Slope Stability and Deformation Analysis of Bangalore MSW Landfills Using Constitutive Model

Abstract

Landfill stability and deformation analysis is one of the most important concerns in the design and operation of municipal solid waste (MSW) landfills. Estimation of landfill capacities based on the deformation characteristics of MSW assumes considerable significance in the estimation of additional landfill capacity before closure. In such analysis, it is important to consider mechanisms that occur in the MSW system, such as primary compression, time-dependent mechanical creep, and biodegradation effects. In this article, a simple case of landfill slope representing the MSW landfill of Bangalore city is considered, and the results of a stability and deformation analysis based on the constitutive modeling approach are presented. The implications for the slope stability and deformation response of MSW for a 5-m-high landfill cell are explained in terms of vertical and horizontal deformations, volume changes, and factors of safety, considering the effects of loading, mechanical degradation, and biodegradation. The effects of time on the strength and stability of the landfill cell are also observed. The study shows that analysis using the constitutive modeling approach provides useful insights for landfill operations. The model predicts that the effect of different mechanisms in a MSW landfill is to increase the overall stability of the landfill with time, and the horizontal and vertical deformations help in estimating landfill volume changes. The influence of lift thickness on the stability and performance of the landfill is also studied.