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REBUILDINGWITH

RESILIENCE

Artifi cial reef for Bunbury

Tunnelling under Sydney Opera House

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COVER STORY

30 Civil Engineers Australia | March 2013

“I love a sunburnt country, a land of sweeping plains, of ragged mountain ranges, of droughts and fl ooding rains. I love her far horizons, I love her jewel-sea, her beauty and her terror – the wide brown land for me! Core of my heart, my country! Land of the rainbow gold, for fl ood and fi re and famine, she pays us back threefold” – Dorothea Mackellar

Dorothea Mackellar penned “My Country” more than 100 years ago, a poem that captures the extremes of the Australian climate – droughts, floods and fires, yet still the Australian community struggles to deal

with these events.It is expected that as Australia’s population grows and its

economy expands, more people and assets will become vul-nerable to the impacts of extreme weather events. But isn’t vulnerability just a design flaw? Does Australia need to change its design standards to ensure infrastructure can withstand the effects of extreme events?

In a submission to the Senate’s Inquiry into recent trends in and preparedness for extreme weather events in January, researchers from Macquarie University’s Risk Frontiers said: “While it is difficult to influence the likelihood of extreme weather events, the exposure and vulnerability components of risk lie within our control. We can decide where and how we build.”

Macquarie University Department of Geography and Envi-ronment Professorial Fellow and Risk Frontiers director Professor John McAneney, and Risk Frontiers catastrophe risk scientist Ryan Crompton conclude that while there is an increasing trend in the cost of natural disasters over time, the main drivers of the increasing trend are demonstrably socio-economic factors, that is more infrastructure and building stock are being built in vulnerable regions.

In his submission to the same inquiry, University of Tasma-nia foundation chair of environmental engineering Professor Stewart Franks said: “There is little empirical evidence that hydroclimatic extremes (flood, drought or bushfire risk) are

any worse today than they have been in the past.“Notwithstanding these observations, there is sufficient con-

cern over future climate change to warrant increased mitigation to the impacts of extreme events, the reduction of vulnerability to their occurrence and the development of increased resilience to such events.”

Franks argued that the recent focus on carbon dioxide (CO2) and anthropogenic climate change has actually distracted the public from discussing mitigation strategies that would provide tangible benefits, as most climate change assessments in recent projects have solely focussed on a project’s contribution to CO2 emissions. He noted the community has access to a range of engineering solutions to climate change mitigation including dams, levees, early flood warning systems, improved irriga-tion systems, and regulatory frameworks for bushfire fuel load reduction programs.

These are some of the solutions Queensland minister for local government, community recovery and resilience David Crisafulli has been tasked with investigating throughout regional Queensland after the past two month’s flood events.

On Monday 25 February, Crisafulli and Queensland premier Campbell Newman passed a Flood Recovery Plan through the state cabinet.

Newman said it was time to end the cycle of constantly re-building after flood events, and was pushing to have Queensland rebuilt to a “flood-proof ” standard.

“We don’t want this cycle to continue so we need to look at flood mitigation. I am calling for a common-sense approach in the way we assess and prioritise reinvestment back into dam-

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Building resilience

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Civil Engineers Australia | March 2013 31

aged infrastructure to reduce the endless rebuilding,” he said.Crisafulli outlined that in the 2013 Flood Recovery Plan, “re-

silience measures we implement will differ from community to community but our commitment to rebuild better than before will remain constant”.

While touring flood affected regions in early February, Cri-safulli noted: “I’ve stood on bridges this past week that have been replaced three times in the past five years. Surely there is an argument that says rather than continue to do the same thing, there is a betterment opportunity to flood-proof this state for a generation.”

At that time, he raised concerns that “betterment” opportuni-ties do not always exist, especially when insurance companies ask for like-for-like replacement of damaged building stock, and even the National Disaster Relief and Recovery arrangements require a like-for-like replacement of damaged infrastructure. At the time of writing, Crisafulli was in talks with the federal government to establish a new protocol to rebuild community infrastructure to a better standard if damaged.

