Wednesday, February 23, 2011

Tragedy [updating . . . ]

It's a dark day for sure, perhaps New Zealand's darkest .

A city already brutalised by quakes and aftershocks, and buildings already weakened by the quake on September 4th and the Boxing Day shake and every aftershock between here and there finally succumbed under a new shock which was lesser in magnitude than the first one, but closer to home and greater and much more tragic in its in its effect.

The ground movement in the first quake imposed a horizontal force on buildings roughly equivalent to 8/10ths of the building’s gravity load. The one-minute shake at lunchtime yesterday imposed a horizontal load roughly equivalent to gravity. It’s as if for one minute each building was picked up and turned on its side, and held by its “foot” just to see what happened—that’s the sort of load, one whole gravity load, that was imposed on the Cathedral tower, on the Pyne Gould Building, on the CTV building, on the Old Arts Building, on the Crowne Plaza hotel, on The Press building, on the Provincial Chambers Building, on sundry new, near-new and frankly ancient buildings that had finally been given more than they could handle.

No wonder they gave up the ghost.

The columns in the Pyne Gould Building and the CTV building gave up, leaving the floors to pancake on top of each other and on the poor folk within. The roof and large parts of the top floors of The Press Building detached themselves from what held them and headed earthwards, while folk within were left sheltering under their desks.  The Forsyth Barr Building maintained its structural integrity and protected the people within, but the stairs (which may have been fixed in such a way they acted as structural bracing) were so mangled as to be unusable. The Cathedral, whose survival in the first quake gave the city the sort of heart the survival of St Paul’s gave Londoners during the Blitz, finally crumbled at the point where base met tower and tower then collapsed in on itself—taking the aspirations of many Cantabrians with it and, it’s feared, many people who were visiting the tower when the shake started.

And that was just the major building disasters. Outer walls in older buildings everywhere peeled off and just collapsed, leaving people inside huddling together for safety. Bridges collapsed. Water, gas and sewerage mains burst. Ground liquefied. The sky cried. And everywhere there was falling masonry, any one piece of which can kill.

It was a disaster.

There was a jolt that threw people off their feet and a sound like a hundred rushing trains. After the shaking stopped, there was a moment of silence. Then a wail of ambulance sirens

In hindsight you could say that these buildings and many others should probably not have been occupied.  The structure of modern buildings are designed economically—designed to withstand an earthquake and allow the occupants to get out, and to be strengthened thereafter.  But these buildings and their occupants had already endured much more than one earthquake without ever being re-strengthened.  Reconstruction had been proceeding at such a snail’s pace that few if any structures had been repaired as they should to take new shakes.

One of the few blessings of yesterday was that the shake happened at lunchtime. Not as good as a shake happening after hours, but at least in some buildings some of the occupants had stepped outside for lunch.

Another was that a medical conference was happening in Christchurch, putting 400 Australian urologists right on the spot to help out (not exactly the speciality you’d order up in the circumstances, but skilled and on the spot nonetheless).

And another is that specialised search and rescue teams from around the world are already hard at work an on their way you help out uncover and rescue the many folk still trapped in the rubble of dead and dying buildings.

It’s hard to feel blessed when there are already 65 people confirmed dead, and talk last night already started about that number reaching 200, or even 400.

In a city with nearly $12 billion of damage, so much at such a time that you’d wonder whether it will be able to rise again.

It’s a dark day for sure. Perhaps New Zealand’s darkest.

PS: For overseas readers concerned about yours truly, I thank you for your concern and can tell you we folk up here in Auckland are all fine and untouched and undamaged. We’re about a thousand kilometres from the quake. But they're not doing so well down in Christchurch.

NZ-quake-web-2_1832504c

Source: UK Daily Telegraph

UPDATE 1: Check out the Christchurch Quake Map to get a feel for what hit Christchurch yesterday.  Select Tuesday 22/2/11 and press play, and  just see what hit it.

UPDATE 2: Important news from Christchurch brewers: Brewers okay, breweries mostly not so. I’ve heard similar news from our friends at Third Man Wines.

UPDATE 3: Just up and running: Quake Help, “a web-based entity aimed solely at helping the people of Christchurch city.”  And looks like the UC Volunteer Student Army is back up and running.

UPDATE 4: Christchurch-based bloggers Trevor Loudon, Eric Crampton and Bernard Darnton report all well with them and theirs (and thanks for asking)—Bernard just needs to shovel his house out of the silt and bring a disobedient concrete slab back into line.

UPDATE 5: Not good looking news: “A temporary mortuary to deal with Christchurch earthquake victims has been moved to the Burnham Military Camp ‘for capacity reasons’ . . . ”

UDPATE 6: Mayor Bob Parker says now 79 75 confirmed bodies, and up to 300 people still missing [via Barry Soper].

UPDATE 7: A camera thrust into rubble at the CTV building discovered a pocket in which around 15 people are still alive. 7 are believed to be still alive at the Pyne Gould Guinness Building. Around 20 are believed not to be at the Cathedral.

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13 Comments:

Anonymous Anonymous said...

I've been a regular visitor to your site for about 2 years. When I heard about this quake I immediately thought about you. Are you all right? Is your family safe?

Bookish Babe

2/23/2011 09:00:00 am  
Anonymous Bizarro #1 said...

