Probabilistic Assessment of Liquefaction Occurrence in Calcareous Fill Materials of Kawaihae Harbor, Hawaii

Abstract

The simplified shear-wave velocity (Vs)–based procedure of liquefaction potential assessment was basically developed for terrigenous deposits, whereas its applicability for calcareous soils is not fully recognized. The present study used the seismological and geotechnical data of Kawaihae Harbor, the most strategic port of Hawaii, to evaluate conservatism of the currently used simplified procedure for this case history. During the Kiholo Bay 2006 earthquake, the port experienced extensive liquefaction and subsequent ground failure in the dredged fill and natural calcareous deposits. Using the Vs profiles of the subsoil in Kawaihae Harbor, the simplified procedure and the Monte Carlo simulation (MCS) technique were used to evaluate liquefaction potential of the site through deterministic and probabilistic frameworks. The results obtained from the deterministic and the site-specific probabilistic approaches indicate extents of liquefaction occurrence in the shallow depths between 3.5 and 6.5 m. In contrast, probabilistic analysis with the available liquefaction probability--factor of safety (PL-FS) correlations resulted in an unconservative prediction, with the liquefied depth ranging between 5.6 and 6.1 m. Results of this study confirm that the current simplified procedure with either deterministic or site-specific probabilistic frameworks obtained reliable estimation of liquefaction occurrence in the studied site. However, further case histories of liquefaction occurrence in calcareous deposits are required to clarify applicability of the simplified procedure for such materials. Based on the results of the current study, there is still potential for liquefaction occurrence in the studied site during future earthquakes.