aegrotatioThat's an interesting problem. The progress of one of the stations being built for Phase Two of the WMATA Silver Line has fallen behind the other stations. The contractor had soil problems and they had to drive a whole bunch of piles. It went on for a few months. Now they're drilling these large tubes into the ground. The pile driver looked like it had steam and smoke coming out of it. I wonder what kind it was.
The pile driver looked like it had steam and smoke coming out of it. I wonder what kind it was.
I believe Pile Drivers these days are diesel powered. The moving head coming down to strike the pile forms a piston that is fed properly timed fuel to ignite the compressed air created by the falling head at the point of impact - what is seen as 'steam & smoke' is the diesel exhaust from what is in effect a single cylinder diesel engine.
Never too old to have a happy childhood!
Per the latest article "Millennium Partners says they are identifying the best experts" (to mitigate the settling). Waiting to see what solution they come up with, popcorn in hand. Meanwhile, I'm not visiting anywhere in the fall zone.
Pile driving along side the existing building seems a bit dicey, and I'd like to see the compact driver that would fit in the basement. Perhaps some plentiful, deep grouting through a drilled hole under the NE corner (the leaning direction) would slow the tilting; experts, please weigh in.
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Measurements by European Space Agency satellites show that the building continues to sink into the landfill at the same rate, possibly more:
http://www.businessinsider.com/satellite-images-san-francisco-sinking-skyscraper-2016-11
An address like no other, indeed.
Florida collaspe causes new worry about Millennium tower. That may cause worry for the new under construction Transbay terminal ?
Millennium Tower: Surfside catastrophe raises concerns about San Francisco's sinking building (msn.com)
The new Transit Center has been open since August 2018, but I'm not sure about the interruption due to the steel defect found and since corrected.
The Millennium Tower spokespersons are not telling all of the history. The tower was originally designed as a conventional steel frame building but was later changed to concrete/steel to 'reduce costs' (hah). Approval of the change is still suspect IMO since the building is on the ocean side of the former shoreline. This area is mostly rubble from the 1906 earthquake cleanup, not sure how that compares to south Florida sand / limestone. The foundation steel pile 'fix' sounds good, but I still wouldn't live in a highrise building with that much concrete structure.
OTOH those buildings in Miami Beach look like more disasters waiting to happen. Concrete and steel rebar in a salt fog environment, now with added rising sea level issues. Color me out of there !!
MikeF90The new Transit Center has been open since August 2018, but I'm not sure about the interruption due to the steel defect found and since corrected. The Millennium Tower spokespersons are not telling all of the history. The tower was originally designed as a conventional steel frame building but was later changed to concrete/steel to 'reduce costs' (hah). Approval of the change is still suspect IMO since the building is on the ocean side of the former shoreline. This area is mostly rubble from the 1906 earthquake cleanup, not sure how that compares to south Florida sand / limestone. The foundation steel pile 'fix' sounds good, but I still wouldn't live in a highrise building with that much concrete structure. OTOH those buildings in Miami Beach look like more disasters waiting to happen. Concrete and steel rebar in a salt fog environment, now with added rising sea level issues. Color me out of there !!
Throw in Florida's lax to corrupt politically inspired building inspections or the lack thereof - and anything above ground level is suspect for its structural integrity.
not a place I would ever want to live, fear of heights, but that is creepy. Just like the Hard Rock collapse in New Orleans, shoddy construction work. Have a friend who works in construction and he said they did not give time to dry concrete out and not enough piers to hold the building together. No thanks, I will stay on ground level. San Francisco used to never build high rises because of earthquakes and saw the Trans-America Needle on my last trip and earthquake proofed or so they said
The Millennium is a puzzle. Everyone says it has sunk 16 inches or whatever, but before they started the recent work on it you could walk into it, and you didn't step down 16 inches as you went thru the front door. You probably didn't step down at all. So has it pulled the surrounding sidewalk down with it? The sidewalk is still higher than the street, so has it pulled Mission St and Fremont St down too?
When I checked in late 2016, it seemed the sidewalk at the east corner of Mission and Fremont was 6 or 6-1/2 inches lower than it was circa 1990.
blue streak 1How is a 2 inch lean measured ?
(As of Sept 2023, it's about 28 inches.)
The confusion continues. Appears that tower took a "sudden" extra tilt. Pilig are scheduledtobe installed to bedrock. However 4 days lasped from piling excavation and grout installed. Was supposed to be done immediately. The though is soil may have migrated into the piling?
More with this link
Leaning San Francisco skyscraper is tilting 3 inches per year as engineers rush to implement fix (msn.com)
Follow up more info about additional leaning. Evidently after doing one mitigation step contractors waited 4 days when to wait to do next step could have been done immediately. Is Caltrain, CA HSR, and maybe Amtrak ever going to be able to use the new train station?
ore leaningbut only 1"
The tilt of San Francisco’s Millennium Tower has deepened as engineers work to reverse lean (msn.com)
The building is not built on fill. The bottom of the fill is 20' down at that location. The bottom of the foundation slab is 25' down. They had to remove all the fill and dig down an additional 5' for the foundation. It's the "glup" below that's causing problems.
