Archinect - News

San Francisco's Millennium Tower is sinking again despite foundational corrections

2024-02-22T17:52:00-05:00

San Francisco’s ill-fated Millennium Tower is making headlines once again for problems taking place beneath its turbulent foundation.

This time, the 58-story skyscraper is sinking even further on its vertical axis as it settles to the north and west, alarming some building scientists who feel the movement could result in significant corrosive damage despite some recent positive corrections.

Engineers say a fix that has been previously made to anchor its foundation into bedrock on the north and west sides has mostly failed to produce the 4-inch reversal their advanced data models had predicted, instead posting a correction of just a quarter-inch a year and, as outside experts surmised, causing the new directional shift that's happening in an unexpected area.

Now, the building is sinking from underneath the center of its foundation mat at a rate of one-tenth of an inch per year. The phenomenon is known as "dishing." A local geothermal engineer who is monitoring the issue told NBC Bay...

Bologna unveils plan to reinforce 12th-century leaning tower

2023-12-08T18:30:00-05:00

Work to prevent the collapse of a leaning medieval tower in the heart of the northern Italian city of Bologna will cost €20m ($21.5m) and take 10 years at least, its mayor has said. Last weekend, the city unveiled a €4.3m (£3.7m) project to shore up the Garisenda tower – one of the city’s two towers that look out over central Bologna, providing inspiration over the centuries to painters and poets and a lookout spot during conflicts.

The Garisenda Tower, like the Tower of Pisa, has leaned for centuries as the ground on which it was built gave way soon after its construction. It slants at four degrees compared to 3.9 degrees the Tower of Pisa leans at. Last month, the area around the Garisenda Tower was cordoned off due to increasing concerns about its potential to collapse. Bologna’s mayor, Matteo Lepore, claims that the time to restore the structure will match the 10 years it took to reinforce the Tower of Pisa.

Built in the 12th century, the Garisenda Tower, which stands at approximately 157 feet, sits alongside the taller, and also leaning, Asinelli Tower. As reported by The Guardian, Italy’s civil protection agency has issued a “yellow” alert for the area around the two towers indicating the space is under watch. However, they aren’t believed to pose any immediate risks to people’s safety. The mayor has also urged the government to work to make the towers UNESCO World Heritage sites. Work to reinforce the to...

San Francisco's Millennium Tower is tilting even further, despite engineering fixes

2023-06-15T16:54:00-04:00

Despite initial progress in the first phase of the so-called fix earlier this year, the sinking and leaning Millennium Tower in San Francisco is now tilting more to the west than ever, according to monitoring data reviewed by NBC Bay Area’s Investigative Unit. The tower is currently leaning more than 29 inches at the northwest corner of Fremont and Mission streets, much of the added tilt occurring during the digging needed to prepare to support the tower along two sides.

The data came from a rooftop monitoring system, which the fix’s chief engineer Ron Hamburger said was less reliable than the one contained in its foundation before stating the half-inch tilt recorded was "negligible."

A geotechnical engineer working on the $100 million project expressed his dismay to reporters, saying: "You spend all this money, but you still have an uncertain result long term."

The structure is leaning so much that some involved think it could potentially be red-tagged in the aftermath of a major earthquake, which the U.S. Geological Survey says has a 20% likelihood of occurring in the next 30 years.

The Real Deal gets straight with Manhattan’s 'Leaning Tower of FiDi'

2023-03-13T11:43:00-04:00

You’ve heard of the Leaning Tower of Pisa, but did you know New York has its very own leaning tower? Manhattan’s “Leaning Tower of FiDi,” developed by Fortis Property Group, has this dubious distinction: It is tilting by three inches to the north, and has been beset by numerous construction delays, disputes with lenders and more. How did this engineering blunder ever come to pass?

One Seaport (aka “161 Maiden Lane”) is now the subject of a contentious lawsuit between Fortis and the project’s construction engineer Pizzarotti. Pizzarotti claims the developers are at fault owing to shoddy preparatory work on its foundation, which left the tower at risk for catastrophic failures for portions of its facade, structural concrete, and even elevators.

Construction has since stalled out as various solutions are proffered. If it is ever actually completed, its 80 luxury units could be filled with tenants lured by yacht rental offers. A rather high-end incentive for the wealthy in a city where their opposites face their own daily risks caused by different forms of structural neglect and incompetence.