Ahead of a nationwide seminar series on the topic of resilience in buildings and infrastructure for the Chartered Institution of Building Services Engineers and environmental not-for-profit organisation Green Cross Australia, Green Cross head of devel-opment Jeremy Mansfield contends that we face a major dilemma in addressing these questions due to our historical approach to current standards and codes, which emphasise life/safety and meeting minimum standards. Under current code objectives, buildings are primarily designed and built to reduce risks to human life, rather than to minimise damage to the building

(see p.36 “Resilience in buildings” for more from Mansfield). “We need to challenge the current premise that a minimum

standard is good enough, because it has worked in the past and is what the ‘market’ desires,” he said.

“We have to shift to a new paradigm by proactively adopt-ing a philosophy of ‘best practice’ and examining how we can improve assets in terms of their continuity, insurability and long-term value.”

“Betterment” solutions have been carried out previously, and include the 2012 Engineers Australia Engineering Excellence Award finalist “Strengthening Grantham Project”.

In Grantham, Lockyer Valley Regional Council, Cardno, GenEng Solutions and Pensar Civil worked together to provide 121 parcels of flood-free land to eligible residents of the Lockyer Valley who owned land affected by the devastating flooding which occurred on 10 January 2011.

Lockyer Valley mayor Steven Jones told ABC Stateline (Queensland) last month that while not every low-lying de-velopment has an opportunity to move to higher ground, he foresaw increasing financial pressure on those developments that continued to exist in low-lying areas.

“I’m confident you will see [housing relocation programs] happen in many parts of Australia for various reasons. In fact, I think you’ll see more of it here in the Lockyer Valley,” Jones told ABC Stateline.

Relocation is still under way in Christchurch, New Zealand where over 6000 properties were deemed to exist in a residen-tial red zone, where the land was so badly damaged by the earthquakes it is unlikely it can be rebuilt on for a prolonged

COVER STORY

by Danny Cameron

e into infrastructure

Taken during the Heyfield fire in Victoria between 18-20 January, 2013. Photographer Sascha Grant said: “Working between Heyfield,

Seaton and Glenmaggie, while the fire front had passed, many trees remained burning and dangerous. Some structures still remained

under threat.”PHOTO: SASCHA GRANT/FLICKR UNDER A CREATIVE COMMONS LICENSE


COVER STORY


period. The New Zealand government’s criteria for defining areas as residential red zone included considerations for the success of engineering solutions given uncertainty around building redesign, its success and the ongoing seismic activity.

Relocation has also occurred in Brisbane, where after the 2011 flood event, its city council’s Lord Mayor’s Recovery Task Group had allocated $10 million to purchase homes in high-risk flood areas.

While relocation was one solution, after the Queensland Floods Commission of Inquiry final report was tabled last March, 177 recommendations were directed at such issues as improving floodplain management, and related planning and building issues.

Improved building standards stem from these recommenda-tions, and in November the Australian Building Codes Board released a draft standard for the construction of buildings in flood hazard areas. A draft Queensland Development Code establishes a standard minimum freeboard of 300mm with an option for local councils to set a greater freeboard height if they consider it necessary.

The Australian Standard AS/NZS 4505:2012 Garage doors and other large access doors has also been recently introduced after it became clear garage doors were a point of structural weakness during Cyclone Yasi in 2011. The new standard is aligned to two other new standards: AS/NZS 1170.2 Structural actions – Part 2 wind actions and AS/NZS 4055:2012 Wind loads for housing.

Standards Australia chief executive Colin Blair said the new standards helped improve building resilience in extreme events.

Indeed, one of the core functions of the Queensland Reconstruc-tion Authority, established after the 2010/2011 natural disasters, was to ensure that Queensland learn and improve asset resilience. With electricity infrastructure, the authority released Planning for stronger, more resilient electrical infrastructure – Improving the resilience of electrical infrastructure during flooding and cyclones. Regarding electricity distribution for example, a review of networks was recommended after each major event to highlight vulner-abilities found during the event. It was also recommended that major electrical infrastructure be designed and located in areas that withstand a minimum one-in-200 year flood event.

