Base isolation is arguably the most reliable method for providing enhanced protection of buildings against earthquake-induced actions, by virtue of a physical separation between the structure and the ground through elements/devices with controlled force capacity, significant lateral deformation capacity and (often) enhanced energy dissipation. Such a design solution has shown its effectiveness in protecting both structural and non-structural components, hence preserving their functionality even in the aftermath of a major seismic event. Despite lead rubber bearings being invented in New Zealand almost forty years ago, the Christchurch Women's hospital was the only isolated building in Christchurch when the Canterbury earthquake sequence struck in 2010/11. Furthermore, a reference code for designing base-isolated buildings in New Zealand is still missing. The absence of a design standard or at least of a consensus on design guidelines is a potential source for a lack of uniformity in terms of performance criteria and compliance design approaches. It may also limit more widespread use of the technology in New Zealand. The present paper provides an overview of the major international codes (American, Japanese and European) for the design of base-isolated buildings. The design performance requirements, the analysis procedures, the design review process and approval/quality control of devices outlined in each code are discussed and their respective pros and cons are compared through a design application on a benchmark building in New Zealand. The results gathered from this comparison are intended to set the basis for the development of guidelines specific for the New Zealand environment.
As a result of the findings and recommendations of the Royal Commission of Inquiry into the Canterbury Earthquake Swarm of 2010-2011 the New Zealand Government has introduced new legislation that will require the mandatory strengthening of all earthquake-prone buildings in New Zealand. An earthquake prone building is currently defined as a building that is less than one third the seismic strength of a new building. If an owner does not wish to strengthen their buildings then they must demolish them. Seismic retrofitting of buildings is a form of property development and as such, the decision to retrofit or not should be based on a robust and soundly conducted feasibility study. Feasibility studies on seismic retrofitting can be particularly challenging for a number of reasons thus making it difficult for owners to make informed and sound decisions relating to their earthquake prone buildings. This paper considers the concept and process of feasibility analysis as applied to earthquake prone buildings and discusses the current challenges posed by such feasibility studies. A number of recommendations are made in an attempt to help develop a best practice model for decision making relating to earthquake prone buildings."
There is a now a rich literature on the connections between digital media, networked computing, and the shaping of urban material cultures. Much less has addressed the post-disaster context, like we face in Christchurch, where it is more a case of re-build rather than re-new. In what follows I suggest that Lev Manovich’s well-known distinction between narrative and database as distinct but related cultural forms is a useful framework for thinking about the Christchurch rebuild, and perhaps urbanism more generally.
The New Zealand city of Christchurch suffered a series of devastating earthquakes in 2010-11 that changed the urban landscape forever. A new rebuilt city is now underway, largely based on the expressed wishes of the populace to see Christchurch return to being a more people-oriented, cycle-friendly city that it was known for in decades past. Currently 7% of commuters cycle to work, supported by a 200km network of mostly conventional on-road painted cycle lanes and off-road shared paths. The new "Major Cycleways" plan aims to develop approximately 100km of high-quality cycling routes throughout the city in 5-7 years. The target audience is an unaccompanied 10-year-old cycling, which requires more separated cycleways and low-volume/speed "neighbourhood greenways" to meet this standard. This presentation summarises the steps undertaken to date to start delivering this network. Various pieces of research have helped to identify the types of infrastructure preferred by those currently not regularly cycling, as well as helping to assess the merits of different route choices. Conceptual cycleway guidelines have now been translated into detailed design principles for the different types of infrastructure being planned. While much of this work is based on successful designs from overseas, including professional advice from Dutch practitioners, an interesting challenge has been to adapt these designs as required to suit local road environments and road user expectations. The first parts of the new network are being rolled out now, with the hope that this will produce an attractive and resilient network for the future population that leads to cycling being a major part of the local way of life.
