Pancaked floors of a multi-storey concrete building, but little sign of steel reinforcing in the columns

There is a very sober message in the pictures and videos coming out of Myanmar and Thailand, after their 7.7 earthquake. A shallow quake, similar to what we expect to receive here one day, but hopefully we do not fare so badly. I doubt that any quake has been studied so closely before – so many videos coming from the tall building that collapsed. At first this building was said to be in Myanmar, but now it appears it was actually in Thailand. It appears not to have fallen at the first blow, but evidently a few moments or minutes later, possibly allowing some people to escape outside and then film its collapse. You’ve all seen the videos by now I presume. The cladding seems to stay on quite well, and folds in half, but does not really fall off, despite the building turning into a giant ball of dust.

At the precise moment that the ground floor columns break, the tall man in the red shirt will not get off his phone

If you remember back to 2001, when the twin towers of the World Trade Centre were destroyed, there were many armchair pundits who said that a multi-storey tower like that could never fall that fast, and that obviously the CIA must have been involved. Remember the people who said there were traces of thermite found, and men dressed in black the weeks before who had “obviously” been planting plastic explosives in the core? Bullshit all of it. This brand new (still under construction) tower fell just as fast, and here the issue is poor construction by bad contractors from China.

Building collapsing behind him, nothing will distract him from his phone call

I’ve watched the collapse several times now, trying to get the right pix, and the reason is the age-old one of a soft story at ground floor. Tall columns at ground floor for the retail areas, and they simply burst with a puff of cement dust, sealing the building’s fate in an instant. You can’t support a 20 storey building without a working ground floor set of columns – remove those and the entire building comes down and pancakes into a pile of rubble, in an instant.

At last he turns around to see what everyone else is screaming about. But he stays on the phone.

What is notable is how little steel reinforcing there is compared to what we would do in NZ. Steel keeps our buildings up, earthquakes reduce the concrete to dust. We are lucky that we are a relatively wealthy country when it comes to our Building Code – we have to pack a lot of steel into our concrete buildings. And of course, the pictures of the collapsed buildings in Myanmar, show walls mainly composed of brick and mortar, with a thin skin of cement render plastered over the top – and all in pieces now. Bricks are NOT your friend in New Zealand, or in any seismic active country.

Pictures after this point are just dust. Imagine what it is like to be up in the cab of that crane….

So when it comes to pictures of local and much-loved architect Roger Walker complaining about the price of his potential strengthening of his heritage building in Egmont Street, my sympathy levels are high, but we all know what is likely to happen to that building if the big one hits. Dust.

Cast iron frame but brick construction (the building behind, not Mr Walker).
Fish

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