SF Tower settlement Part II 18

[1503-44]

"Appreciation has dropped to 2%"
Well that's less than inflation, but more than interest rates.

Although as I said, probably nobody bought in for either of those reasons.

“What I told you was true ... from a certain point of view.” - Obi-Wan Kenobi, "Return of the Jedi"

 

[apper.42]

In my mind the Millennium Tower is similar to the miami pedestrian bridge in that it was a really bad idea right from the start. Think about building a structure more that 5x heavier per sq. ft. than steel structures around it and building it on clay fill. Call it a mistake but in my mind it is a stupid lapse of judgement; if that is hubris so be it.

 

[dik]

I think it goes a bit beyond hubris...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[SwinnyGG]

A certain Jurassic Park quote comes to mind.

 

[apper.42]

"God help us, we're in the hands of engineers."

Is the first that comes to mind for me. Or possibly "Yeah, yeah, but your scientists were so preoccupied with whether or not they could that they didn't stop to think if they should."

 

[Walnuts]

apper.42, it is not "built on a clay fill". There is fill at the site but the embedded part of the building goes through the fill and the forest of concrete piles goes down to a sand layer of variable composition and thickness at a depth of something like 80-100 feet. The problem is that the Old Bay Clay, which starts at about 100 feet is overloaded (technically was pushed back on to the virgin compression curve). Worst case is that there is an incipient bearing capacity failure in the Old Bay Clay - in laymen's term the Old Bay Clay is trying to squish out under Mission and Fremont Streets and under the podium building. (It can't squish under the Transbay Terminal because of the Arup/Koutsoftas "buttress".) It is hard to say what the Perimeter Pile Upgrade will do to this situation but one knowledgeable friend has suggested that the PPU "perforates" the sand layer, like the perforations in a roll of toilet paper, so that the sand layer distributed less of the weight of the building and more of the weight of the building is applied to the Old Bay Clay. Pretty hard to calculate with any accuracy but could be true. But regardless of that, the Old Bay Clay is susceptible to "secondary consolidation" due to re-orientation of clay minerals, which is one reason why the Tower has been settling an average of something like 1/2 inch per year for the last ten years (with a little fluctuation due to changes in the groundwater elevation). Slate seems to think that this is going to magically stop in about six years time (when with the north and west sides underpinned, the building might have leveled up), but I think that is unlikely. Also, a strong gust of wind from the west, let alone an earthquake, might be enough to squish more Old Bay Clay under the podium building. Old Bay Clay is a little stronger than young Bay Mud but has the same composition. It is just older and tends to be a little more "over-consolidated". But when pushed back on to its "virgin curve", it is a pretty soft clay. All this should have been known to the geotechnical engineers on the original design team. When Professor Jack Moehle tried to explain it away as an "act of God", he must have been out to lunch.

 

[Keith_1]

Walnut, I agree, and I think you hit the bore with the proverbial hammer. I love the use of the technical term "squish", because it is the most descriptive word to describe the conditions.

CHeers

 

[apper.42]

Agree 100% also. As the guy described when they were tunnelling, it is a bit like elephant sh*t. Yes I exaggerated about the "clay fill" but in terms of geological time it really is just over consolidated fill which unfortunately is prone to more consolidation under the high load imposed by the building.

 

[Keith_1]

I think what Hamburger is trying to say in regards to the mat being "hung up", is that the compression capacity is greater on the side in which the soil is basically captured, than the other side in which it is not, which is in my personal view is valid.

There is a train box, which DOT standards are pretty strict in terms of the amount of deflection allowed, and given the boring results implies that it is anchored in shale, with well points. . The only thing I can conceptualize to fix it would be to drive some caissons under the slab into bedrock and then bellow out the bottoms. I really don't understand why friction was even considered given the conditions of the soil.

When you build in a city, it is negligent to assume that nothing will ever be constructed near you, because everything is basically infill, and to claim "its there fault" for a faulty design is even worst.

What I don't understand is why hamburger didn't sink some 2" spoonbills into the side that he claims is hung up, in order to gain an understanding of what the condition actually is; strikes per foot, soil characterization, and moisture content can tell you a whole lot about what is happening -- and in my experience the more you know the closer you are to a solution.

 

[epoxybot]

I think what Hamburger is trying to say in regards to the mat being "hung up", is that the compression capacity is greater on the side in which the soil is basically captured, than the other side in which it is not, which is in my personal view is valid.

