Saturday, September 11, 2010

Strict Building Standards Worked In New Zealand Mag 7 Quake

Once again, the lesson is super clear.   Our modern building standards minimize loss of life for quakes up to and including 7.0 on the Richter scale and that fortunately covers just about every nasty quake we are likely to have.  Haiti was a glaring example of grossly inadequate code enforcement since the code is well established and was adequate to have saved Haiti.

It is possible to provide superior building able to handle magnitude 8.0 at the same cost structures but with manufactured housing through certain innovations.  Such structures may even be able to withstand far greater stresses but we reach the point in which an occupant would be killed anyway.

I suspect survivability at magnitude 7.0 is a pretty good standard and has been clearly reached in California and New Zealand.

It is always a good sign when facades collapse, but the building structure is unaffected It actually shed a lot of non structural weight while is rode out the quake.  That was messy but survivable.

Strict standards behind N. Zealand quake 'miracle': experts

A picture shows the wrecked facade of the Westende Jewellers and rubble blocking a street after a powerful 7.0 earthquake in Christchurch on September 4, 2010. A state of emergency was declared in New Zealand's second largest city Christchurch after a powerful quake, which struck before dawn and caused widespread damage. Photo courtesy AFP.

New Zealand city braces for more destruction after quake

Christchurch, New Zealand (AFP) Sept 5, 2010 - New Zealand prepared for further destruction on Sunday as aftershocks and an approaching storm threatened an area hit by the most devastating earthquake in decades. Prime Minister John Key said it was "a miracle" no one had died when the major 7.0 magnitude quake wreaked more than a billion dollars of damage on the nation's second-biggest city Christchurch. Civil defence officials warned that ongoing aftershocks with magnitudes of up to 5.4, coupled with a ferocious storm blowing in, could threaten already-weakened buildings. Despite widespread damage, none of the city's 340,000-strong population died when the quake struck before dawn Saturday. "The only conclusion you can draw is that it's a miracle nobody was killed," Key said as he surveyed the devastation. "Parts of the city look like they've been put in the tumble dryer and been given a darn good shake."

Central Christchurch remained cordoned off Sunday although most of the power, water and sewage facilities that were cut in the earthquake had been restored. Emergency evaluation teams picked their way through streets piled with rubble and littered with shattered glass to inspect buildings and determine whether evacuations were necessary. Coastal and riverside suburbs were among the worst-hit areas, and health fears may yet force evacuations, the civil defence agency said in a statement. More than 200 people have moved into welfare centres for temporary accommodation while hundreds more sheltered with friends after fleeing damaged homes.

The Salvation Army said it was feeding 1,000 people and launched an appeal for those affected by the quake. "Not since the 1930s have we experienced an earthquake as severe and it is important that we do everything we can to help," Salvation Army national fundraising coordinator Major Robbie Ross said. Key also pledged government support, with initial damage estimates at two billion dollars (1.44 billion US). "We are here to support them. We are not going to let Christchurch suffer this great tragedy on its own," the prime minister said. The earthquake was New Zealand's most destructive since the 1931 tremor in the North Island city of Napier, which killed 256 people.

Although nobody died in Saturday's quake, civil defence officials warned the emergency was not over, as more than 30 aftershocks had hit the region within 24 hours of the main quake and were likely to continue for several weeks. A storm was also likely to bring fresh challenges with wind gusts up to 130 kilometres (80 miles) an hour expected during Sunday night and heavy rain to follow on Monday. As night fell, the storm hit Dunedin, around 400 kilometres (250 miles) south of Christchurch. "(There are) trees down, lines down, roofs lifting, trees falling on houses all that sort of thing, the wind is moving up the island so we're expecting Timaru, and later Christchurch to get hammered as well," fire service shift manager Jan Wills said.

In Christchurch, weather forecaster Philip Duncan said the storm could further damage trees and buildings that were weakened in the earthquake

by Staff Writers

Wellington (AFP) Sept 5, 2010

While New Zealand Prime Minister John Key says it is "a miracle" no one was killed in the Christchurch earthquake, experts believe it was the country's strict building codes that prevented mass fatalities.

The 7.0 magnitude quake brought down building facades, buckled train lines and caused damage estimated at more than a billion dollars in New Zealand's second largest city, but did not result in the high death tolls seen in similar disasters worldwide.

The statistics just this year make grim reading: at least 220,000 dead in a 7.0 magnitude quake in Haiti last January, more than 2,000 killed when a 6.9 magnitude tremblor struck northwest China in April and more than 500 lives lost when an 8.8 mega-quake hit Chile in February.

Officials say Christchurch residents were lucky the quake occurred before dawn on Saturday, when most were asleep in the relative safety of their homes. A few hours later and the streets would have been thronged with Saturday morning shoppers.

But they have nevertheless expressed amazement that no one died when such a powerful seismic jolt struck so close to a city of 340,000. So far, there have only been two reports of serious injuries.

"The only conclusion you can draw is that it's a miracle nobody was killed," said Key. "Parts of the city look like they've been put in the tumble dryer."

