Miami Beach, Champlain Towers South apartment building collapse, Part 03 148

[SFCharlie]

A continuation of our discussion of this failure. Best to read the other threads first to avoid rehashing things already discussed.

Miami Beach, Champlain Towers South apartment building collapse

Miami Beach, Champlain Towers South apartment building collapse, Part 02

Thank you

SF Charlie
Eng-Tips.com Forum Policies

 

[spinspecdrt]

Good eye. I wonder if the beam was even there? Per the typical beam detail the top bars (2 #6) should have 180° hooks. I would think there would be major damage to both columns if those pulled out....

I'd be curious to see as built conditions at lobby level <K/14.1. The way the 14.1 beam connects to the column west of the 1' step at K.

 

[DavPc]

Has anyone heard how they are going to get the pets out (of the un-collapsed part), before demolition?

Sadly, I fear the answer is they aren't, and the optics for that decision are going to be pretty bad - to say nothing of the optics of dropping the rest of the building on the undiscovered remains of the residents that didn't make it out. I hope I'm wrong though and something can be done.

The fire department has been feeding and watering any pets from balconies that have their doors open using their ladders:

https://youtu.be/G57mhnZWF_w

But because no sweeps are being done anymore there's no way to know which pets are still there and are still alive. It must be awful being in a building with no AC where the temps are 80-90 degrees every day.

 

[Roga50]

Regarding pets: Link

 

[IEGeezer]

Document received on June 29, 2021:

REPORT PREPARED BY THE HISTORIC PRESERVATION COMMUNITY

https://www.townofsurfsidefl.gov/do...-preservation-community.pdf?sfvrsn=8c1f1194_4

On page 8 there is a little different take on how the collapse occurred.

 

[Retiredat46]

It's being reported on CNN that the mayor has signed an order for the remaining part of the building to be demolished. There's no time frame for that to happen yet, and the search and rescue effort will continue.

 

[warrenslo]

Yes, we all agree the structural plans are a mess, but I think the roof anchor plans are a mess too. This work was occurring the day of the collapse. So I continue to start there as the initial cause. Remember the Kansas City collapse was down to a simple bolt detail.

The reading of this note appears incorrect:

The 5,000 lbs. testing number doesn't make sense with the Hilti adhesive anchors.
HAS-V-36 et all is carbon steel and HAS-R is stainless steel and both have very different capacities at 5/8" dia.
Stainless steel should have been used due to being near the water but "carbon steel" was specifically stated in the note on the plans.
And, neither of them divide to any reasonable multiple of 5,000 lbs. for testing, but the OSHA rule does for the entire assembly including 4 x adhesive anchors do see below.

The OSHA Rope Descent System (RDS) Anchorage (not a fastener) needs to withstand 5,000 lbs. ultimate load in any direction.
In Florida rope decent systems are allowed in buildings less than 300 feet and above 300 feet if it is the only feasible method of access.
Rope Descent System (RDS) Anchorages must be tested before first use and at regular intervals.
IWCA/ANSI I-14.1-2001 Section 8.1.3 requires testing of twice the 1,250 lbs. design load in each primary direction or 2,500 lbs.

OSHA 2019 Testing Interpretation

January 25, 2019

Mr. Reg Ranahan
GSS Corporation
80 Hudson Road, Ste. 100
Canton, Massachusetts 02021

Dear Mr. Ranahan:

Thank you for your letter to the Occupational Safety and Health Administration (OSHA)[. Your letter has been referred to the Directorate of Enforcement Programs for an answer to your specific question] regarding 29 CFR 1910.27(b)(1)(i). [This letter constitutes OSHA's interpretation only of the requirements herein, and may not be applicable to any question not delineated within your original correspondence.] Your letter requests clarification of the requirements for rope descent system anchorages under 29 CFR 1910.27(b)(1)(i). Your paraphrased question and OSHA's response are below.

Question: International Window Cleaning Association/American National Standards Institute (IWCA/ANSI) I-14.1-2001 Section 8.1.3 requires that anchorages "be tested by applying a minimum static load of twice the design load in each (primary) direction that a load may be applied. For example, an anchorage with an ultimate capacity of 5000 pounds (2268 kg) has a four to one safety factor. Therefore the anchor's design load is 1,250 pounds (567 kg) and it shall be tested at 2500 pounds (1134 kg)." Under 29 CFR 1910.27(b)(1)(i), must anchorages be tested at 5,000 pounds, or is it permissible to test them at 2,500 pounds, as described in IWCA/ANSI I-14.1-2001?

Response: 29 CFR 1910.27(b)(1)(i) requires that building owners inform employers, in writing, that the building owner has identified, tested, certified, and maintained each anchorage so that it is capable of supporting at least 5,000 pounds, in any direction, for each worker attached. Certification of each anchorage must be performed by a qualified person. Because the OSHA standard does not specify criteria for testing anchorages, the qualified person may utilize any scientifically-valid testing criteria to determine whether an anchorage is capable of supporting at least 5,000 pounds (2,268 kg) per attached worker. In general, this means using criteria that would be accepted by an industry consensus group, or that are certified by a registered professional engineer. OSHA would consider the testing criteria described in your letter – wherein an anchorage with a 5,000-pound ultimate capacity/strength and a four to one safety factor with a design load of 1,250 pounds is tested at 2,500 pounds – to be acceptable under 29 CFR 1910.27(b)(1)(i).

