
A photograph of liquefaction at a reserve between Greers Road and Harris Crescent in Papanui.
The city of Christchurch and its surrounds experienced widespread damage due to soil liquefaction induced by seismic shaking during the Canterbury earthquake sequence that began in September 2010 with the Mw7.1 Darfield earthquake. Prior to the start of this sequence, the city had a large network of strong motion stations (SMSs) installed, which were able to record a vast database of strong ground motions. This paper uses this database of strong ground motion recordings, observations of liquefaction manifestation at the ground surface, and data from a recently completed extensive geotechnical site investigation program at each SMS to assess a range of liquefaction evaluation procedures at the four SMSs in the Christchurch Central Business District (CBD). In general, the characteristics of the accelerograms recorded at each SMS correlated well with the liquefaction evaluation procedures, with low liquefaction factors of safety predicted at sites with clear liquefaction identifiers in the ground motions. However, at sites that likely liquefied at depth (as indicated by evaluation procedures and/or inferred from the characteristics of the recorded surface accelerograms), the presence of a non-liquefiable crust layer at many of the SMS locations prevented the manifestation of any surface effects. Because of this, there was not a good correlation between surface manifestation and two surface manifestation indices, the Liquefaction Potential Index (LPI) and the Liquefaction Severity Number (LSN).
A photograph of liquefaction on the ground near the Kaiapoi River.
A photograph of liquefaction and surface flooding around a lamp post near Anzac Drive in Bexley.
A photograph of liquefaction near Anzac Drive in Bexley. UC Geology students are out collecting data.
A tombstone submerged in a pile of liquefaction in a cemetery in Christchurch.
Sand volcano of liquefaction silt outside McDonald Hartshorne on Manchester Street.
A photograph of liquefaction on the ground near the Kaiapoi River.
A photograph of liquefaction silt captioned by Paul Corliss, "Avonside and Retreat Roads post earthquake".
Uneven paving and liquefaction on the corner of Durham Street and Armagh Streets.
Flooding and liquefaction in a residential property in Bexley.
A photograph of liquefaction and flooding in a residential street in Christchurch.
A Transfield Services worker digging liquefaction out of a manhole in north-east Christchurch.
Flooding and liquefaction silt on St Johns Street in Woolston.
Liquefaction In Brooklands.
Photograph captioned by Fairfax, "Volunteers help clean up liquefaction on Acland Avenue. Volunteer Shona Green sweeping dust from liquefaction".
A photograph of mud and liquefaction in Hagley Park following the 22 February 2011 earthquake.
A photograph of mud and liquefaction in Hagley Park following the 22 February 2011 earthquake.
A photograph of a pile of liquefaction with animal prints running through it.
A large patch of liquefaction amongst graves and tombstones in a cemetery in Christchurch.
A large patch of liquefaction amongst graves and tombstones in a cemetery in Christchurch.
A large patch of liquefaction amongst graves and tombstones in a cemetery in Christchurch.
A photograph of mud and liquefaction in Hagley Park following the 22 February 2011 earthquake.
Liquefaction silt surrounding a large crack on the side of Ferry Road.
A photograph of cracks and liquefaction in the surface of Hagley Park.
A photograph of liquefaction in a garden on Avonside Drive.
A photograph of cracks and liquefaction in the surface of Hagley Park.
Flooding and liquefaction in a residential property in Bexley.
A photograph captioned by BeckerFraserPhotos, "Flemington Avenue in New Brighton with a digger and a pile of liquefaction. Most of the rest of the liquefaction has now been removed from the street with the help from the Student Volunteer Army".
A photograph captioned by BeckerFraserPhotos, "Liquefaction bubbled up into the shower and the bath after 22nd February and several other aftershocks. This shower has been cleaned several times, but the liquefaction keeps coming back".