
Workers operate a drilling rig inside a Terra Probe truck, which has been raised on jacks to make it stable. The photographer comments, "Another completely different company testing what is below the surface to determine what type of foundations new houses will need. This is in one the blue/green area of earthquake shaken Christchurch. Strangely this is 3 metres away from where the other testing was done".
The Mw 6.2 February 22nd 2011 Christchurch earthquake (and others in the 2010-2011 Canterbury sequence) provided a unique opportunity to study the devastating effects of earthquakes first-hand and learn from them for future engineering applications. All major events in the Canterbury earthquake sequence caused widespread liquefaction throughout Christchurch’s eastern suburbs, particularly extensive and severe during the February 22nd event. Along large stretches of the Avon River banks (and to a lesser extent along the Heathcote) significant lateral spreading occurred, affecting bridges and the infrastructure they support. The first stage of this research involved conducting detailed field reconnaissance to document liquefaction and lateral spreading-induced damage to several case study bridges along the Avon River. The case study bridges cover a range of ages and construction types but all are reinforced concrete structures which have relatively short, stiff decks. These factors combined led to a characteristic deformation mechanism involving deck-pinning and abutment back-rotation with consequent damage to the abutment piles and slumping of the approaches. The second stage of the research involved using pseudo-static analysis, a simplified seismic modelling tool, to analyse two of the bridges. An advantage of pseudo-static analysis over more complicated modelling methods is that it uses conventional geotechnical data in its inputs, such as SPT blowcount and CPT cone resistance and local friction. Pseudo-static analysis can also be applied without excessive computational power or specialised knowledge, yet it has been shown to capture the basic mechanisms of pile behaviour. Single pile and whole bridge models were constructed for each bridge, and both cyclic and lateral spreading phases of loading were investigated. Parametric studies were carried out which varied the values of key parameters to identify their influence on pile response, and computed displacements and damages were compared with observations made in the field. It was shown that pseudo-static analysis was able to capture the characteristic damage mechanisms observed in the field, however the treatment of key parameters affecting pile response is of primary importance. Recommendations were made concerning the treatment of these governing parameters controlling pile response. In this way the future application of pseudo-static analysis as a tool for analysing and designing bridge pile foundations in liquefying and laterally spreading soils is enhanced.
In a Christchurch street still covered in liquefaction man weeps over his four-wheel drive car, which has a number plate showing the word 'macho'. Two women who are working at clearing the road of silt watch and one of them observes that 'he's not handling the quake well at all... Keeps getting silt smears on the 4 x 4!' Context - The Christchurch earthquake of 22 February 2011. Liquefaction is a particular problem. There is a point being made here about the 'macho' man who sobs over his car and the two staunch women who get on with the cleaning-up effort. Quantity: 1 digital cartoon(s).
The majority of current procedures used to deduce liquefaction potential of soils rely on empirical methods. These methods have been proven to work in the past, but these methods are known to overestimate the liquefaction potential in certain regions of Christchurch due to a whole range of factors, and the theoretical basis behind these methods cannot be explained scientifically. Critical state soil mechanics theory was chosen to provide an explanation for the soil's behaviour during the undrained shearing. Soils from two sites in Christchurch were characterised at regular intervals for the critical layers and tested for the critical state lines (CSL). Various models and relationships were then used to predict the CSL and compared with the actual CSL. However none of the methods used managed to predict the CSL accurately, and a separate Christchurch exclusive relationship was proposed. The resultant state parameter values could be obtained from shear-wave velocity plots and were then developed into cyclic resistance ratios (CRR). These were subsequently compared with cyclic stress ratios (CSR) from recent Christchurch earthquakes to obtain the factor of safety. This CSL-based approach was compared with other empirical methods and was shown to yield a favourable relationship with visual observations at the sites' locations following the earthquake.
