Non-linear elastic model for MSW considering dilatancy effect

Abstract

Study of the stress-strain behaviour of municipal solid waste (MSW) is important in landfill design and management. Non-linear elastic constitutive models are usually in a simple form and convenient in engineering applications; however, most existing non-linear elastic models do not adequately consider the dilatancy behaviour, which has a significant influence on the strength and deformation behaviours of MSW. In this paper, a non-linear elastic model for the prediction of stress-strain behaviour of MSW is proposed based on the results of consolidated drained triaxial compression tests. The influence of dilatancy behaviour is identified and highlighted. The generalised shear stress can be normalised well by dividing the shear stress by the power function of the mean normal stress. Total expressions of normalised volumetric strain and generalised shear strain were established, and the dilatancy modulus and hardening modulus of the proposed model were obtained. The proposed model was used to simulate test results obtained from both published studies and the authors' laboratory testing. The simulation results were in good agreement with the experimental values in general, although deviations were observed in the simulations of volumetric strain or shear stress for the high-dispersion characteristics of MSW.