Use of ambient noise records in seismic engineering: An approach to identify potentially liquefiable sites

Abstract

Nakamura and Takizawa (1990) proposed a shear strain model from experimental studies using the horizontal-to-vertical spectral ratio (HVSR) in potentially liquefiable sites. This model allows estimating the maximum surface layer shear strain during an earthquake. In this paper, the model’s experimental verification is performed by analyzing more than 130 earthquakes in two monitoring centers with potentially liquefiable soils. It is concluded that the model may be used to estimate the maximum soil shear strain for earthquakes with peak ground acceleration greater than 5 cm/s2 and when the soil deposit has a soft surface layer over a rigid layer. A methodology to identify potentially liquefiable sites based on this model was proposed and tested in an alluvial soil deposit in Santiago de Cali (Colombia). The results are compared with those obtained from the liquefaction assessment using CPT and Vs, and a good match between the methodologies is observed.