Failure properties and stability monitoring of strip and column cemented gangue backfill bodies under uniaxial compression in constructional backfill mining

• Published in: Environmental science and pollution research international Vol. 29; no. 34; pp. 51411 - 51426
• Main Authors: Ran, Hongyu, Guo, Yuxia, Feng, Guorui, Li, Chunqing
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2022; Springer Nature B.V
• Subjects: Acoustic emission; Acoustic properties; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Axial stress; Backfill; Coal mining; Compression; Compressive strength; Constitutive models; Damage; Discrete element method; Ductility; Earth and Environmental Science; Ecotoxicology; Electrical resistivity; Environment; Environmental Chemistry; Environmental Health; Environmental science; Evolution; Finite element method; Gangue; Mathematical models; Mechanical properties; Mining; Monitoring; Research Article; Stability; Stress; Strip; Waste Water Technology; Water Management; Water Pollution Control; Strip; Length-height ratio; Failure properties Stability monitoring; Cemented gangue backfill body; Constructional backfill mining; Column
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-022-19336-2

The strip and column cemented gangue backfill bodies (CGBBs) are the main supporting components in the design of constructional backfill mining for coal mining, which determines the stability of goaf. Previous researches have mostly focused on the mechanical properties of column CGBB, but the mechanical properties of strip CGBB are still unclear. Herein, the uniaxial compression experiments for strip and column CGBBs were conducted to compare the failure properties. The acoustic emission (AE) and two types of resistivity monitoring were used to monitor the damage evolution. The effect of the length-height ratio on the mechanical characteristic of strip CGBB was analyzed by discrete element simulation. The results show that the strength and peak strain of strip CGBB under uniaxial compression is higher than those of column CGBB and the strip CGBB shows better ductility. The stress of column CGBB decreases significantly faster than that of strip CGBB at the post-peak stage. The strength and ductility of strip CGBB increase with the increase of length-height ratio. The strip CGBB is destroyed from both ends to the middle under uniaxial compression, and the core bearing area is reduced correspondingly. The AE signal evolution of CGBBs under uniaxial compression before the peak stress contains three stages, and the AE signals of strip CGBB at the peak stress will not rise sharply compared with column CGBB. The resistivity monitoring effect of the horizontally symmetrical conductive mesh is better than that of the axial. The horizontal resistivity increases gradually with the increase of stress under uniaxial compression, and increases sharply at the peak stress, and then drops after the peak stress. The damage constitutive models and the stability monitoring models of the CGBBs are established based on the experimental results. This work would be instructive for the design and stability monitoring of CGBB.