Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search

 


International pointers for rebuilding Christchurch

.

International experience provides pointers for rebuilding Christchurch


22 March 2011


The experience of rebuilding the Italian town of L’Aquila after its devastating earthquake in 2009 showed people who have been through such disasters have a preference for timber, according to Italian engineers.

Engineer Paolo Lavisci from the Society of Engineers in Italy said the people in L’Aquila “were asking for no more concrete” immediately after the earthquake. The substantial wooden buildings erected as a result have met with people’s “full satisfaction”.

“This has projected a very good image of timber construction everywhere in Italy,” Mr Lavisci says.

Since then, the use of wood in construction has taken off in Italy. “Now we have completed designs for six and eight storeys and are designing for 12 storeys for large ‘traditional’ building companies who just a year ago would never even commission a timber house.”

The shallow 5.8 magnitude earthquake killed 308 people, destroyed up to 11,000 buildings and left 65,000 of the medieval town’s population of around 100,000 homeless.

Mr Lavisci’s company won a tender, along with several other contractors, to build a number of three storey, 27-apartment blocks using timber. Their construction took only 72 days – only 14 days for the erection of the watertight outer shell.

Made from cross-laminated timber sections, the completed block weighed around 430 tonnes compared with what would have been more than 2,000 tonnes in concrete.

The lower mass (weight) of a building, can lessen the damage sustained from earthquakes.

Dr Geoff Thomas from Victoria University’s School of Architecture says earthquake loads or forces on a building are also proportional to its weight.

“A timber building, typically lighter than a brick, concrete or steel building, therefore induces lower earthquake loads.”

Being inherently lighter and more flexible, timber buildings need not be as strong as a more rigid structure in order to resist the same level of earthquake shaking.

“In the event of a collapse, survival is much more likely in timber buildings as the lower weight of any falling debris from the structure is less likely to cause serious injury than that of heavier materials,” Dr Thomas says.

“Understanding these facts has resulted in better building design which saved many lives in the Christchurch and other earthquakes around the world.”

Following the Kobe earthquake in 1995 which killed 6,300 people, Makoto Watabe, chairman of the Earthquake Disaster Committee of the Architecture Institute of Japan did a comparison of mortality rates from people killed in wooden or concrete structures.

Because of the pre-dawn timing of the Kobe quake, most people were in their own homes at the time. More than 80,000 houses – almost 10 percent of all homes in the area – either collapsed totally or were substantially destroyed.

Mr Watabe said that in Kobe, while the number of wooden house collapses was very high largely due to their light frames and very heavy tile roofs designed to resist typhoons, they killed relatively fewer people than the reinforced concrete buildings which collapsed. Approximately one person was killed for every 16 collapsed wooden houses.

“Assuming an average of three people lived in each house, that is about a two percent mortality rate,” he said.

"In the case of reinforced concrete construction, while there weren't as many collapses, that percentage went up to 15 percent - a big difference."

In short, while in Kobe there was less chance of a reinforced concrete building collapsing than their poorly designed houses, if you were in one that did, you had a greater chance of being killed.

Dr Thomas said that timber buildings of six stories or more are now being designed and built to resist earthquake loads.

“Such buildings are common in earthquake prone regions such as Vancouver, Canada and Seattle.

“A full size seven storey cross-laminated timber building survived testing at levels of up to 0.8 times the force of gravity, on the E-Defense earthquake shaking table in Japan in 2007.”

ends

.

© Scoop Media

 
 
 
 
 
Parliament Headlines | Politics Headlines | Regional Headlines

Gordon Campbell: On The Tokenism Of New Zealand's Role Against Islamic State

To date, the Opposition has continued to occupy itself with the marginalia of the issue. E.g. whether Key did or didn’t know whether Barack Obama would be present at the US briefing last week on IS, or whether New Zealand’s military involvement is or isn’t already a fait accompli.

It might be better to tackle the issue, head on. Our contribution against IS will be to send SAS forces to train the Iraqis? That’s like offering trainers to General Custer just as the 7th cavalry reached the Little Big Horn.
More>>

 

Parliament Today:

Scoop Business: Shell And Todd Caught Drilling Without Approval

Multi-national oil company Shell’s New Zealand arm and local energy giant Todd Energy have breached the new law governing New Zealand’s Exclusive Economic Zone, the Environmental Protection Authority says in an Oct. 10 document released by the Green Party. More>>

ALSO:

Labour: Tea Breaks 'Gone By Lunch Time'

“How cynical that on the eve of Labour weekend, the National government is pushing through legislation that takes away the statutory right to tea and meal breaks along with collective bargaining protections, and makes vulnerable workers jobs even less secure." More>>

ALSO:

Gordon Campbell: On Pharmac, Gough Whitlam And Sleater-Kinney

We’re not at the outset of these negotiations. The outset was six years ago, and negotiators were hoping to have some sort of ‘framework’ deal finished in time for the APEC meeting in a few weeks’ time. These ‘extreme’ positions are what we’ve reached near the intended end of the negotiations… More>>

ALSO:

PM Of Many Hats: Questions, No Answers On Whale Oil

Dr RUSSEL NORMAN (Co-Leader – Green) to the Prime Minister: How many times since November 2008 has he spoken with blogger Cameron Slater on the phone and how many times, if any, has he texted him?
Rt Hon JOHN KEY (Prime Minister): None in my capacity as Prime Minister. More>>

ALSO:

Aussie Investigation Dropped: Call On Minister McCully To Pursue The Case Of Balibo Five

West Papua Action is deeply concerned at the lack of any clear outcome from the Australian Federal Police inquiry into the 1975 deaths of the ‘Balibo Five’ including NZ journalist Gary Cunningham. More>>

ALSO:

'Feed The Kids' Bill: Metiria Turei To Lead Fight On Feeding Hungry Children

Green Party Co-leader Metiria Turei is urging all political parties to support the Feed the Kids Bill which she inherited today from Mana leader Hone Harawira. More>>

ALSO:

Parliament Today: State Opening Of Parliament

The House sat at 10.30am on Tuesday before MPs were summoned to hear the Speech from the Throne in the Legislative Council Chamber. More>>

ALSO:

Tertiary Education: Students Doing It Tough As Fees Rise Again

The Government is making it increasingly difficult for Kiwis to gain tertiary education as fees continue to rise and access to student support becomes even more restricted, Labour’s Tertiary Education spokesperson Chris Hipkins says. More>>

ALSO:

Housing, Iraq: PM Press Conference – 20 October 2014

Prime Minister John Key met with press today to discuss:
• Housing prices and redevelopment in Auckland
• Discussions with Tony Abbott on the governmental response to ISIS, and New Zealand’s election to the UN Security Council More>>

ALSO:

Get More From Scoop

 

LATEST HEADLINES

 
 
 
 
 
 
 
 
Regional
Search Scoop  
 
 
Powered by Vodafone
NZ independent news