A photograph of the earthquake damage to a house in Christchurch. The front and side of the house has collapsed, the bricks and other rubble spilling onto the garden, exposing the rooms inside. Emergency tape has been draped across the front of the property as a cordon.
A photograph of the earthquake damage to the Kenton Chambers on Hereford Street. The bottom right section of the building has collapsed, the bricks and other rubble spilling onto the footpath below. Large cracks have formed between the windows of the building.
Water and liquefaction flows into the Avon River in Richmond. The water level is very high, and the water is cloudy with silt. The photographer comments, "Water from Dudley Creek took a shortcut across the road into the Avon. It doesn't have much of a drop from the road to the river".
Workers on the opposite side of the river stop for the River of Flowers memorial event. The photographer comments, "One year on, Riverside residents gather for a 2 minute silence and to cast flowers in the river. Riverside residents met at the Medway St bridge to commemorate the anniversary of the 22/2/11 quake".
Workers on the opposite side of the river stop for the River of Flowers memorial event. The photographer comments, "One year on, Riverside residents gather for a 2 minute silence and to cast flowers in the river. Riverside residents met at the Medway St bridge to commemorate the anniversary of the 22/2/11 quake".
An aerial photograph of Cambridge Terrace with the cleared PGC site in the upper centre. The photograph was captioned by BeckerFraserPhotos, "The area inside the cordon that is north of the river which encompasses the PGC site and Kilmore Street. The expectation is that this area will soon be outside the cordon".
A photograph of the middle section of the Townsend Telescope. The telescope is in the Observatory at the Christchurch Arts Centre. A plate on the side reads, "T Cook & Sons, 1864, York & London". This image was used by Graeme Kershaw, Technician at the University of Canterbury Department of Physics and Astronomy, to identify the telescope's parts after the 22 February 2011 earthquake.
A photograph of the Stranges Building on the corner of High Street and Lichfield Street. In the background are the Mexican Café and Honey Pot Café buildings. The outer wall of the top storey of the Stranges Building has collapsed and the rubble has spilled onto the footpath below.
A photograph of looking west out a window of the PricewaterhouseCoopers Building on Armagh Street. To the left is the Victoria Apartments with a slight forward lean. Victoria Square is in the centre of the photograph and to the right is the Crowne Plaza Hotel. In the foreground is the Copthorne Hotel.
A photograph of earthquake damage to the Cranmer Centre on the corner of Armagh and Montreal Streets. Large sections of the wall have collapsed, the bricks spilling onto the footpath below. Wire fencing has been placed around the building as a cordon. Scaffolding has been erected up the side of the building to the left.
A photograph of the McKenzie & Willis building on Tuam Street. Small pieces of masonry have crumbled from the pillars between the windows and fallen onto the footpath below. The front door has also shattered and broken glass has spilled onto the footpath in front. The word "clear" has been spray-painted on the bottom-storey window to the left.
A photograph of the earthquake damage to the Christchurch Chinese Methodist Church on Papanui Road. The gable walls have crumbled, bricks spilling onto the ground. The tower has been removed and braced on the ground in front. Cordon fencing has been placed around the building. Parts of the fence have been decorated with hearts and the word 'love'.
A photograph of the middle section of the Townsend Telescope. The telescope is in the Observatory at the Christchurch Arts Centre. A plate on the side reads, "T Cook & Sons, 1864, York & London". This image was used by Graeme Kershaw, Technician at the University of Canterbury Department of Physics and Astronomy, to identify the telescope's parts after the 22 February 2011 earthquake.
Flowers float under the twisted Medway Street Bridge during the River of Flowers memorial event. A colourful cross has been attached to the centre of the bridge. The photographer comments, "One year on, Riverside residents gather for a 2 minute silence and to cast flowers in the river. Riverside residents met at the Medway St bridge to commemorate the anniversary of the 22/2/11 quake".
