Add Anand Bhatt response on the India quake.

1 March 2001

Gregory Wharton is an architect.

Date: Thu, 1 Mar 2001 09:01:04 -0800
From: Gregory Wharton <jgw@DEMETRIOU.NET>
Subject: Shaken, not stirred...
To: DESIGN-L@LISTS.PSU.EDU

Official Measurements of Seattle Quake:

6.8 Magnitude
45 second duration
35 miles southwest of Seattle in the southern tip of Puget Sound (just north of Olympia)
30 miles underground

Had this quake not been so deep (i.e. if it had been a crustal quake instead) it would have been "cataclysmic," as one USGS seismologist put it, because of its longer duration.  Fortunately, we got off easy.

For comparison's sake, the 1994 Northridge Quake in the Bay Area was 6.7 in magnitude, but was much shallower, causing far more localized damage.

Around town, many older buildings which had been through seismic upgrades in the last few years fared very well.  Old, unreinforced cornices and chimneys were the primary casualties of the quake.  The chimney on my in-city house (which is 100 years old) suffered two major shear cracks and will have to be replaced (fortunately, it didn't come down onto the sidewalk, as did our neighbor's).  The chimney on the house behind us was so badly damaged that I am very surprised it didn't actually fall down.

The cornices of several older brick commercial buildings in Pioneer Square and the SoDo district came loose and crushed some parked cars (you know that morning the owners were thinking, "What a great parking place--right out front!").  Amazingingly, nobody appears to have been struck by falling debris.  At last report, only 18 people had been hospitalized as a result of the quake, and the only death was a woman who suffered a heart attack.

SoDo Center, formerly the Sears Roebuck Building and now the international headquarters of Starbucks Coffee, suffered some medium-scale damage (I have mixed emotions about this).  While it was reported that the giant spread-legged mermaid logo on top of the building had fallen through the roof, this is incorrect.  Rather, the entire roof cornice around the sign collapsed, but the internally-lit soft-porn corporate logo remains in its position of honor.

In answer to a previous question about soil conditions in Seattle, most of the downtown area is built on fill.  In the late 1800s, Seattle burned to the ground in much the same fashion as Chicago (and at right about the same time).  When the city was rebuilt, most of the debris was just bulldozed out into the bay to expand the downtown area.  So, downtown soil conditions, particularly next to Elliot Bay, are somewhat unstable.

Much worse are the conditions in SoDo (the area South of the Dome, or South of Downtown now that the Kingdome is no more).  SoDo was built over a drained, sandy swamp and presents an extreme liquifaction hazard.  Everybody knows about this, and new buildings are built to accommodate the bad soil. However, most of the buildings in this area are very old.  This area suffered the most damage in the city yesterday.

Here in our new office building in Kirkland, my first instinct when the quake hit was to get right next to one of the internal steel columns and sit down, looking up at the suspended ceiling to see if it would come down.  As soon as I realized it was a quake, the structural diagrams of the building (which I designed and managed in construction) flashed through my head.  All I could think was, "get AWAY from the windows."  Damage was minor, as this building was built under the 1997 code requirements.  A few cracks, one broken window and that was it.

Our various job sites also fared pretty well.  On one in particular, the superintendent was still shaking three hours later when I called him.  He'd been walking around on the roof superstructure when the quake hit, and he dropped down to grab a beam and hold on for dear life.  Some freshly-laid brickwork crashed down to the street, but otherwise everything was fine.

I can't help think, particularly after Anand's vivid first-hand accounts of the quake damage in India, that we were very lucky here, partially by accident and partially by design.  First, the quake was big but deep.  I can't emphasize enough how much that small fact saved us.  Second, nearly twenty years ago by my reckoning, the northwest woke up to the threat we faced from earthquakes, and embraced new seismic design methods with a vengence.  Seismic retrofits are now standard operating procedure for any building built more than twenty years ago.  For more than a decade and a half, all new construction has been built to survive major earthquakes. Awareness of the threat was already very high and we planned for it as best we could.

