Cal Stadium and the Hayward fault

I mentioned UC Berkeley’s Andrew Lawson in connection with the Claremont Shale. Lawson also recognized, mapped and named the Hayward fault. It was very well known that the fault crossed the upper part of the Cal campus, and Lawson was not shy about it in 1921, when the University planned its big new stadium right atop the active trace. Like all geologists, Lawson knew that in a bet against nature, nature tends to win, but as a professor he also knew that in a bet against the university, professors tend to lose. So Cal Memorial Stadium sits where it sits, being slowly pulled apart by aseismic creep. (Lawson’s own home, at 1515 La Loma Avenue in Berkeley, was designed for earthquake resistance by Bernard Maybeck.)

Here’s the canonical view of the offset looking up from the parking lot at its south end.

cal stadium

Immediately east is this chunk of lumber amid the stadium’s reinforced concrete. It’s important to remember that good codes and good designs don’t ensure good construction.

cal stadium

Underneath the structure, there are cracked columns in many places. This one, cracked on its south side, shows that the ground is being carried north while the stadium, being a fairly rigid structure, is stationary.

cal stadium

The stadium is actually built in halves, with the idea that during an earthquake the two sides would gently slip past each other. No one knew about creep at the time. These two columns have been pulled out of parallel over the years.

cal stadium

Lawson may have thought that the stadium design was OK. He was not aware of much we have learned about faults and earthquakes since his time.

7 Responses to “Cal Stadium and the Hayward fault”

  1. Andrew Says:

    A few days ago in The Berkeley Daily Planet, Cal emeritus professor Garniss Curtis held nothing back in critiquing the plans for Memorial Stadium and other buildings in Strawberry Canyon: “absolutely do not construct any buildings.” For a real geo-geek’s look at the issue, go read his letter. (Curtis is the man responsible for some of the most important age dating from Olduvai Gorge, among many other professional accomplishments.)

  2. Andrew Says:

    Today’s San Francisco Chronicle has a story about a novel retrofit plan for the stadium involving a plastic underlayment for the west side that will allow the stadium to slide as the earth moves beneath it, similar in concept to base isolation techniques in other buildings (like Oakland City Hall). I commented there that the stadium is our own version of the Hetch Hetchy Dam, a tragedy as well as a benefit. We’re stuck with the stadium until Cal gives up football or Hell freezes over, whichever comes first.

  3. Maria Says:

    There’s some dispute as to whether or not the stadium was actually built in two halves as seismic protection. I’ve heard it suggested that the split design was meant to handle differential settling rates (the west side is mostly built on fill, while the east was dug into the hill), and this strikes me as pretty plausible, but there’s surprisingly little documentation either way.

  4. Andrew Says:

    Once they’re shaken, that’s true.

  5. Ken Clark Says:

    I guess maybe it was perspective/opticall illusion, I was asking because some of those columns looked like they were no longer vertical, even a little bit of lean will drastically reduce their load bearing ability, thanks though:)

  6. Andrew Says:

    The stadium is being rehabbed right now, so problems are being noticed. I should also point out that the cracked column is still good for its design purpose, which is to handle a vertical load. The big spall in the outer shell, ugly as it is, doesn’t significantly weaken the stadium. I don’t mean to suggest that the stadium will collapse—although in the extreme conditions of a big M7 quake, the damage will be worse due to these relatively small flaws.

  7. Ken Clark Says:

    how often do they send in the engineers to inspect the stadium structures?

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