Undoubtedly the Tower/Podium shoring wall, the 105 ft deep TJPA shoring wall and the bedrock socketed buttress wall, result in higher modulus of subgrade at the S/E corner but the condition of the 3 ft mat being "hung up", existed BEFORE the TJPA had installed their shoring wall and later their buttress wall. Arup installed the 103 crack gauges in the basement of the tower in 2009, nearly 3 years before any ground work took place on the Transbay Transit Center property.

Transworld, the subcontractor to Balfour Beatty Infrastructure, responsible for moving the 301 Mission Screen Wall, 5 feet towards the tower, discovered cracks in the existing foundation/basement wall. The cracks are where the tower's basement/foundation adjoin the Parking Garage E/W Podium wall. It is recorded in Field Condition Report FCR-043 and reference in Webcor/Obayashi's W/O RFI T-0130

I came across this yesterday. It suggests that Hamburger's 2014 report, expressing concerns about the outriggers, during lower intensity earthquakes; might be the result of work by USGS' Mehmet Celebi.
"Responses of a 58-Story RC Dual Core Shear Wall and Outrigger Frame Building Inferred from Two Earthquakes"

Here's an interesting tidbit. The original EOR for the 301 Mission St. project, Dr. Niaz A. Nazir, joined DeSimone in July 2001 and immediately went to work on the Millennium Tower. This was when it had 3 and later 4 basement levels beneath the tower.

Previously, he had worked at EQE International, Oakland, CA. He joined EQE in 1999. In September 2001, Ron Hamburger was a Principal at EQE and head of Structural in Oakland. Hamburger was sent to work on the World Trade Center Disaster and in December 2001, Niaz Nazir was made EQE's Structural Group Manager.

Niaz Nazir passed away, unexpectedly, in May of 2004. Two days after his death, Treadwell & Rollo returned to the 301 Mission property to perform Bores B-6 & B-7, to sample the Old Bay Clay. It is the first physical indication, the tower was going to be heavier because of Webcor's scheme to move three of the tower's four basements to the podium/mid-rise.

 

[SwinnyGG]

Is the first that comes to mind for me. Or possibly "Yeah, yeah, but your scientists were so preoccupied with whether or not they could that they didn't stop to think if they should."

This is the quote I meant, but your selection is equally applicable.

Life lessons as taught by Michael Crichton and Steven Spielberg.

 

[epoxybot]

NBC: Original Cost to Build to Bedrock for Tower Like Millennium Put at Just $4 Million

After watching this video, I went looking for the Deposition of the TJPA's Executive Director from 2002 to 2015, Maria Ayerda. I had the right case number but was unable to find her deposition. What I did find was a lot more interesting, Exhibit materials! SF Superior Court case# CGC-16-553758 – Appendix of Exhibits in Support of TJPA’s Opposition to Langan Engineering’s Motion for Summary Judgment Volume 1 of 9. 2019-03-15

If you care to download the pdf file (free) it is 126mb. Go to the SF Superior Court website to query the case# and scroll down to 2019-03-15 Volume 1.

Beginning on page 50, are email exchanges, regarding settlement & the tower moving to the east, beginning in March of 2007. Webcor didn't notify Treadwell & Rollo until June 8, 2007. Ramin Golesorkhi of Treadwell & Rollo, under a sworn oath, told the SF Govt. Audit & Oversight Committee's Hearing on May 16, 2018 that there was only one settlement survey marker to monitor the tower. That wasn't the truth, the whole truth & nothing but the truth.

Page 62 shows that the podium wall was cracked and leaking before October 2008.

Starting on page 65, are settlement calculations based on the equivalent footing approach. The calculations are dated 10/28/2008 but the correspondence is from 2005. The deadload data was produced 6/16/2006 and doesn't quite match up to the 4 volume foundation calculations, dated May 24, 2005. There were two subsequent addendum to the foundation; with the last dated March 6, 2006. The deadload of the tower in 2005 was 208,622 and in March 2006 it is 221,180. At some point between May 2005 & March 2006, the mat slab increased from 9 ft to 10 ft and then they had to do some beefing up of the 2nd & 3rd floor due to the sloping SMRF at the south end of the tower.

On page 132 to 225, Treadwell & Rollo provide recommendations regarding the piling. This includes the full set of Indicator Pile driving records, the letter/s from InSituTech & CapWap results. InSituTech's letter date Nov. 17, 2005 comes with an expired engineering stamp. Granted, it is only 7-1/2 months out of date.

