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Images for bw; more images...

Images, eqnz.chch.2010

Took this back in September after the Canterbury quake - gives a different perspective on how powerful this really was.

Images, eqnz.chch.2010

The twisted and buckled bridge over the river. View looking down the bridge. Damaged from the Christchurch Earthquake Twitter | Facebook |

Images, eqnz.chch.2010

Selective colour full size view from one of my previous shots. Edgeware Road, Christchurch. Damaged from the Christchurch Earthquake Twitter | Facebook |

Images, eqnz.chch.2010

Hotel Grand Chancellor on verge of collapse but still standing after the 6.3 magnitude quake hit Christchurch on 22 February 2011 because of concrete being poured into the lower floors.

Images, eqnz.chch.2010

Tell me... Why This is the path I'll never tread These are the dreams I'll dream instead This is the joy that's seldom spread These are the tears... The tears we shed This is the fear This is the dread These are the contents of my head And these are the years that we have spent And this is what they represent And this is how I feel Do you know h...

Images, eqnz.chch.2010

The Cranmer Court demolition started today in Christchurch. The 1876 building was originally a Normal School and was in a derelict state in the early 1980s when it was rescued and converted into apartments. The heritage-listed building was red-stickered after the February 2011 earthquake.

Images, eqnz.chch.2010

The Old Lyttelton Post Office, opened in 1874, showing damage after a series of earthquakes hit Christchurch and Lyttelton over the last 9 months. Processed to capture the "feel" of the sign "Now and Forever Images".

Images, eqnz.chch.2010

A local inspecting the damage to St Lukes Church after the 6.3 quake hit. For whom the bell tolls Time marches on For whom the bell tolls Take a look to the sky just before you die It's the last time you will Blackened roar, massive roar, fills the crumbling sky Shattered goal fills his soul with a ruthless cry Stranger now are his eyes to this...

Research papers, University of Canterbury Library

Using case studies from the 2010-2011 Canterbury, New Zealand earthquake sequence, this study assesses the accuracies of paleoliquefaction back-analysis methods and explores the challenges, techniques, and uncertainties associated with their application. While liquefaction-based back-analyses have been widely used to estimate the magnitudes of paleoearthquakes, their uncertain efficacies continue to significantly affect the computed seismic hazard in regions where they are relied upon. Accordingly, their performance is evaluated herein using liquefaction data from modern earthquakes with known magnitudes. It is shown that when the earthquake source location and mechanism are known, back-analysis methods are capable of accurately deriving seismic parameters from liquefaction evidence. However, because the source location and mechanism are often unknown in paleoseismic studies, and because accurate interpretation is shown to be more difficult in such cases, new analysis techniques are proposed herein. An objective parameter is proposed to geospatially assess the likelihood of any provisional source location, enabling an analyst to more accurately estimate the magnitude of a liquefaction-inducing paleoearthquake. This study demonstrates the application of back-analysis methods, provides insight into their potential accuracies, and provides a framework for performing paleoliquefaction analyses worldwide.

Research papers, University of Canterbury Library

In practice, several competing liquefaction evaluation procedures (LEPs) are used to compute factors of safety against soil liquefaction, often for use within a liquefaction potential index (LPI) framework to assess liquefaction hazard. At present, the influence of the selected LEP on the accuracy of LPI hazard assessment is unknown, and the need for LEP-specific calibrations of the LPI hazard scale has never been thoroughly investigated. Therefore, the aim of this study is to assess the efficacy of three CPT-based LEPs from the literature, operating within the LPI framework, for predicting the severity of liquefaction manifestation. Utilising more than 7000 liquefaction case studies from the 2010–2011 Canterbury (NZ) earthquake sequence, this study found that: (a) the relationship between liquefaction manifestation severity and computed LPI values is LEP-specific; (b) using a calibrated, LEP-specific hazard scale, the performance of the LPI models is essentially equivalent; and (c) the existing LPI framework has inherent limitations, resulting in inconsistent severity predictions against field observations for certain soil profiles, regardless of which LEP is used. It is unlikely that revisions of the LEPs will completely resolve these erroneous assessments. Rather, a revised index which more adequately accounts for the mechanics of liquefaction manifestation is needed.

Research papers, University of Canterbury Library

Data from the 2010-2011 Canterbury earthquake sequence (CES) provides an unprecedented opportunity to assess and advance the current state of practice for evaluating liquefaction triggering. Towards this end, select case histories from the CES are used herein to assess the predictive capabilities of three alternative CPT-based simplified liquefaction evaluation procedures: Robertson and Wride (1998); Moss et al. (2006); and Idriss and Boulanger (2008). Additionally, the Liquefaction Potential Index (LPI) framework for predicting the severity of surficial liquefaction manifestations is also used to assess the predictive capabilities of the liquefaction evaluation procedures. Although it is not without limitations, use of the LPI framework for this purpose circumvents the need for selecting “critical” layers and their representative properties for study sites, which inherently involves subjectivity and thus has been a point of contention among researchers. It was found that while all the assessed liquefaction triggering evaluation procedures performed well for the parameter ranges of the sites analyzed, the procedure proposed by Idriss and Boulanger (2008) yielded predictions that are more consistent with field observations than the other procedures. However, use of the Idriss and Boulanger (2008) procedure in conjunction with a Christchurch-specific correlation to estimate fines content showed a decreased performance relative to using a generic fines content correlation. As a result, the fines correction for the Idriss and Boulanger (2008) procedure needs further study.

Images, eqnz.chch.2010

The Cathedral of the Blessed Sacrament, Christcurch, after the 6.3 magnitude quake on 22 February 2011. When The Angels Fall Take your father's cross Gently from the wall A shadow still remaining See the churches fall In mighty arcs of sound And all that they're containing Yet all the rugged souls Looking for their lost homes Shuffle to...

Research papers, University of Canterbury Library

The focus of the study presented herein is an assessment of the relative efficacy of recent Cone Penetration Test (CPT) and small strain shear wave velocity (Vs) based variants of the simplified procedure. Towards this end Receiver Operating Characteristic (ROC) analyses were performed on the CPT- and Vs-based procedures using the field case history databases from which the respective procedures were developed. The ROC analyses show that Factors of Safety (FS) against liquefaction computed using the most recent Vs-based simplified procedure is better able to separate the “liquefaction” from the “no liquefaction” case histories in the Vs liquefaction database than the CPT-based procedure is able to separate the “liquefaction” from the “no liquefaction” case histories in the CPT liquefaction database. However, this finding somewhat contradicts the assessed predictive capabilities of the CPT- and Vs-based procedures as quantified using select, high quality liquefaction case histories from the 20102011 Canterbury, New Zealand, Earthquake Sequence (CES), wherein the CPT-based procedure was found to yield more accurate predictions. The dichotomy of these findings may result from the fact that different liquefaction field case history databases were used in the respective ROC analyses for Vs and CPT, while the same case histories were used to evaluate both the CPT- and Vs-based procedures.