Leaning Skyscaper in San Francisco

https://www.msn.com/en-us/news/us/leaning-san-francisco-skys…
The engineer trying to stabilize the Millennium Tower, a luxury residential skyscraper in San Francisco that is sinking into the ground and now leaning over two feet off of center, said the building is now tilting three inches per year.

The 58-story, 645-foot tall tower — opened to residents in 2009 — is now tilting 26 inches north and west at Fremont and Mission Streets in the heart of San Francisco’s financial district, according to NBC Bay Area.

But efforts to stabilize the sinking and leaning skyscraper seemed to worsen matters. Engineers halted construction on the fix in summer 2021 so they could “determine why increased foundation movement was occurring and how this could be mitigated.”

More at link

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The 58-story, 645-foot tall tower
…tilting … north and west at Fremont and Mission Streets in the heart of San Francisco’s financial district,

Just call it 200m tall (antennas and stuff).
Assuming it fell straight over… collapse would perhaps directly affect an area 250m x 250m?
And indirectly 500m x 500m?

Google MAPS shows buildings, that are more or less equally tall to MT, surrounding Millenium Tower. They might contain it, into a smaller area?

Lotta WFH?

:thinking:
ralph

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Have they considered moving all the residents to one side of the building?

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The 58-story, 645-foot tall tower
…tilting … north and west at Fremont and Mission Streets in the heart of San Francisco’s financial district …

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In the early 1970s there was an old 6 story building at this very spot that Bechtel leased because it was just across the street from Bechtel Headquarters at 50 Beale Street. I worked in this old building for about 6 years on nuclear power projects. Then the building was sold and torn down quickly without any permits from the City. This set off years of litigation and the City would not allow and construction to take place for about 20 years. This site has bad karma and bad Bay Mud as the soil/silt. IIRC bedrock could not be found. Pile driving is done 24/7 for months/years. Most buildings in SF Financial District are on piles.

This is a one of a kind soil-structure interaction problem that is baffling the best engineers. It is also a potential danger to the surrounding buildings should an earthquake happen before the truly stabile the building.

Jaak

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Have they considered moving all the residents to one side of the building?

Pfft. Wait 900 years and it’ll be a big tourist attraction.

My solution isn’t to jack up the side that’s low, it’s to lower the side that’s high. Put in steps and do like Newbury Street in Boston, retail on two levels! Then take over the lowest level and start putting some pile drivers to work. Might shake and rattle the building some, I suppose, but what could be worse than having your food slide off the table because the building is so far out of kilter?

One of my favorite TV programs on PBS is NOVA that I recently watched last week on 1/5/2022 a new hour-long airing, HIGH RISE HIGH RISK about the science behind the risks of sky high buildings from structural limits to threats presented by fire, wind and earthquakes.
https://mediaplayer.whro.org/program/nova/e/high-risk-high-r…

The San Francisco Millennium Tower is shown in the NOVA opening introduction with more revealing details and illustrations about the sinking and leaning of what is so-called the “Leaning Tower of San Francisco” at the 15:50 minute mark.
In 2016 when the news broke about the tower’s sinking and tilting, the building’s developers hired Ronald Hamburger, a veteran structural engineer from Simpson Gumpertz & Heger, to find out why the building was sinking and if it could be stopped.

The narrator explained: San Francisco rests on ancient layers of sand and clay, whereas in New York, a hard bedrock-type layer called schist lies close to the surface in many places, so anchoring tall buildings here is ideal. But in San Francisco, bedrock lies deep below the surface. And reaching it with supporting piles is difficult and expensive, so tall buildings are often placed on concrete mats with piles that don’t go to bedrock. But the piles do transmit the building’s weight through the weak upper soil layers to deeper, firmer layers. And the system normally works quite well. But for some reason, the Millennium’s extreme weight push down with force to press the soil under the piles causing the building to settle unevenly. The tower’s owners claim a neighboring construction project called the Trans Bay Terminal contributed to the uneven setting by dewatering the soil under the Millennium.

Hamburger commented: Dewatering is done in order to have a dry excavation so that you can actually build what you want to build.

Narrator: Whether the fault was dewatering or poor engineering, the sinking has slowed to about a quarter inch a year and could stop entirely. Regardless, Ron Hamburger is now heading up a multi-million dollar foundation fix that will shore up the building by extending the concrete foundation mat on the sinking corner and adding additional supporting piles that go all the way to bedrock. It is hoped that the fix will allay public fears about the building’s stability.

The NOVA program also gave a premonition of a tragedy that occurred 2 days after the show - the Bronx apartment building fire on 1/9/2022 - by addressing fires in mid-rise residential/apartment buildings and shelter in-place guidance that is widely recommended in the U.S.
John Esposito, Chief of Special Operations Command FDNY, addressed some of the significant shortcomings of current codes, commenting about older mid-rise residential/apartment buildings lacking sprinkler systems, fire alarm systems and public address systems. He stated:
It seems counterintuitive to stay in the building, but you really are safer if there’s no fire in your apartment, ‘cause to leave and go through the hallway where there’s gonna be smoke, you’re really exposing yourself to danger.

Charles Jennings, a Fire Safety Policy expert added:
The problem is, people don’t have the expertise to evaluate if there’s smoke in their hallway, is it heavy smoke? Is it incidental to a fire? They don’t know, so they are left and immediately put into a position of great anxiety. And so, sooner or later, some of them are gonna say, “The heck with this, I’m gonna try to get out of here.”
Narrator: And once in an exit stairway, there could be even greater danger.
Jennings: What may appear to be a clear stairwell on your floor, may be contaminated with smoke at a lower level. People die in stairwells trying to evacuate fires.

