Engineers Soothe Nervous Panel on Bay Bridge

SACRAMENTO (CN) — Engineers reassured California officials Thursday that despite a constant, seeping influx of corrosive salt water into vital framework of San Francisco-Oakland Bay Bridge’s new $6.4 billion eastern span, the bridge can withstand a major earthquake.
     Bay Bridge Chief Engineer Brian Maroney told a three-member oversight panel that while most of the 424 anchor rods have been damaged by salt water intrusion, historic and intensive bridge testing suggests that the 3-year-old span “is in pretty good shape.”
     “You’re still going to be able to drive a tractor-trailer across it even after [an earthquake],” Maroney said.
     Maroney was tasked with leading studies on the damaged rods after microscopic cracks were noticed last summer. Caltrans officials said the 26-foot-long rods that help stabilize the 520-foot tower on the ocean floor could be failing and might need to be replaced at extreme cost to taxpayers.
     That announcement was the latest in a long line of failures since the design plans were released decades ago. With broken rods, misaligned decks and questionable Chinese and Korean steel, one of the most expensive public works projects in California history has repeatedly left officials and taxpayers demanding answers.
     The state’s legislative analyst has said that most of the landmark bridge’s problems stem from its complex design, which was chosen for “aesthetics” and not ingenuity.
     The eastern span was completed in 2013, six years behind schedule and billions over budget. The state is still trying to recover millions of dollars from contractors that failed to produce quality, timely work.
     On Thursday, Maroney updated the Toll Bridge Program Oversight Committee on the anchor rod testing that has been conducted in the past months. He said researchers compiled six computerized time tests that simulated 100-year seismic events on the bridge under various conditions.
     Researchers tested what could happen to the eastern span with all of the anchor rods in place, half in place and none in place. In each scenario there was no measureable impact to the functionality of the bridge, Maroney said.
     “I’m not worried about this tower,” he assured the panel.
     Maroney said the six time sets are the most ever performed on a California bridge and that testing should be completed in June.
     In previous meetings, the panel asked Maroney and other Caltrans engineers about possible fixes or repairs to the faulty rods, specifically, how to counteract the corrosion.
     Caltrans officials have been studying cathodic protection, which would divert the corrosive effects of sea water to an insignificant, “sacrificial” metal piece.
     An official from the Federal Highway Administration told the panel that the cathodic protection approach seems to be a good option, and complimented Caltrans for seeking fixes to the anchor rods.
     “We continue to be very impressed with the talent gathered to address this problem,” said FHA official Vincent Mammano. “Definitely an A-team.”
     The panel acknowledged that while the rods are less structurally important now that the tower is connected to the main structure by heavy cables, they may minimize damage to the bridge during an earthquake, and should be left in place.
     Mammano agreed that the rods “add value during a seismic event.”
     During his update, Maroney advocated a plan to regrout sleeves that hold the anchors in place. The panel agreed and approved a $15 million plan to regrout the sleeves to prevent further salt water intrusion.
     Caltrans officials also updated the long-awaited and also problematic bicycle path that connects Oakland to Yerba Buena Island, which sits beneath the Bay Bridge. Caltrans engineer Steven Whipple said the path is due to open in September, two years behind schedule and at an increased cost.
     Whipple told the panel that issues with sections of Korean steel have delayed the project and caused Caltrans to send the materials to a fabricator to be reworked.
     Committee member Steve Heminger lamented the latest delay and asked if the contractor should bear the cost, not the state.
     Whipple said the state will likely eat the price of the rework, and attributed the increase to a design change, not a product flaw.
     “It looks like we’re going to open the bike path three years after the bridge,” Heminger said. “This adds insult to injury.”
     The panel meets next on Aug. 5 in Oakland.

%d bloggers like this: