In the wake of the Canterbury earthquakes, one of the biggest threats to our heritage buildings is the risk of earthquakes and the associated drive to strengthen or demolish buildings. Can Small Town NZ balance the requirements of the EQPB legislation and economic realities of their places? The government’s priority is on safety of building occupants and citizens in the streets. However, maintaining and strengthening privately-owned heritage buildings is often cost prohibitive. Hence, heritage regulation has frequently been perceived as interfering with private property rights, especially when heritage buildings occupy a special place in the community becoming an important place for people (i.e. public benefits are larger than private). We investigate several case studies where building owners have been given green light to demolish heritage listed buildings to make way for modern developments. In two of the case studies developers provided evidence of unaffordable strengthening costs. A new trend that has emerged is a voluntary offer of contributing to an incentive fund to assist with heritage preservation of other buildings. This is a unique example where private owners offer incentives (via council controlled organisations) instead of it being purely the domain of the central or local governments.
Seismic isolation is an effective technology for significantly reducing damage to buildings and building contents. However, its application to light-frame wood buildings has so far been unable to overcome cost and technical barriers such as susceptibility to movement during high-wind loading. The precursor to research in the field of isolation of residential buildings was the 1994 Northridge Earthquake (6.7 MW) in the United States and the 1995 Kobe Earthquake (6.9 MW) in Japan. While only a small number of lives were lost in residential buildings in these events, the economic impact was significant with over half of earthquake recovery costs given to repair and reconstruction of residential building damage. A value case has been explored to highlight the benefits of seismically isolated residential buildings compared to a standard fixed-base dwellings for the Wellington region. Loss data generated by insurance claim information from the 2011 Christchurch Earthquake has been used by researchers to determine vulnerability functions for the current light-frame wood building stock. By further considering the loss attributed to drift and acceleration sensitive components, and a simplified single degree of freedom (SDOF) building model, a method for determining vulnerability functions for seismic isolated buildings was developed. Vulnerability functions were then applied directly in a loss assessment using the GNS developed software, RiskScape. Vulnerability was shown to dramatically reduce for isolated buildings compared to an equivalent fixed-base building and as a result, the monetary savings in a given earthquake scenario were significant. This work is expected to drive further interest for development of solutions for the seismic isolation of residential dwellings, of which one option is further considered and presented herein.
Buildings subject to earthquake shaking will tend to move not only horizontally but also rotate in plan. In-plan rotation is known as “building torsion” and it may occur for a variety of reasons, including stiffness and strength eccentricity and/or torsional effects from ground motions. Methods to consider torsion in structural design standards generally involve analysis of the structure in its elastic state. This is despite the fact that the structural elements can yield, thereby significantly altering the building response and the structural element demands. If demands become too large, the structure may collapse. While a number of studies have been conducted into the behavior of structures considering inelastic building torsion, there appears to be no consensus that one method is better than another and as a result, provisions within current design standards have not adopted recent proposals in the literature. However, the Canterbury Earthquakes Royal Commission recently made the recommendation that provisions to account for inelastic torsional response of buildings be introduced within New Zealand building standards. Consequently, this study examines how and to what extent the torsional response due to system eccentricity may affect the seismic performance of a building and considers what a simple design method should account for. It is concluded that new methods should be simple, be applicable to both the elastic and inelastic range of response, consider bidirectional excitation and include guidance for multi-story systems.
The National Science Challenge ‘Building Better Homes, Towns and Cities’ is currently undertaking work that, in part, identifies and analyses the Waimakariri District Council’s (WMK/Council) organisational practices and process tools. The focus is on determining the processes that made the Residential Red Zone Recovery Plan, 2016 (RRZRP) collaboration process so effective and compares it to the processes used to inform the current Kaiapoi Town Centre Plan - 2028 and Beyond (KTC Plan). This research aims to explore ‘what travelled’ in terms of values, principles, methods, processes and personnel from the RRZRP to the KTC planning process. My research will add depth to this research by examining more closely the KTC Plan’s hearings process, reviewing submissions made, analysing background documents and by conducting five semi-structured interviews with a selection of people who made submissions on the KTC Plan.
The link between community involvement and best recovery outcomes has been acknowledged in literature as well as by humanitarian agencies (Lawther, 2009; Sullivan, 2003). My research has documented WMK’s post-quake community engagement strategy by focusing on their initial response to the earthquake of 2010 and the two-formal plan (RRZRP and KTC Plan) making procedures that succeeded this response.
My research has led me to conclude that WMK was committed to collaborating with their constituents right through the extended post-quake sequence. Iterative face to face or ‘think communications’ combined with the accessibility of all levels of Council staff – including senior management and elected members - gave interested community members the opportunity to discuss and deliberate the proposed plans with the people tasked with preparing them. WMK’s commitment to collaborate is illustrated by the methods they employed to inform their post-quake efforts and plans and by the logic behind the selected methods. Combined the Council’s logic and methods best describe the ‘Waimakariri Way’.
My research suggests that collaborative planning is iterative in nature. It is therefore difficult to establish a specific starting point where collaboration begins as the relationships needed for the collaborative process constantly (re)emerge out of pre-existing relationships. Collaboration seems to be based on an attitude, which means there is no starting ‘point’ as such, rather an amplification for a time of a basic attitude towards the public.
