Bearing capacity mechanism of soilbagged graphite tailings

• Published in: Bulletin of engineering geology and the environment 2024, Vol.83 (1), p.24, Article 24
• Main Authors: Du, Changbo, Xu, Zhan, Yi, Fu, Gao, Jian, Shi, Kailong
• Format: Article
• Language: English
• Subjects: Bearing capacity; Comparative analysis; Compression; Compression tests; Deformation; Earth and Environmental Science; Earth Sciences; Foundations; Geoecology/Natural Processes; Geoengineering; Geotechnical Engineering & Applied Earth Sciences; Graphite; Health risks; Hydraulics; Mechanical properties; Mine tailings; Multilayers; Nature Conservation; Numerical analysis; Original Paper; Particle size; Roads & highways; Sand; Shear strength; Shear tests; Soils; Stacks; Tailings; Waste materials
• ISSN: 1435-9529; 1435-9537
• DOI: 10.1007/s10064-023-03531-7

Graphite tailings, a type of waste material, pose significant environmental and human health risks when stored in tailing ponds. One effective large-scale recycling method for these tailings is to use them as fill for soilbags, which can then be applied to support areas along empty lanes. This study examines the vertical bearing capacity of soilbags filled with graphite tailings. Uniaxial unconfined compression tests were conducted to determine the effects of filling degree, unit-area mass, and the inclusion of geogrid reinforcement on the vertical bearing capacity of the soilbags. To investigate the vertical bearing capacity of soilbagged graphite tailings, the impact of filling degree, unit area mass of the soilbag, and geogrid reverse wrapping on the vertical bearing capacity of the soilbag were explored via uniaxial unconstrained compression tests. This study introduces and assesses several classical models for load-bearing in multi-layer soilbag stacks, presents modifications to the soilbag wrap sand semi-circular boundary model, and conducts a comparative analysis. Experimental findings suggest that the initial failure in soilbags is predominantly at the interface contact. Even during this failure, the lateral sides of the soilbags maintain significant confinement ability, allowing continued load-bearing. The rupture of a soilbag is evident when it is compressed to the point of lateral cracking, and this is accompanied by the leakage of lateral graphite tailings. The employment of reverse encapsulation techniques with geogrids can delay the total failure of these bags, thereby significantly improving their load-bearing capability. Compared to the traditional stress model for multi-layer soilbag stacks, the modified multi-mode soilbag wrap sand semi-circular boundary model provides a more accurate prediction of stress when a three-layer soilbag stack, with a filling degree exceeding 75%, faces initial failure. The research findings provide a reference for the feasibility of using soilbagged graphite tailings in the construction of mine roadways along empty lanes.