Building Earthquake-Proof in Chile

Science/Environment

Building Earthquake-Proof in Chile

A UCSD engineering professor who’s advised Chile on its seismic building code talks about how the country prepared.

The 8.8-magnitude earthquake that struck Chile on Saturday was estimated to be about 500 times stronger than the 7.0 earthquake in Haiti, but initial reports show that Chile’s death toll will be much lower than the estimated 220,000 people killed in Haiti.

José Restrepo, a professor of structural engineering at UCSD’s Jacobs School of Engineering, said Chileans have their buildings to thank. Six months ago, Restrepo was invited to advise a committee in Chile that helps the country draft its buildings’ seismic design code. He’s from Colombia and has many colleagues in Chile.

Through his work with the committee — which included visiting Chile and sitting in on regular meetings online — Restrepo saw its efforts to stabilize buildings first hand. We asked him about what his Chilean colleagues were attempting to do and why he thinks it helped the country avert a larger disaster.

What were your colleagues working on?

They are drafting the design code for seismic design of buildings. They are writing a new code right now and are coming up with new seismic design criteria. There were different currents on the committee about whether the seismic codes should be removed, increased, or remain as they are, so actually this earthquake comes in handy despite the damage. Now they all see the importance of the codes.

Why is it that buildings in Chile didn’t suffer the same damage as in Haiti?

They’ve seen a lot of damage in houses that are not seismically designed, but the modern buildings have done very well with some exceptions. When you have 500 buildings, and one or two fall down, it’s not a big deal. Many of the buildings have load-bearing walls. Occasionally we use these in California, but I wish we used them more. They have very tough buildings. The architects there are very proficient, know about seismic behavior, and work well with engineers.

So then these building codes in Chile helped them avert some of the disaster?

Absolutely. Chile has an earthquake every 20 to 30 years, so they were very well aware that they were going be hit by a big earthquake. In Chile, they have a tradition in their building codes to be very strong. They also have a very good education system, where they go to universities for six years, so when they’re finished they are very well trained. The training of architects and contractors, when it goes hand in hand with the building codes, gives a very good result.

Is California prepared for a big earthquake?

We are reasonably prepared, but it’s like when you have a child — you don’t see the defects until they show up somewhere. With our building codes, most of our buildings should suffer some damage. Unless someone wants to pay more, our buildings should be expected to have some damage.

Are there things California could do better?

We haven’t had a major earthquake in many years — 1989 and 1994 were fairly small — so it’s hard to tell. If I had a crystal ball, I would say that older buildings, which there are quite a few of in San Diego County, are going to suffer. Buildings that are built prior to 1971 and have never been retrofitted are very exposed. Also, our communication system and water supply systems may be big problems.

Have you spoken to your friends and colleagues in Chile since Saturday? Are they all right?

I have spoken to them. They have seen some buildings that were damaged, but people are alive. Some buildings are in bad shape, but mostly things are all right. In my opinion, this is a clear message about the responsibility of engineers, architects, and building codes working together.

— CLAIRE TRAGESER

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