The damaged Christ's College Rowing Club building at Kerrs Reach. The building has visibly slumped to one side. The photographer comments, "This is the sad state of the building after 3 earthquakes has caused the rowing club to sink like a leaky boat".
A worker repairs a leaning power pole in Bexley. The photographer comments, "I was told that this electricity pole in Bexley always leans after every big earthquake. Maybe it might take more than a one man and one shovel to put 'straight'".
A fence along the side of the Avon River near the Retour Restaurant has broken and is leaning towards the river. The photographer comments, "After the Christchurch earthquakes the land moved towards the river Avon and in a lot of places buildings and walls sagged down in the direction of the waterway".
Text reads 'Latest Christchurch East band' The name of the band is 'The Silty Stones' and the band sings 'We can't get no... sa-tis-faction! 'Cos we got more li-qui-faction! And we cry, and we cry, and we try to get by We can't get no sa-tis-faction!' The band are cleaning up the latest liquefaction from around a house and are using their tools as musical instruments. Context: there was a 4.9 magnitude aftershock in Canterbury on December 26th (Boxing Day 2011) The song is a take-off of the 'Rolling Stones' song 'We can't get no satisfaction'. Quantity: 1 digital cartoon(s).
The seismic performance of soil profiles with potentially liquefiable deposits is a complex phenomenon that requires a thorough understanding of the soil properties and ground motion characteristics. The limitations of simplified liquefaction assessment methods have prompted an increase in the use of non-linear dynamic analysis methods. Focusing on onedimensional site response of a soil column, this thesis validated a soil constitutive model using in-situ pore pressure measurements and then assessed the influence of input ground motion characteristics on soil column response using traditional and newly developed metrics. Pore pressure recordings during the Canterbury Earthquake Sequence (CES) in New Zealand were used to validate the PM4Sand constitutive model. Soil profile characterization was key to accurate prediction of excess pore pressure response and accounting for any densification during the CES. Response during multiple earthquakes was captured effectively and cross-layer interaction demonstrated the model capability to capture soil response at the system-level. Synthetic and observed ground motions from the Christchurch earthquake were applied to the validated soil column to quantify the performance of synthetic motions. New metrics were developed to facilitate a robust comparison to assess performance. The synthetic input motions demonstrated a slightly larger acceleration and excess pore pressure response compared to the observed input motions. The results suggest that the synthetic motions may accumulate higher excess pore pressure at a faster rate and with fewer number of cycles in the shear response. This research compares validated soil profile subject to spectrally-matched pulse and non-pulse motions, emphasizing the inclusion of pulse motions with distinctive characteristics in ground motion suites for non-linear dynamic analysis. However, spectral matching may lead to undesired alterations in pulse characteristics. Cumulative absolute velocity and significant duration significantly differed between these two groups compared to the other key characteristics and contributed considerably to the liquefaction response. Unlike the non-pulse motions, not all of the pulse motions triggered liquefaction, likely due to their shorter significant duration. Non-pulse motions developed a greater spatial extent of liquefaction triggering in the soil profile and extended to a greater depth.
An advertising poster outside Minx Dining Room and Bar on Lichfield Street depicts Katy Perry in a bird cage. The photographer comments, "One of the sites you will see on the Christchurch CBD red zone tour".
A man wearing shorts and gumboots stands surrounded by liquefaction beside his collapsing house. He tries to phone the 'Quake helpline' for assistance and gets the response 'You have reached the quake helpline... If you're up to your knees in liquefaction... Press 1. If your house is down around your ears... Press 2. If you're looking for assistance or answers press on'. Context - The increasing frustration and misery of many Christchurch residents who are experiencing huge difficulty getting assistance after months of delays and continuing aftershocks following the Christchurch earthquakes of 4th September, 22 February and the two most recent ones on 13 June. Quantity: 1 digital cartoon(s).
