Effects of Near-Fault Ground Motions on Liquefaction-Induced Building Settlement at the Port of Wellington, New Zealand

Near-fault ground motions can have a significant impact on structural performance. Their effect on liquefaction triggering and their impact on dynamic soil–structure interaction (SSI) effects warrant study. The effects of the 2016 Kaikōura earthquake (Mw 7.8) at the Port of Wellington have been studied by several researchers, and the results of nonlinear dynamic analyses have been shown to provide good insights. This paper investigates the SSI analysis of a representative structure at the Port of Wellington to forward-directivity ground motions from an event on the nearby Wellington fault. Dynamic analyses of a 2-story reinforced concrete frame structure founded on spread footings are performed with the PM4Sand, PM4Silt, and UBCHyst constitutive models within the FLAC finite difference program after calibrating dynamic soil properties using site investigation data. Results of the SSI analyses during the 2016 Kaikōura earthquake are validated using field measurements. Subsequently, the response of the structure is analyzed for a Wellington fault earthquake scenario, characterized by near-fault pulse-like ground motions. Near-fault effects are found to have marginal impacts on liquefaction-induced building settlement.