Following the release of a new information paper on earthquake engineering, the media have examined new challenges in building safe structures.

The paper,  released this week by the Royal Society of New Zealand, was titled “The Canterbury earthquakes: Answers to critical questions about buildings”. The document represented input from several expert groups -the Royal Society of New Zealand, the Institution of Professional Engineers New Zealand, the Structural Engineering Society New Zealand, the New Zealand Geotechnical Society and the New Zealand Society for Earthquake Engineering.

The paper answers questions such as ‘What is an earthquake prone building?’, ‘Why did buildings collapse in these earthquakes?’, and ‘Given that a building has been through one earthquake, how do we know how much of its “earthquake life” has been used up?’

The Science Media Centre held an online briefing to launch the paper, audio and more information are available here. The information paper itself can be found here.

The information paper has promoted media coverage of the engineering and social considerations involved in the Christchurch rebuild.

Media Coverage:

NZPA (published in the New Zealand Herald, The Otago Daily Times, National Business Review, Stuff.co.nz) : Some Christchurch buildings may be regarded as “uninsurable”

3News: New paper provides post-quake building information

9 MSN: Quake impact on design to be outlined

As more buildings in Christchurch are tagged for demolition, NZ Herald reporter Paul Harper looks at what the future holds for the city’s planners and how they might be informed by the Pacific Earthquake Engineering Conference currently being held in Auckland today.

Update: The conference has also received coverage on TV3′s morning show Firstline, which interviewed Canterbury University’s Assoc Prof Rajesh Dhakal, an attendee at the conference.

An excerpt from the Herald (read the article in full here):

…Dr Andy Buchanan, Professor of Civil and Natural Resource Engineering at Canterbury University, said “lots of buildings in the Christchurch earthquake behaved exactly as expected, but they still ended up buggered”.

“We designed buildings to withstand earthquakes with the expectation that they would be damaged. Unfortunately, many were damaged so badly that they will have to be pulled down,” he told the Science Media Centre.

“Looking to the future, what we have to do now within the research community is to start designing buildings so that no matter how big the earthquake, buildings won’t be damaged. This is the new paradigm. There are ways of doing this. We know how to do it, we just haven’t started doing it yet.”

Engineers are calling for a rethink in building design and standards in the wake of the Christchurch earthquakes. Designing to save buildings as well as lives would improve the resilience of crucial infrastructure following high magnitude quakes.

A major gathering of earthquake engineers from New Zealand and overseas kicks off in Auckland tomorrow (14-16 April). The Pacific Conference on Earthquake Engineering takes place once every four years, bringing together over 300 geotechnical experts, seismologists and engineers from NZ and abroad. Its theme this year is ‘Building an Earthquake Resilient Society’. The conference, which has been in the planning stages since before the September quake, has been adapted to address major issues emerging from Christchurch, including:

• New perspectives in seismic hazard: from observation to quantification
• Advances in seismic retrofit of reinforced concrete buildings
• Engineering seismology: ground and site effects, seismic hazard and risk analyses
• Social-economic issues: human behaviour, education, insurance and public policy
• Geotechnical earthquake engineering: soils, liquefaction, foundation and soil-structure interaction
• Structural engineering: design of buildings, bridges, lifeline structures
• Lessons learned from recent earthquakes

In the lead up to the event, the Science Media Centre gathered comment from earthquake engineers about the challenges ahead.

To talk to these or other engineering experts, or for more information, contact the SMC (NZ).

Assoc Prof Greg MacRae, earthquake engineer at Canterbury University, comments:

“The most important factor to consider during rebuilding is seismic sustainability. That means that we build our structures so that we protect our infrastructure during a major earthquake.

“At at the moment we are building to protect lives, which means after a major earthquake like this, we expect this kind of damage.

“We can change our focus, and build to protect our infrastructure as well, using advanced technologies that are available for all materials.

“People have a choice. They can design and rebuild using 1980s technology, and they’ll get the kind of results we’ve seen. Or they can use modern technology and get very little damage.

“Some of these new technologies cost the same or less than existing construction techniques. Some of these, like base isolation, have been around for a number of years and are well-proven. Some are less robust, and require more extensive testing and research.

“However, when you’ve got that choice, I think it’s a no-brainer. The barrier to implementation is largely ignorance. A lot of it has also been lack of will. People have never really believed that an earthquake could occur here in Christchurch.”

Prof Michael Pender, geotechnical engineer at Auckland University, comments:

“[From a structural perspective] the MAJOR casualty after the September 04 earthquake was house foundations. The susceptibility of these to lateral spreading was emphasised again after February 22. We need revised standards for construction, and methods of site investigation that flag the risk of liquefaction.