Sadly two days after the NOVA program, on the morning of January 9, 2022, a high-rise fire killed 17 people, including 8 children, at the Twin Parks North West, Site 4, high-rise apartment building in the Bronx of New York City. Forty-four persons were injured, and 32 with life-threatening injuries were sent to five different borough hospitals

NOVA also showcased the innovative design of New York’s Bloomberg LP Building that must have been filmed prior to the COVID-19 pandemic because there are lots of people interacting and working close together inside the building with no masks and no social distancing.

I highly recommend watching the entire NOVA presentation.

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More on topic here, I found most interesting the following comments from the NOVA program:

• Carol Willis, Director of the Skyscraper Museum, commented:
After 9/11, most people said this is the end of the skyscraper, that people will be too afraid to live in them, they’ll be too afraid to work in them.

• Antony Wood, Executive Director of the Council on Tall Building & Urban Habitat: Certainly, many people in the profession believed that it’d be the death of the tall building.

• Even William Baker, one of the world’s foremost tall building engineers and engineer at SOM (Skidmore Owings & Merrill) had his doubts: I thought that my specialty was over, that would be the end of tall buildings. Soon thereafter I was designing the world’s tallest building, i.e., the Burj Khalifa in Dubai, 2,700 feet tall, more than twice as tall as the Empire State Building.

• More recently, Antony Wood: The real driver for tall buildings are the twin effects of population growth and urbanization …. I’m often asked, what is the biggest barrier to how tall we can go? And there’s only one barrier, and it’s not technological, it’s financial. It’s whose going to pay for it?

MY THOUGHTS

While tall buildings survived the scare from 9/11, what about the impact of the COVID-19 pandemic on the workplace, specifically, high-rise office buildings, with many employees up to now having to work at home, (a) enjoying no travel time and expenses commuting back and forth to work on a regular basis, (b) having presence and time to take care of children who would normally be in day care centers or attending secondary education schools, (c) learning first hand about what school age children are being taught online and so on. Many employers in my area are rotating their employees in and out of their traditional office spaces. I have no idea how long this will last and when these office spaces will return to full capacity.

There is, however, a significant ongoing employment trend afoot that already has significantly impacted the traditional workplace and traditional jobs, i.e., freelancing/remote working. When I did my own deep dive due diligence before investing in Fiverr International Ltd. (FVRR) back in 2020, I found the following:

Market Size

The estimated United States freelancer market is $815 B annually, and Fiverr estimates that their current addressable market in the U.S. alone is over $115 B, which will continue to increase as the company launches new categories. Fiverr is in over 160 countries, yet approximately 70% of revenue today is generated from English-speaking countries.

Prior to the Corona-virus pandemic, freelancing was already a rapidly growing industry/gig-economy. Here’s a 10/17/2017 Forbes article “Are We Ready For A Workforce That is 50% Freelance?” that reported:
https://www.forbes.com/sites/elainepofeldt/2017/10/17/are-we…

If freelancing continues to grow at its current rate, the majority of U.S. workers will be freelancing by 2027, according to projections in the Freelancing in America Survey, released today by the Freelancers Union and the giant freelance platform Upwork. The survey found that 50.9% of the U.S. population will be freelancing in 10 years if a current uptick in freelancing continues at its current pace.

The number of U.S. freelancers hit 57.3 million this year, from 53 million in 2014—an 8.1 percent increase, according to the survey. That means 36% of the U.S. workforce has freelanced this year. Meanwhile, the U.S. workforce grew from 156 million to 160 million in the same timeframe, reflecting just 2.6% growth.

“The growth of the freelance workforce is three times faster than the traditional workforce,” noted Stephane Kasriel, CEO of Upwork, in an interview. And in a sign of just how much freelancing could grow, 47% of working millennials now say they freelance in some capacity, the survey found.
(snip)
Not everyone welcomes the growth of freelancing. Many people are concerned about the lack of a social safety net to support freelancers once they no longer have access to employer-sponsored benefits, such as healthcare. Buying healthcare independently, even if it’s an Affordable Care Act plan, can be costly.
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From my files, here’s an excellent macro-view of freelancing that provides a ton of food for thought that might help answer post-covid concerns/questions.

30+ Freelance Stats – Why the Gig Economy is Growing in 2020
https://www.websiteplanet.com/blog/freelance-stats/

Living in a time where remote working is not only a perk but an essential part of safe and effective business, companies are forced to rethink the way they operate.

The question of whether freelancing is just a fad is no longer relevant – it’s here, and work flexibility is now a serious consideration for organizations and individuals alike. The real question is: can you actually make a decent living doing it? And is hiring a freelancer for your project a good investment?

Vague reassurances and promises aren’t enough. You need hard data and reliable information before making an investment or changing the course of your career.

We’ve combed through the most recent reports and studies and have pulled together a ton of information that proves freelancing is something that everyone should be taking seriously, whether you’re looking for work or looking to hire.

But don’t take our word for it. The numbers speak for themselves.”
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Here’s another 6/24/2020 article “21+ Freelance Statistics to Know in May 2020” that highlights the following Jaw-Dropping Freelance Statistics among others:
https://spendmenot.com/blog/freelance-statistics/

• US freelancers earned almost $1 trillion in 2019

• Freelancers could represent 80% of the global workforce by 2030 (Source: Peerism)

57 million people freelance in America

• Freelance platforms (e.g., Fiverr, Upwork and Gigster) provide gigs for 73% of freelancers.

• An experienced freelancer earns $70,536 annually.

• A former Google employee made more than $800,000 on Fiverr

• 51% of freelancers say they won’t switch back to their traditional job. (Source: World of Freelancers)

Regards,
Ray

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