Mechanism and control of deformation in gob-side entry with thick and hard roof strata

• Published in: Journal of the South African Institute of Mining and Metallurgy 2023-08, Vol.123 (8), p.423-434
• Main Authors: Guo, J.S., MaII, L.Q., Ngo, I.
• Format: Article
• Language: English
• Subjects: Coal mines; Control methods; Cutting; Deformation effects; Dynamic pressure; Longwall mining
• ISSN: 2225-6253; 0038-223X; 2411-9717
• DOI: 10.17159/2411-9717/1707/2023

Deformation of gob-side entries has always been a critical concern for ensuring stability in longwall coal mines. This paper addresses the significant deformation and support challenges that arise in thick and hard roof longwall faces (THRLF) due to dynamic pressure. The study aims to elucidate the characteristics and mechanisms of deformation during the retreat of the longwall face. The research findings indicated that the primary cause of deformation was the combination of advanced abutment stress resulting from longwall face mining and the movement of the lateral roof over the chain pillar. To mitigate this issue, we propose a deformation control method known as cutting off the lateral roof (COLR) over the chain pillar. Simulation results demonstrate a significant reduction in roof stress and deformation of the gob-side entry after implementing the lateral roof-cutting technique. These findings provide valuable guidance for effectively managing deformation in gob-side entries, particularly when dealing with thick and hard roof strata.