Seismic Stability Procedures for Solid-Waste Landfills

U.S. federal regulations require that municipal solid-waste landfills located in seismic impact zones be designed to resist earthquake hazards. However, due to the lack of well-documented case histories, analytical procedures for evaluating the seismic performance of waste fills are not well established. Typically, procedures that were developed to analyze the seismic stability of earth embankments are applied to landfills, but waste fills are significantly different from earth embankments. In this paper, the application of pseudostatic stability and seismically induced deformation analyses to waste fills is assessed. The results of one-dimensional wave propagation analyses indicate that the seismic stability of waste fills depends primarily on the dynamic properties and height of the waste fill, and the characteristics of the design bedrock motions (intensity, frequency content, and duration). For many cases in which the waste fill's fundamental period is at least two times higher than the design bedrock motion's predominant period, the maximum horizontal equivalent acceleration will be less than about half of the bedrock maximum horizontal acceleration.