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.
Following the 2010/2011 Canterbury earthquakes the seismic design of buildings with precast concrete panels has received significant attention. Although this form of construction generally performed adequately in Christchurch, there were a considerable number of precast concrete panel connection failures. This observation prompted a review of more than 4700 panel details from 108 buildings to establish representative details used in both existing and new multi-storey and low rise industrial precast concrete buildings in three major New Zealand cities of Auckland, Wellington and Christchurch. Details were collected from precast manufacturers and city councils and were categorised according to type. The detailing and quantity of each reviewed connection type in the sampled data is reported, and advantages and potential deficiencies of each connection type are discussed. The results of this survey provide a better understanding of the relative prevalence of common detailing used in precast concrete panels and guidance for the design of future experimental studies. http://www.nzsee.org.nz/publications/nzsee-quarterly-bulletin/
Colour photograph of the side view of the Hotel Grand Chancellor, leaning to the side even more precariously after the June aftershock.
None
Due to earthquake damage.
This paper outlines the deconstruction, redesign and reconstruction of a 2 storey timber building at the University of Canterbury, in Christchurch, New Zealand. The building consists of post tensioned timber frames and walls for lateral and gravity resistance, and timber concrete composite flooring. Originally a test specimen, the structure was subjected to extreme lateral displacements in the University structural testing laboratory. This large scale test of the structural form showed that post tensioned timber can withstand high levels of drift with little to no structural damage in addition to displaying full recentering characteristics with no residual displacements, a significant contributor to post earthquake cost. The building subsequently has been dismantled and reconstructed as offices for the Structural Timber Innovation Company (STIC). In doing this over 90% of the materials have been recycled which further enhances the sustainability of this construction system. The paper outlines the necessary steps to convert the structure from a test specimen into a functioning office building with minimal wastage and sufficient seismic resistance. The feasibility of recycling the structural system is examined using the key indicators of cost and time.
The Canterbury earthquake series of 2010/2011 has turned the city of Christchurch into a full scale natural laboratory testing the structural and non-structural response of buildings under moderate to very severe earthquake shaking. The lessons learned from this, which have come at great cost socially and economically, are extremely valuable in increasing our understanding of whole building performance in severe earthquakes. Given current initiatives underway on both sides of the Tasman towards developing joint Australasian steel and composite steel/concrete design and construction standards that would span a very wide range of geological conditions and seismic zones, these lessons are relevant to both countries. This paper focusses on the performance of steel framed buildings in Christchurch city, with greatest emphasis on multi-storey buildings, but also covering single storey steel framed buildings and light steel framed housing. It addresses such issues as the magnitude and structural impact of the earthquake series, importance of good detailing, lack of observed column base hinging, the excellent performance of composite floors and it will briefly cover research underway to quantify some of these effects for use in design.
A photograph of a man standing outside an earthquake-damaged building on Tuam Street.
A photograph of buildings on Armagh Street, taken near the intersection of Madras Street.
Filing cabinets broken, a pot plant smashed in an office in the Registry Building.
Filing cabinet draws fallen out and damaged in an office in the Registry Building.
Workers photographed infront of one of temporary buildings being built on the Ilam Oval.
Workers building the floor of one of the temporary classrooms on the Ilam Oval.
Files and boxes fallen off their cubbies in an office in the Registry Building.
A photograph of a partially-demolished building with steel sticking out of the concrete.
A photograph of rubble from a partially-demolished building in the Christchurch central city.
A photograph of rubble from a partially-demolished building in the Christchurch central city.
A photograph of rubble from a partially-demolished building in the Christchurch central city.
A photograph captioned by BeckerFraserPhotos, "The old Telecom building on Hereford Street".
A photograph of a map of CBD building evaluations as of 27 February 2011.
A photograph of waterproof sheets covering parts of the earthquake-damaged Cranmer Courts building.
A crane holds a shipping container against a building while it is being demolished.
Three diggers clearing material from a demolished building on a site on Kilmore Street.
Photograph captioned by BeckerFraserPhotos, "McKenzie and Willis building in Tuam Street".
A photograph of the BNZ building in Cathedral Square, with the Chalice in front.
A photograph of the earthquake damage to a building in the Christchurch central city.
A photograph of a block of buildings along the south side of Gloucester Street.
A photograph of the boarded-up entrance to the Farmers building on Gloucester street.
A photograph of the remains of the McKenzie & Willis building on Tuam Street.
A photograph of the badly-damaged Canterbury Provincial Council buildings, taken from Durham Street.