Liquefaction-Induced Ground-Surface Disruption

Abstract

Although liquefaction is a major cause of earthquake damage, little harm occurs unless the liquefied condition leads to some form of ground disruption or ground failure. Thus, the ability to accurately predict potential for ground-surface disruption is a major concern for geotechnologists charged with the safe siting of constructed works. In 1985 Ishihara presented preliminary empirical criteria to assess the potential for ground-surface disruption at liquefaction sites. Those criteria are based on relationships between the thickness of liquefiable sediment beneath a site and the thickness of overlying nonliquefiable soil. The purpose of this study is to further evaluate and verify Ishihara's criteria by testing them against thicknesses calculated from a wide range of earthquake and site conditions. The newly developed data lead to the following conclusions: (1) For sites not susceptible to ground oscillation or lateral spread, the thickness bounds proposed by Ishihara appear valid; (2) for sites susceptible to ground oscillation or lateral spread, the bounds suggested by Ishihara are not valid for the prediction of ground-surface disruption.