People stand in front of a damaged house in New Brighton. The upper storey at the front of the house has collapsed onto the floor below. The photographer comments, "This house at 158 Marine Parade, New Brighton, Christchurch was owned by the man leaning on the fence. He lived next door and his daughter lived here. During the earthquake the 2nd storey stayed mainly whole, but the 1st collapsed. Luckily the daughter was in the top storey. She was rescued from the building by neighbours, by climbing out of the window and down a ladder. Another piece of luck is that most of the belongings were stored in boxes in the garage at the front. Though the garage also collapsed the boxes appear intact. The owner had tried to sell it previously without success".
A two-storey wooden house on Montreal Street.
A photograph of the earthquake damage to a house on Woodham Road. The bottom storey of the house has crumbled, bringing the top storey to the ground. A large pile of bricks and two bay windows now lie beneath the top storey. A red sticker on one of the bay windows indicates that the house is unsafe to enter.
A two-storey house where the ground level walls have been boarded up.
The empty site of what was formerly a two-storey house on Canterbury Street, Lyttelton.
A photograph of the earthquake damage to a Stonehurst Accommodation building on Gloucester. The bottom storey of the building has collapsed and the top two storeys are resting on the rubble. One wall of the building has also collapsed, exposing the rooms inside.
A photograph of the bottom storey of the Observatory tower at the Christchurch Arts Centre. Rubble from the top two storeys of the tower has spilled into the courtyard in front of the tower. A digger was used to clear the rubble away from the building.
Currently there is a worldwide renaissance in timber building design. At the University of Canterbury, new structural systems for commercial multistorey timber buildings have been under development since 2005. These systems incorporate large timber sections connected by high strength post-tensioning tendons, and timber-concrete composite floor systems, and aim to compete with existing structural systems in terms of cost, constructability, operational and seismic performance. The development of post-tensioned timber systems has created a need for improved lateral force design approaches for timber buildings. Current code provisions for seismic design are based on the strength of the structure, and do not adequately account for its deformation. Because timber buildings are often governed by deflection, rather than strength, this can lead to the exceedence of design displacement limitations imposed by New Zealand codes. Therefore, accurate modeling approaches which define both the strength and deformation of post-tensioned timber buildings are required. Furthermore, experimental testing is required to verify the accuracy of these models. This thesis focuses on the development and experimental verification of modeling approaches for the lateral force design of post-tensioned timber frame and wall buildings. The experimentation consisted of uni-direcitonal and bi-directional quasi-static earthquake simulation on a two-thirds scale, two-storey post-tensioned timber frame and wall building with timber-concrete composite floors. The building was subjected to lateral drifts of up to 3% and demonstrated excellent seismic performance, exhibiting little damage. The building was instrumented and analyzed, providing data for the calibration of analytical and numerical models. Analytical and numerical models were developed for frame, wall and floor systems that account for significant deformation components. The models predicted the strength of the structural systems for a given design performance level. The static responses predicted by the models were compared with both experimental data and finite element models to evaluate their accuracy. The frame, wall and floor models were then incorporated into an existing lateral force design procedure known as displacement-based design and used to design several frame and wall structural systems. Predictions of key engineering demand parameters, such as displacement, drift, interstorey shear, interstorey moment and floor accelerations, were compared with the results of dynamic time-history analysis. It was concluded that the numerical and analytical models, presented in this thesis, are a sound basis for determining the lateral response of post-tensioned timber buildings. However, future research is required to further verify and improve these prediction models.
A photograph of the earthquake damage to a Stonehurst Accommodation building on Gloucester Street. The bottom storey of the building has collapsed and the top two storeys are resting on the rubble. The closest wall of the building has also collapsed, exposing the rooms inside.
A photograph of the earthquake damage to a Stonehurst Accommodation building on Gloucester Street. The bottom storey of the building has collapsed and the top two storeys are resting on the rubble. The closest wall of the building has also collapsed, exposing the rooms inside.
Minor damage to tiles over the window of a two-storey house. A crane can be seen in the background.
A damaged brick building. Walls on two sides of the upper storey have collapsed, but the roof is still standing.
A damaged brick building. Walls on two sides of the upper storey have collapsed, but the roof is still standing.
Detail of wooden bracing supporting a two-storey building on the corner of Barbadoes and Worcester Streets, seen through the cordon fence.
A photograph of the earthquake damage to a building on Gloucester Street. The building is part of Stonehurst Accommodation. The bottom storey of the building has collapsed and the top two storeys are resting on the rubble. The closest wall of the building has also collapsed and is resting on top of the rubble to the right of the building.
