[Pedestrian]

SF builders struggle to keep transit center from rising
Matier & Ross | on October 1, 2018

Its neighbor, the Millennium Tower, might be sinking, but — get this — the new $2.2 billion Transbay Transit Center has the potential to go in the opposite direction. One of the main challenges the builders faced was keeping the three-block-long monster from rising . . . .

According to the Transbay’s website, “Unlike adjacent high-rises that generally have foundations anchored into bedrock to keep from sinking, the transit center’s foundation must keep the building from floating up.”

The reason is that unlike the 58-story-tall Millennium, which has all of its weight bearing down on a half-block base, the transit center is akin to taking the Millennium and laying it down on its side.

In effect, the transit center is like a 1,500-foot-long barge floating atop a lake of deep mud . . . .

“For that reason, we did not go to bedrock,” as you would with a high-rise, Zabenah said.

Instead, the building is tied down — held in place — by 1,896 eighty-foot-long anchors embedded in the mud.

Asked whether the beams could crack because the transit center might be rising, Zabenah said: “No, it’s a localized issue” happening only above ground . . . .

https://m.sfgate.com/bayarea/matier-...p?t=c4488d053d