~g

Anand Bhatt is an architect.

Date: Thu, 1 Mar 2001 23:31:42 +0530
From: Anand Bhatt <anand.bhatt@VSNL.COM>
Subject: Re: Shaken, not stirred...
To: DESIGN-L@LISTS.PSU.EDU

[The earthquake in India.]

8.1 Magnitude
180 second duration
20 KM northeast of bhuj, kutch.
120 KM underground

Ahmedabad is on a KM of river silt, scooped inside a rock basin. the rock vibrated and set ripples forth, which concentrated at some points, one right next to my house: considerable damage. some places disperced the ripples, no damage. the earth caved in at places.

I was in the middle of my morning toddy, with a neighbour who is a ranking officer in the air-force, this being a holiday when the quake hit us. both of us had been in one before, so we could hear it coming, the noise travels faster than the waves I think. 'Quake' he says, 'big one' moments before the building began to shake. 'Bugger won't quit' I say a moment later.

The building is five or six individual very tall thin towers just pegged together by structural expansion joints, more like a series of promotories thrust into the sky it is -- the reason I stay there. And the joints cracked open first. Considerable shaking and lots of people who didn't know better [we do not have earthquake drills in India] running down the stairs. I notice a woman running down, holding a pillow like she normally holds her baby. We didn't know if the building would stay.

So Wingco and I start rushing up the building, just to verify if it was actually breaking at the seams, as planned, or otherwise. I see the elevators shear wall just tear apart like silk as I run up. Lots of old people frozen in the middle of stairs, actually quietly waiting, their bodies would just not move fast enough. There is a strange serenity about them, a image etched into my memory.

Terrific crashes, the building down the road goes, killing two. I look down from about twenty meters into the school yard next door and there is a mild mist about the ground, the dust is rising. Wingco wants to clear the building, still shaking, of the old people and the baby this woman forgot so we start entering the open apartments where we knew people could still be. I think I hear a whimper from the lift, stuck in the middle of two floors and file it into my memory. Electrity goes now and the stairwell is dark. There is a tearing noise as the central fin holding the staircase starts ripping. But the background noise, the throb, subsides. And then dies down.

End of act one.

We mostly clear the building, I somehow remember wondering if this woman I knew once is safe -- she would be because she is in Seattle. I have remembered and imagined a number of people I knew. The cell phone rings but the caller id shows # 1111111111, a bogus number.

Wingco and I have reached the very top of the building, one of the tallest in Ahmedabad and are actually on the top of the water tanks, some forty meters above ground and the vista strikes us. We see some collapsed buildings, some smoke from fires when the second shock hits us, 6.2 magnitude. We brace.

The damage doesn't look much, both of us have flying experience, he in fighters, me in para and we know that a dozen sorties set loose on a city would produce worse. We have seen pictures from Iraq and Yugo from a similar point of view. We know this one is different though, this is brought about by mediocracy and corruption.

We make our way down, I remember the lift. there is a three year old inside, with his bicycle. Bleeding. we tie him up, telling him a story -- actually finishing a story we started telling him about the Second World War and a wounded spitfire pilot who had trouble sleeping because his eye-lids went missing -- and fascinate him and bandage him and send him off to the clinic.

End of act two.

We need a drink now, after the morning's excitement. So back to my apartment and make a stiff one. drink it.

An hour later I walk out of this damaged building with cracks running all over, and surprisingly, the shops have opened, and chaps are going about their daily business in a sort of daze. I realise there is nothing else they could do. i walk into a hair saloon, and get myself a cut. good barber, two afterquakes and not a nick on my scalp.

The cellphone rings incessently, all sorts of information -- a lot of it irrelevant for now, Louis Kahn's IIM has taken a serious hit, primlinary visual assessment says. The Le Corbusier buildings are fine, not a scratch, not even in the plaster of paris false ceilings. Score one for straight modernism.

No news yet from the epicenter. The airforce stations there have reported its own casualties, and then they all go out into the city. Then silence. I realise I must make my way there.

Phew!