That the writer of the above story made that mistake causes me to doubt the qualifications of that writer to, uh, write.
As of June 7, the lateral roof deflection is about 27". The foundation (and each floor above) has a slope of about 2.4" in 181'.
Ed
blue streak 1 Is Caltrain, CA HSR, and maybe Amtrak ever going to be able to use the new train station?
The explanation I heard last summer in SF about Amtrak (buses) not using the terminal has more to do with the rent being charged than anything else, including the precipitous leaning.
Waiting outside on the street in any weather for the Amtrak bus, or being dropped off by it on the street, has been part of the SF Amtrak experience for decades and is a reproach to both the City and the railroad.
CMStPnPThis is something you expect in a third world country NOT the United States.
Errors like this can and do happen to the best of them. When Japan built Kansai International, it was sinking at 150% percent of the expected settling rate. This wasn't a couple inches either, but it overshot the settling rate and protected distance above sea level decades ahead of schedule and sank nine more feet that it was supposed to. The whole dang airport had to be jacked up.
blue streak 1ore leaningbut only 1" The tilt of San Francisco’s Millennium Tower has deepened as engineers work to reverse lean (msn.com)
A look from a year ago
https://www.youtube.com/watch?v=ph9O9yJoeZY
7j43kAs of June 7, the lateral roof deflection is about 27". The foundation (and each floor above) has a slope of about 2.4" in 181'.
timz 7j43k As of June 7, the lateral roof deflection is about 27". The foundation (and each floor above) has a slope of about 2.4" in 181'. The building is 1 in 300 off of vertical, but the floors are only 1 in 900 off of horizontal?
7j43k As of June 7, the lateral roof deflection is about 27". The foundation (and each floor above) has a slope of about 2.4" in 181'.
The building is 1 in 300 off of vertical, but the floors are only 1 in 900 off of horizontal?
I am reporting numbers from the following source (Report 109, in particular):
https://sf.gov/resource/2022/monitoring-reports-about-millennium-tower-retrofit
Lateral roof deflection from page 5, foundation slope from page 4.
Thanks for that link -- I hadn't seen that. Looks like what you read as "foundation slope" is actually the increase in slope since May 2021. So the building is something over 1 in 300 off of vertical, and the floors are probably? about the same off of horizontal. (Dunno how warped the building can get.)
timz Thanks for that link -- I hadn't seen that. Looks like what you read as "foundation slope" is actually the increase in slope since May 2021. So the building is something over 1 in 300 off of vertical, and the floors are probably? about the same off of horizontal. (Dunno how warped the building can get.)
I hadn't noticed that note about "since May 2021". I thought it was true slope--my mistake.
I don't think the building can warp enough to notice. If it did, there'd be cracks everywhere. There ARE problems in the parking garage.
Since the building is about 28% wide as it is high, and the tilt is about 27" I'll assume the slope of the "floor" is about 7 1/2 " overall.
7j43k timz Thanks for that link -- I hadn't seen that. Looks like what you read as "foundation slope" is actually the increase in slope since May 2021. So the building is something over 1 in 300 off of vertical, and the floors are probably? about the same off of horizontal. (Dunno how warped the building can get.) I hadn't noticed that note about "since May 2021". I thought it was true slope--my mistake. I don't think the building can warp enough to notice. If it did, there'd be cracks everywhere. There ARE problems in the parking garage. Since the building is about 28% wide as it is high, and the tilt is about 27" I'll assume the slope of the "floor" is about 7 1/2 " overall. Ed
Don't set a ball down on the floor and expect it to remain in the spot where you placed it.
BaltACD Don't set a ball down on the floor and expect it to remain in the spot where you placed it.
Yeah. I've noticed that in my kitchen.
7j43kI don't think the building can warp enough to notice.
https://goo.gl/maps/t6TJJHKpnj6bMNHf9
And for all we know, maybe the next structure to the NE as well.
timz 7j43k I don't think the building can warp enough to notice. Which raises the question: what does "building" mean? Far as we can tell, the low building next to the tower is part of, or at least attached to the tower. https://goo.gl/maps/t6TJJHKpnj6bMNHf9 And for all we know, maybe the next structure to the NE as well.
7j43k I don't think the building can warp enough to notice.
Which raises the question: what does "building" mean? Far as we can tell, the low building next to the tower is part of, or at least attached to the tower.
building: a structure with a roof and walls meant for long-term use
Neither the "...low building next to the tower...", nor the "...structure to the NE..." is a part of the Millennium Tower, as they do not show on the construction plans for same.
They are also on separate lots with different addresses.
If square and plumb don't mean anything - set golf ball or similar hard surface ball on a hard surface floor and see if it stays where it is place.
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