The influence of soft plastic material in the shear strength parameters of pre-treated municipal solid waste

Abstract

Nowadays the stability of MSW landfills with or without pre-treated waste has become one of the most challenging topics in geotechnical engineering. For an appropriate analysis of stability, the shear strength parameters of MSW should be well-defined in order to give a more realistic assessment of its mechanical behaviour. The mechanical strength of municipal solid waste is determined by two different components: friction (between granular particles) and apparent fibrous cohesion. Concerning apparent fibrous cohesion, it consists typically of a large group of substances (fibres and foil matter): paper/cardboard, soft plastic, hard plastic and wood. The high volumetric concentration of the soft plastic material in the MSW composition has increased considerably in recent years and its influence on the shear strength parameters is considerable. This study intends to give a better understanding of the influence of the soft plastic matter on the urban solid waste shear strength parameters, considering pre-treated municipal solid waste. In other words, it underwent some degradation process prior to final disposal, which is an already mandatory procedure in countries such as Germany and Austria.