Integrating seismic hazard analyses with geotechnical site characterization for liquefaction potential assessment in Kaohsiung area

Probabilistic Seismic Hazard Analysis (PSHA) has been widely used to estimate the ground motion intensity that should be accounted for in structure design. Here, an in-depth PSHA study for Kaohsiung, the metropolitan area in South Taiwan, is carried out. On the other hand, soil liquefaction and subsequent structural damage are usually reported in a catastrophic earthquake event, such as numerous significant incidents of liquefaction in inland alluvial areas during the 1999 Chi-Chi earthquake. A quantitative framework to evaluate earthquake-induced soil liquefaction potential is proposed herein, including earthquake hazard assessment and geotechnical liquefaction evaluation. This framework is further demonstrated with a case study for a thoroughly- investigated site in Kaohsiung. Results show that the liquefaction potential evaluated with existing methods is to some extent dependent on the earthquake hazard in terms of the occurrence probability of large-size earthquakes at the study site. Ground improvement is suggested considering severe consequences of ground failure.