Creep and strength characteristics of cemented gangue backfill under coupling effect of load and acid corrosion

Abstract

Cemented gangue back ll technology is bene cial to the reuse of solid waste and sustainable economic development. However, Mine water has a great impact on the strength and deformation of cemented gangue back ll (CGB). In this study, the CGB specimens under load were placed in simulated acid mine water (H 2 SO 4 solution). The changes of deformation, resistivity, and ultrasonic pulse velocity (UPV) of CGB were monitored. On the 360th day, the stress-strain curve and acoustic emission (AE) energy of the specimen during loading were recorded. the degradation mechanism of CGB was discussed by scanning electron microscope (SEM), and X-ray diffraction (XRD). The results showed that: the deformation of CGB increased with time. The effect of H 2 SO 4 solution concentration on the deformation was different in early and late stages. Applying 80% stress-strength ratio (SSR) reduced the strength and increased the deformation. The UPV and resistivity had different characteristics at different corrosion ages, which could be used as long-term stability monitoring of CGB. The CGB showed the strongest AE energy characteristics near the peak stress. The AE energy decreased with the increase of pH value in the pore compaction stage, and the AE activity of the CGB under 80% SSR was much greater than that of the CGB under 40% SSR. The erosion of H 2 SO 4 solution on the CGB was inhibited by applying a small load.Excessive load aggravated the erosion deterioration of CGB due to initial plastic damage. The research results can provide reference for durability design of CGB.

Preparation of Paste Filling Body and Study on Supported Transportation Laws Using Flac3D Simulation

“…It effectively controls rock movement and surface subsidence [3][4][5][6] and also mitigates the environmental impact of coal mining, thus enhancing economic, environmental, and social benefits. This approach provides a new perspective for constructing green mines [7][8][9][10][11].…”