Downtown San Francisco - from the Associated Press:
TILTING, SINKING SAN FRANCISCO HIGH-RISE RAISES ALARM
Pamela Buttery noticed something peculiar six years ago while practicing golf putting in her 57th-floor apartment at the luxurious Millennium Tower. The ball kept veering to the same corner of her living room.
Those were the first signs for residents of the sleek, mirrored high-rise that something was wrong.
The 58-story building has gained notoriety in recent weeks as the "leaning tower of San Francisco." But it's not just leaning. It's sinking, too. And engineers hired to assess the problem say it shows no immediate sign of stopping.
A bit more:
Completed seven years ago, the tower so far has sunk 16 inches into the soft soil and landfill of San Francisco's crowded financial district. But it's not sinking evenly, which has created a 2-inch tilt at the base - and a roughly 6-inch lean at the top.
And it is in an earthquake zone. More:
Several documents involving the downtown building were leaked in recent weeks, including exchanges between the city's Department of Building Inspection and Millennium Partners, the developer. They show both sides knew the building was sinking more than anticipated before it opened in late 2009, but neither made that information public.
And this:
The tower's troubles are apparent in its five-floor underground garage, where Porsches and Lamborghinis sit near walls bearing floor-to-ceiling cracks, many bracketed by stress gauges to measure growth.
Follow the money:
Dodson and other residents blame developers for what they say is a flawed design. The tower's foundation, for instance, uses piles driven 60 to 90 feet into landfill, rather than the pricier option of going down at least 240 feet to bedrock.
And he said, they said:
Jeffries blames the building's problems on an adjacent construction site where a city rail terminal is being built. He says the Transbay Joint Powers Authority, the public agency building the $4.5 billion transit hub, dug a 60-foot hole to create a dry construction site and pumped out millions of gallons of groundwater that wound up compressing and weakening the soil under the Millennium Tower.
Transbay says the tower's "inadequate foundation is the sole cause of the excessive settlement and tilt." It released a statement saying the building had sunk 10 inches and started to lean before the agency broke ground in 2010.
Emphasis mine - kind of hard to refute those facts... Someone is looking at spending a lot of money to fix this. My bet is that the developers tried to cheap out on the foundation and will be paying the price for it. If the buildings foundation is buoyant and floating in the soil, the first Mag 8 earthquake to hit will cause significant damage regardless of internal bracing. It will be interesting to see what the original engineers specified for the foundation - going to bedrock for a 58 story building is a zero-brainer.
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