HAZARD CONSISTENT SEISMIC PERFORMANCE ASSESSMENT OF ROCKFILL DAMS
MetadataShow full item record
Slope systems such as earth/rockfill dams, waste storage landfill, or natural slopes can undergo significant damage during a seismic event. In the seismic design of slope systems, engineers often consider the amount of seismically-induced displacements as the key engineering demand parameter. The current state of practice procedures to estimate seismically-induced slope displacements are dominated by deterministic or pseudo-probabilistic approaches that do not directly quantify the hazard associated with the estimated displacements. Instead, these approaches assume that the hazard of the ground motion intensity measure of interest (e.g., peak ground acceleration) also represents the hazard of the estimated displacements. In contrast, performance-based approaches, which are the focus of this study, can provide hazard curves for the engineering demand parameter of interest (i.e., the amount of seismically-induced displacements in the context of this study), from which the estimated displacements can be directly related to the hazard design level. In this study, we propose to combine the conditional scenario spectra approach with advanced numerical modeling as a benchmark to evaluate performance-based approaches that rely on simplified and analytical procedures for the estimation of seismically-induced displacements in rockfill dams. The evaluations show that the displacement hazard curves obtained through computationally intensive numerical analyses (performed with three different constitutive models) are more conservative than the hazard curves from simplified or analytical methods. Insights from the comparisons are shared, and potential explanations for the differences are provided. Finally, there are also differences in the displacement hazard curves estimated through numerical analyses, which depend on the trade-off of volumetric/deviatoric mechanisms and damping in each constitutive model.