Performance of masonry buildings during the 2010 Darfield (New Zealand) earthquake (original) (raw)

Performance of unreinforced masonry buildings during the 2010 Darfield (Christchurch, NZ) earthquake

2011

Canterbury earthquakes a detailed campaign of door to door assessments was conducted in a variety of areas of Christchurch to establish the earthquake performance of residential dwellings having masonry veneer as an external cladding attached to a lightweight timber framing system. Specifically, care was taken to include regions of Christchurch which experienced different levels of earthquake shaking in order to allow comparison between the performance of different systems and different shaking intensities. At the time of the inspections the buildings in the Christchurch region had been repeatedly subjected to large earthquakes, presenting an opportunity for insight into the seismic performance of masonry veneer cladding. In total just under 1100 residential dwellings were inspected throughout the wider Christchurch area, of which 24% were constructed using the older nail-on veneer tie system (prior to 1996) and 76% were constructed using screw fixed ties to comply with the new 1996 standards revision (post-1996), with 30% of all inspected houses being of two storey construction. Of the inspected dwellings 27% had some evidence of liquefaction, ground settlement or lateral spreading. Data such as damage level, damage type, crack widths, level of repair required and other parameters were collected during the survey. A description of the data collection processes and a snapshot of the analysis results are presented within.

Performance of unreinforced and retrofitted Masonry buildings during the 2010 Darfield earthquake

Bulletin of the New Zealand Society for Earthquake Engineering

A brief history of Christchurch city is presented, including information on the introduction of unreinforced masonry as a popular building material and an estimate of the number of unreinforced masonry buildings in the Canterbury region currently. A general overview of the failure patterns that were observed in unreinforced clay brick and stone masonry buildings in the Christchurch area after the 2010 Darfield earthquake is provided. Case studies of the damage sustained to five unreinforced masonry (URM) buildings that were unretrofitted at the time of the earthquake, including photographic details, is documented. The performance of eight retrofitted URM buildings is then commented on, detailing the building characteristics and retrofit techniques. The case studies include the use of moment resisting frames, steel strong backs and strapping, diaphragm anchoring, surface bonded fibre reinforced polymer (FRP) sheets and cavity ties.

Seismic Performance of Masonry Buildings in the Christchurch Earthquakes 2010-2011: A Progress Report

2012

Following the Christchurch earthquake of 22 February 2011 a number of researchers were sent to Christchurch, New Zealand to document the damage to masonry buildings as part of "Project Masonry". Coordinated by the Universities of Auckland and Adelaide, researchers came from Australia, New Zealand, Canada, Italy, Portugal and the US. The types of masonry investigated were unreinforced clay brick masonry, unreinforced stone masonry, reinforced concrete masonry, residential masonry veneer and churches; masonry infill was not part of this study. This paper focuses on the progress of the unreinforced masonry (URM) component of Project Masonry. To date the research team has completed raw data collection on over 600 URM buildings in the Christchurch area. The results from this study will be extremely relevant to Australian cities since URM buildings in New Zealand are similar to those in Australia.

Damage Assessment of Unreinforced Stone Masonry Buildings After the 2010-2011 Canterbury Earthquakes

International Journal of Architectural Heritage, 2014

The sequence of earthquakes that has affected Christchurch and Canterbury since September 2010 has caused damage to a great number of buildings of all construction types. Following post-event damage surveys performed between April 2011 and June 2011, an inventory of the stone masonry buildings in Christchurch and surrounding areas was carried out in order to Downloaded by [University of Auckland Library] at 20:24 16 June 2015

The Performance of Unreinforced Masonry Buildings in the 2010/2011 Canterbury Earthquake Swarm

Canterbury earthquakes a detailed campaign of door to door assessments was conducted in a variety of areas of Christchurch to establish the earthquake performance of residential dwellings having masonry veneer as an external cladding attached to a lightweight timber framing system. Specifically, care was taken to include regions of Christchurch which experienced different levels of earthquake shaking in order to allow comparison between the performance of different systems and different shaking intensities. At the time of the inspections the buildings in the Christchurch region had been repeatedly subjected to large earthquakes, presenting an opportunity for insight into the seismic performance of masonry veneer cladding. In total just under 1100 residential dwellings were inspected throughout the wider Christchurch area, of which 24% were constructed using the older nail-on veneer tie system (prior to 1996) and 76% were constructed using screw fixed ties to comply with the new 1996 standards revision (post-1996), with 30% of all inspected houses being of two storey construction. Of the inspected dwellings 27% had some evidence of liquefaction, ground settlement or lateral spreading. Data such as damage level, damage type, crack widths, level of repair required and other parameters were collected during the survey. A description of the data collection processes and a snapshot of the analysis results are presented within.

