Breaking Down Transbay Transit Center

We jumped on board an intimate tour of Transbay Transit Center, first convening at Transbay Joint Powers Authority's home base at 201 Mission to get a bird's eye view and hear opening remarks from TJPA senior construction manager Dennis Turchon. Above, superintendent Monique Hawn gives us the sidewalk tour of the rising project. Attendees included some heavy hitters (Shorenstein's Jim Collins and New York Life Real Estate Investors' Dave Cumming), as well as local kids on a field trip through Boys & Girls Clubs of S.F. The 14-year-olds posed some great questions, such as what would happen to the transit center during an earthquake? (Curious teenagers: Nature's consultants.)

You've got to be prepared long before an earthquake happens, says Dennis. The Transbay Transit Center's been designed to stay operational immediately, with no major loss. There are two ways to withstand an earthquake, he says. One is the Western Bay Bridge route (let it move and be flexible); the other way is to make it solid, which is Transbay's approach. In short, Transbay is comprised of a concrete boat. Because of the power of the water underneath, 1,900 micro piles—or 12-inch holes with a rod going into them—have been pushed into the ground to keep that concrete box down. Above, a rendering of the interior of the transit hub. The project will rise 70 feet from the ground, and is so long that nearly two Ferry Buildings could fit into the excavation.

Excavation is now done, he says, with 640,000 cubic yards that came out of the ground. (That included some of the best beach sand they've ever seen, which had a nice after-market.) In late summer or early fall, structural steel will start to go in. Dennis calls the tubular steel the bones of the structure, taking on the look of the Yerba Buena Gardens/Moscone (but much stronger). It'll be the antithesis of what the 1930s dark and tight terminal looked like, which even had a prison. It's going to be so beautiful, Monique suggested the kids' weddings could be there some day (as expected, the tweens groaned). Dennis touched on the second phase, which is still unfunded (estimated cost is $2.5B to $3B). It's 35% designed and will stay that way (if it gets down to a p3 design-build, you don't want the whole thing designed at that point).