Back in October we first heard the news that, among all the other problems with the new span of the Bay Bridge, most of the 423 steel rods securing the span's tower base had been bathing in potentially corrosive water, and were therefore in danger of cracking. Now, as the Chronicle reports, it's been confirmed via an integrity test that some of the rods are probably already compromised.
The "mechanical pull test" was conducted Wednesday seeing if one of the rod's fasteners moved when tugged. It should not, but it did.
Bridge engineers insist the bridge is still safe and this testing is all with a view toward long-term maintenance, but the news comes just days after we learned that salt water may also have been seeping into the foundation of the tower, helping to soak the steel rods and the sleeves they sit in. Previously it had been believed that it was just faulty grouting that was to blame for the seepage, but now it looks more complicated than that.
This all comes after the $45 million fix that had to be put in place after the opening of the bridge and the revelation that steel bolts on another part of the bridge had been weakened and/or cracked. In that case, the compromised bolts were at the eastern end of the new suspensions span where the suspended portion of the bridge is secured to a concrete support beam below. The NYT made a nice info-graphic at the time explaining the issue, and the "saddle" solution that was put in to fix that problem.
The new problems at the tower base sound much bigger even than that problem, and sound downright un-solvable. But let's just hope that our next big earthquake doesn't hit before they figure this out.
