Análisis de respuesta no lineal de sitio de depósitos aluviales licuables: pruebas in situ, modelos empíricos y deformación del terreno

Abstract

CONDITIONING OF PROJECT PUBLICATION. Reliable assessment of liquefaction consequences remains a central challenge for levelground alluvial deposits. The state of practice relies on empirical procedures derived from in-situ tests and calibrated against manifestations from past earthquakes. While these methods provide reasonable estimates of liquefaction triggering, they fail to capture liquefaction at depth and cannot quantify transient ground deformations, which are critical for assessing seismic demands. Laboratory evidence further shows that silty sands exhibit lower cyclic resistance and more severe liquefaction effects than clean sands, challenging fines correction factors embedded in simplified procedures. A key limitation of empirical methods is that they treat each soil layer independently, neglecting the system-level response of interbedded deposits. Deeper liquefiable horizons separated by clayey layers may trigger first, dissipating seismic energy and altering stress transmission, often leading simplified procedures to misclassify the critical stratum. Simplified approaches also omit the rate of excess pore pressure generation, a parameter strongly influenced by non-plastic fines. This study integrates an extensive in-situ geotechnical and geophysical characterization campaign with nonlinear effective-stress site response analyses in an alluvial deposit located in Samborondon city (Guayaquil, Ecuador). Results highlight that seismic demand is strongly influenced by the non-stationary characteristics of input motions. Findings further emphasize the need for explicit treatment of shear strength derived from empirical in-situ cyclic resistance ratio correlations, which provide a more reliable approach for characterized a model for nonlinear effective stress site response analysis. Keywords: site response analysis, liquefiable alluvial deposits, in-situ tests, cyclic resistance ratio, cyclic stress ratio, liquefaction safety factor