SAN FRANCISCO (KRON) — We are getting a first look at a new type of shock absorber designed to protect buildings during an earthquake, and it is being used right here in the Bay Area.
And it is the first time the technology has been used in the United States. KRON4’s Charles Clifford explains the thick, sticky stuff is polyisobutylene, basically a type of man-made rubber. And it could be the future of seismic safety in large buildings.
Along Van Ness Avenue in San Francisco, California Pacific Medical Center is constructing a new 12-story hospital. Scattered throughout the frame of the building are 119 tall, slender shock absorbers that sit between floors. Inside each is a thin steel plate that is submerged in the gooey rubber.
In the event of an earthquake, the plate will move back and forth horizontally, and the rubber will absorb the energy created by the quake.
“We believe that these will absorb, and 80 or 90 percent of the total energy during that is imparted to the building during an earthquake,” structural engineer Jay Love said. “80 to 90 percent. Without this, we would have to rely on the steel beams flexing and stretching. With this, we will be able to absorb that energy without the damage to the building.”
Love said the technology has been in place for decades in Japan, but this is the first time these shock absorbers are being installed in the U.S.
“It is the first time it’s been tried in California and the U.S.,” Love said. “We have tested it extensively at our lab in San Diego to make sure it can withstand the kind of earthquakes we see.”
In addition to improving the seismic safety of the building, the shock absorbers also mean that engineers will use less steel building this structure, which will bring down the cost of the project.
“We have been able to reduce the amount of steel in this building by about 20 percent,” Love said.