The full scale, in-situ investigations of instrumented buildings present an excellent opportunity to observe their dynamic response in as-built environment, which includes all the real physical properties of a structure under study and its surroundings. The recorded responses can be used for better understanding of behavior of structures by extracting their dynamic characteristics. It is significantly valuable to examine the behavior of buildings under different excitation scenarios. The trends in dynamic characteristics, such as modal frequencies and damping ratios, thus developed can provide quantitative data for the variations in the behavior of buildings. Moreover, such studies provide invaluable information for the development and calibration of realistic models for the prediction of seismic response of structures in model updating and structural health monitoring studies. This thesis comprises two parts. The first part presents an evaluation of seismic responses of two instrumented three storey RC buildings under a selection of 50 earthquakes and behavioral changes after Ms=7.1 Darfield (2010) and Ms=6.3 Christchurch (2011) earthquakes for an instrumented eight story RC building. The dynamic characteristics of the instrumented buildings were identified using state-of-the-art N4SID system identification technique. Seismic response trends were developed for the three storey instrumented buildings in light of the identified frequencies and the peak response accelerations (PRA). Frequencies were observed to decrease with excitation level while no trends are discernible for the damping ratios. Soil-structure interaction (SSI) effects were also determined to ascertain their contribution in the seismic response. For the eight storey building, it was found through system identification that strong nonlinearities in the structural response occurred and manifested themselves in all identified natural frequencies of the building that exhibited a marked decrease during the strong motion duration compared to the pre-Darfield earthquakes. Evidence of foundation rocking was also found that led to a slight decrease in the identified modal frequencies. Permanent stiffness loss was also observed after the strong motion events. The second part constitutes developing and calibrating finite element model (FEM) of the instrumented three storey RC building with a shear core. A three dimensional FEM of the building is developed in stages to analyze the effect of structural, non-structural components (NSCs) and SSI on the building dynamics. Further to accurately replicate the response of the building following the response trends developed in the first part of the thesis, sensitivity based model updating technique was applied. The FEMs were calibrated by tuning the updating parameters which are stiffnesses of concrete, NSCs and soil. The updating parameters were found to generally follow decreasing trends with the excitation level. Finally, the updated FEM was used in time history analyses to assess the building seismic performance at the serviceability limit state shaking. Overall, this research will contribute towards better understanding and prediction of the behavior of structures subjected to ground motion.
We present initial results from a set of three-dimensional (3D) deterministic earthquake ground motion simulations for the northern Canterbury plains, Christchurch and the Banks Peninsula region, which explicitly incorporate the effects of the surface topography. The simu-lations are done using Hercules, an octree-based finite-element parallel software for solving 3D seismic wave propagation problems in heterogeneous media under kinematic faulting. We describe the efforts undertaken to couple Hercules with the South Island Velocity Model (SIVM), which included changes to the SIVM code in order to allow for single repetitive que-ries and thus achieve a seamless finite-element meshing process within the end-to-end ap-proach adopted in Hercules. We present our selection of the region of interest, which corre-sponds to an area of about 120 km × 120 km, with the 3D model reaching a depth of 60 km. Initial simulation parameters are set for relatively high minimum shear wave velocity and a low maximum frequency, which we are progressively scaling up as computing resources permit. While the effects of topography are typically more important at higher frequencies and low seismic velocities, even at this initial stage of our efforts (with a maximum of 2 Hz and a mini-mum of 500 m/s), it is possible to observe the importance of the topography in the response of some key locations within our model. To highlight these effects we compare the results of the 3D topographic model with respect to those of a flat (squashed) 3D model. We draw rele-vant conclusions from the study of topographic effects during earthquakes for this region and describe our plans for future work.