Other critical infrastructure in Queensland, such as the recently completed cyclone emergency management centres, were designed to be located above probable maximum flood levels. In NSW, the new sections of the Pacific Highway are all built higher than the one-in-100 year flood level and snaked above the flood waters during the flood events late last month.

In the Northern Territory, sections of the Kings Highway and the Carpentaria Highway are continually being improved and low-lying sections raised as part of the federal government’s Nation Building Flood Immunity Program. In the past month for example, Allan King and Sons completed a $1.5 million proj-ect to elevate 1km of road, 40km south of Katherine. Another project, a $2 million upgrade to the Carpentaria Highway has also improved flood immunity. The construction project has substantially improved drainage along 12.7km of the highway, in four sections that includes a major floodway.

Engineering and construction company VDM started on a similar project on a 3.2km section of the Bruce Highway in Queensland in December.

A number of projects in the Operation Queenslander recon-struction program have also been built to improved standards and found to be resilient in the latest floods. The Queensland Department of Transport and Main Roads released a report in mid-February on the state of the reconstruction projects after the Australia Day flood event.

The report noted that some projects in the reconstruction program were once again damaged in the recent event, but this was largely due to incomplete works prior to the latest flood event leaving exposed and vulnerable surfaces.

The report did note that repairs around abutments to prevent scouring on the Lockyer Creek Bridges at Gatton and the Laidley Creek Bridge were found to be unaffected by the Australia Day flood event. Repairs to the landslips on Cunningham Highway at Cunningham’s Gap and on Beechmont Road, where major slope stabilisation works were carried out, were also found to be largely unaffected.

It is an area where the department has been active in learning all it can about its infrastructure in light of the extreme events. In particular, Department of Transport and Main Roads deputy chief engineer (structures) Dr Ross Pritchard submitted a paper for publication on the lessons learnt by the department after analysing the 2010-2012 extreme weather events and how the department could improve its infrastructure resilience.

He found that of the $7 billion of damages across state-controlled roads over the period, 85% of costs were related to damage to pavement, including loss of seals and damage to culverts. Around 10% of the cost was for land stabilisation and 5% was for bridge repairs.

In his paper, bridges in particular were singled out because

We have to shift to a new

paradigm by proactively

adopting a philosophy of ‘Best

Practice’ and examining how we

can improve assets in terms of their

continuity, insurability and long-

term value.”

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Pritchard noted bridges play a key role in post disaster recovery, as they are critical infrastructure links that need to be service-able once floodwaters have receded.

“In order for bridges to serve a post disaster function, there is a need for infrastructure design to be robust,” he wrote.

He looked at a number of issues relating to bridge designs and infrastructure resilience in extreme events.

Looking at urban flooding situations, Pritchard noticed an increase in urban debris placing strain on bridge structures during flood events. For example, urban debris in Toowoomba during the 2011 event included cars trapped under bridge structures, while in Brisbane, bridge structures needed to contend with loose pontoons and ferry terminals.

Regarding bridge span lengths, he noted: “Span lengths of bridges and culverts are often selected on economic grounds with little consideration of performance during an extreme event. [For example, in Toowoomba] the hydraulic jumps created in streams were in part caused by the damming of waterways due to small bridge spans being blocked.”

Focussing on the bridge repairs, Pritchard found scour from the floodwaters was a major issue, with traditional abutment protection not suitable for high velocity flow situations, and piers not necessarily designed to withstand scour. He said heavy-duty gabions provide a means of achieving a high performance

abutment scour protection.In the paper, Pritchard also called for more guidance in bridge

design codes around these issues. He called for preventative design improvements in abutment protection as well as strength-ened road approach embankments. He also recommended the Australian Standard AS 5100 Bridge Design Code be amended, with a review to include: flood loads on all bridges; ship impact during floods; debris type in urban areas; debris loads on piers; abutment scour; amourment of stream bed against scour; storm surge events; land use changes; and achievement of post disaster functionality for bridges on critical transport links.

