The work that has to be done is below the bridge roadbed and high above the water, so job one was to build platforms for the workers to stand on. Now that work is done so they can move on.
A Caltrans photo shows how they've begun chipping away at the concrete underneath the new eastern span. They are also drilling into it, preparing to thread high strength steel wires across and around. Those wires will be the cinch for the steel saddles.
"The bolts are no longer useful, so we're putting a saddle over the top. It's like a U-shaped saddle that goes over the top and pulls the whole shear key base right down and holds it nice and tight in exactly the same way the bolts would have held it down," said William Casey, a Caltrans resident engineer.
In March, 32 rods broke when tensioned inside a block of concrete around a shear key and bearing. Those are seismic features that help the road bed sway, but not break in an earthquake.
Pieces of the broken bolts could be taken out for testing, but because of their location, could not be replaced with new ones. Instead, Caltrans settled on a saddle retrofit that is supposed to serve the same function as the bolts, equally well.
"I mean, this will be safe. The saddle we're building and putting on serves exactly the same function the bolts did at exactly the same level," said Casey
The work crews are working 12 hours a day, 7 days a week, racing to get the fix in place by the opening, now scheduled for Labor Day weekend.
The saddles have yet to be fabricated; the contractor is talking to Mare Island-based XKT for the job.
"XKT has worked on this project before. They worked on the skyway portion of the Bay Bridge as well as the Yerba Buena Island transition structure. So ultimately, if they're the ones doing the work, they're not strangers to this project," said Andrew Gordon from Caltrans.
Meanwhile, there is a bevy of home-stretch work also going on, on the bridge with an eye to opening whenever that may be.
"In the home stretch, there's what's called the punch list. There is still a quite a lot of work to be done. There's painting going on, there's electrical work going on, they're still installing seismic hinges, there's paving, striping. There's a long list," said Gordon.
We should learn more about whether or not that Labor Day weekend opening date will hold next week at a special Wednesday afternoon meeting of the Bay Area Toll Authority.
