Damage evolution and strength prediction model of soda residue modified cemented tailings backfill under uniaxial compression

Abstract

Recycling of solid waste materials reduces filling costs and reduces environmental pollution. This paper analyzed the availability of soda residue modified cemented tailings backfill (SRMCTB), and carried out uniaxial compression experiments to investigate the mechanical properties, energy evolution and damage characteristics of SRMCTB. The results show that the addition of soda residue effectively improves the compressive properties of SRMCTB. The uniaxial compressive strength and elastic modulus of SRMCTB increase and then decrease, and the elastic energy storage limit and total energy storage limit of SRMCTB increase and then decrease with increasing soda residue content. The damage constitutive models considering the compaction stage of SRMCTB were established and the damage evolution curves were plotted. Combined with the damage curves, the damage of SRMCTB can be divided into damage-free stage, damage stable development stage and damage rapid growth stage. The addition of soda residue has an effect on the stable development stage of the damage. When the soda residue content increased, the rate of variation of damage development stages first increases and then decreases. The proportioning parameters of SRMCTB were optimized in combination with the response surface methodology. It shows that when the soda residue content is at 5.45 wt%, the mass concentration is 76 wt% and the tailings gradation is 2:5, SRMCTB has the highest uniaxial compressive strength. A prediction model for the uniaxial compressive strength of SRMCTB was proposed and validated. The average error between the experimental and theoretical values is 8.30%, indicating that the model has a strong applicability and degree of extension.