Numerical simulation of stress-strain behaviour of cemented paste backfill in triaxial compression

Abstract

This paper develops a numerical model to reproduce the stress-strain curve of cemented paste backfill (CPB) based on the discrete element method-2 dimensional particle flow code (PFC2D), mainly to predict the CPB mechanical properties the model fully considers the special nature of CPB, including its wide range in grain-size distribution, evolving void ratio with the cementing process and deficient cementation due to the low binder content. The grain size distribution and initial void ratio in the numerical sample correspond to the true values of the CPB specimen. The cementing particles are used to simulate the cementation product and increase with the CPB hydration process. Results show that the numerical model performs well in simulating the true stress-strain behaviour of the CPB material. Sensibility Study of the parameters indicates that bond characteristic and particles friction coefficient strongly influence the model performance. This model can be used for strength prediction and binder additive optimization for CPB material.