What is noteworthy about Treadwell & Rollo's - Ramin Golesorkhi's calculations, is that it doesn't account for the interference to the calculation by the tower/podium shoring wall. This is in October 2008, when the tower was already topped-out. Dare I quote Ron Hamburger and his statements regarding the south end of the foundation & the TJPA's Buttress Wall resulting in higher modulus of sub-grade?

Maria Ayerda was blowing smoke in her deposition. The TJPA was completely clueless to what Millennium was doing with the tower foundation. Why would the TJPA update their FEIR to proceed with a "Top-Down" design for 4 to 6 months and then immediately change course when they signed the Easement Agreement with Millennium Partners?

It turns out, the Perimeter Pile Upgrade is holding up Ron Hamburger's https://www.enr.com/articles/48570-ronald-o-hamburger-named-legacy-award-winner-for-northern-california+&cd=3&hl=en&ct=clnk&gl=us&client=firefox-b-1-d]retirement[/url] as managing principal. He will still be Chairman of SG&H.

SFDBI has given Shimmick/Legacy permission to install 8 ea. 36 inch casings on Mission St. based on the "Success" of the 36 in. casing. By my count, that is 41 of 42 total; so it could be the final 8, to finish the 36 inch casings. Shimmick/Legacy apparently needs a part for the 24 inch casing rig. Haven't they had at least a month?

Ron Hamburger claimed the 36 inch casing test was a success, yet the settlement result over the remaining week's time, resulted in the maximum settlement and they haven't even drilled the 24 inch casing for the so-called test pile.

 

[apper.42]

So, using my simple minded approach 1/4" per pile (which I understood was their limit for the test) with a total of 8 piles gives another 2" of total settlement which could be likely, doesn't sound very hopeful to me. Sounds more as if this disaster is going to worsen soon if they don't stop what they are doing. Oh and we would still have 8 20" piles left to finish.

Stop, stop!!

 

[epoxybot]

The SF Govt. Audit & Oversight Committee will hold a hearing on the status of the Millennium Tower Perimeter Pile Upgrade this Thursday, along with other business. The committee's meeting time is 10 AM Pacific.

I'm stunned! I have been suspicious and hard on Millennium Partners in my postings to this thread yet today I find that the TJPA was made aware of Millennium's design changes from 4 basement levels to just one in 2005.

In 2004 the TJPA's Executive Director enlisted the help of Arup, who was working on behalf of URS for the Caltrain component of the Transbay Transit Center, to evaluate a project that was in conflict with the footprint of the future rail approach to planned transit center. That project was 80 Natoma, a 52 story concrete high-rise that would have been the tallest, heaviest residential tower, west of the Mississippi.

In 2004 Demetrious C Koutsoftas, associate principal at Arup's San Francisco office, won the Ralph B Peck award for his paper 'Post-preload settlements of a soft bay mud site.'

Demetrious Koutsoftas assembled a Blue-Ribbon panel of Geotechnical Experts to look at 80 Natoma.
Dr. Jonathan Bray, Dr. Thomas D. O'Rourke, Professor Youssef Hashash, Dr. Andrew J. Whittle & Professor Emeritus Charles C. Ladd (Deceased). Not only did these eminent geotechs have concerns regard subsidence of 80 Natoma and also express their reservations as to the prospect of the TJPA's subsequent train tunnel build under the tower; two of the geotechs hinted that ground failure was a possibility, were the tower and the train tunnel to be built. A buttress wall of the tower was one scenario examined.

80 Natoma was a Tubex/Fundex piled project on similar strata but inshore and uphill of the 1852 Yerba Buena cove. 301 Mission was in the tidal zone of the cove, where tidal influence persists.

It turns out, according to court records, that the TJPA's Executive Director, Maria Ayerda, the TJPA's Chief Engineer, Elizabeth Wiezcha & Arup's Demetrious C Koutsoftas, were apprised of Millennium Partners new tower design & foundation in 2005. So they could have taken steps to insist that the foundation go to bedrock but instead chose to ignore it. The Aug. 23/24, 2005 email stream between TJPA's Chief Engineer, Elizabeth Wiezcha & Arup's Demetrious C Koutsoftas begins immediately prior to the Peer Review panels acceptance of the foundation design and demolition of existing structures remaining at the site.

Oddly, it was Demetrious Koutsoftas, in emails that expressed concern regarding disclosure of the revised 301 Mission tower foundation at a TJPA workshop, advising that there were people attending the workshop who could spread this information and how it would effect the TJPA's relationship with Millennium Partners!

