Reliability analysis of municipal solid waste landfill settlements

Abstract

In the analysis and design of municipal solid waste (MSW) landfills, there are many uncertainties associated with the properties of MSW during and after MSW placement. For the analysis of time dependent settlement response of MSW, a composite compressibility model that accounts for instantaneous compression under the applied load, time dependent mechanical creep and biological decomposition is used. The objective of the present study is to demonstrate the influence of variability in model input parameters on the prediction of MSW settlement and to study the implication of different processes on settlement with an aim to assess landfill capacities and develop landfill closure plans. For this purpose regression equations based on response surface method (RSM) are developed to represent the complex behaviour of MSW. Probabilistic settlement analysis of MSW with due consideration to spatial and temporal variation of geotechnical properties is also performed. The published data on geotechnical properties of MSW are used to define the spatial variation of such parameters. The results of MSW settlements using reliability analysis framework are compared and discussed.