File: Evaluating the Dynamic Characteristics of Municipal Solid Waste for Geotechnical Purpose
Abstract-In order to analyse the engineering behavior of refuse material subjected to dynamic loadings, it is essential to determine its dynamic modulus, Poisson’s ratio, and strength. The shear modulus (G) is a major property in the evaluation of dynamic response of MSW, since it relates shear stress to shear strains. The dynamic shear modulus can be estimated from its mass density and shear wave velocity. The combination of shear wave and compression wave velocities are used to determine the Poisson’s ratio. This paper presents the results of cyclic triaxial tests performed on municipal solid waste (MSW). One sample was collected from the Mavallipura landll area and another sample was from a illegal dump around the same landfill area located in Bangalore. This illegal dump underwent substantial degradation with over a period of time. Dynamic properties of municipal solid waste for both dumped waste and drywaste (landfill) are obtained from laboratory cyclic triaxial shear tests using stress controlled cyclic triaxial tests. MSW degrades with time and its shear modulus and damping ratio are expected to vary with time and degradation. Dynamic shear modulus values for dumped waste varied from 0.8 MPa to 4.2 MPa and for dry waste varied from 2 MPa to 4.2 MPa. Dynamic shear modulus of the waste increases with increasing confining pressure and shear strains for both dry and dumped wastes. The increase is more with more confining pressure. The dynamic shear modulus slightly increases at a higher number of cycles of cyclic loading. Damping ratio varied from 14% to 32% for dumped waste. For dry waste damping ratio varied from 14% to 18%. Damping ratio decreases with increasing confining pressure. However, there is not much change with shear strain or number of cycles.Keywords- Damping; Municipal Solid Waste; Shear Modulus; Poisson’s Ratio
