Simplified Procedure for Estimating Earthquake-Induced Deviatoric Slope Displacements

TLDR

Uncertainty in earthquake performance of earth/waste systems mainly stems from input ground motion. The study presents a simplified semiempirical model to estimate permanent earthquake‑induced deviatoric displacements, usable probabilistically or deterministically. The model employs a nonlinear stick‑slip sliding‑block framework, calibrated with 688 recorded ground motions, to predict displacement based on yield coefficient, fundamental period, and spectral acceleration at 1.5 Ts, distinguishing zero‑from non‑zero displacements and validated against 16 case histories.

Abstract

A simplified semiempirical predictive relationship for estimating permanent displacements due to earthquake-induced deviatoric deformations is presented. It utilizes a nonlinear fully coupled stick-slip sliding block model to capture the dynamic performance of an earth dam, natural slope, compacted earth fill, or municipal solid-waste landfill. The primary source of uncertainty in assessing the likely performance of an earth/waste system during an earthquake is the input ground motion. Hence, a comprehensive database containing 688 recorded ground motions is used to compute seismic displacements. A seismic displacement model is developed that captures the primary influence of the system's yield coefficient (ky), its initial fundamental period (Ts), and the ground motion's spectral acceleration at a degraded period equal to 1.5Ts. The model separates the probability of "zero" displacement (i.e., ⩽1cm) occurring from the distribution of "nonzero" displacement, so that very low values of calculated displacement do not bias the results. The use of the seismic displacement model is validated through reexamination of 16 case histories of earth dam and solid-waste landfill performance. The proposed model can be implemented rigorously within a fully probabilistic framework or used deterministically to evaluate seismic displacement potential.