Seismic Design of Buildings:

Historical Developments and New Horizons


In October 2021, our Built Environment co-leader Prof Tim Sullivan of the University of Canterbury gave a keynote presentation (online) at the 1st International Conference On Recent Advances In Civil And Earthquake Engineering, in Peshawar, Pakistan.

Tim provided a historical review of the way seismic design methods for buildings have evolved, identifying the key changes that have taken place since the early 1900s and examining how recent earthquakes, such as the Canterbury earthquakes in New Zealand, are prompting further developments.

It was shown that seismic design methods have evolved significantly over the last century as our understanding of earthquakes and building response improves and as performance expectations change. The public in New Zealand, and other parts of the world, now expect more than the basic need of life-safety for buildings.

While engineers have responded admirably to these calls for change, Tim questioned the manner with which engineers currently quantify and describe seismic performance. Rather than talking about the return period earthquake that has been used to check different design limit states, Tim argued that future seismic design approaches should enable designers to control risk and quantify modern building performance objectives, such as likelihood of different levels of repair cost and downtime.



Finally, Tim highlighted a number of on-going initiatives to deliver improved seismic performance of buildings in New Zealand, reviewing research related to support whole-of-building design, innovative new structural systems and a new seismic rating system for non-structural elements.  


Impact case study:
Responsive science for national emergencies


September 2021

Once again, 2020-21 provided numerous opportunities for our researchers to provide high quality analysis, advice and public commentary as natural hazard events unfolded, and in the aftermath.

On the morning of September 18th, winds picked up in Auckland and an extreme gust measured at over 120km/hr blew two trucks sideways on the Harbour Bridge, seriously damaging the bridge structure. Several lanes were closed for weeks while repairs took place, leading to lengthy traffic delays and flow-on economic impacts.

Research carried out by NIWA as part of our Weather & Wildfire programme combined a computer model of wind patterns in the harbour with a three-dimensional model of the bridge and found the bridge itself causes the wind to speed up.

“The effects here are very localised and it is really important to understand these better because of the risk high wind events have to a range of assets such as transport and distribution networks and the potential knock-on to economic impacts,” said our Weather & Wildfire programme co-leader Dr Richard Turner in a media story. The research has demonstrated a potential tool that could be a component of a warning system that could halt traffic on the aging bridge and prevent a repeat incident. 

March 5 sequence. Credit: GNS Science

On the morning of March 5th, a M7.2 earthquake struck off the East Coast of the North Island, and an M7.4 and M8.1 followed soon after in the Kermadecs. The quakes triggered a tsunami alert for large parts of Aotearoa New Zealand. Our Earthquake & Tsunami programme co-leader Dr Bill Fry (GNS Science) provided science advice to the National Crisis Management Centre and explained the situation at the press conference fronted by Minister Allan.

The Earthquake & Tsunami team’s synthetic seismicity catalogue had previously been used to test the Tsunami Early Warning (TEW) system being developed under the aligned ‘Rapid Characterisation of Earthquakes and Tsunami’ Endeavour programme, also led by Bill Fry. On March 5th, Bill and other team members used a prototype of the TEW system to inform decision making during the response. Testing using the RNC synthetic catalogue gave the team confidence that the prototype TEW system was appropriate to base scientific advice on. This led to a much quicker input of advice supporting tsunami warning cancellation.

The NEMA post-event report recognised Fry’s contribution, stating: “There was recognised value in having a GNS Science representative (Fry) contributing to the media stand-ups to provide scientific context and advice, and to support the preparation of the Minister for Emergency Management and Acting Director CDEM.” The timing of the March 5 events also created significant interest in our scheduled webinar on the synthetic earthquake catalogue the following week.

Autumn 2021 saw record-breaking drought in parts of the country after an exceptionally dry 2020. Dr Nick Cradock-Henry of Manaaki Whenua Landcare Research, co-leader of our Resilience in Practice programme, has worked extensively with rural communities, agri-business groups and local and central government on natural hazard responses and resilience solutions. Focusing on climate change and drought, Nick’s research in North Canterbury and Marlborough has highlighted the need for applied resilience solutions, including improved monitoring and evaluation, climate services and targeted support. Both in the media, and in a well-attended webinar as part of our rolling symposium on drought (see Impact Case Study: Partnership as the Pathway to Impact), Nick provided informed commentary on the ways that drought can exacerbate existing social and economic vulnerabilities, and evidence-led solutions for drought-affected communities. 

