of coal cutting to reduce the thickness of the top coal, and design hydraulic support for large-height top coal caving to improve the mobility of the top coal.
- (2)
- The formula for calculating the arching rate of top coal is given; the larger the top coal lump size is, the lower the top coal caving rate is. Combined with the analysis of the balance mechanics of the coal caving arch, the critical coal caving opening size is obtained, and the design adopts a three-stage coal caving device to increase the size of the coal caving opening and reduce the arching rate of the top coal.
- (3)
- The oversize height comprehensive caving stent provides a new effective method for mining hard and 15~25 m extra-thick coal seams, and offers practical guidance for improving mining efficiency and recovery in similar thick seam conditions.
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
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Zhang, J.; Cheng, Z.; Lei, S.; Guo, K.; Chen, L.; Zhang, Z.; Chen, J. Research on the Law of Top Coal Movement and Influence Factors of Coal Caving Ratio for Fully Mechanized Top Coal Caving Working Face. Energies 2025, 18, 4312. https://doi.org/10.3390/en18164312
Zhang J, Cheng Z, Lei S, Guo K, Chen L, Zhang Z, Chen J. Research on the Law of Top Coal Movement and Influence Factors of Coal Caving Ratio for Fully Mechanized Top Coal Caving Working Face. Energies. 2025; 18(16):4312. https://doi.org/10.3390/en18164312
Chicago/Turabian StyleZhang, Jinhu, Zhiheng Cheng, Sheng Lei, Kai Guo, Liang Chen, Zherui Zhang, and Jiahui Chen. 2025. "Research on the Law of Top Coal Movement and Influence Factors of Coal Caving Ratio for Fully Mechanized Top Coal Caving Working Face" Energies 18, no. 16: 4312. https://doi.org/10.3390/en18164312
APA StyleZhang, J., Cheng, Z., Lei, S., Guo, K., Chen, L., Zhang, Z., & Chen, J. (2025). Research on the Law of Top Coal Movement and Influence Factors of Coal Caving Ratio for Fully Mechanized Top Coal Caving Working Face. Energies, 18(16), 4312. https://doi.org/10.3390/en18164312