Demetrious Koutsoftas had worked on the downtown Caltrain Extension for URS & then Arup, since 1997. He left Arup in 2006 ~retiring~. Later he filed article of incorporation with the Calif. Secretary of State in 2006.

After Pelli, Clark, Pelli contracted with Arup to provide subsurface engineering design for the transit center, Arup requsted that the TJPA permit the wording of their contract be changed to include the word 'negligent' ahead of the wording errors & omissions. It seems the negligence had already occurred.

Maybe Demetrious Koutsoftas' 'retirement' was a swift kick out the door.

 

[dik]

It seems to get more interesting... as I noted earlier, my experience with Arup is limited and based on that they are 'top drawer'. I'm surprised that this wasn't dealt with in greater depth.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Walnuts]

epoxybot, I believe that Demetrious left Arup because of internal company politics.

But here is something really shocking. I finally got around to reading Treadwell & Rollo's 2005 revised geotechnical report (available on Larry Karp's web site.) Here is the piece on the foundation recommendation:

8.1 Foundations
8.1.1 Tower

We considered deep (piles) and shallow (mat) foundations for the support of the proposed tower structure. The sandy fill encountered in the upper 12 to 23 feet of the borings will be removed in its entirety during excavation for the proposed basement. However, Marine Deposits will be exposed at the base of the planned excavation and are unsuitable for support of a mat foundation. In addition, medium dense sandy layers encountered are expected to liquefy in the event of a major earthquake, as discussed in Section 7.2.1. Therefore, we judge a mat foundation would not be appropriate for the proposed 60-story tower.

On the basis of the results of our analyses and evaluation, we conclude the proposed structure should be supported on piles. Piles would derive their capacity from a combination of skin friction in the medium dense to very dense sand and medium stiff to stiff clay, and end bearing in the dense to very dense sand. From our experience with similar projects, we conclude precast, prestressed concrete piles or an auger displacement pile system (details are described in Section 9.2) are the most appropriate pile types for the project. We understand on the order of about 1,000 piles will be required to support the tower. Although piles will transfer building loads to less compressible strata, some settlement of the pile foundations will still occur. The settlement of the large group of piles will be due to the consolidation settlement of the underlying overconsolidated Old Bay Clay. We estimate settlements on the order of four to six inches could occur under the tower.

That's it! For a high profile 60-story building! No mention of the stress that will be applied to the Old Bay Clay. No mention of whether the Old Bay Clay might be pushed on to the virgin consolidation curve. No mention of secondary consolidation. Total reliance on "our experience with similar projects" when they had never done a similar project!

 

[dik]

...and with the concrete mass, this is not likely similar to any other project done.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[epoxybot]

Yesterday, I was asking myself, 'Why didn't Millennium Partners just come right out and say, they shared their foundation plans with the Transbay Joint Powers Authority in Oct. 2005, after receiving SF Planning Commission approval in July of 2005?' The most Chris Jeffries ever said, was that 'they were never asked to extend piles to bedrock.'

Now, for some reason, in the last 24 hours, I have been reminded that 2016 was an election year. California Gov. Newsom was mayor of SF in 2005, and running for Governor. It would have brought the wrath of many, had it been disclosed that the TJPA, which is weighted 3/2 with SF TJPA board members, had dismissed concerns about 301 Mission; with the specter of 80 Natoma rising up in the press. Newsom, who is House Speaker Pelosi's nephew, would have been rag-dolled by the GOP nationwide.

I've been through all the TJPA Board of Director meetings from 2003 to 2006 and the TJPA Citizens Advisory Committee meetings and not a word was ever mentioned about 301 Mission until the Item appeared on the agenda, in 2009, to vote on authorization for the Executive Director the execute the Easement Agreement with Millennium.

The subsequent confidentiality agreement is looking a lot like Quid-Pro-Quo.

Maria Ayerda, the Executive Director of the TJPA, was hand picked by Willie Brown and given an office at the San Francisco Municipal Transit Authority, prior to the creation of the TJPA.

Silly me, it all makes sense now.

 

[epoxybot]

Fix Designer Says Millennium Tower Could Tilt 6.5 Feet, Still Withstand Major Quake

 

[Walnuts]

Yes, but what will happen to the tops of the existing concrete piles if the building tilts that much. Oh, they are made of spaghetti?

 

[dik]

'could'? what happens if it can't? I have no idea of what secondary stresses develop in a brittle concrete structure with that sort of deformation... I hope the design is as robust as the foundation.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik