Development of a Practical Method for the Estimation of Maximum Lateral Displacement in Large Landfills

Abstract

An extensive database of mechanical properties of municipal solid waste (MSW) is available as a result of significant advances made in the past few years in terms of understanding its mechanical behavior. It is, however, difficult to interpret and use this database in practice because of inherent heterogeneity of MSW and the variations in the sampling and testing procedures. The database also appears to be dominated by shear strength properties and contains limited information on elastic properties. As such, it is rather difficult to estimate the deformation within landfills and to quantify its effect on the performance and the integrity of leachate and gas collection systems installed within landfills. This paper presents results from an extensive on-going research program at the University of Saskatchewan to study the mechanical behavior of MSW. This research program includes laboratory and field testing of intact and recompacted MSW samples and numerical simulations incorporating stochastic modeling. A practical tool in the form of a design chart is presented, which can be used for the estimation of maximum horizontal displacement in a landfill using the height and the side slope of the landfill and the unit weight and the elastic properties of MSW. The validity of the design chart is confirmed using the results from an instrumented municipal landfill located in eastern Canada.