The performance of retrofitted unreinforced masonry (URM) bearing wall buildings in Christchurch is examined, considering ground motion recordings from multiple events. Suggestions for how the experiences in Christchurch might be relevant to retrofit practices common to New Zealand, U.S. and Canada are also provided. Whilst the poor performance of unretrofitted URM buildings in earthquakes is well known, much less is known about how retrofitted URM buildings perform when subjected to strong ground shaking.
A photograph of cracks around a window of the Observatory tower at the Christchurch Arts Centre. The cracks formed as a result of the 4 September 2010 earthquake.
A photograph of cracks around a window of the Observatory tower at the Christchurch Arts Centre. The cracks formed as a result of the 4 September 2010 earthquake.
A photograph of cracks around a window of the Observatory tower at the Christchurch Arts Centre. The cracks formed as a result of the 4 September 2010 earthquake.
A view across Norwich Quay in Lyttelton showing the historic Post Office building and Forbes' Store. Masonry has fallen from the walls of both buildings and the awning of Forbes' Store has collapsed.
A view across Lichfield Street to the historic Mayfair building. Masonry has collapsed from the top storey of the building and the resulting gaps have been weather proofed with timber and building paper.
A view across Lichfield Street to the historic Mayfair building. Masonry has collapsed from the top storey of the building and the resulting gaps have been weather proofed with timber and building paper.
Damage to one of the gables of the Music Centre of Christchurch building on Barbadoes Street. The gaps left by the collapse of the building's masonry have been weather proofed with a tarpaulin.
The west side of the Arts Centre further damaged by an aftershock after the 22 February 2011 earthquake. The tower on the corner has crumbled, and the masonry fallen onto the pavement below.
Damage to one of the gables of the Music Centre of Christchurch building on Barbadoes Street. The gaps left by the collapse of the building's masonry have been weather proofed with a tarpaulin.
A view inside the safety fence surrounding the Cranmer Courts on Montreal Street. Sections of masonry from the building have collapsed onto the footpath. In the background a crane can be seen working on the building.
A photograph of the Durham Street Methodist Church blocked off by wire fencing. The tip of the façade is damaged.
Damage to the former Sumner Borough Council building. The brickwork is badly cracked, and parts of the wall have collapsed, exposing the interior. Shipping containers below the building protect the street from falling masonry.
A video recording of a lecture presented by Professor Rajesh Dhakal and Professor Andy Buchanan as part of the 2011 University of Canterbury Earthquake Lecture Series.
The Seido Karate Shibu building on Barbadoes Street. The top section of the building has been weather proofed with plywood where the masonry has fallen away and its side has been braced with timber.
Damage to the former Sumner Borough Council building. The brickwork is badly cracked, and parts of the wall have collapsed, exposing the interior. Shipping containers below the building protect the street from falling masonry.
Damage to the former Sumner Borough Council building. The brickwork is badly cracked, and parts of the wall have collapsed, exposing the interior. Shipping containers below the building protect the street from falling masonry.
A view across Armagh Street to the Cranmer Centre. Scaffolding has been constructed on the building's Armagh Street face, while on the Montreal Street side masonry from the walls has collapsed onto the road.
This thesis describes the strategies for earthquake strengthening vintage clay bricks unreinforced masonry (URM) buildings. URM buildings are well known to be vulnerable to damage from earthquake-induced lateral forces that may result in partial or full building collapse. The 2010/2011 Canterbury earthquakes are the most recent destructive natural disaster that resulted in the deaths of 185 people. The earthquake events had drawn people’s attention when URM failure and collapse caused about 39 of the fatality. Despite the poor performance of URM buildings during the 2010/2011 Canterbury earthquakes, a number of successful case study buildings were identified and their details research in-depth. In order to discover the successful seismic retrofitting techniques, two case studies of retrofitted historical buildings located in Christchurch, New Zealand i.e. Orion’s URM substations and an iconic Heritage Hotel (aka Old Government Building) was conducted by investigating and evaluating the earthquake performance of the seismic retrofitting technique applied on the buildings prior to the 2010/2011 Canterbury earthquakes and their performance after the earthquakes sequence. The second part of the research reported in this thesis was directed with the primary aim of developing a cost-effective seismic retrofitting technique with minimal interference to the vintage clay-bricks URM buildings. Two retrofitting techniques, (i) near-surface mounted steel wire rope (NSM-SWR) with further investigation on URM wallettes to get deeper understanding the URM in-plane behaviour, and (ii) FRP anchor are reported in this research thesis.
