Unreinforced stone masonry buildings in New Zealand: Inventory and material characterisation (original) (raw)

An inventory of unreinforced load-bearing stone masonry buildings in New Zealand

Almost all unreinforced stone masonry (URSM) buildings in New Zealand were constructed between 1860 and 1910, typically in regions where natural stone was sourced from local quarries, fields and rivers. These buildings form an important part of the country's architectural heritage, but the performance of URSM buildings during earthquake induced shaking can differ widely due to many aspects related to the constituent construction materials and type of masonry wall cross-section morphology. Consequently, as a step towards gaining greater knowledge of the New Zealand URSM building stock and its features, an exercise was undertaken to identify and document the country-wide URSM building inventory. The compiled building inventory database includes: (i) general building information, such as address, building owner/tenant and building use; (ii) architectural configuration, such as approximate floor area, number of storeys, connection with other buildings, plan and elevation regularity; and (iii) masonry type, such as stone and mortar types, wall texture and wall cross-section morphology. From this exercise it is estimated that there is in excess of 668 URSM buildings currently in existence throughout New Zealand. A large number of these vintage URSM buildings require detailed seismic assessment and the implementation of seismic strengthening interventions in order to conserve and enhance this component of New Zealand's cultural and national identity. The entire stock of identified buildings is reported in the appended annex (688 total), including 20 URSM buildings that were demolished following the Canterbury earthquake sequence.

Comparing New Zealand's unreinforced masonry details with those of other seismically active countries

2006

Unreinforced Masonry (URM) was a very common building material in New Zealand during the later part of the 19 th and early part of the 20 th centuries, up until the 1931 Napier Earthquake. This paper outlines the prevalence and discusses typical details for unreinforced masonry in New Zealand. These findings are contextualised through comparison with the corresponding information from a selection of other seismically active countries. It has been found that New Zealand shares common URM structural details with Australia, the United States, Portugal and Italy. A lack of positive connection between URM walls and timber diaphragms is the most significant problematic detail common to all countries considered in this paper. The next most common detail was a lack of adequate connection between wall leaves, which can lead to out-of-plane failures under earthquake loading. New Zealand's building practices for URM construction are most closely aligned with those found in Australia and the United States.

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

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.

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.

Material properties of existing unreinforced clay brick masonry buildings in New Zealand

The material properties of New Zealand's heritage clay brick unreinforced masonry (URM) buildings were investigated and are reported herein. Material data was collected from a total of 98 New Zealand clay brick URM buildings and a database was compiled that was comprised of various masonry material properties. The intention behind the reporting of information and data presented herein was to provide indicative values to the professional engineering community to aid as preliminary input when undertaking detailed building assessments for cases where in-situ testing and brick and mortar sample extraction are not feasible. The data presented is also used to support the relationships for URM material properties that have been recommended by the authors for incorporation into the next version of the NZSEE seismic assessment guidelines for URM buildings. Although researchers from Europe, USA, India and Australia have previously studied the material properties of clay brick unreinforced masonry, knowledge on New Zealand URM material properties was poor at the time the study commenced. Therefore, a research programme was undertaken that was focused on both in-situ testing and laboratory testing of samples extracted from existing New Zealand clay brick URM buildings.

Seismic Vulnerability of Historic Stone Masonry: A Critical Review

2015

Historic structures are of great importance to current and future generations as they convey historical and cultural aspects of past civilizations. Many historic structures were built of stone masonry in the form of residential and religious buildings, bridges, and monuments. Some of those structures have survived earthquakes for centuries while others collapsed, revealing our lack of knowledge concerning the seismic behaviour of such structures. Historic structures are typically massive and stiff and can be vulnerable to seismic events even ones of low to moderate severity. The seismic vulnerability of such structures arises possibly due to the attraction of high inertial forces, the lack of ductility to dissipate seismic energy and the deterioration and weakening of the material over time. Historic structures were typically built based on the builders’ experience: seismic codes did not exist at the time. To conserve those structures, seismic resistance should be evaluated carefull...