He said engineers have a duty to consider the impact of ex-treme events: “The dilemma of a designer is to meet minimum code standards, provide a cost effective solution for a client and comply with the professional bodies’ code of ethics. These ethical obligations mean designers should not blindly follow a code, but consider what other loads will occur during the life of the infrastructure. The challenge for professional engineers is to have a clear understanding of the damage an extreme event can cause on infrastructure and respond accordingly.”

In its submission to the Inquiry into recent trends in and pre-paredness for extreme weather events, Engineers Australia said: “Most engineering standards and codes do not reflect future climate, meaning that designs produced today do not reflect

The damaged Don Tallon Bridge in Bundaberg post Cyclone Oswald, February 2013. PHOTO: QUEENSLAND DEPARTMENT OF TRANSPORT AND MAIN ROADS

View online


COVER STORY


the performance requirements needed to withstand extreme weather events in future decades.”

Engineers Australia noted that engineering standards and guidelines only change after a significant body of evidence had been established. It said: “Until engineering and infrastructure codes are updated to reflect a changing climate, [there should be initiatives to] promulgate guidelines on appropriate variation of existing codes and standards.”

The submission noted that while the inquiry was focusing on preparation for extreme weather events, “it is more useful to examine the issue as part of climate change adaptation”.

Engineers Australia defined: “Building climate change adapta-tion in infrastructure means increasing its ability to withstand extreme weather events, and more rapidly recover from them.”

The organisation went on to note that adaptation has not yet been deeply embedded in Australia’s infrastructure-related institutional guidelines and regulations.

The submission recommended that Infrastructure Australia uses an adaptation element as a selection criteria for proposed assessments, and adaptation issues are included in statement of works or output requirements in government contracts, both within Australia and internationally.

However, Engineers Australia noted that while the benefits of adaptation are recognised conceptually, “there is very little hard evidence of its economic benefits”.

“Given that financial decisions by infrastructure owners/op-erators are based on cost-benefit analysis, this lack of evidence makes it difficult for it to be factored in,” the submission stated.

Engineers Australia proposed that case studies be developed for actual and hypothetical projects that identify the costs and benefits of adaptation that accrue to the infrastructure owner and operator, and those that accrue to other parties. Engineers Australia also recommended the development of information on the cost-effectiveness of adaptation options and identification of the cost of inaction.

At the Australasian Transport Research Forum in 2011, Queensland Department of Transport and Main Roads economist Wayne Davies argued this same point in his paper Advanced methods of evaluating benefits from improved flood immunity in Queensland.

“Very little literature exists on methods of evaluating the benefits of improving flood immunity through better road infrastructure,” he said.

He also noted: “Many flood immunity projects do not have

An aircrewman looks out over flooded areas as the Black Hawk helicopters from 5th Aviation Regiment provide

aerial assistance to the residents of flood-stricken

Bundaberg.PHOTO: DEFENCE FORCE 1ST JOINT

PUBLIC AFFAIRS UNIT, CPL JANINE FABRE,

COMMONWEALTH OF AUSTRALIA


COVER STORY


enough quantifiable benefits when analysed with current prac-tised cost benefits analysis approaches … the current practised methodology does not sufficiently account for the possible benefits obtainable.”

In the paper he proposed a model to address this issue, but concluded that incorporating wider economic benefits was still required to further enhance the assessment process.

While the costs and benefits of improved resilience in in-frastructure continue to be argued, it is not the only response on the table. In its submission to the Inquiry into recent trends in and preparedness for extreme weather events, the Bureau of Meteorology argued that early warning systems have proven to be a very cost-effective approach to mitigating loss of life and economic losses arising from extreme weather events. Early warning systems help reduce the risk of injury and loss of life and property by providing essential information for emergency management decisions.