On 28 May MetService issued a red alert for the Canterbury region forecasting 200-300 millimeters which they warned could cause significant flooding. An extreme rainfall event followed, causing extensive, damaging flooding in the South Canterbury area, and resulting in the declaration of a region-wide state of emergency from 30 May to 10 June.

Our researchers provided expert commentary on the floods. In particular, Asaad Shamseldin of The University of Auckland and our Built Environment team provided useful expertise on ‘atmospheric rivers’, how this phenomenon contributed to the devastating impacts in South Canterbury, and the increased frequency of atmospheric river events in a changing climate.


Damage from May 2021 flooding. Credit: Timaru District Council

There has also been public discussion on the description of such events as ‘a 1 in 100 year flood’ or similar, given underlying climate conditions are changing so rapidly. Prof Ilan Noy of Te Herenga Waka Victoria University of Wellington and our Multihazard Risk team, was on the ground in Westport during the devastating floods in July and critiqued this terminology and the false impression it creates regarding likely recurrence.


This case study was submitted to the Ministry of Business, Innovation and Employment as part of our 2020-21 annual reporting. 


Student Profile: Thomas Wallace

Understanding the Physical and Systemic Vulnerabilities in Integrated Stopbank-Dam Catchments

June 2021

I grew up in sunny Nelson, New Zealand where I enjoyed many opportunities to connect with nature through tramping, mountain biking and family holidays in the Marlborough Sounds. In my final year of high school (after causing a lot of stress for Mum) I decided to pursue engineering. During my undergrad, I found a passion for water. Water is essential for life and connects us to the natural environment.

Following my undergrad, my friend connected me with my primary supervisor who took me on for a Masters project, ‘Determining the flood effects of undocumented stopbanks within the Waimea floodplain’. This project helped me to find myself, my passion for research, and a desire to improve the lives of individuals and communities. After my Masters, I sought to continue with research where I am now working toward my PhD at the University of Canterbury investigating vulnerabilities in flood management. My supervisors are Kaley Crawford-Flett, Tom Logan, and Matthew Wilson, and my PhD research is supported by the Resilience Challenge through the Built Environments programme.

During my free time, I enjoy trail running, rogaining (orienteering), alpine skate touring, and reading (in particular Terry Pratchett).

My project

My research is looking at the management of stopbank-dam catchments during floods.

The aim is to help move the management of these structures away from an individual element approach towards a broader system perspective. In particular, focus is being given to deepening the understanding of their operational and physical vulnerabilities. This will contribute to building New Zealand’s flood resilience to flood disasters.

The phases of research will be focused on:

  • Developing the understanding of maturity in operational elements in our flood defence systems so that risk-reducing activities may be more effectively prioritised
  • Using operational vulnerabilities to undertake probabilistic breach flood modelling to determine the exposure of communities and infrastructure to flooding
  • Developing alternative operational strategies and high-level recommendations that are able to reduce the exposure of communities and infrastructure

My research aims to raise the awareness of vulnerabilities in these systems and highlight their potential effects while providing recommendations to address these. This is hoped to shift the management of these catchments towards a more systematic view where the importance of each dam and stopbank, and the connections between them, is acknowledged. A more systematic approach to catchment management will improve resilience and reduce risk in our flood exposed communities. Because although some flooding is normal, we don’t want it to be a dam problem!



Next steps

The next steps for me are to complete my research proposal and begin developing the maturity matrices used to assess the maturity of the operational elements in our flood defence systems. After this, I’ll be undertaking a series of interviews with stakeholders for data collection.



