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. Notation

A comparison between constitutive models for the municipal solid waste

“…The constitutive model for MSW has captured many researchers’ attention during the past few years, and some valuable works have been performed. Most studies have obtained the strain–stress curves of the waste using parametric analysis and curve fittings (Carvalhod and de Vilar, 2004; Gao and Kavazanjian, 2021; Gharabaghi et al, 2008; Ke et al, 2017; Machado et al, 2008, 2010; Zekkos et al, 2005). Some researchers have used the results of their experiments to predict the behavioural model of the waste; however, these experimental results have not been compared with those of other researchers (Alidoust et al, 2018; Karimpour-Fard et al, 2011; Shariatmadari et al, 2009, 2014; Zhao et al, 2016).…”