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San Francisco Luxury High-Rise is Gradually Sinking

 A luxury high-rise in downtown San Francisco has started to gradually sink, and recent satellite images confirm that the problem is growing urgent.

The 58-storey Millennium Tower has already subsided into the soft earth of the busy financial district by 16 inches since its completion in 2009.  Satellites from Sentinel-1, the European space agency, have transmitted images that show the skyscraper sinking approximately 40 mm every year. The sinking is not even, resulting in a two-inch tilt at the base of the building and a six-inch lean at the top.

The tower is located in a major earthquake fault zone, creating alarm and turning the situation into a public scandal. Although the cause for the sinking has not been pinpointed, the general belief is that the supporting piles are not sitting firmly on bedrock. Engineers say that there are no immediate signs of the problem stopping.

One tenant noticed something amiss around six years ago while golf putting in her apartment on the 57th floor. The ball kept rolling to the same corner of the room. Other residents soon started wondering if it was safe to stay in the building.

The situation is readily apparent in the underground parking garage, where the walls have floor-to-ceiling cracks, many of them marked by stress gauges to determine growth.

Documents involving the Millennium Tower were recently leaked, such as communications between developer Millennium Partners and the San Francisco Department of Building Inspection. They reveal that both sides were aware of the gradual sinking prior to the building’s opening in 2009, but neither entity made the information public.

Structural Defects Insurance

Raymond Lui, a chief buildings inspector, contacted DeSimone Consulting Engineers, the building’s engineering firm, in February 2009 to express concerns and ask what was being done. The firm replied that although the Millennium Tower had settled an unexpected 8.3 inches, the structures were believed to be safe.

When asked why the building was declared safe for occupancy, Mr. Lui replied that the problem was assumed to be under control.

Arguments over who is to blame are running rampant among tenants, developers, city officials, and politicians.

Engineers have been working to determine why the tower keeps sinking and if there’s a way to stop it. The assessment process, which involves deep drilling and soil sample testing, is expected to take months.

The geotechnical engineer in charge of the project said that current data suggests the tower could potentially sink a total of 31 inches maximum, but the exact depth is currently impossible to predict.

When the Millennium Tower opened, its 400-plus apartments were quickly snatched up by the city’s well-to-do. Purchasers included Tom Perkins, the late venture capitalist, and Joe Montana, former Francisco 49er.

The building, whose penthouses have sold for over $10 million, has a health club and spa, 75-foot indoor pool, and a restaurant presided over by Michael Mina, the renowned celebrity chef.

Millennium Partners founding partner Chris Jefferies insisted that the building is “100 percent safe” and that many San Francisco skyscrapers have similar foundations. He blamed the problems on an adjacent construction site, where a rail terminal is being built.

 

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