Shear Strength of Municipal Solid Waste (MSW): Beyond the Raw Values of "cohesion" and Friction Angles

Understanding the mechanical behavior of municipal solid waste (MSW) is still a major challenge in engineering. The purpose of this paper is to critically review published literature on MSW shear strength from the past 20 years, including the major strength mechanisms and failure criteria, so a landfill engineer can access key behavioral concepts, beyond just the raw values of friction angle and "cohesion" parameters that are required for design. In addition, this paper explores the relationship of shear strength parameters with MSW composition and urban population, which are useful proxies for economic development. To revisit the state of the practice since the introduction of commonly used design charts, an enhanced database of shear strength parameters as well as Mohr-Coulomb envelopes was compiled. Also, a relationship was developed between strength parameters, MSW composition, and population data for a number of cities in a developing country. This study supports the concept that the consumption habits of an urban area are very relevant when it comes to designing landfills. Furthermore, instead of introducing a new recommended range of design parameters or a new strength envelope, the compiled data are interpreted under a simple statistical basis, so the designer can make informed decisions on which parameters to choose for design.