Transbay Center denies responsibility for Millennium Tower sinkage

On the heels of today’s jarring news that the tony Millennium Tower is both tilting and sinking—a rumor that was bandied about for years but confirmed by Matier and Ross—the Transbay Joint Powers Authority issued a strong, pointed statement denying any and all responsibility for "settlement."

After the TJPA received claims for damages from residents of the Millennium Tower, the TJPA says that, after compiling years’ worth of data, "full responsibility for the tilting and excessive settlement of the building lies with Millennium Partners, the developer of the Tower."

TJPA fires a lethal blow via a press release, which, in part, states:

The 60-story Millennium Tower is made of concrete rather than steel, resulting in a very heavy building. This heavy structure rests on layers of soft, compressible soil. The foundation of the Tower, however, consists only of a concrete slab supported by short piles that fail to reach the bedrock below. That foundation is inadequate to prevent settlement of a building with the weight of the Tower. In contrast, the Salesforce Tower and 181 Fremont Tower, also adjacent to the Transit Center, are supported on piles drilled down to bedrock. Millennium Partners’ poor design decision is the cause of the tilt and excessive vertical settlement of the Millennium Tower.

Here’s why the building is sinking, according to the TJPA

[...] When Millennium Partners started construction of the Tower in 2006, they knew that the TJPA intended to excavate adjacent to their building. Nonetheless, Millennium elected short piles that did not reach bedrock. The engineers who designed the foundation for the Millennium Tower predicted that the Tower would settle vertically a maximum of six inches over the life of the building. By the time the TJPA started work on its project in 2010, the Millennium Tower had already settled ten inches – four more inches than Millennium’s engineers predicted over the life of the building. The building has continued to settle vertically, now 16 inches, even after the TJPA completed the excavation for the Transit Center. A foundation of piles down to bedrock would have prevented.

As for the tilt, the Millennium Tower is now tilting northwest, away from the Transit Center, and that tilt is only going to get worse. "Again, had Millennium Partners invested in piles extending to bedrock, the Tower would not be tilting today," slaps back TJPA.

TJPA goes on to accuse Millennium Partners of being willfully ignorant, saying that "[b]ecause the TJPA has shared with Millennium Partners its data monitoring the Tower’s settlement and the causes of the settlement, Millennium Partners has been fully aware of the extent of, and reasons for, the Tower’s unusual settlement."

In the original Matier and Ross piece, TJPA says that the Millennium Partners frugal-like ways during construction is why the building is sinking today.

In other words, the cheap came out expensive. And how.

• Millennium Tower is tilting, sinking [Curbed SF]
• A brief history of the sinking Millennium Tower [Curbed SF]
• Millennium Tower [Cured SF]
• Over-the-Top Millennium Tower Penthouse Will Make You Swoon for $9.45M [Curbed SF]
• First Look at Orlando Diaz-Azcuy-Designed 181 Fremont Residences [Curbed SF]
• SF’s landmark tower for rich and famous is sinking and tilting [Chronicle]