Experimental study on AE response and damage evolution characteristics of frozen sandstone under uniaxial compression

GCTS RTX-1500 low-temperature rock triaxial and acoustic emission (AE) testing systems were employed to evaluate frozen sandstone samples under uniaxial compression. Based on the AE responses, the mechanical properties, failure modes, and damage evolution characteristics of the sandstone samples at different temperatures were investigated. The results showed that (1) with decreasing temperature, the compressive strength, modulus of elasticity, and peak strain of the samples increased, and failure mode transformed from the single slope-failure to combined slope-failure and split-failure; (2) the AE response during the entire loading process could be divided into three stages: slow growth, rapid increase, and saturation stages, and the AE response characteristics of each stage were significantly influenced by the temperature of the sandstone samples; (3) with decreasing temperature, the AE events and parameters of the sandstone samples increased gradually, and the AE responded sharply; (4) AE location technology did not only reflect the spatial evolution trend of internal damage precisely during loading but was superior to the AE parameters during the early signs of brittle failure of the frozen sandstone. A damage evolution model of the frozen sandstone reflecting the temperature effect was established using a power function to fit the cumulative AE count. The calculated results consistently fit with the experimental results.