However, existing early warning systems can still be improved and the bureau noted that under current arrangements there were “simply too many players with varied responsibilities and capacities for an adequate, let alone future-ready, national

monitoring network”. It argued that improved environmental intelligence is necessary for coping with events as they occur, while also vital for the design and timing of mitigation strategies.

This was similar to a recommendation of the Queensland Floods Science and Engineering and Technology Panel, which included WMAWater director and Australian Rainfall and Runoff revision technical committee chair Mark Babister. The panel released its report in July 2011 titled Understanding floods: Questions and answers.

The report outlined how the increase in flood risk due to climate change, population growth and urbanisation can be managed through a combination of measures including im-proved flood forecasting and warning technologies, better land use planning and enhanced floodplain management.

The report stated: “Flood warning and evacuation plans can be very cost effective and may, in some cases, be the only economically justifiable risk management measure.”

The Environment and Communications References Committee that held the Senate Inquiry into recent trends in and preparedness for extreme weather events is due to table its report by 20 March. To read the report, go to the APH website at http://goo.gl/Q7ehO.

Flood warning and evacuation plans may, in some cases, be the only economically justifiable risk management measure. Pictured here is the Brisbane River in flood in Janurary 2011. PHOTO: JONO HAYSOM/FLICKR, USED UNDER

CREATIVE COMMONS LICENCE


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Resilience in buildings

by Dr Tim Kannegieter

W hile much attention has been focused on the impact of natural disasters on infrastructure, a marked feature of the 2011 Queensland floods was the inability of many industrial and com-

mercial buildings to resume work quickly after flood waters had receded. This was primarily because many building services, traditionally supported by basement infrastructure, had to be repaired first.

Green Cross Australia head of development Jeremy Mansfield has argued that recent disasters require Australia to rethink its approach to building standards. There is a need to go beyond minimum standards to reduce human risk and place a much greater emphasis on outcomes that also minimise damage to buildings and support minimal disruption to business.

“We need to rethink what we mean by cost-effective designs, in light of the need to cope with increasingly adverse future climatic scenarios and the challenges current weather patterns and population growth place on existing infrastructure.”

Mansfield is currently leading a series of half-day seminars across Australia and New Zealand, in conjunction with the Chartered Institution of Building Services Engineers, to address issues of building resilience, supported by presenters from the insurance and building services industries. A key focus of the seminars is to explore the issue of improving resilience in the built environment and addressing mechanisms to apply forethought in the way we design, construct and operate these premises.

According to Mansfield, building for resilience is a critical response that ensures buildings, and the people working in them, have the flexibility to mitigate the impacts of climate change and enable communities to continue to thrive in the face of increased weather extremes.

Mansfield said: “Many current standards and building codes are based on data from up to 30 years ago. New buildings based on current standard may not cope with the anticipated future environment. For example, projections by CSIRO suggest that the annual average number of days above 35°C in Perth could increase from 28 to up to 67 days by 2070. Perth has just sweltered through its hottest summer on record, enduring the longest streak of temperatures above 37°C in its history.”

There are many ways in which buildings can be made more resilient. For example, building services equipment for large commercial buildings are often located in the basement, but where there is a potential for inundation they could be moved

to higher levels in the building. Trying to relocate services after construction would be extremely costly and also enormously disruptive. Similarly, switchboards could be configured to allow emergency generator connection.

The increasing percentage of areas exposed to bushfire risk means that ventilation filters need to be employed more often. In contrast coastal developments, and sites such as those located near the Brisbane River, the prevention of backflows arising from storm surges should be addressed.

Simple solutions in construction such as protecting electrical conduits from becoming sources for water ingress into basement substations and ensuring that suitable capacity is available for stormwater pumps with the controls located at an area accessible in a flood can make the difference between a simple return to business as normal or extended outage and damage.

Mansfield said that many developers and building owners have shied away from taking such measures because the cur-rent industry focus is on minimising upfront costs. However, if insurance premiums are going up, then lifecycle analysis may make many of these measures more compelling.

