

The saga of the cracked bolts on the Bay Bridge's two-year-old eastern span continues as experts testified Tuesday at a bridge oversight panel meeting. Even though there was a minor bit of good news a couple weeks back suggesting that perhaps the rods were not all exposed to corrosion from sea water, it's looking more like the compromised bolts are going to require a very costly fix.

As the Chronicle reports, several engineering experts weighed in suggesting that microscopic cracks found on at least two of the steel bolts/rods anchoring the bridge's suspension tower to its base could endanger the integrity of all 423 rods. One even called the cracks "a portent of catastrophe."

There's been a lot of back-and-forth news over Bay Bridge troubles, and it's frustrating to everyone involved. In May, a mechanical pull test found at least one fractured rod among the group, and it's been reported that about a quarter, or a full 100 of the rods, are sitting in "sleeves" that were improperly sealed and regularly allow seawater to "flood" into them within days of being drained. Prolonged exposure to hydrogen in water can cause the steel to become brittle, and the concern now is that the bridge is not only not earthquake safe, but potentially not safe even to drive on as-is. That's at least what one of the engineers said yesterday, Lisa Fulton of Berkeley, saying, "there doesn’t have to be a lot of force on those rods for them to break."

The decision now, which won't get made until after Caltrans receives recommendations from an expert panel, is whether to modify, repair, or replace the rods. It's been suggested that replacement was nearly impossible, but experts now say that they can be replaced, it just will cost an enormous amount of money.

The bridge already cost $6.4 billion to construct, and $4 million is being spent just to investigate this problem.

All previous coverage of the Bay Bridge bolts/rods on SFist.