Contributor Q&A: Marita Davison on earthquake-proofing the Bay Bridge

TechKnow: Tell us about your most recent story for the show.
Marita Davison: This story is about seismic innovations that are being implemented at California’s new Bay Bridge [linking San Francisco to Oakland] and how similar technologies are also being put into use in buildings and homes to make them safer for earthquakes.

TK: What surprised you the most about this story?
MD: With a lot of these technologies, I was thinking they'd be super high tech and they really aren't. A lot of the folks that we talked to were saying, you know, we've known about these for a long time. It's just that now we're starting to implement them in the context of things like bridges and homes. The technologies are evolving, but it was just surprising to me how simple some of the solutions are—like the crumple zone technology that they're using in the Bay Bridge and adopting for household and building use. Basically they're building structures that are meant to absorb the energy of an earthquake and pieces that are meant to contort and distort. They're essentially disposable pieces that can be swapped out. It's a simple solution but it makes a lot of sense in the context of an earthquake.

TK: What's your impression of the bridge?
MD: What initially impressed me is that in contrast to the original bridge, which was definitely utilitarian, it's all about function. The new Bay Bridge is about function but it's also about beauty and aesthetics and obviously, safety. But aesthetically it's really gorgeous to look at, especially the suspension portion of it. And at night with those LED lights, it was a really beautiful sight to see. It reminded me of driving around at Christmas time. It's these bright white lights and it almost gave me almost a peaceful kind of feeling. It's really cool. I haven't seen anything quite like it actually.

TK: You actually got to go inside the bridge. What was that like?
MD: Oh, that was cool. Climbing through the bridge I think was one of the coolest things of this story for me. I mean, it's kind of dorky, but I felt like I was in “Battlestar Galactica” at certain points because it's dark, it's cavernous and you have to kind of climb through these really tight areas. It's got that industrial feel and smell to it. I've always wondered how these structures come about and what they're actually like. When else in my life am I gonna be able to be inside a bridge? Probably never.

TK: And then you got to stand at the base of it as well, right?
MD: Yeah, from underneath, the view from the water of the bridge gives you the sense that this is a massive structure that was built into water. I mean, it was built and supported by the Bay, it's supported by the mud and all the sediment and it really gives you a sense of the magnitude of the effort that went into building a bridge.

TK: What was most exciting thing about this story for you?
MD: The most exciting part for me, hands down, was taking a look at the area where the hinge pipe beam is allowing for a gap in the bridge. It can move back and forth in the event of an earthquake, allowing the bridge to kind of sway with the movement. We were standing there, and all that was separating us from falling down was like a quarter-inch or a half-inch grate. You can see down into the Bay and you can really start to appreciate how simple the technology is but also how important and how useful it can be to help weather through an earthquake.

TK: You also visited some laboratories.
MD: The labs were really impressive. I've never been to a lab quite like either of the two that we went to. They're huge and they've got lots of industrial looking machinery. Basically they're simulating earthquakes, making things shake and making things move and testing to see how materials are distorting and contorting or how they're holding up. To hold the shear link beam and hinge pipe beam up close and see it really drove it home for me what it's meant to do. It’s designed to withstand that horizontal movement and the way it's designed will allow it to kind of shift and actually distort and contort. Then it has these holes on the end so you basically bolt it in and when it distorts it can just be unscrewed and replaced and a new one is good to go.

TK: What do you think about all these technologies? Can they help prevent more damage the next time there’s a big earthquake?
MD: I think it makes a lot of sense to develop structures in that way. It seems almost modular, so that you can swap out parts that either break down or fail in this case and replace them with the same one. Hopefully in the future when you have to swap them out, you'll swap them out with even better and better materials and solutions. But to me it makes total sense to design things with that in mind and make it more cost effective and easier to recover from an earthquake when it happens.