Full
Outline
Addressing the issue of top pillar recovery beneath the overlying graded tailings backfill at the Liutangfang Iron Mine in Anhui, this study first comprehensively determined the maximum recoverable thickness of the top pillar using the load transfer line intersection method, the thickness-to-span ratio method, and the Protodyakonov arch theory. Subsequently, the maximum exposed area of the top pillar under varying stope widths was established via the Mathews stability chart method. Finally, incorporating on-site mining practices, numerical simulations of excavation were performed for two mining methods (cross-vein and strike-vein) across five stope structures. A comprehensive analysis was conducted to evaluat roof settlement, stress distribution, plastic zones, and excavated ore volume under different mining methods and stope structural parameters. The results indicate that for a stope span of 6 m, the safe thickness of the top pillar is 5 m. Based on the actual hydraulic radius derived from the Mathews stability chart method, the calculated maximum stope drift length is 30 m. When the strike-vein mining method is employed, the roof settlements corresponding to different drift pillar widths are 16 mm, 18 mm, and 20 mm; when cross-vein mining method is used, the maximum roof settlement is 33.52 mm, with the maximum roof stress increasing by 0.1 MPa. A comprehensive comparative analysis reveals that adopting the strike-vein mining method with a 4 m drift pillar keeps roof settlement within a controllable range, thereby optimally satisfying the safety, efficiency, and economic prerequisites of mine production. This scheme is projected to recover approximately 480 000 tons of top pillar resources, ensuring a smooth transition in mine production capacity and providing a reference for similar engineering projects.
40
13
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