“Another major casualty of both earthquakes was unreinforced masonry buildings. We have known about this problem since the 1931 Napier earthquake. We have worked at developing solutions but, with the benefit of hindsight, clearly with not enough urgency. There still remains this major problem in nearly every NZ city and town.

“During rebuilding, there will be an excellent opportunity for collaborative endeavours between the structural and geotechnical engineering teams. We have structural and foundation details of the buildings subjected to the earthquakes. We have soil profile details for the central business district. We have a reasonably good idea of the ground motions the structures were subjected to. We know how the structures and foundations behaved. This provides an important opportunity to analyse the behaviour of the structures and foundations, particularly those that performed well.

“These insights will be an ideal springboard for re-design. But to get best benefit it needs, as I said above, to be a joint geotechnical – structural endeavour. In other words, we need to considering the integrated design of structure-foundation systems, and not the design of a foundation to support a particular structure.

“From the engineering perspective, we can say that the two earthquakes have provided us with an enormous pool of data about the response of engineering systems. In other words, we are the beneficiaries of outputs from a huge natural laboratory. What we need to do now is winnow this information to obtain the best understanding of how to go forward.”

Dr Andy Buchanan, Prof of Civil and Natural Resource Engineering at Canterbury University comments:

“Lots of buildings in the Christchurch earthquake behaved exactly as expected, but they still ended up buggered.

“We designed buildings to withstand earthquakes with the expectation that they would be damaged. Unfortunately, many were damaged so badly that they will have to be pulled down.

“Looking to the future, what we have to do now within the research community is to start designing buildings so that no matter how big the earthquake, buildings won’t be damaged. This is the new paradigm. There are ways of doing this. We know how to do it, we just haven’t started doing it yet.”

Dr Charles Clifton, Assoc. Professor of Civil Engineering at Auckland University comments:

“There are three levels of earthquake design for modern structures (post 1975 approx). The first (serviceability limit state level) is the level of earthquake expected more than once during the lifetime of the structure, for which the structure is expected to remain fully functional. The second (ultimate limit state level) is the level at which a typical structure is expected to undergo controlled damage but must remain standing and allow evacuation. It is also likely to be repairable afterwards although this is not an explicit requirement of current design practice. The third (maximum considered event [MCE] level) is the strongest earthquake expected at that location and for which a modern structure should remain standing but will suffer considerable structural damage.

“For most of the Christchurch CBD the intensity of this earthquake was close to the MCE but the duration was shorter than would have been expected for an MCE event.

“For reinforced concrete multi-story structures, modern buildings remained standing, which meets the criteria for MCE response. However, I would have expected them to be repairable and at least two of the highrise buildings have not met this criterion. There are some specific areas of failure, e.g. shear walls failing in compression, which were not expected.

“Unreinforced masonry buildings were subjected to between 5 and 6 times their design limit so it is surprising there were not more collapses. Retrofitted buildings have performed well, which is very credible given the level of acceleration was some 2.5 to 3 times design level.

“Failure of shear walls in compression and patterns of plastic hinge cracking in reinforced concrete beams (small number of wide cracks instead of larger number of small cracks) and beam elongation causing floor failures and column detachment from floors are problem areas needing addressing in modern concrete structures.

“The intensity of shaking was amongst the highest recorded in a city. It has already led to a rapid review of the current measure of seismicity for Christchurch (the zone (Z) factor), and this is expected to increase.

“However, this shows that the seismology modelling has considerable uncertainties and it is the response of the built environment to the event that is critical. This response must be best understood and improved given that we cannot predict the time or severity of a severe earthquake at a given location in other than general terms.”

Dr Rolando Orense, Senior Lecturer in engineering at Auckland University and specialist in liquefaction, comments:

“There are many methods of remediating the areas affected by liquefaction and prevent re-liquefaction in the future. Densification techniques (increasing the density of soil), making the skeleton of soil particles more stable (through injection of cement grouts and chemicals), dewatering techniques (to lower saturation) and improvement of resistance to deformation (through sheet pile walls, diaphragm walls, etc.) among others. Lateral spreading (near the rivers) can be prevented through compacted walls, stone columns, piles, etc.

“The technology is available and has been implemented in many parts of the world; it is just a question of cost.

“The buildings and residential houses affected by liquefaction can be retrofitted to make them stronger and to resist damage from future liquefaction.”

Dr Peter Stafford is a New Zealander born in Christchurch now working as the Willis Research Fellow RCUK Fellow / Lecturer in Modelling Engineering Risk Department of Civil & Environmental Engineering Imperial College London.

He was born in Christchurch and has family and friends living in the city. He completed his undergraduate degree and his PhD at the University of Canterbury,

He prepared this commentary on yesterday’s earthquake:

A well-developed understanding of seismic hazards and how to construct earthquake-resilient buildings was crucial to avoiding loss of life in September’s 7.1 magnitude earthquake near Christchurch, say scientists who have evaluated the quake damage.