Q & A with Prof Tim Sullivan


Q. Tēnā koe Tim. Can you tell us how you got into Civil Engineering? Were you always interested in building things?

Kia ora! As a kid I always thought I would become an architect. I loved playing with lego and art and thought that being an architect is sort of like combining the two. However, at a school careers expo day I came across a stand on engineering and saw that all the subjects I was taking at school were well suited to engineering. I had heard very little about engineering and so it was a hard choice between engineering and architecture but in the end, I am glad that engineering won out.    

Q.You completed your PhD at the University of Pavia in Italy. What was your PhD topic?

My PhD topic was “The Seismic Design of Frame-Wall Structures”. I loved this very broad PhD topic that was proposed because my main supervisors (Professors Nigel Priestley and Michele Calvi) had begun questioning the traditional approach engineers use to undertake seismic design. They had identified a number of significant shortcomings with traditional thinking and wanted me to help develop a new approach for structures possessing both frames and walls. Frame-wall structures are very common and yet the interaction between frames and walls (and the floors that connect them) is often not well understood.

Q. You lived in Italy for a long time, and became head of the Design Methods Section of the European Centre for Training and Research in Earthquake Engineering, as well as Assistant Professor at the University of Pavia. How did your time there shape your research interests?

My main research interests are in the fundamentals of seismic design, assessment and retrofit. These research interests were really sparked by the critical thinking of my PhD supervisors and the other academics I met at the ROSE School in Pavia. I was given tremendous opportunities to explore and advance my research ideas in the years that followed and these eventually saw me take an interest in loss-assessment and the seismic performance of non-structural elements (SPONSE). A colleague in Pavia, Prof. Andre Filiatrault, was also very influential in the world of SPONSE and working with him certainly helped spark my research into non-structural elements.

Q. Could you briefly summarise the objectives of the Vertical Infrastructure workstream you’re leading in the Built Environment programme?

Our workstream will seek to identify effective means of reducing the damage and disruption caused by future earthquakes. The research will focus on two main research areas; Quantifying and mitigating the risk (in terms of monetary losses, which can be linked to disruption and downtime) associated with different design solutions and building technologies; Supporting the development of design and assessment standards for NZ buildings to enable enhanced performance objectives to be achieved in practice.

Q. What do you hope will come out of your project that will have real world impact for communities? 

The research findings should help engineers and building owners/developers make better-informed choices during building design and assessment that will lead to a more effective use of our resources.

Q. I understand some of your research relates to cost-effective ways to reduce damage and safety risks in buildings. Can you tell us a bit more about that?

Our seismic design and assessment procedures tend to focus on checking that life-safety criteria are met for earthquake shaking intensities that have a certain return period (e.g. 500 years). However, while two buildings may appear to perform equally well at a 500-year return period intensity level, they may perform very differently in other return periods. Differences in performance can arise due to the characteristics of the structural system used (e.g. base-isolated versus steel braced frame buildings) and the types of connections used for non-structural elements (such as ceilings, cladding elements and plasterboard partition walls). Our research in this area is helping to highlight how various design choices and improvements to certain building components can most effectively reduce a building’s seismic risk.

Q. What do you like to do outside work?

I like to spend time with my wife and two kids. I particularly enjoy taking them biking and  playgrounds (gives me an excuse to be a kid again!) I also really love trout fishing and golf with my dad (who can go round under his age!)

Q. What are your future research aspirations?

I would really like to help develop high-performance housing solutions, both low-rise and medium density that are adopted in practice so that we are much less affected by future earthquake events. I’m also keen to continue developing the seismic design and assessment guidelines that help engineers quantify seismic risk and communicate differences in seismic performance more effectively.  



Impact case study:

Model and tools for decision-making


How did Resilience Challenge research have an impact in 2019-2020?


Central to our mission to accelerate natural hazard resilience is the development of new models and tools to quantify hazards and impacts in more realistic ways, providing better assessments of resilience options to decision-makers.

Development of new models is iterative, requiring repeated testing and validation, and their application usually comes at the end of an extensive period of development. RNC is driving meaningful enhancements and innovations in this area, building on work in Phase 1, the Natural Hazards Research Platform, and leveraging existing New Zealand tools such as RiskScape and MERIT.