The Leaning Tower of Pisa is still straightening things out (a bit)

2023-01-05T12:16:00-05:00

Results from the Leaning Tower of Pisa’s annual checkup are in, as of November 30. After a stabilization project, begun in 1990, reduced the quirky monument’s dangerous lean by a full 15 inches, the tower has straightened itself out by an additional 1.6 inches since 2001. Some Italian officials are taking that optimism further, claiming the Tower could stand all the way straight on its own some day.

This is the second update to the engineering project since 2018. The tower is expected to last at least another 300 years. In a statement to the press, the Italian heritage group Opera Primaziale Pisana said the nearly 850-year-old monument's overall health was "excellent."

Repeated attempts of tourists to correct the lean themselves still appear not to be having any effects.

The Millennium Tower is now sliding as it sinks (and tilts)

2022-03-01T11:06:00-05:00

It’s doing it (again). San Francisco’s Millennium Tower is on the move once more, this time in an entirely different dimension as the 13-year-old building is sliding while it sinks and tilts.

Now the tower is said to be moving to the east, specifically. The firm in charge of stabilizing the former Handel project testified the 58-story building’s “horizontal movement” in documents that were provided to the city during last year, according to NBC Bay Area.

The reflection of a building and crane on Millennium Tower's (301 Mission Street) curtainwall glass. Image courtesy Wikimedia Commons user Hydrogen Iodide.

Ron Hamburger is back again as the engineer telling everybody they were essentially fine to occupy and that the building’s shift left has added another half inch since beginning construction on the perimeter pile upgrade late last summer, coupling with the 24-inch tilt on the roof to create an inch-wide gap between the tower’s foundation mat and adjacent building's five-floor und...

San Francisco’s infamous Millennium Tower is still sinking… and it may be running out of time

2022-01-11T19:35:00-05:00

[...] Millennium Tower – a luxury condominium where star athletes and retired Google employees bought multimillion-dollar apartments before they realized it was sinking – is continuing to sink and tilt to the side by about 3in (7.5 cm) a year, according to the engineer responsible for fixing the troubled building.

At that rate, the building’s elevators and sewage systems would cease to function within a few years according to engineer Ron Hamburger’s report to the city’s municipal Board of Supervisors last week. He also told the 11-member body that the movement was inevitable, adding that, based on his observations, the degradation would continue “whether we are conducting work at the site or not.”

Hamburger did reportedly declare the building safe for use, however, stating that the placement of 18 steel piles in the bedrock of the structure would help significantly increase its stability.

The 58-story Handel Architects-designed tower became a headache for the property managers shortly after opening in 2009 to considerable fanfare. Repairs had to be halted back in August after it was discovered to be sinking at an accelerated rate just weeks after the $100 million rescue scheme had begun. The sinking process has thus far reaped a lot of unwelcome consequences, although some inventive onlook...

Work on San Francisco's Millennium Tower repair halted after further sinking discovered

2021-08-30T13:24:00-04:00

Work on the $100 million fix of the Millennium tower has halted as engineers scramble to figure out why the building has suddenly sunk an inch in a matter of weeks since construction began, NBC Bay Area’s Investigative Unit has learned.

The “perimeter pile upgrade” project, paid for as part of a confidential settlement reached last year, is designed to reinforce the foundation of the 58-story, luxury Millennium Tower after it had been discovered in 2016 that the northwest corner of the structure had sunk 16 inches since its opening in 2009. Fast forward to 2018, an inspection revealed the building had descended an additional two inches.

Previously on Archinect: Settlement reached for sinking Millennium Tower in San Francisco

The upgrade project was developed over several years and calls for the installation of 52 concrete, 140,000-pound piles that would anchor the building to bedrock approximately 250 feet below ground. However, shortly after work began on the stabilization project in May, apparent acceleration in both the tower’s sinking and tilting to the west has appeared. And, as reported by NBC Bay Area, the foundation has sunk an inch since the start of the work, resulting in a tilt of 22 inches.

The Milleni...

Faulty foundation blamed for leaning 60-story One Seaport tower in Manhattan

2019-04-26T14:57:00-04:00

Construction at One Seaport, aka 161 Maiden Lane, has been noticeably paused for the past several months. [...] new reports have revealed the 670-foot-tall building is actually leaning three inches to the north, leading to a series of legal disputes between Fortis Property Group, LLC, the developer, and Pizzarotti LLC, the current contractor. The project is being designed by Hill West Architects while Groves & Co is serving as the interior designer.

