"Strong Columns Weak Beams Systems"- Building in earthquake prone regions

[Are_grits_groceries]

<snip>
People in Chile knew the safest places to go to when the earthquake struck.

Also, since an even stronger earthquake in 1960, Chile has developed a seismic design code for new buildings, which has made them better able to stay standing in an earthquake.

One system that helps buildings stay up is called the "strong columns weak beams" system.

The idea is that buildings are held up by reinforced concrete columns, which are strengthened by a steel frame. Reinforced concrete beams are joined onto the columns to make floors and the roof.

If there is an earthquake, the idea is that the concrete on the beams should break near the end, which dissipates a lot of the energy of the earthquake, but that the steel reinforcement should survive and the columns should stay standing, which means the building will stay upright.

The problem is that an 8.8 magnitude earthquake is "towards the top end of what you're designing for", according to Professor Colin Taylor, professor of earthquake engineering at Bristol University.
http://news.bbc.co.uk/2/hi/americas/8543324.stm

An 8.8 quake will severely strain or break most designs. However, using this as one technique can improve the ability of people to survive a quake as Chile proved. It is only one technique and many more have been or are being developed.

[zeemike]

1. Interesting, and it makes sense.

Even if the building is destroyed most living in it will survive.

But sometimes I wonder if man was not meant to live in tall buildings.

[Are_grits_groceries]

2. We do take more risks by working

and living in buildings that go up so high. They seem minimal because the problems don't occur in such groups that will catch attention.

[diane in sf]

3. As long as the building stays intact enough that people can get out alive, it can

always be demolished later.

[diane in sf]

4. Re building height: more people get killed in stone and unreinforced masonry

buildings than steel framed high rises or wooden frame buildings. When we had the 1989 earthquake here in the Bay area fewer than 100 people were killed. Within a year there was a similarly sized quake in the Middle East that killed around 10,000 people. For the most part, they lived in small stone houses to mid-rise unreinforced masonry buildings that completely collapsed and buried them.

[Are_grits_groceries]

5. There are a lot of what I call "pancake" buildings.

They are built with concrete floors and little support. They go up and up with one floor after another. When a quake occurs, the walls collapse and the floors drop one on top of the other.

They are cheap to build and have been a major problem when quakes occur. That was one reason the Chinese parents were so upset when the school collapsed and killed so many kids. There was supposed to be much more support and columns, but the builder cut corners.