Creep properties of geopolymer cemented coal gangue-fly ash backfill under dynamic disturbance

A testing machine was developed to test the creep disturbance effect and explore the creep disturbance law of geopolymer cemented coal gangue-fly ash backfill (GCGFB). A creep disturbance constitutive model of GCGFB was established by introducing a disturbance element that connects an improved fractional Burger's model and nonlinear viscous dashpot with a strain trigger. Experimental results indicated that dynamic disturbances significantly influence the creep process of GCGFB. Increasing the disturbance impact energy increases the deformation and shortens the time to reach the failure strain. The disturbance deformation generated by GCGFB is negatively correlated with the static load stress at a low disturbance energy and positively correlated at a high disturbance energy. The calculated results of the disturbance constitutive model showed good agreement with the experimental data. (C) 2018 Elsevier Ltd. All rights reserved.