A view across Canterbury Street in Lyttelton to The Volcano Cafe and The Lava Bar. Masonry from the buildings has collapsed onto the footpath, and the site has been cordoned off by a safety fence.
An earthquake-damaged building on Ferry Road. A silver tarpaulin has been used to weather proof a section of the building where masonry has fallen away, and a safety fence has been erected at the building's base.
A view across Cambridge Terrace to the former Canterbury Public Library. Masonry from the building's corners and end gable has fallen onto the footpath below. Wire fencing has been placed around the building as a cordon.
St John the Baptist Church on Latimer Square. The masonry of the bell tower has crumbled onto the lawn, exposing the inside. Damage to the roof and the tip of the gable can also be seen.
A photograph of the earthquake damage to the Canterbury Provincial Chambers. The top section of the building has crumbled, the masonry spilling onto the footpath. Wire fencing has been placed around the building as a cordon.
A view across Hereford Street to the former Canterbury Public Library. Masonry from the building's corners and end gable has fallen onto the footpath and wire fencing has been placed around the building as a cordon.
A photograph of the earthquake damage to the Iconic bar on the corner of Manchester and Gloucester Streets. Large sections of the outer walls have collapsed, the bricks and other rubble spilling onto the footpath below.
A view across Cambridge Terrace to the former Canterbury Public Library. Masonry from the building's corners and end gable has fallen onto the footpath and the base of the building has been cordoned off with wire fencing.
Structural damage to St Elmo Courts with diagonal cracks between the windows of the building. These cracks show that there has been rocking of the masonry piers which means there is no vertical reinforcement provided in the walls.
Following the 2010–2011 Canterbury earthquakes, a renewed focus has been directed across New Zealand to the hazard posed by the country‘s earthquake-vulnerable buildings, namely unreinforced masonry (URM) and reinforced concrete (RC) buildings with potentially nonductile components that have historically performed poorly in large earthquakes. The research reported herein was pursued with the intention of addressing several recommendations made by the Canterbury Earthquakes Royal Commission of Inquiry which were classified into the following general categories: Identification and provisional vulnerability assessment of URM and RC buildings and building components; Testing, assessment, and retrofitting of URM walls loaded out-of-plane, with a particular focus on highly vulnerable URM cavity walls; Testing and assessment of RC frame components, especially those with presumably non-ductile reinforcement detailing; Portfolio management considering risks, regulations, and potential costs for a portfolio that includes several potentially earthquake-vulnerable buildings; and Ongoing investigations and proposed research needs. While the findings from the reported research have implications for seismic assessments of buildings across New Zealand and elsewhere, an emphasis was placed on Auckland given this research program‘s partnership with the Auckland Council, the Auckland region accounting for about a third each of the country‘s population and economic production, and the number and variety of buildings within the Auckland building stock. An additional evaluation of a historic building stock was carried out for select buildings located in Hawke‘s Bay, and additional experimental testing was carried out for select buildings located in Hawke‘s Bay and Christchurch.
Following the 22 February 2011 Christchurch earthquake a comprehensive damage survey of the unreinforced masonry (URM) building stock of Christchurch city, New Zealand was undertaken. Because of the large number of aftershocks associated with both the 2011 Christchurch earthquake and the earlier 4 September 2010 Darfield earthquake, and the close proximity of their epicentres to Christchurch city, this earthquake sequence presented a unique opportunity to assess the performance of URM buildings and the various strengthening methods used in New Zealand to increase the performance of these buildings in earthquakes. Because of the extent of data that was collected, a decision was made to initially focus exclusively on the earthquake performance of URM buildings located in the central business district (CBD) of Christchurch city. The main objectives of the data collection exercise were to document building characteristics and any seismic strengthening methods encountered, and correlate these attributes with observed earthquake damage. In total 370 URM buildings in the CBD were surveyed. Of the surveyed buildings, 62% of all URM buildings had received some form of earthquake strengthening and there was clear evidence that installed earthquake strengthening techniques in general had led to reduced damage levels. The procedure used to collect and process information associated with earthquake damage, general analysis and interpretation of the available survey data for the 370 URM buildings, the performance of earthquake strengthening techniques, and the influence of earthquake strengthening levels on observed damage are reported within. http://15ibmac.com/home/