Classification and mechanical behaviour relationships for municipal solid waste: study using synthetic wastes

Mechanical behavior of the waste body controls many aspects of landfill lining system design and performance, including stability issues and integrity of the geosynthetic and mineral lining components. The constituents of municipal solid waste deposits vary between countries and regions and are constantly altering as a result of changes in lifestyle and legislation. This paper describes an investigation using a family of synthetic wastes to assess the relationship between classification and mechanical behavior of the waste body via a program of one-dimensional compression and direct shear tests. Measured mechanical behavior is compared with results for real wastes to assess the validity of using synthetic samples. Compression and shear behavior of the synthetic wastes were found to be within the range of published values for real waste. Both stiffness and shear strength values for a synthetic “real” waste were found to be at the lower bound of published values. Lower unit weights and dry conditions for the synthetic wastes are considered to be responsible for the observed differences with real waste behavior. It is concluded that synthetic wastes can be used to assess the relationship between classification and mechanical behavior and that compression and shear behavior can be related to waste classification.