Updated hazard map for Whakapapa skifield. Credit: GNS Science

Earlier this year, Volcano programme research was integrated into updated hazard posters  for Turoa and Whakapapa skifields, as part of a collaboration with the Department of Conservation. Researchers were also commissioned by Ruapehu Alpine Lifts to produce a technical report on potential lahar hazard in the Whakapapa ski area. A new lahar simulation model, calibrated to previous lahars, was used to estimate the lahar footprint and impact for a range of scenarios. Results of the report have been used to develop safety measures for the new Sky Waka gondola.



Dr Nicky McDonald and colleagues from ME Research produced economic modelling utilising the MERIT (Measuring the Economics of Resilient Infrastructure Tool) capability developed in Phase 1, to assess the economic consequences of fuel outage scenarios following the Auckland-Marsden Point fuel pipeline failure. MERIT was applied to five disruption scenarios, which were then evaluated with and without mitigation options to better understand the impact of disruption and potential value of mitigation actions for New Zealand. The report was prepared for MBIE and findings also contributed to the Board of Inquiry into the 2017 Auckland Fuel Supply Disruption.

As part of our Coastal Flooding project led by Prof Karin Bryan (University of Waikato) and Dr Scott Stephens (NIWA), Dr Shari Gallop and Masters student Akuhata Bailey-Winiata (Te Arawa, Ngāti Tūwharetoa) carried out a summer project to determine the proximity of coastal marae (located within 2km of the coast) to coastal and river waterbodies. They found that 93% of coastal marae are located in the North Island; over 45% of coastal marae are within 200 meters of the coastline; and approximately 70% of coastal marae are located below 20 meters elevation relative to mean sea level. Data will be used as a baseline for determining risk and vulnerability of coastal marae to coastal hazards and sea-level rise. Akuhata’s research was recognised by the New Zealand Coastal Society who awarded him with a Māori and Pacific Island Research Scholarship in July 2020. 

Our Built Environment programme has completed new hazard maps for Bay of Plenty marae (showing fault lines, flooding, geothermal, liquefaction, and tsunami zones) using data from Rotorua City Council and Environment Bay of Plenty. The maps were provided to Te Arawa Lakes Trust collaborators, and are intended to be used to catalyse conversations with marae regarding adaptation and preparedness planning.

Part of our Weather and Wildfire programme involves the modelling of credible ‘what-if’ scenarios. What if the path of ex-Tropical Cyclone Cook (which did much damage in eastern Bay of Plenty in 2017) had been further west and hit our biggest population centre, Auckland? Weather scenario modelling at such fine-grid resolutions is a first for New Zealand, and allows detailed impact modelling to be carried out for a variety of coincident weather, flood, and landslide hazards, building a credible worse-case impact scenario for Auckland and surrounding districts. The early modelling is highlighting the potential for extreme impacts in Auckland, and in other areas well away from Auckland such as the higher elevations of the Kaimai ranges.


New modelling shows what could have happened if ex-TC Cook has tracked over Auckland. Credit: Ian Boutle, 2020

The primary goal of our Earthquake-Tsunami programme is to generate synthetic earthquakes using computer models. Big earthquakes and tsunamis (thankfully) don’t happen very often. A downside of this infrequency is that limited information from past earthquakes makes the job of forecasting future earthquakes and tsunamis challenging. One way of getting over these limitations is to generate synthetic earthquakes over millions of years using computer programs.

The team, led by Dr Bill Fry and Prof Andy Nicol, now has a first iteration of a synthetic seismicity model for New Zealand that incorporates all of the faults used for the National Seismic Hazard Model. This is a successful proof of concept. Further, through extended international collaboration, they have produced basic ground motion predictions from this model. This is an exciting and important stepping-stone in a programme of work that aims to improve future earthquake, tsunami and landslide hazard models in New Zealand.


This case study was submitted to the Ministry of Business, Innovation and Employment as part of our 2019-2020 annual reporting. 


Impact case study:
Partnership as the pathway to impact


How did Resilience Challenge research have an impact in 2019-2020?