In January, more than 200,000 people were killed when a similarly-sized earthquake struck Haiti. The main difference in quake outcomes – New Zealand building practices that focused on minimising loss of life in earthquakes.

A new Royal Society of New Zealand paper The Darfield Earthquake: The Value of Long-term Research will be released tomorrow and looks at how geological and engineering research has progressed in New Zealand and how it has influenced building practices.

In this Science Media Centre online briefing for journalists, a geologist and an engineer explain how “seismic design” developed in New Zealand from as early as the magnitude 8 Wairarapa earthquake of 1855.

The briefing focuses on the following questions:

- What were the major findings from geological and seismological research that influenced building practices in New Zealand?

- What particular challenges does New Zealand’s geology pose to building engineers?

- What are the priorities for current and future research to make buildings more earthquake-resilient?

- What did building engineers learn from the Darfield earthquake?

Click below to listen to the briefing featuring Professor Martha Savage of Victoria University and Professor Andy Buchanan from the University of Canterbury:

Download the audio here

Kyoto focus in Cancun climate talks

Predictably fraught negotiations appear to have dominated the COP16 climate summit in Cancun, Mexico, as representatives from 190-odd countries try to come to agreement on how to lower greenhouse gas emissions.

The overall goal of the conference is to progress the hastily-drafted Copenhagen Accord that was put together at the tail end of last year’s conference, and build a consensus among developed and developing countries about how to tackle climate change.

Ironically, it was Japan, which hosted the talks that came up with that Protocol, who was in the gun this week at Cancun for its refusal to commit to legally-binding emission cuts beyond 2012. Rather than have countries sign up to a second commitment period under Kyoto, the Japanese want to see a much more expansive deal involving all of the signatories to the Copenhagen Accord.

“[Signatories] to Kyoto only represent 15% of global emissions, but the countries who have signed up to the Copenhagen accord cause 80% of emissions. We want a single binding treaty,” said Japan’s deputy minister for global environment Hideki Minamikawa.

The first commitment period for the Kyoto Protocol ends in 2012, the point by which the developed nations, including New Zealand, are supposed to have reducing their greenhouse gas emissions an average of 5.2% below 1990 levels. Extending Kyoto would leave out the two biggest emitters, the US and China who are not currently party to it. But coming up with a replacement deal involving Accord signatories seems an even more remote prospect than an extended Kyoto…

Three hot years

Meanwhile, the World Meteorological Organisation used Cancun to release its draft annual statement on the status of global climate.

It reported that 2010 is likely to be among the warmest three years since recordings began in 1850 – the other years being 1998 and 2005. NIWA climate scientist Dr Jim Renwick said there were “significant real risks of major negative impacts” in the course of this century as a result of climate change.

“After a small downturn in 2009, greenhouse gas emissions have bounced back in 2010 , continuing the upwards trend seen in the last decade. The extra carbon dioxide will be in the atmosphere for centuries, and sea levels look set to keep rising for a thousand years or more. The sooner the global community seriously tackles this issue, the better. Let’s hope Cancun delivers a positive outcome.”

SMC wrap up on Year of Biodiversity

The world fell far short of its 2010 targets for global biodiversity conservation. Despite a nearly two decades of international efforts, the relentless speed of species loss worldwide not only hasn’t slowed – it continues to accelerate.

2010 also marks the midpoint of New Zealand’s own twenty-year National Biodiversity Strategy. As we round out the International Year of Biodiversity, how are we are measuring up?

In this online Science Media Centre briefing for journalists, Landcare Research ecologist Dr Bill Lee, Department of Conservation officer Dr Avi Holzapfel, and independent biodiversity & sustainability consultant, former Auckland University professor John Craig discuss major challenges, significant trends and weigh in on the prognosis for New Zealand’s unique biodiversity.

SMC Online Briefing:

Where: online and by phone

When: 10:30 am, Tuesday December 7th

Briefing details will be emailed to journalists registered with the SMC.

Engineering for seismic hazards

Three months on from the Darfield earthquake, some Cantabrians face a wait of years before their homes will be fully repaired.

Despite the frustrating delays and disruption for quake victims, scientists contributing to the latest Royal Society of New Zealand Emerging Issues paper suggest the situation could have been far worse.

In a review of the research that has taken place over the last hundred years or so and influenced building standards, they suggest that critical knowledge built up by seismologists and earthquake engineers in New Zealand means lives were were saved in Canterbury when the 7.1 magnitude quake struck.

In a Science Media Centre online briefing for journalists, Victoria University seismologist Professor Martha Savage and University of Canterbury engineer Professor Andy Buchanan look at how building practices evolved to take account of New Zealand’s distinctive seismic hazards and what we can learn from the Canterbury quake to improve the earthquake resilience of our cities.

