Oakland Bay Bridge 1989 Loma Prieta partial collapse

Tom mentions a section collapsed but doesn't recall fatalities. Brief reference; not developed.

What happened in Northridge in Southern California in the early '80s is they had fractures. No one died — well, I wouldn't say no one, there might have been some home or concrete structure that fell down on a couple of people, but the number of people who died in the Northridge earthquake from anything collapsing was probably less than 100, probably less than a couple of dozen. In San Francisco, the Oakland Bay Bridge, actually a section of it collapsed, but I don't remember any deaths from that. It's a question of how we know how to design for an earthquake. What we didn't realize in Northridge is that when these things start swaying as rapidly as they were — not as rapidly but as far as they were — they started getting brittle fractures because of impact loading. So they have updated the building codes dramatically. They went through two iterations since Northridge. Instead of the old beam formulas, which is what we did for a hundred years, they now have load factor resistance design, LRFD. It's a whole new way of doing calculations, and it's nice if you have a computer to do them for you — it's a more sophisticated way of calculating loads.