New Zealand, which sits at the junction of two tectonic plates, is no stranger to earthquakes and experts said it had learned harsh lessons from a 1931 disaster at Napier, when a 7.8 magnitude tremor killed 256 people at Hawke's Bay.

The director of the Joint Centre For Disaster Research at Wellington's Massey University, David Johnston, said that resulted in the implementation of stringent building standards.

"There's no doubt it's a very, very significant reason why there wasn't more destruction," he told AFP.
"In developing countries we've seen the wholescale collapse of buildings. In Christchurch, it's been the older buildings on the outskirts of the CBD that have been worst affected but the vast majority of structures have maintained their integrity.

"It's a testament to the efforts in New Zealand since 1931."

Pieter Burghout, chief executive of BRANZ, an industry-funded construction safety research body, said the most severely damaged buildings in Christchurch were made of bricks and mortar, materials that do not cope well with earthquakes.

He said modern homes in New Zealand were mostly constructed around light timber frames, which provided flexibility when a quake hit.

"I've seen pictures of a house in Christchurch which fell off its foundations but it was still structurally sound," he said.

Burghout said New Zealand was among the world leaders in earthquake-resistant design and BRANZ had a large research facility in Wellington where a full-scale house could be built so testers could "shake it to bits" in a simulated tremor.

He said new office blocks in the country were built on isolated foundations, meaning they rest on a bed of rubber shock absorbers or ball bearings "so they can wobble around a bit if the big one comes".

Many historic buildings have been retro-fitted with earthquake dampening devices, a measure the Anglican Dean of Christchurch Peter Beck said paid off when the city's Anglican cathedral escaped with only minor damage on Saturday.

"Thank God for earthquake strengthening 10 years ago," he told national television.

Burghout conceded New Zealand's building standards were expensive, making them all-but-impossible to impose in developing nations such as Haiti, one of the world's most impoverished nations.
But he said the strict rules had been validated in Christchurch.

"I think the people of Christchurch would pay any price to come through this earthquake unscathed," he said.

earlier related report

New Zealand quake victims remain positive amid destruction

Christchurch, New Zealand (AFP) Sept 5, 2010 - The response among New Zealanders to the most devastating quake in decades has been "tremendous", with an "astonishing atmosphere of resilience" among affected communities, politicians and media said Sunday.

The government said it had turned down international offers of aid after Saturday's 7.0 magnitude quake, as people pulled together to help those left without shelter, food or water.

Civil Defence Minister John Carter said the disaster, which cut a swathe through Christchurch and the Canterbury district, had brought out the best in people.

"It has been tremendous to see the people of Canterbury rally around each other in this disaster and this has certainly reduced demand on the welfare centres," he said.

"It is a great testament to our country that Kiwis can call on family, friends and neighbours, and even in some cases strangers, in times of emergency."

Although the streets were strewn with rubble and shattered glass, and large holes and fissures had appeared in main roads, officials on Sunday said they had the situation under control.

Offers of help from the United States military and from various United Nations programmes were refused, civil defence director John Hamilton said, with the nation of four million able to fend for itself.

"I suppose they're probably surprised that we turned down their offers of assistance because in most cases an earthquake of the magnitude that we've experienced would inevitably result in high casualty numbers and the need for humanitarian assistance," he said.

"We're very grateful that the offers were made and fortunately we were able to say 'not required'."

A state of emergency declared soon after the quake would be reviewed on Monday, officials said.

Saturday's earthquake caused a mess of crumbled buildings, crushed cars and mangled roads which Prime Minister John Key described as looking like parts of the city had been "put in the tumble dryer and been given a darn good shake".

But after the initial shock, New Zealanders quickly set about providing food and accommodation for those who had lost their homes.

With electricity and water supplies cut, neighbourhood barbecues were organised as families pooled food and water supplies.

In rural areas, farmers set up a network of generators to ensure all milking would be completed as quickly as possible.

Opposition leader Phil Goff said he was amazed at the attitude of a couple he met removing possessions from their house, which was only fit for demolition.

"They were saying things like 'well, it could be a lot worse, think of the people in Pakistan where their homes and property have been destroyed, they have nobody to help them out, their kids are suffering from disease'."

Throughout the day the media arrived to collect stories of survival and found "an astonishing atmosphere of resilience", the Sunday Star-Times reported.

"Christchurch took on a carnival atmosphere as strangers compared notes.

"A community rallied and shared its bottled water with its neighbours... even those who had lost almost everything were remarkably upbeat."

Roderick Smith and partner Nina refused to let the earthquake interrupt their wedding day and used the destruction as a backdrop for their wedding photos.

"All the places we were going to do photos were blocked (so) what we've been doing is driving around and finding nice looking rubble and making the most of a bad situation," Nina told the Stuff website.
The chapel where they held the wedding was unscathed but the reception venue was unusable so the party packed into a coffee shop instead.

Nigel Smith spent Saturday using his four-wheel drive to pull stuck cars out of people's driveways.

"Something like this brings people together," he said. "It's amazing how everyone has come out and is helping each other."

Key said it looked like a scene out of a movie: "The roads were just ripped apart. I saw a church completely broken in half."

The earthquake was New Zealand's most destructive since the 1931 tremor in Napier that killed 256 people.

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