SMC Online Briefing:

Where: online and by phone

When: 11am, Thursday December 9th

Briefing details will be emailed to journalists registered with the SMC.

The annual Engineering Excellence Awards took place last night in Wellington, in what proved to be a very entertaining (and quite educational) evening.

The awards were set up in 2005 as a way to recognise, and reward, the engineering achievements of both people and organisations in New Zealand.  They are split into two primary groups:

• Product and Project Awards, which recognise achievements in various industry areas, including building and construction, energy systems and transportation infrastructure.  There is also a Supreme Award, which is awarded to the best of the Product and Project winners.
• Awards Recognising People, which recognise innovation leadership, entrepreneurship and young engineers.

Kevin Milne, of Fair Go, was the MC for the night, and presided over an evening of much laughter, good-natured congratulations, and great conversation.  Of course, the projects themselves were also fascinating, and it was an unrivalled opportunity to talk with the people involved.

This year, the winners of each award were as follows (taken from the Engineering Excellence Awards site):

Awards Recognising People:

William Pickering Award for Engineering Leadership
Won by Gavin Cormack.
Sponsored by IPENZ Foundation

New Zealand Engineering Entrepreneur of the Year
Won by Sir Kenneth Stevens.
Sponsored by Aecom

New Zealand Engineering Innovator of the Year
Won by Rory Flemmer.
Sponsored by Beca

New Zealand Young Engineer of the Year
Won by Michael Newcombe.
Sponsored by Roadshare

Award for Excellence in Engineering Journalism
Won by Charmian Smith.

Her article, entitled ‘The anatomy of a city’, can be found here.

Project and Product Awards

Supreme Award for New Zealand Engineering Excellence
Aircraft Hangar Maintenance Docks, Beca
Sponsored by Standards New Zealand

Building and Construction
Foundation System for the Gisborne Police Station, Opus International Consultants
Sponsored by the Department of Building and Housing

Energy Systems
Weta Digital – New Supercomputer Centre, Intellex Ltd
Sponsored by Energy Efficiency and Conservation Authority

Food, Bioprocess and Chemical
Hautapu Lactose Evaporator, Aurecon New Zealand Ltd

Information, Communication, Electronic and Electrical Technology
High Voltage DC Power Distribution for Telecommunications Facilities, Opus International Consultants Ltd

Mechanical and Manufacturing
Aircraft Hangar Maintenance Docks, Beca
Sponsored by Industrial Research Limited

Sustainability and Clean Technology
Meridian Energy Building, Site 7 Kumutoto Plaza, Beca and Dunning Thornton Consultants Ltd
Sponsored by Meridian Energy

Transportation Infrastructure
Northern Busway, Opus International Consultants Ltd, Beca Infrastructure Ltd, Aurecon New Zealand Ltd and Fletcher Construction Company Ltd

Water, Waste and Amenities
Project Storm 2: Dynamic Model Engineering, MWH New Zealand Ltd
Sponsored by Watercare Services Ltd

Eloise Gibson of the New Zealand Herald and Kiran Chug of the Dominion Post report on the top science award given to NZ scientist Professor Peter Hunter at the Royal Society’s annual Science Honours Dinner.

The Rutherford Medal, which comes with $100,000 in prize money,is the country’s top science award, and was given to Professor Hunter in recognition of his work developing the world’s first computer model of a human heart.  Professor Hunter is now director of the Auckland Bioengineering Institute, where work continues to model the other 12 major organ systems of the human body, starting from the genes and building up.

A number of other scientists also scooped awards recognising excellence in technology, earth sciences, leadership, social sciences, and writing, amongst others.

News coverage:

NZ Herald: Revolutionary medical work wins scientist $100,000 prize

Dominion Post: Top science award goes to computer modeller

Anthony Doesburg, of the New Zealand Herald, writes about a report released last month by the British Institution of Mechanical Engineers (IMechE), a large, and venerable, organisation. The report proposed three new ways of postponing the effects of climate change: artificial trees, incorporating photobioreactors into building structures, and solar radiation management.

An excerpt: (read in full here)

“Whereas Dyson’s trees would be specially bred to consume lots of carbon, the British engineers are recommending artificial ones – 100,000 of them at an estimated cost of US$20,000 ($29,000) each – to capture all of Britain’s “non-stationary and dispersed” emissions, at a rate of about 10 tonnes each a day.

“Sorbent (able to collect molecules of another substance) material on the trees’ “leaves” would make them several thousand times more effective at removing carbon dioxide than any natural tree, according to the report. The carbon dioxide would then be stored, most feasibly in depleted oil and gas reservoirs.

“Non-stationary and dispersed emissions make up about half of the global total, the report says. With a fifth of all emissions coming from the transport sector, the logical place to plant artificial trees would be along motorways.”