The homeowners of the Millennium Tower in San Francisco are expected to file a permit application for 50 new 24-inch diameter piles approximately 250 feet long to hopefully stabilize the building and perhaps even reverse some of the tilt. The 58-story luxury condo tower opened in April 2009 and has since settled approximately 18 inches and is tilting approximately 14 inches to the west, earning it the nickname “leaning tower of San Francisco.” The piles will be installed along the north and west sides of the street. The initial work in the permit is priced at about $30M, but the total price tag is expected to be $100M. The repairs will be funded from proceeds of an ongoing, confidential mediation. The developers blamed the settlement on dewatering that took place during the construction of the adjacent Transbay Transit Center.
The residential high-rise Millennium Tower in San Francisco has settled a total of 16 inches since opening, 2 inches deferentially. A spokesman for the tower owner blames the settlement on the excavation next door for the Transbay Transit Center, a $2.4 billion dollar project being constructed 60 feet underground.
However, the Transbay Joint Powers Authority (Transbay) hired geotechnical firm Arup in 2010. Their initial report indicated that the tower had already settled 10 inches by the time excavation began for the Transit center. Arup seems to have been tasked with design, installation, and perhaps monitoring of a geotechnical monitoring program, some information on the scope is available in a 2012 presentation given by Arup available on the Transbay website.
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