A ritzy San Francisco condo tower is now leaning 26 inches and is expected to tilt by a further three inches annually after work to stabil...
A ritzy San Francisco condo tower is now leaning 26 inches and is expected to tilt by a further three inches annually after work to stabilize it ended up worsening the issue.
Just months earlier, the Millennium Tower - a high-end condo tower that opened in the earthquake-prone city in 2009 and sold units for millions of dollars - was only leaning 22 inches.
However, the 58-story, 645-foot tall building is now leaning 26 inches after stabilization work to help stop the sinking was halted because the removal of earth to add stabilizing piles was worsening its slant.
Construction workers were also found to have delayed pouring in grout after removing soil from under the building, potentially worsening the issue further.
The building has already sunk 17 to 18 inches. It was only originally estimated to sink 5.5 inches by 2028, although engineers insist there is no danger of it collapsing, and residents can continue to live in its luxurious apartments.
Engineers paused the project to 'determine why increased foundation movement was occurring and how this could be mitigated.'
Structural engineer Ronald O. Hamburger has now suggested the building lose more than half of the support beams - known as piles - under the structure, going from 52 to 18 to 'minimize additional building settlement.' The holes for the support beams were originally determined to be too big in September and caused soil movement.
The lavish Millennium Tower in San Francisco has tilted an additional four inches since summer
It is now tilted 26 inches and has sunk up to 18. Structural engineer Ronald O. Hamburger has now suggested the building lose more than half of the support beams under the structure, going from 52 to 18 to 'minimize additional building settlement'
In a letter to the general manager of the building last month, engineers suggested two potential causes for the sinking: 'Vibration of the soils associated with pile installation activity, and unintentional removal of excessive soil as the piles were installed.'
Hamburger said the 18 support beams will anchor in the bedrock beneath the building.
It was later learned, during the stabilization work, construction teams had a one to four day gap between evacuating loose soil and inject grout to reduce soil collapse, NBC Bay Area discovered in an exclusive investigation.
The delay goes against protocol and could have had a significant impact on the tilt and the rapid settlement, according to NBC Bay Area.
However, a spokesperson for the Millennium Tower Homeowners Association said support beams won't stop the sinking until it is driven into bedrock, which is supposed to happen later this year, NBC reported.
Earlier this summer, stabilization work was halted after the holes for the support beams were determined to be too big and had cause soil movement
The San Francisco Department of Building Inspection has approved the 18-support-beam plan and said it was 'satisfied that the associated settlement and tilt remain within safe ranges and support [Hamburger's] proposal to continue the retrofit using the modified installation procedures.'
The Department will also inspect the beams.
Residents were first informed of the sinking in 2016, and launched a flurry of lawsuits, one of which resulted in the currently-paused remedial work.
The building's well-off residents include former San Francisco 49er Joe Montana, Giants outfielder Hunter Pence and venture capitalist Tom Perkins, who died shortly after selling his penthouse for $13million in 2016.
In 2016, the geotechnical engineer leading the investigation, Pat Shires, suspected the building could sink between 24 to 31 inches.
Chris Jeffries, a founding partner at Millennium Partners, blamed the tower's structural issues due to the adjacent Transbay Join Powers Authority transit hub in 2016.
That site also includes San Francisco's tallest building, the Salesforce Tower.
Jeffries said the soil was weakened when the transit hub dug a 60-foot hole to create a dry construction site and pumped out millions of gallons of groundwater that led to the soil weakening until the Millennium Tower.
The accelerated sinking has reportedly reduced to normal speed - equivalent to roughly an inch a year - since the construction stopped, Zaratin insisted in September.
The ritzy building is 58 stories high and is 645 feet tall
It comes with a pool, spa, in-house cinema, and a restaurant
The glossy, 58-story, all-glass building, located at 301 Mission Street, was completed in 2009 and is the tallest residential building in the city.
Equipped with a 75-foot indoor lap-pool, a health club and spa, in-house cinema, and a restaurant and wine bar run by celebrity chef Michael Mina, all 419 apartments were quickly filled with wealthy residents when it opened.
Penthouse suites sold for more than $10million, with the cheapest apartment selling for $1.6million.
But the ongoing structural concerns have spooked many residents who have decided to sell, despite assurances from city officials that the tower remains safe.
An estimated 100 condos have lost $320,000 in resell values due to the sinking.
Ongoing structural concerns have spooked many residents who have decided to sell, despite assurances from city officials that the tower remains safe
An estimated 100 condos have lost $320,000 in resell values due to the sinking
Residents of the high rise reported hearing creaking and popping sounds coming from the building in September 2018.
Former venture capitalist Tom Perkins bought his apartment for $9.4 million, and sold it for $13 million in 2016. But he spent $9 million on renovating it, and would likely have recouped more of that sum had the tower not suffered its well-publicized lean.
He died in June 2016.
A resident on the 38th floor later reported a window fissure.
The parking garage not only houses expensive cars, but floor-to-ceiling cracks. Stress gauges have been placed to measure the cracks.
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