Acoustic emission characteristics and damage evolution process of layered cemented tailings backfill under uniaxial compression

In order to understand the failure mode, crack evolution and damage constitutive relationship of layered cemented tailings backfill (LCTB), the uniaxial compression test were carried out on four different types of LCTB. Test results show that: (1) The greater the height (h(1)/H) ratio and the smaller the cement-to-tailings (c/t) ratio, the smaller the uniaxial compressive strength (UCS) and elastic modulus (EM). The LCTB is mainly manifested as tensile failure. (2) The evolution characteristics of acoustic emission (AE) signal show an inverted U-shaped distribution, which first rises and then falls. It can be divided into five stages: quiet period, slow rising period, fast rising period, fast falling period, and slow falling period. (3) A cusp catastrophe model was established to predict the failure of LCTB. The prediction results are accurate. A damage constitutive model of LCTB was constructed. The total damage D of LCTB is composed of the damage value D-1 and D-2. All damage curves demonstrate an S-shaped distribution, first rising slowly, then rising quickly, and finally rising slowly again and approaching the maximum. (C) 2021 Elsevier Ltd. All rights reserved.