Orientation: Large-scale events such as disasters, wars and pandemics disrupt the economy by diverging resource allocation, which could alter employment growth within the economy during recovery. Research purpose: The literature on the disaster–economic nexus predominantly considers the aggregate performance of the economy, including the stimulus injection. This research assesses the employment transition following a disaster by removing this stimulus injection and evaluating the economy’s performance during recovery. Motivation for the study: The underlying economy’s performance without the stimulus’ benefit remains primarily unanswered. A single disaster event is used to assess the employment transition to guide future stimulus response for disasters. Research approach/design and method: Canterbury, New Zealand, was affected by a series of earthquakes in 2010–2011 and is used as a single case study. Applying the historical construction–economic relationship, a counterfactual level of economic activity is quantified and compared with official results. Using an input–output model to remove the economy-wide impact from the elevated activity reveals the performance of the underlying economy and employment transition during recovery. Main findings: The results indicate a return to a demand-driven level of building activity 10 years after the disaster. Employment transition is characterised by two distinct periods. The first 5 years are stimulus-driven, while the 5 years that follow are demand-driven from the underlying economy. After the initial period of elevated building activity, construction repositioned to its long-term level near 5% of value add. Practical/managerial implications: The level of building activity could be used to confidently assess the performance of regional economies following a destructive disaster. The study results argue for an incentive to redevelop the affected area as quickly as possible to mitigate the negative effect of the destruction and provide a stimulus for the economy. Contribution/value-add: This study contributes to a growing stream of regional disaster economics research that assesses the economic effect using a single case study.
Damaged pavement on the Williams Street bridge in Kaiapoi. The concrete abutment has risen during the earthquake, forcing its way through the pavement of the footpath into the open.
Damaged pavement on the Williams Street bridge in Kaiapoi. The concrete abutment has risen during the earthquake, forcing its way through the pavement of the footpath into the open.
The remains of a Mexican-style house at the foot of the cliff in Redcliffs. The house was destroyed when the cliff collapsed on it during the 22 February 2011 earthquake.
The east side of the Odeon Theatre, showing the severe damage at the back of the theatre. Shipping containers in front of the building protect Tuam Street in case it falls.
Part of the forecourt at the Shell Shirley petrol station has lifted above the rest, after the underground petrol tanks were pushed upwards by liquefaction. Liquefaction silt covers the lower part of the forecourt.
Building rubble behind cordon fencing at the corner of Salisbury and Montreal Streets. In the background is the Victoria Clock Tower, with the clock stopped at 12:51, the time of the 22 February earthquake.
A line of shipping containers along the base of the cliffs in Sumner protects the road from rockfalls. On the right is the rubble of a house which has partially fallen from the cliff.
Cracks in the plaster of the wall of the reception area of the English department at the University of Canterbury.
Detail of damage to the Cathedral of the Blessed Sacrament. The cross on the roof has been removed.
Detail of damage to the Cathedral of the Blessed Sacrament. The cross on the roof has been removed.
Existing unreinforced masonry (URM) buildings are often composed of traditional construction techniques, with poor connections between walls and diaphragms that results in poor performance when subjected to seismic actions. In these cases the application of the common equivalent static procedure is not applicable because it is not possible to assure “box like” behaviour of the structure. In such conditions the ultimate strength of the structure relies on the behaviour of the macro-elements that compose the deformation mechanisms of the whole structure. These macroelements are a single or combination of structural elements of the structure which are bonded one to each other. The Canterbury earthquake sequence was taken as a reference to estimate the most commonly occurring collapse mechanisms found in New Zealand URM buildings in order to define the most appropriate macroelements.
Paul Nicholls, a member of the University of Canterbury's E-Learning team, in their temporary office in KB02 in Kirkwood Village, the complex of prefabs set up after the earthquakes to provide temporary office and classroom space for the university. The photographer comments, "The e-learning group and the video conferencing team are now located in the Kirkwood Village at the University of Canterbury. It's a very impressive project, about 60 buildings arranged in various configurations with some used for teaching or computer labs, and others as staff offices. We will probably stay here for several years now. Our "techy corner", with Paul waiting for the desk-assembler to come back and put his desk together. My desk is in the corner, and Jess is on the right of the window".
An aerial photograph of the Christchurch central city. The photograph has been captioned by BeckerFraserPhotos, "The central city, with the Majestic Theatre in the centre of the photograph. Lichfield Street runs from bottom left diagonally up the photograph to the top right. The City Council building is prominent in the bottom left corner and Latimer Square in the top left corner".