"It remains unclear how this will affect the plans for 80 South Street directly next door," writes Michael Young for New York YIMBY about the unclear fate of the 670-foot-tall tower which structurally topped out last September. "There is a question of whether One Seaport should remain standing or be demolished for imposing a safety concern for the surrounding area and the possible construction of the adjacent supertall."

Leaning Tower of Pisa now actually a bit straighter

2018-11-26T13:39:00-05:00

The Leaning Tower of Pisa is known worldwide for its precarious tilt - but now experts have revealed it's going straight. The tower's Surveillance Group, which monitors restoration work, said the landmark is "stable and very slowly reducing its lean." The 57m (186ft) medieval monument has been straightened by 4cm (1.5in) over the past two decades, the team said. "It's as if it's had two centuries taken off its age," Professor Salvatore Settis explained.

Meanwhile in San Francisco, owners of the leaning Millennium Tower are far less eager to turn their tilting property into a tourist magnet.

San Francisco's sinking Millennium Tower now emitting unsafe odors found to be a fire hazard

2017-12-19T13:36:00-05:00

In a December 2016 assessment of the issue obtained by NBC Bay Area, Palo Alto-based building consultants Allana Buick & Bers Inc. trace the odors to openings between the building’s façade, or curtain wall, and the core structure. The consultants point to the “excessive” settlement as a likely source of the issue, adding, “This condition may be more widespread than these two test areas and may be present in the entire stack. We recommend further investigation of this issue.”

New fire hazards have been found in San Francisco's infamous Millennium Tower, making the luxury high-rise that has sunk 17 inches since 2009 even less safe than previously thought. According to a December 2016 assessment carried out by building consultants Allana Buick & Bers Inc., gaps between the building's walls and structural frame have been found. These openings "represent a breach in the fire and smoke barrier" that in the event of a fire, would allow smoke to jump floors posing a huge safety risk to the occupants.

Allana Buick & Bers Inc. were hired by condo owner Paula Pretlow to assess the tower in order to trace the source of foul orders that had been plaguing the occupant. The consultants discovered that smells were likely coming from gaps that had occurred as a result of the structure's settlement. However, these findings were redacted from the copy of the report they returned to Pretlow.

Pretlow has spent a year in court fighting to see the original reports and after ...

SF Millennium Tower continues to sink; engineers suggest a possible fix

2017-07-19T17:29:00-04:00

A fix appears to be in the works for San Francisco’s sinking and tilting Millennium Tower — just as a new report estimates the 58-story luxury high-rise has sunk yet another inch in the past seven months. [...] That lean is now up to nearly 14 inches at the building’s roof — an additional 2-plus inches more than the tilt measured in January.

A pair of engineering firms hired by developer Millennium Partners think there's still hope to save the troubled structure and straighten it up again: "The LERA firm and DeSimone Consulting Engineers say the problem can be remedied by drilling 50 to 100 new piles down to bedrock from the building’s basement," the Chronicle reports. "The engineering firms estimate the fix will cost $100 million to $150 million — more than your average home foundation repair, but a lot less than the billion-dollar-plus price tag that some experts have feared."

Urgency is increasing though as a new engineering report by Arup Group presents evidence that the rate of sinking remains steady and cracking in the basement continues.

Still no end in sight of San Francisco's 'Leaning Tower' fiasco

2017-01-05T13:01:00-05:00

Pamela Buttery lives on the 57th floor. To demonstrate how her home tilts slightly to the left, Buttery hits a golf ball straight ahead toward the window. [...] The ball takes a sharp left turn toward the direction of the tilt, and it ends up in the northwest corner of her living room. [...] How to fix the tower, or at least keep it from leaning even more? Some solutions include pouring a concrete collar around the foundation or building a buttress.

Representatives of the sinking luxury condo tower put the blame on the Transbay Transit Center, a sizable new train and bus terminal currently under construction nearby:

"Millennium spokesman P.J. Johnston says workers have been pumping out huge amounts of water as they tunnel through the soil. Johnston says that process, known as dewatering, is destabilizing the ground. [...] Johnston says engineers have inspected the tower and confirm it's safe."

Many of the million-dollar-property owners at this now infamous address aren't easily quietened though, and a permanent engineering fix has yet to be found.

The troubled structure previously in the Archinect news: