Can The New San Francisco Bay Bridge Withstand An Earthquake?

The eastern span of the San Francisco Bay Bridge cost taxpayers $6.4 billion, but that may not have been enough to ensure it will withstand the stress of an earthquake as it was designed to.

Tiny cracks have previously been discovered in the rods at the base of the bridge’s tower, and now Caltrans admits it didn’t inspect more than 2,000 other rods before installing them. Some of those support rods have now been discovered to fail industry thread standards.

Experts argue the previously discovered mini cracks could allow the rods to become brittle and make the Bay Bridge vulnerable to failure in the future, while Caltrans states the damage is unlikely to cause further problems.

The east side span of the Bay Bridge, between Treasure Island and Oakland, was built to replace the original span that was damaged during the 1989 Loma Prieta earthquake. The upper section of the bridge collapsed, killing a motorist.

The new span was designed to withstand the stress of an earthquake, but continued reports of brittle support rods suggest the Bay Bridge may not live up to its promise.

An earlier Inquisitr report cited a report from Berkeley engineer and corrosion expert Lisa Fulton, who complained to the San Francisco Chronicle that the bridge may collapse under its own weight.

“There doesn’t have to be a lot of force on those rods for them to break. That could indicate that we don’t need an earthquake for them to snap, that they are unreliable in the service loads that they are under now. It’s a portent of catastrophe.”

Now, the poor quality of threads threatens the stability of the bridge. In a Caltrans report obtained by the San Francisco Chronicle, the agency admits no one checked the rods’ quality during production, after shipment, or before they were installed, contrary to the agency’s own rules.

“They never should have been accepted this way.”

First bid out at $250 million, construction costs of the eastern span of the Bay Bridge ballooned to $6.4 billion, making it the costliest public improvement project in California’s history.

The 2,500 percent increase inspired a new book, Remaking the San Francisco-Oakland Bay Bridge, by UC Berkeley scholar Karen Trapenberg Frick, who tracks the cost overruns from design modifications to engineering mistakes. Frick says the $6.5 billion current cost estimate doesn’t include interest or financing costs, which would bring the real total to $13 billion, according to CityLab.

“Basically at the onset of a project I think the higher ups prefer a dollar amount and schedule that doesn’t shock the public. Which, as the Bay Area knows, only makes the shock that much worse when it finally arrives.”

Even though the Bay Bridge oversight committee has fined the bridge’s main builder, American Bridge/Fluor, some $11 million in fines, the company remains profitable. It received $49 million in bonus pay for completing the bridge by Labor Day, 2013.

The rush job may wind up costing taxpayers millions.

Some 400 support rods at the base of the bridge tower have been flooded with salt water, causing at least one to fail.

The Bay Bridge’s designer admits there may be damage to the deck during an earthquake because the two large sections of the bridge didn’t fit together during construction as they should have.

Leaks have also been spotted affecting the bridge since 2012, although Caltrans claims there has been no damage from rust or corrosion.

Experts warned Caltrans needs to retrofit the Bay Bridge’s main cables to protect it from corrosion.

A review panel recommended the bridge’s main cables undergo immediate treatment to protect them from rusting, according to the Contra Costa Times. The proposed dehumidification system would protect the entire length of 18-mile cable that is inaccessible for inspection or repair.

“The technology is now well-proven and is the only protection system that will prevent deterioration and strength loss within the main cable, which arguably is the most critical element of the whole structure.”

[Photo by Justin Sullivan / Getty Images]