Characterisation and seismic vulnerability assessment of unreinforced masonry buildings in Dunedin CBD

Bulletin of the New Zealand Society for Earthquake Engineering, 2013

The need for Territorial Authorities (TA) to compile an earthquake-prone building register has been highlighted by the Canterbury Earthquakes Royal Commission and with this in mind the following research was undertaken to enable the characterisation and assessment of potentially earthquake-prone historic unreinforced masonry (URM) buildings in Dunedin. To achieve the research goals, associated technical literature was reviewed and an earthquake-prone building register containing data on 226 URM buildings located in the Dunedin central business district (CBD) area was compiled. Additionally, structural performance of these buildings was also assessed using both the literature suggested initial evaluation procedure and the proposed risk based assessment method. It was estimated that 680 of the existing 750 Dunedin URM buildings are likely to be earthquake-prone and merit detailed assessment. It was also established that the earthquake risk in the city is primarily based on the fact th...

Seismic Characterisation of Unreinforced Masonry Buildings in Auckland, New Zealand

The 2010-2011 Canterbury earthquakes and corresponding Royal Commission reports have resulted in changes to the legislative environment and led to increased public awareness in New Zealand of the earthquake performance of unreinforced masonry (URM) buildings. As a result, building regulators, owners, tenants, users, and heritage advocates will be facing a unique challenge in the near future where improvements and demolitions of URM buildings are expected to occur at an unusually high rate. Auckland is the largest city in New Zealand, and because of the relative prosperity of Auckland during the period 1880-1930 when most URM buildings were being constructed in New Zealand, the city has the greatest stock of URM buildings in the country. Identifying those buildings most at risk in Auckland's large and varied building stock has warranted a rapid field assessment programme supplemented by strategically chosen detailed assessments. Information that can be procured through rapid field inspections includes the building geometric typologies (e.g., heights, building footprint geometry, isolated versus row configuration, and the relationship of these factors to pounding potential), elevation type (e.g., perforated frame versus solid wall), presence of bond beams, wall construction (e.g., solid versus cavity, number of leafs), bond patterns, and basic construction material type (e.g., clay brick versus stone). Furthermore, investigation into the architectural history, heritage status, functional use, and perceived social/community value of Auckland's URM buildings will affect the direction of retrofit strategies and priorities. As the owner of a large and varied portfolio of URM buildings as well as the local organisation responsible for assessing building safety, Auckland Council is developing exemplar inspection, assessment, and prioritisation strategies that will target the risks associated with URM buildings, in particular, so as to preserve and enhance safety, and the economic and community value of these special buildings.

Performance of early masonry, cob and concrete buildings in the 14 November 2016 Kaikoura earthquake

Bulletin of the New Zealand Society for Earthquake Engineering

The performance of historic buildings during the 14 November 2016 Mw7.8 Kaikoura, New Zealand earthquake is reported, focusing on early stone and clay brick masonry buildings, vintage concrete structures, cob cottages, and the non-structural masonry chimneys and veneers of buildings located in the upper part of the South Island (Marlborough and North Canterbury regions). To better document structural response, the intensity of horizontal and vertical ground motion from the nearest recording station is graphically placed alongside the assessed level of damage. In response to numerous strong earthquakes that have previously occurred in the area a large number of highly vulnerable buildings or non-structural building components were previously either seismically retrofitted or demolished, thereby reducing the level of damage and loss of life during the 2016 Kaikoura earthquake. Seismically retrofitted stone and clay brick masonry buildings and cob cottages exhibited good performance, w...