An Innovative Approach for Gob-Side Entry Retaining With Thick and Hard Roof: A Case Study

• Published in: Tehnički vjesnik Vol. 25; no. 4; pp. 1028 - 1036
• Main Authors: Zhang, Zizheng, Wang, Weijun, Li, Shuqing, Bai, Jianbiao, Hao, Shengpeng, Wu, Hai, Yu, Xianyang
• Format: Journal Article Paper
• Language: English
• Published: Slavonski Baod University of Osijek 01.08.2018; Josipa Jurja Strossmayer University of Osijek; Strojarski fakultet u Slavonskom Brodu; Fakultet elektrotehnike, računarstva i informacijskih tehnologija Osijek; Građevinski i arhitektonski fakultet Osijek; Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek
• Subjects: Blasting; Case studies; Coal mines; Deformation effects; Deformation mechanisms; Field tests; gob-side entry retaining; Innovations; large area roof weighting; Longwall mining; LS-DYNA3D; Mathematical models; Parameters; Roads; shallow-hole blasting; thick and hard roof
• ISSN: 1330-3651; 1848-6339
• DOI: 10.17559/TV-20160816155022

An innovative roadway layout in a Chinese colliery based on gob-side entry retaining (GER) with thick and hard roof (THR) was introduced. Suspended roof is left with a large area in GER with THR, which leads to large area roof weighting (LARW). LARW for GER with THR and mechanism of shallow-hole blasting to force roof caving in GER were expounded. Key parameters of shallow-hole blasting to force roof caving are proposed. LS-DYNA3D was used to validate the rationality of those key parameters, and UDEC was used to discuss and validate shallow-hole blasting to force roof-caving effect by contrast to the model without blasting and the model with shallow-hole blasting. Moreover, shallow-hole blasting technology to force roof caving for GER with THR was carried out in the Chinese colliery as a case study. Field test indicates that shallow-hole blasting technology effectively controls ground deformation of GER with THR and prevents LARW.