Development of a constitutive model for fibre reinforced cemented Toyoura sand

Abstract

In this study, the modified Severn-Trent constitutive model is used to simulate the mechanical behaviour of unreinforced, cemented, fibre, and fibre reinforced cemented Toyoura sand consolidated under drained and undrained triaxial compression and extension loading conditions. The model parameters are derived based on the experimental results in the current study, parametric study, trial and error, and by comparison with previous research studies. The comparisons covered ranges of material from 0–3% fibre, 0–3% cement, and 20–60% relative densities. The experimental results and model simulations were compared in terms of deviatoric stress versus axial strain, volumetric strain versus axial strain, and stress path behaviour. Two additional parameters () obtained from the laboratory tests are added to the standard Severn-Trent model to simulate the stress–strain behaviour of cement and fibre reinforced Toyoura sand. Calibration exercises based on studies in the literature and comparisons with the experimental studies herein are conducted with the modified version of the Severn-Trent model. A close agreement of model simulations with the experimental results is observed for many of the tests performed on pure Toyoura sand, cemented, fibre, and fibre reinforced cemented Toyoura sand. The modified model successfully captured the main features of the behaviour (e.g., increase in strength and stiffness with cement additive, increase in volumetric dilatancy due to fibre and cement additives, and general stress path behaviour for drained and undrained conditions) for different types of composite materials with reasonable accuracy. Hence, the current study might serve and should be considered as a step towards modelling of the behaviour of composite materials.