A top engineer on the shuttered Transbay Transit Center project said Wednesday that while much of the reinforcement work for its cracked beams will be done over the next two weeks, officials still don’t have a firm reopening date for the $2 billion project.
“We are making satisfactory progress, better than we hoped on the actual repair installation itself,” said Senior Construction Manager Dennis Turchon, after taking media on a tour of the site.
Turchon showed off 14-feet-long 2-inch thick steel plates awaiting installation on the bus deck of the center. The wing-like plates, he says, will reinforce the top and bottom of girder beams that cracked in September, a month after it opened.
“I call it a sandwich plate repair and strategy,” he said.
A total of 16 plates – four on each of the four compromised beams — will be attached using 224 high strength steel bolts – at the key joint where weld access holes had been cut into four inch thick steel.
It’s those holes, NBC Bay Area’s Investigative Unit first reported, where the cracks started. Transbay officials say the edges of the holes should have been ground smooth. That’s required by welding code because rough surfaces promote cracking.
But the steel contractor blames the project’s unique design. During the tour, Turchon pointed to gaps at the base of one beam, where the weld access hole had been.
“You can see there was an opening about one foot wide, about two feet deep, that’s been removed, that’s where the crack that we found was on this particular girder that has been removed,” he said.
“It allows us to repair this existing girder to receive the sandwich plates. Two-inch plates that will go on the top and the bottom.”
Much of the critical work will be done in the next two weeks, and the jacks installed in the center of Fremont and First streets will be removed then while work will continue till June 1.
Meanwhile, a team of engineers sort through inspection documents and photographs on 47 similar details on the massive project, looking for signs of hidden problems.
“It’s forty seven details, but those are repeated over and over and over again,” Turchon said, noting that the review thus covers thousands of connections on the project.
So far, nothing out of the ordinary has been found during the review, which is expected to be competed in two weeks. Once that’s done, Transbay officials say they hope to set a firm reopening date.
This post was originally posted at http://www.nbcbayarea.com/investigations/Repairs-Set-for-San-Francisco-Transbay-Transit-Center-508412001.html.