Study on Deformation and Supporting Measures of Mining Roadway with Compound Roof

• Published in: Geotechnical and geological engineering 2022-03, Vol.40 (3), p.1449-1462
• Main Authors: Dong, Hongjuan, Zhang, Jinshan, Zhang, Feng
• Format: Article
• Language: English
• Subjects: Abscission; Anchor bolts; Civil Engineering; Coal; Coal mines; Coal mining; Coking; Deformation; Deformation effects; Earth and Environmental Science; Earth Sciences; Finite element method; Fracture zones; Geotechnical Engineering & Applied Earth Sciences; Heavy metals; Hydrogeology; Mathematical models; Mine ventilation; Original Paper; Roads; Rock deformation; Rocks; Roofs; Simulation; Spalling; Terrestrial Pollution; Ventilation; Waste Management/Waste Technology
• ISSN: 0960-3182; 1573-1529
• DOI: 10.1007/s10706-021-01974-x

The No. 3 coal seam is one of the primary mineable coal seams in Du’erping coal mine of Shanxi Coking Coal Group Co., Ltd. The direct roof of No. 3 coal seam is a compound roof with two layers of 0.3–0.5 m extremely soft coal seams in the unstable rock stratum. The mining roadway has a large amount of deformation and is difficult to support. This paper takes 63,409 ventilation roadway of Du’erping coal mine as the engineering background. The RFPA2D numerical simulation software was used to compare and analyze the distribution characteristics of surrounding rock fracture zone and surrounding rock deformation in the mining roadway of the general roof and compound roof under the conditions of coal body–coal body and coal body–coal pillar. The supporting form and main supporting parameters of the mining roadway with compound roof were determined. Through simulation and comparison, the deformation of the mining roadway with compound roof under unsupported and three different support conditions were analyzed, and the combined support method of "bolt + anchor cable + metal mesh" was field tested. By analyzing the monitoring data of the roadway roof subsidence, floor heave, ribs displacement and roof abscission layer, the results show that the combined support method of “bolt + anchor cable + metal mesh” effectively controls the large deformation of the mining roadway with compound roof, improves the stability of the surrounding rock, suppresses the occurrence of roof fall and rib spalling, and ensure the safety of the roadway.