Overlying strata movement rules and safety mining technology for the shallow depth seam proximity beneath a room mining goaf

• Published in: International journal of mining science and technology Vol. 25; no. 1; pp. 139 - 143
• Main Authors: Wang, Fangtian, Zhang, Cun, Zhang, Xiaogang, Song, Qi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2015; Elsevier
• Subjects: Closely-separated coal seams; Longwall mining; Overlying strata movement rules; Room mining goaf; Shallow depth seam; 安全; 岩层移动规律; 岩层运动规律; 开采技术; 房间; 浅埋煤层; 表面裂纹; 采空区; Shallow depth seam; Overlying strata movement rules; Room mining goaf; Longwall mining; Closely-separated coal seams
• ISSN: 2095-2686
• DOI: 10.1016/j.ijmst.2014.12.007

Aiming at the shallow depth seam proximity beneath a room mining goaf, due to that the shallow depth seam is exploited using the longwall mining and overlain by thin bedrock and thick loose sands, many accidents are likely to occur, including roof structure instability, roof step subsidence, damages of shield supports, and the face bumps triggered by the large area roof weighting, resulting in serious threats to the safety of underground miners and equipment. This paper analyses the overlying strata movement rules for the shallow seams using the physical simulation, the 3DEC numerical simulation and the field mea- surements. The results show that, in shallow seam mining, the overburden movement forms caved zone and fractured zone, the cracks develop continuously and reach the surface with the face advancing, and the development of surface cracks generally goes through four stages. With the application of loose blast- ing of residual pillars, reasonable mining height, and roof support and management, the safe, efficient and high recovery rate mining has been achieved in the shallow depth seam proximity beneath a room min ing goal.