Index Geophysics

en-US Geotechnical aspects of the 22 February 2011 Christchurch earthquake

en-US The 22 February 2011, Mw6.2-6.3 Christchurch earthquake is the most costly earthquake to affect New Zealand, causing 181 fatalities and severely damaging thousands of residential and commercial buildings, and most of the city lifelines and infrastructure. This manuscript presents an overview of observed geotechnical aspects of this earthquake as well as some of the completed and on-going research investigations. A unique aspect, which is particularly emphasized, is the severity and spatial extent of liquefaction occurring in native soils. Overall, both the spatial extent and severity of liquefaction in the city was greater than in the preceding 4th September 2010 Darfield earthquake, including numerous areas that liquefied in both events. Liquefaction and lateral spreading, variable over both large and short spatial scales, affected commercial structures in the Central Business District (CBD) in a variety of ways including: total and differential settlements and tilting; punching settlements of structures with shallow foundations; differential movements of components of complex structures; and interaction of adjacent structures via common foundation soils. Liquefaction was most severe in residential areas located to the east of the CBD as a result of stronger ground shaking due to the proximity to the causative fault, a high water table approximately 1m from the surface, and soils with composition and states of high susceptibility and potential for liquefaction. Total and differential settlements, and lateral movements, due to liquefaction and lateral spreading is estimated to have severely compromised 15,000 residential structures, the majority of which otherwise sustained only minor to moderate damage directly due to inertial loading from ground shaking. Liquefaction also had a profound effect on lifelines and other infrastructure, particularly bridge structures, and underground services. Minor damage was also observed at flood stop banks to the north of the city, which were more severely impacted in the 4th September 2010 Darfield earthquake. Due to the large high-frequency ground motion in the Port hills numerous rock falls and landslides also occurred, resulting in several fatalities and rendering some residential areas uninhabitable.

Cubrinovski, Misko

Bradley, Brendon

Wotherspoon, Liam

Green, Russell

Bray, Jonathan

Wood, Clint

Pender, Michael

Allen, John

Bradshaw, Aaron

Rix, Glenn

Taylor, Merrick

Robinson, Kelly

Henderson, Duncan

Giorgini, Simona

Ma, Kun

Winkley, Anna

Zupan, Josh

O’Rourke, Thomas

DePascale, Greg

Wells, Donnald

en-US New Zealand Society for Earthquake Engineering

2011-12-31

info:eu-repo/semantics/article

info:eu-repo/semantics/publishedVersion

en-US Article

application/pdf

https://bulletin.nzsee.org.nz/index.php/bnzsee/article/view/218

10.5459/bnzsee.44.4.205-226

en-US Bulletin of the New Zealand Society for Earthquake Engineering; Vol 44 No 4 (2011); 205-226

2324-1543

1174-9857

eng

https://bulletin.nzsee.org.nz/index.php/bnzsee/article/view/218/205

en-US Copyright (c) 2011 Misko Cubrinovski, Brendon Bradley, Liam Wotherspoon, Russell Green, Jonathan Bray, Clint Wood, Michael Pender, John Allen, Aaron Bradshaw, Glenn Rix, Merrick Taylor, Kelly Robinson, Duncan Henderson, Simona Giorgini, Kun Ma, Anna Winkley, Josh Zupan, Thomas O’Rourke, Greg DePascale, Donnald Wells

en-US https://creativecommons.org/licenses/by/4.0