ABSTRACT
This study evaluates the effect of excess pore water pressure (EPWP) in liquefiable sand sub-layers on the seismic response of the soil profile. A series of shaking table tests were conducted to evaluate the liquefaction performance of a loose to dense subsurface sandy layer on the site effect phenomena. The results confirmed that the liquefied subsurface layer could attenuate or amplify the main characteristics of the seismic site response from 10% to 60%, primarily depending on the level of EPWP and soil softening in the layer. It is important to consider the detrimental effects of liquefaction-induced settlement in these estimations.