Since the 2011 Queensland floods, a number of recommen-dations arising from the Queensland Floods Commission of Inquiry have been adopted into the Queensland Development Code. For example, electrical infrastructure in new high-rise buildings are now required to be located above the defined flood level, in line with the 2012 standard on Construction of Buildings in Flood Hazard Areas issued by the Australian Build-ing Codes Board. This new standard will also be referenced by the Building Code of Australia.

According to Mansfield, a key issue that needs to be ad-dressed is the non-retrospective nature of building regulation.

“Given that existing properties form 90% of the building stock, a greater focus is needed on how existing buildings can be made more resilient,” Mansfield said. “We need to examine how we can improve building assets in terms of their continuity, insurability and long-term value.

“How many building owners do a post-disaster audit, rather than just fixing up the obvious damage? We need to be anticipating problems that are increasingly likely to manifest in the future.”

As natural disasters recur, those buildings able to respond faster and with greater business continuity advantages will grow in value compared to others.


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Rebuilding communities and economies

by David Hull

O ver the past three years, Queensland has experienced unprecedented levels of damage and during this time SKM has been working with the state government to quantify these damages and respond.

As a result of the recent flood events, the Queensland gov-ernment is managing some of the largest capital expenditure projects in its history as it works to rebuild the state’s infra-structure. The damage bill for the 2013 natural disaster events currently stands at $2.4 billion.

Queensland premier Campbell Newman is calling for Queensland to be rebuilt to a “flood-proof ” standard. Flood-proofing Queensland may not be as simple as it sounds and will require a holistic and pragmatic approach, the National Climate Change Adaptation Research Facility (NCCARF) said. NCCARF highlights the addition of climate change into the equation and the increasing complexity this creates for the decision making process.

“While we would like to think these events might be once in a lifetime, unfortunately it is clear that history does repeat itself and that communities continue to be at risk of natural disasters. With climate change this risk could further increase or create new risks that put pressure on buildings, infrastructure and communities,” said NCCARF research fellow Dr Sarah Boulter.

“To truly ensure a community is ‘disaster-proof ’ means

anticipating the worst possible scenario. But we may be yet to experience the worst record-breaking disaster.”

Irrespective of climate change, decisions made today lacking suitable foresight in areas such as major infrastructure invest-ment, land use planning and building design, may create greater costs and risks in the future.

Boulter said that what we can do, however, is “adapt” to our changing environment.

“With repeated disasters, significant investment and ongoing financial loss, new approaches may be needed when looking to rebuild communities,” she said.

“Adapting to future disasters is complicated and expensive. However, if government and community are unwilling to face the same risk again, then an exercise of cost-benefit analysis will be essential. What will adaptation cost and how does it compare to the potential damage bill and what are the associ-ated risks to life?”

Take Queensland’s road network. In Monto for example, a $7 million bridge rebuilt after damage three years ago, was gouged again by floodwaters in January this year. Under the current Natural Disaster Relief and Recovery Arrangement guidelines, it may be rebuilt to its pre-disaster state.

Under the betterment clause of the funding guidelines, a road may be restored or replaced to an improved and more disaster resilient state if it can be established that the proposal is cost-effective and will mitigate the impact of future natural disasters.

SKM economist Jon Frew noted that current funding criteria and mechanisms for rebuilding disaster affected assets fail to take into consideration potential re-occurrence and other impacts on local communities. Financial and economic savings may be realised by rebuilding some assets to an improved condition.

“By conducting whole-of-life cost analysis, we have been able to demonstrate that the annual maintenance expenditure currently being disbursed for unsealed roads in far north Queensland far exceeds the cost to maintain and repair flood damages to a sealed road,” said Frew.

Additional economic, social, and environmental benefits could also be achieved by sealing this road.

David Hull is manager of SKM Buildings & Infrastructure.

The Neerkol bridge wash out after the January 2013 flood.PHOTO: QUEENSLAND DEPARTMENT OF TRANSPORT AND MAIN ROADS


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Rebuilding with resilience