A photograph of the earthquake damage to Stonehurst Accommodation on Gloucester Street. The bottom storey of the closest building has collapsed and the top two storeys are sitting on a pile of rubble. More rubble has also spilled into the driveway to the right. Wire fencing has been placed around the buildings as a cordon.
One portrait colour digital photograph taken on 25 February 2011 showing the damaged façade of a two storey shop on Norwich Quay. The brick wall has completely fallen off the top storey and crushed a car parked on the footpath outside. Damage to the Lyttelton Hotel is visible to the left of the photo. The design of many older commercial build...
The first stone structure built in Cathedral Square was the small Gothic stone Torlesse building. Situated in the south-west corner of the square, the two storey, three gable dormer windowed buildi…
Wooden bracing supports a two-storey building on the corner of Barbadoes and Worcester Streets. The house has been fenced off and on the walls are the words "Do not demolish".
Wooden bracing supports a two-storey building on the corner of Barbadoes and Worcester Streets. The house has been fenced off and on the walls are the words "Do not demolish".
Detail of wooden bracing supporting a two-storey building on the corner of Barbadoes and Worcester Streets. The house has been fenced off and on the walls are the words "Do not demolish".
A photograph of the earthquake damage to Sullivans Bar and Restaurant on Manchester Street. Brickwork around the windows of the top storey has crumbled. Two skips sit outside for the collection of rubble and other debris.
Rubble in front of a two-storey house on Peterborough Street, the brick side wall of which has fallen away, exposing the rooms inside. Further rubble from a neighbouring house lies in the foreground.
The Iconic Bar on the corner of Manchester and Gloucester Streets. The top storey of the bar has crumbled, and the bricks fallen into the street. Two crushed cars can be seen.
A collapsed two-storey house. The photographer comments, "After we finally made it to our home in the Aranui and Bexley areas, we saw a different level of destruction. Some houses were badly damaged such as this one where the top floor had collapsed onto the ground floor".
A photograph of the Observatory tower at the Christchurch Arts Centre. There are cracks in the masonry of the tower near where the two storeys join. The cracks formed as a result of the 4 September 2010 earthquake.
A photograph of the Observatory tower at the Christchurch Arts Centre. There are cracks in the masonry of the tower near where the two storeys join. The cracks formed as a result of the 4 September 2010 earthquake. Wire fencing has been placed at the entrance to the courtyard in front as a cordon.
An extensive research program is on-going at the University of Canterbury, New Zealand to develop new technologies to permit the construction of multi-storey timber buildings in earthquake prone areas. The system combines engineered timber beams, columns and walls with ductile moment resisting connections using post-tensioned tendons and eventually energy dissipaters. The extensive experimental testing on post-tensioned timber building systems has proved a remarkable lateral response of the proposed solutions. A wide number of post-tensioned timber subassemblies, including beam-column connections, single or coupled walls and column-foundation connections, have been analysed in static or quasi-static tests. This contribution presents the results of the first dynamic tests carried out with a shake-table. Model frame buildings (3-storey and 5-storey) on one-quarter scale were tested on the shake-table to quantify the response of post-tensioned timber frames during real-time earthquake loading. Equivalent viscous damping values were computed for post-tensioned timber frames in order to properly predict their response using numerical models. The dynamic tests were then complemented with quasi-static push and pull tests performed to a 3-storey post-tensioned timber frame. Numerical models were included to compare empirical estimations versus dynamic and quasi-static experimental results. Different techniques to model the dynamic behaviour of post-tensioned timber frames were explored. A sensitivity analysis of alternative damping models and an examination of the influence of designer choices for the post-tensioning force and utilization of column armouring were made. The design procedure for post-tensioned timber frames was summarized and it was applied to two examples. Inter-storey drift, base shear and overturning moments were compared between numerical modelling and predicted/targeted design values.
A photograph of the earthquake damage to the Observatory tower at the Christchurch Arts Centre. The top two storeys of the tower collapsed during the 22 February 2011 earthquake and the rubble spilled into the courtyard in front. A digger was used to clear the rubble away from the building. A tarpaulin has been draped over the top of the tower.
A photograph of the earthquake damage to the Observatory tower at the Christchurch Arts Centre. The top two storeys of the tower collapsed during the 22 February 2011 earthquake and the rubble spilled into the courtyard in front. A digger was used to clear the rubble away from the building. A tarpaulin has been draped over the top of the tower and the roof of the building behind.