Abstract
In general, gravelly soil layers are considered to be less susceptible to liquefy during earthquakes than sandy soil layers. However, traces of liquefaction that occurred in gravelly soil layers are discovered recently.
In this paper, firstly, detailed site investigation was conducted at the site where a diluvial gravelly soil layer might have liquefied during a strong earthquake. As a result, no evidence showing that the gravelly soil layer at the site had liquefied was found. Secondly, relationships between maximum shear stress ratios during earthquakes and penetration resistance were investigated for both liquefied sites and nonliquefied sites. It was revealed that the boundary between liquefied sites and nonliquefied sites could be approximated by existing equations.