Would You Survive the Big One at the Office?

By James Ross Gardner April 22, 2011 Published in the May 2011 issue of Seattle Met

AFTER A 9.0-MAGNITUDE earthquake rocked Japan and killed more than 12,000 people, just weeks after another quake toppled Christchurch, New Zealand—both incidents in the middle of the workday—I had to know: Would my office building withstand the wobble?

Seattleites, after all, sit near the Cascadia subduction zone, which we’re reminded—repeatedly—is a fault line that could slip at any second. At the University of Washington’s civil and environmental engineering department, where I went for answers, one professor declined to participate, but not before scaring me even more. “Given the right earthquake that could occur, I would suspect that a lot us of should feel very concerned about our safety,” he said. “However, given other earthquakes that may occur, there could be minimal risk.”

His colleague, professor John Stanton, was more willing to speculate—and more doomsy. Comparing Japan’s recent shaker with the 6.8 Nisqually earthquake that bounced our city on the morning of February 28, 2001—and caused one death and up to $2 billion in damage—Stanton said that if a 9.0 hit here “we would see a response like the Nisqually earthquake on steroids.”

Characteristics that spell trouble, he said, include structures built on soft ground (like the Alaskan Way Viaduct and just about anything else along the Elliott Bay waterfront); anything built asymmetrically (such as wharfs, which have long pilings in deep water and short pilings closer to shore); “tilt-up” buildings such as big box stores (“often built with more of an eye towards economy than great seismic robustness”); very heavy edifices, where larger mass produces greater inertia (like older buildings with lots of brick).

Watch out for structures pushing 40 years or more.

Speaking of old, watch out for structures pushing 40 years or more. “There was a fairly major change in building codes in the 1970s,” Stanton warned. “So anything designed before that would be inherently more suspect.”

While Professor Doom couldn’t soothe me or my fellow office tenants—brick building next to the Viaduct—he had good news for desk jockeys in the Columbia and 1201 Third Avenue skyscrapers, built to resist the force of constant wind. “The quick and dirty is that if a very tall building is strong enough to resist wind forces, it will also be strong enough to resist earthquake forces. In addition, if they’re very tall, they’re probably modern”—and designed with earthquakes in mind.

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