The Earthquake-Proof Building that's Built to Collapse

The Earthquake-Proof Building that's Built to Collapse

 

The Brilliant Idea: A replaceable, building-wide system to help hospitals, apartment buildings, and office towers survive severe seismic shaking.

Innovators: Gregory Deierlein, Stanford University; Jerome F. Hajjar, Northeastern University

  "Elastic high-strength steel cables run down the middle of the system’s frame. The cables control the rocking of the building and, when the earthquake is over, pull it back to proper alignment." "A steel frame situated around a building’s core or along exterior walls offers structural support. The frame’s columns, however, are liberal to rock up and down within steel shoes secured at the bottom ." "Steel fuses (in blue) at the frame’s center twist and contort to soak up seismic energy. Like electrical fuses, once they “blow out” they will get replaced, restoring the structural system to pre-earthquake conditions." For decades, the goal of seismic engineers has seemed straightforward: Prevent building collapse. then they add steel braces to a skyscraper’s skeleton or beefier rebar to concrete shear walls. After absorbing the brunt of seismic shaking, however, the compromised structures often must be demolished. “The building, during a sense, sacrifices itself to save lots of the occupants,” says Gregory Deierlein, a Stanford University civil and environmental engineer. A team Deierlein led with Jerry Hajjar, a Northeastern University engineer, hopes to vary that, designing a system that protects both people and therefore the structures they live and add. Last fall, the engineers successfully tested a 26-foot-tall, three-story, steel-frame building outfitted with the new system, built atop the E-Defense shake table—the world’s largest earthquake simulator—in Miki City, Japan. Steel “fuses,” not structural elements, absorbed the shock of an earthquake greater than magnitude 7, and cables pulled the building back to plumb once the shaking stopped. After an earthquake of that scale, the deformed fuses might be replaced in about four days—while the building remained occupied. Jim Malley of the San Francisco firm Degenkolb Engineers calls the system subsequent step within the evolution of a green building. “As structural engineers,” he says, “our sustainable design is that the ability to not need to tear buildings down after earthquakes, but to use them for many years.”

Er.SP.ASWINPALANIAPPAN., M.E.,(Strut/.,)

Structural Engineer

Madras Terrace Architectural Works

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