Shows three new houses sinking into liquefaction after another series of strong aftershocks in early January. A sign reads 'Parklands' and an observer confidently asserts that it is safe to rebuild. Context: the suburb of Parklands in north east Christchurch has been badly damaged by liquifaction. Quantity: 1 digital cartoon(s).
The 4 September 2010 Darfield and 22 February 2011 Christchurch earthquakes caused significant damage to Christchurch and surrounding suburbs as a result of the widespread liquefaction and lateral spreading that occurred. Ground surveying-based field investigations were conducted following these two events in order to measure permanent ground displacements in areas significantly affected by lateral spreading. Data was analysed with respect to the distribution of lateral spreading vs. distance from the waterway, and the failure patterns observed. Two types of failure distribution patterns were observed, a typical distributed pattern and an atypical block failure. Differences in lateral spreading measurements along adjacent banks of the Avon River in the area of Dallington were also examined. The spreading patterns between the adjacent banks varied with the respective river geometry and/or geotechnical conditions at the banks.
Liquefaction-induced lateral spreading in Christchurch and surrounding suburbs during the recent Canterbury Earthquake Sequence (2010-2011) caused significant damage to structures and lifelines located in close proximity to streams and rivers. Simplified methods used in current engineering practice for predicting lateral ground displacements exhibit a high degree of epistemic uncertainty, but provide ‘order of magnitude’ estimates to appraise the hazard. We wish to compare model predictions to field measurements in order to assess the model’s capabilities and limitations with respect to Christchurch conditions. The analysis presented focuses on the widely-used empirical model of Youd et al. (2002), developed based on multi-linear regression (MLR) of case history data from lateral spreading occurrence in Japan and the US. Two issues arising from the application of this model to Christchurch were considered: • Small data set of Standard Penetration Test (SPT) and soil gradation indices (fines content FC, and mean grain size, D50) required for input. We attempt to use widely available CPT data with site specific correlations to FC and D50. • Uncertainty associated with the model input parameters and their influence on predicted displacements. This has been investigated for a specific location through a sensitivity analysis.
This report describes the earthquake hazard in Kaikoura district and gives details of historic earthquakes. It includes district-scale (1:250,000) active fault, ground shaking zone, liquefaction and landslide susceptibility maps. The report describes an earthquake scenario for a magnitude 7.0-7.3 Hope Fault earthquake near Kaikoura, and a subsequent local tsunami.
A PDF copy of pages 232-233 of the book Christchurch: The Transitional City Pt IV. The pages document the transitional project 'SVA - The Clean Up'. Photos: Peter Walker, Three Chairs Photography. With permission from Volunteer Army Foundation.
Our Street - Cleaning Up (02.03.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-a...
Our Street - Cleaning Up (03.03.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-a...
Our Street - Porta-loo (03.03.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-are...
Our Street - Cleaning Up (02.03.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-a...
For six weeks after the February 2011 Christchurch earthquake millions of litres of raw sewage - along with lots of liquefaction - poured into the Avon and Heathcote Rivers. A team of biologists quickly got to work to measure the impact of this catastrophe on life in the Heathcote River and as they tell Alison Ballance, they were surprised by what they recorded over the next few months.
Our Garage - Sandbags (27.02.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-area...
Our Street - Cleaning Up (28.02.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-a...
Our Garage - Sandbags (27.02.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-area...
Our Street - Cleaning Up (28.02.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-a...
Our Street - Cleaning Up (28.02.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-a...
Our Street - Sand (27.02.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-area 7 p...
Our Street - Cleaning Up (02.03.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-a...
Our Street - Cleaning Up (28.02.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-a...
Our Street - Sand (27.02.2011) Woolston Christchurch Canterbury New Zealand © 2011 Phil Le Cren Photo Taken With: Canon EOS 1000D + Canon EF/EF-S lenses + 10.1 effective megapixels + 2.5-inch TFT color LCD monitor + Eye-level pentamirror SLR + Live View shooting. + EOS Built-in Sensor cleaning system + Wide-area 7 p...