Municipal solid waste slope failure. I: Waste and foundation soil properties

This paper describes a slope failure in a municipal solid waste landfill, with lateral and vertical displacements of up to 275 and 61 m, respectively. The wasteslide involved approximately 1.2 million m³ of waste, making it the largest landfill slope failure to occur in the United States. Failure developed through the weak native soil underlying the waste. The analyses and related studies conducted to determine the cause of the failure are the subject of this and a companion paper by Stark et al. (2000). To facilitate the analyses, this paper investigates shear strength of municipal solid waste using field and laboratory test results and back-analysis of failed waste slopes. It also presents details of a geological study and laboratory testing program undertaken to quantify the mobilized shear strength of the weak native soil.