Study of An Innovative Approach of Roof Presplitting for Gob-Side Entry Retaining in Longwall Coal Mining
Abstract
:1. Introduction
2. RPGER Approach
2.1. Roof Presplitting
2.2. RPGER Principle
2.3. Numerical Simulating Effect of RPGER
2.3.1. Numerical Model
2.3.2. Simulation Results
3. Field Test
3.1. Geological Condition
3.2. Test Design
3.2.1. Presplitting Angle
3.2.2. Presplitting Length
3.3. Test Effect
3.3.1. Roof Splitting Effect
3.3.2. Mining Pressure
3.3.3. Gob-Side Entry Deformation
4. Discussion and Conclusions
Author Contributions
Funding
Conflicts of Interest
References
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Rock Strata | Density/(kg/m3) | Elasticity Modulus (GPa) | Friction (deg) | Cohesion (MPa) | Tensile Strength (MPa) |
---|---|---|---|---|---|
Roof III | 2550 | 18.6 | 33 | 2.6 | 1.18 |
Roof II | 2600 | 19.4 | 32 | 2.8 | 1.24 |
Roof I | 2750 | 22.6 | 30 | 3.2 | 1.60 |
Coal | 1500 | 4.0 | 22 | 0.8 | 0.36 |
Floor | 2550 | 18.2 | 30 | 2.4 | 1.12 |
Rock Strata | Normal Stiffness (GPa) | Sheer Stiffness (GPa) | Friction (deg) | Cohesion (MPa) |
---|---|---|---|---|
Roof III | 2.2 | 1.1 | 5 | 0.03 |
Roof II | 2.7 | 1.4 | 9 | 0.04 |
Roof I | 3.2 | 2.6 | 10 | 0.02 |
Coal | 0.6 | 3.8 | 3 | 0 |
Floor | 2.6 | 1.2 | 8 | 0.04 |
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Zhang, X.; Chen, L.; Gao, Y.; Hu, J.; Yang, J.; He, M. Study of An Innovative Approach of Roof Presplitting for Gob-Side Entry Retaining in Longwall Coal Mining. Energies 2019, 12, 3316. https://doi.org/10.3390/en12173316
Zhang X, Chen L, Gao Y, Hu J, Yang J, He M. Study of An Innovative Approach of Roof Presplitting for Gob-Side Entry Retaining in Longwall Coal Mining. Energies. 2019; 12(17):3316. https://doi.org/10.3390/en12173316
Chicago/Turabian StyleZhang, Xingyu, Liang Chen, Yubing Gao, Jinzhu Hu, Jun Yang, and Manchao He. 2019. "Study of An Innovative Approach of Roof Presplitting for Gob-Side Entry Retaining in Longwall Coal Mining" Energies 12, no. 17: 3316. https://doi.org/10.3390/en12173316