4/26/2007

Thursday, April 26, 2007 (04-26) 08:18 PDT WASHINGTON, D.C. -- The Golden Gate Bridge is being honored with a national engineering award for a retrofit project meant to help the iconic span withstand a large earthquake, the American Society of Civil Engineers announced this week.

The second phase of the bridge's seismic retrofit project, which allows the suspension span to withstand up to an 8.3 earthquake on the nearby San Andreas fault, beat out four other projects to be named the winner of the ASCE's 2007 Outstanding Civil Engineering Achievement.

The project included major modifications to southern end of the nearly 70-year-old span, the second-largest suspension bridge in the U.S. The largest piece of the retrofit was the strengthening of two 220-foot tall hollow concrete pylons on the bridge's southern side, according to Mary Currie, spokeswoman for the Golden Gate Bridge, Highway and Transportation District.

The project also included the complete replacement of a 235-foot long wall, which faces the ocean; the transformation of the southern viaduct into a "modern steel structure"; and the modification of the Fort Point arch structure.

In announcing the award, ASCE's president lauded the project for balancing modern engineering standards with the bridge's historic and architectural integrity. The fact that the bridge remained open to traffic throughout the retrofit was also notable, he said. The bridge is located between the San Andreas Fault, located seven miles to the west and the Hayward Fault, which is about ten miles east. The project was managed by the Bridge District, the HNTB Corporation and the Duffey Company, Currie said; the project designer was Jacobs-Sverdrup/Thomas Jee & Associates; and the construction company was Shimmick Construction/Obayashi Corporation, a Joint Venture.