Simplified Soil Liquefaction Assessment Based on Cumulative Kinetic Energy Density: Attenuation Law and Probabilistic Analysis

Liquefaction of sandy soils has led to catastrophic damage to structures during past earthquakes. Implementing simplified procedures such as the shear-stress method is the most prevalent current practice in assessing liquefaction. Because there may be no perfect single simplified procedure, use of multiple methods is reasonable to minimize the risk of uncertainty. This paper presents an alternative simplified method for assessing soil liquefaction that is based on the cumulative kinetic energy density (CKED). Strong ground-motion data were employed, and with the aid of a genetic programming tool, an attenuation relationship was developed for estimating the CKED in liquefiable sites. CKED at a given layer depth was estimated by applying a depth-reduction factor. A simple correlation was developed for estimating the depth-reduction factor by way of equivalent linear site-response analysis on actual liquefiable soil profiles. The performance of the model presented herein was evaluated by implementing two databases of field liquefaction case histories. Probabilistic and deterministic curves are suggested for practice application.