Interdisciplinary science is an approach well suited to natural hazards research. It is almost never the case that an exclusively engineering, social, or geological research output is the solution to a resilience need. Multiple perspectives and diverse knowledge must be integrated to facilitate change and achieve impact. The coordination necessary for success requires leadership by those willing to work across the boundaries of their discipline or organisation, and agencies that are willing to partner with others with shared aims.

The Alpine Fault earthquake preparedness and planning programme AF8 (with science support from RNC’s Rural programme and co-funding from CDEM and QuakeCore) continues to be a very effective cross-boundary collaboration. It provides an effective direct pathway for RNC to connect multiple strands of resilience research into practical initiatives to build community-level resilience, and facilitate sector planning and preparedness.

This year the AF8 scenarios, including RNC’s network infrastructure disruption work, have been used by agencies including Fire & Emergency New Zealand, Ministry for Social Development and MBIE in their emergency planning for an Alpine Fault earthquake. For MBIE this includes the development of plans for temporary housing following a national-scale emergency, filling what was a critical gap in national emergency planning.

In September, AF8 hosted the inaugural Tourism Forum in Te Anau, attracting over 100 participants including emergency managers and tourism stakeholders. RNC researchers Prof Tom Wilson and Mat Darling presented on the AF8 science scenario, and tourism and disaster risk research. Minister Peeni Henare (Minister of Civil Defence and Associate Minister of Tourism) attended and is very supportive of AF8’s work.

RNC knowledge of infrastructure network vulnerabilities to multiple natural hazards was integrated in the updated  New Zealand Critical Lifelines Infrastructure National Vulnerability Assessment, published in May 2020. Our Built Environment science leader Assoc Prof Liam Wotherspoon is named as a contributor in the report, along with science leaders Dr Rob Bell and Prof Tom Wilson.


Orewa, the most exposed community to tsunami in the Auckland region

We’ve also seen partnerships delivering greater resilience at a local level. A team of RNC researchers including Dr Emma Hudson-Doyle, Dr Caroline Orchiston, Dr Julia Becker, Lisa McLaren, and Prof David Johnston worked with Rotary and Auckland Council in Orewa, the most exposed community to tsunami in the Auckland region. The citizen-science initiative sought active participation from schools, families and the wider community. Researchers co-designed a survey to understand perceptions of tsunami risk, how prepared the community were for a tsunami, and what they were likely to do in a tsunami event. They then carried out a tsunami evacuation exercise with two schools to observe how long it took for the students to get to high ground, and the factors affecting evacuation times. The community-led initiative was successful at engaging and motivating the residents of Orewa to improve their knowledge and awareness, so that they will be quicker to react following the next long, strong earthquake.

In another tsunami-prone community, Napier City Council have used RNC research to inform the three phases of their Hill Hosts project. The project aims to raise awareness about tsunami risk, and the need for evacuation to Napier Hill following a long or strong earthquake. Hill residents were encouraged to prepare and plan for evacuees; and the council also identified infrastructure and services improvements that would support evacuation. Napier City Council CE Wayne Jack wrote to the research team acknowledging their contribution to the council’s planning and preparedness process.

2019 research co-authored by Scion social fire scientist Lisa Langer  describes wildfire experiences and actions by predominantly Māori residents during the 2011 Karikari Peninsula wildfire, and preparedness before and after the event. Researchers gathered information through semi-structured interviews and a focus group, and found that experiencing the fire encouraged a majority of residents to become better prepared. Whānau and marae also helped to inform and support residents during and after the wildfire.

The paper provides useful recommendations for improving preparedness for wildfires and encouraging safe fire use in rural communities across New Zealand. The success of this study led to Scion social and kairangahau Māori researchers conducting a study with a hapū in the Hokianga to explore what a resilient hapū would look like and to contribute towards planning with Māori communities to reduce natural hazard risk. The Karikari study also helped shape other Scion-led social fire research on targeted protection against extreme fire. The combined research has helped inform Fire & Emergency New Zealand’s Māori engagement policy and contributed to their work with tangata whenua to build resilience of Māori communities.


This case study was submitted to the Ministry of Business, Innovation and Employment as part of our 2019-2020 annual reporting.