Liquefaction effects and associated damages observed at the Wellington CentrePort from the 2016 Kaikoura earthquake

Abstract

Widespread liquefaction occurred in the end-dumped gravelly fills and hydraulically-placed dredged sandy fill at the CentrePort of Wellington as a result of the 14 November 2016 Mw7.8 Kaikoura earthquake. This liquefaction resulted in substantial global (mass) settlement and lateral movement (spreading) of the fills towards the sea, which adversely affected wharf structures and buildings constructed on shallow and deep foundations. This paper presents key observations from the QuakeCoRE-GEER post-earthquake reconnaissance efforts at the CentrePort Wellington. The different materials and methods used to construct the reclaimed land at CentrePort influenced the patterns of observed liquefaction and its effects. Areas of gravel liquefaction at the port are especially important due to the limited number of these case histories in the literature. Liquefaction-induced ground deformations caused the wharves to displace laterally and damage their piles and offloading equipment. Lateral ground extension and differential settlement damaged buildings, whereas buildings in areas of uniform ground settlement without lateral extension performed significantly better.