In light of Sasha Volokh's recent controversial musings on the matter, I was wondering: do Libertarianz think civil defence is a legitimate function of government?

(sorry if it seems insensitive to discuss politics - it's not intended that way)

2/23/2011 09:30:00 am  
Blogger PC said...

Hi Bookish Babe. Thanks for your concern. Yes, we folk up here in Auckland are fine. They're not doing so well in Christchurch.

2/23/2011 09:31:00 am  
Blogger Berend de Boer said...

Very soon after the earthquake I already heard the head of civil defence questioning the structural integrity of ChristChurch.

PC, do you think buildings having undergone two of such quakes can actually be strengthened?

2/23/2011 10:12:00 am  
Blogger PC said...

@Berend: As far as modern buildings are concerned, some can be and some can't--not easily.

Buildings designed to resist by ductility will generally have weakened floor beams after a shake, as they're designed to. It's difficult to repaid these, and essential if you do to make sure they're not made stronger than the columns--because you want the beams to fail first.

But other modern buildings are designed to be easier to repair--buildings with k-braced frames, for example.

And some of the older masonry buildings could have been strengthened moderately easily with long steel tie rods tying walls together to act as a unit in a quake, in a moderately ductile fashion.

Some of this work may have been done over the last few months, but anecdotal evidence suggests most of the work done since the first quake involved waving clipboards around, not structural steel.

2/23/2011 10:39:00 am  
Blogger Owen McShane said...

Go to Phil McDermott’s blog for commentary on “Resilient Cities”:
http://cities-matter.blogspot.com/

Sample: from today’s post:

“And what can urban designers and planners take from this devastation? What does it tell us about the importance of space in the central city, of wide boulevards, generous parks, and civic squares? About the need for more space, not less. The centre of Christchurch is still relatively open, and perhaps that has saved some lives. It was possible to take refuge in the streets, the squares, and the parks.
This event must surely erode planners’ resistance to the decentralisation that is the mark of a prosperous, modern city, that makes it that little bit more liveable, and so much more resilient in the face of disaster? Perhaps we should be thankful that a diminishing share of Christchurch’s people actually works in the CBD – today just 26% of the total. And that not too many dwellings – and residents — had been crammed into retrofitted buildings or high rise apartments assembled in inner city precincts.”

Then read the earlier blog post on resilience stimulated by the devastation of the floods in Queensland.

http://cities-matter.blogspot.com/2011/02/cities-in-search-of-resilience.html

Hence my own view that fundamentally, our planners should stop worrying about sea levels rises that MIGHT happen in 100 years – with plenty of warning – and start thinking about making our cities resilient in the face of catastrophic events which we know can happen tomorrow – cyclones, volcanoes, earthquakes and tsunumai. eg. Don’t put our motorways in tunnels below sea level. Don’t further intensify the central city, especially near the harbour edge.

I suspect given the trauma in Christchurch the city will be re-built as a multi-nucleic low-rise decentralised urban area.

Now matter how good the engineering, people will be reluctant to work in buildings more than a few stories high. And any CBD will probably be built somewhere else. The cathedral and square are a symbol of Christchurch – like the Eiffel Tower – and may be worth rebuilding for that emotional content.

But Auckland Council should take note that all cities in NZ are prone to catastrophe and the “spatial plan” should embody this reality.

2/23/2011 12:44:00 pm  
Anonymous Anonymous said...

A Dark Day-yes- New Zealands Darkest- No: That doubious honour is still the 12th October 1917 when we sufferred more than 2700 New Zealand casualties, of which 45 officers and 800 men were either dead or lying mortally wounded between the lines. In terms of lives lost in a single day, this remains the blackest day in New Zealand’s post-1840 existence.

And this doesnt included the casluties from the 4th October (the Battle of Gravenstafel Spur) which clioamed the life of my Uncle. Lest we Forget

2/23/2011 02:47:00 pm  
Blogger Lyndon said...

GNS report now finds up to 220%g shaking.

2/23/2011 04:44:00 pm  
Blogger Lyndon said...

Oh, and link http://www.geonet.org.nz/news/feb-2011-christchurch-badly-damaged-by-magnitude-6-3-earthquake.html

2/23/2011 04:44:00 pm  
Anonymous Anonymous said...

Well done Owen! We wouldn't want a terrible tragedy to be wasted by not trying to score ideological points! Now here's Mark Hubbard to blame the government?

2/23/2011 07:24:00 pm  
Anonymous Marcus said...

Hawke's Bay Earthquake of 1931 still remains the darkest natural disaster. 256 dead.

2/23/2011 10:29:00 pm  
Anonymous Marcus said...

With so many people still missing, it looks like Christchurch is set to become NZ's worst natural disaster. Darkest day was indeed prescient.

2/24/2011 11:09:00 pm  
Anonymous adrian said...

The quake did not kill the victims the buildings did!When will there be answers to the open questions about whether the Pyn Gould Building and CTV building were reinforced and repaired after the last quake . Was there valid warrant of fitness certificates issued for these buildings? The chancellor hotel is still standing no deaths !! Accountability needs to be placed at the feet of those responsible for designing , building and approving these 2 death traps

2/27/2011 11:26:00 am  

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