Thank you for your interest in occupational safety and health. We hope you find this information helpful. OSHA's requirements are set by statute, standards, and regulations. Our letters of interpretation do not create new or additional requirements but rather explain these requirements and how they apply to particular circumstances. This letter constitutes OSHA's interpretation of the requirements discussed. From time to time, letters are affected when the Agency updates a standard, a legal decision impacts a standard, or changes in technology affect the interpretation. To assure that you are using the correct information and guidance, please consult OSHA's website at

http://www.osha.gov.

If you have further questions, please feel free to contact the Directorate of Enforcement Programs at (202) 693-2100.

Sincerely,

Patrick J. Kapust, Acting Director
Directorate of Enforcement Programs

[Corrected 4/17/2019]

My hypothesis continues to be:
The roof anchors were installed on the cantilevered sections of the roof (not per the plans, this is evidenced by actual installation on the remaining portion of the building.)
Then the fall protection anchors (either the entire assembly or only the adhesive anchor fasteners) were tested at much too high of a force (note on plans is unclear.)
This improper placement and testing then damaged the concrete roof slab above the penthouse over the x11 unit.
This concrete slowly failed through the evening, completely failing that night around 1 am causing the cantilevered portion and parapet to crash onto the pool deck and into the backside of column I/12.1
I/12.1 is the column with the unverified report of a possibly missing beam, and the column with impact damage to the backside according to the ENR report I posted a link to in a previous post.
I/12.1 shifted due to the impact that caused the guest parking and pool deck to fail.
The pool deck failed due to additional load and column damage causing the columns under x11 stack to fail.

Another note:
Morabito is the structural engineer and someone with that name works for the roof anchorage contractor - they are located within 20 miles of each other near Baltimore, MD and they both also have offices in South Florida.
I'm pretty sure they have a relationship.
The roof anchorage contractor appears to have been doing unpermitted work, they pulled their permit the day of the collapse.
With that said, I don't think we should rely on Morabito's statements at the current time.
I believe it's likely Morabito emailed the report to the city (they received it after the collapse) in an attempt to divert attention and cover up a roof anchorage mistake.

From a recent HOA letter:

 

[Torai]

Well, as we suspected, there's my barricade I mentioned in the previous page of the thread

I looked at

https://gisweb.miamidade.gov/MDCPictometryIPA/pictometry.aspx?lat=25.872848&lon=-80.120845

(Switch to top view)
where you pointed out the barricade is on the West side of the square planter box sitting on M11. In the image it is the square planter on the right. The barricade was where I drew the rightmost red circle. DB27 pointed it out too. Left square planter is on L11.

Can anybody identify the three circled features, they were not there a year before.

I think the photo of lucky555 is from another place. The sun angle does not make sense. It’s morning or late afternoon, then eliminate when the building would cast a shadow. Also the pavers/tile and layout is different.

 

[dold]

The 5,000 lbs. testing number doesn't make sense with the Hilti adhesive anchors.
HAS-V-36 et all is carbon steel and HAS-R is stainless steel and both have very different capacities at 5/8" dia.
Stainless steel should have been used due to being near the water but "carbon steel" was specifically stated in the note on the plans.
And, neither of them divide to any reasonable multiple of 5,000 lbs. for testing, but the OSHA rule does for the entire assembly including 4 x adhesive anchors do see below.

Even though the note states "carbon steel", the HAS-R is stainless as you noted. If you specify HAS-R, they will (should) install HAS-R. If not, and an inspector catches it, they would be made to replace and relocate the anchors.

The Hilti design tables you are referencing (above) are only for the steel strength of the anchor. Steel strength rarely controls. Generally, pull tests (tension only tests) are used to test the anchor/adhesive bond strength, and the base material's (concrete) in-situ strength. 5000lb is roughly 90% of the design strength of this particular anchor in 3000psi concrete (roof slab), and the controlling limit state is concrete breakout. Steel strength utilization is about 40%. I suspect the 5000lb proof load for the anchor is not necessarily related to the 5000lb rating for the actual davit/anchorpost assembly itself.

I see what you're getting after, but I still find it very unlikely that anything dealing with these davits/anchorposts/whatever, had anything to do with the collapse.

 

[Roga50]

Interesting. The picture in the Miami Herald article which shows the core samples seems to make it look like the feature on the right would be the core sample hole (neatly-cut, removed tiles in a square pattern). So that returns us to the question of what is the feature in the middle?

Yes, I realize that is a different hole, but one would assume they were all done the same way--not haphazardly like that damage/hole in the middle.

 

[Roga50]

Now that they are paying attention, it has begun: evacuations of another condo deemed unsafe: Link

 

[hokie66]

I wonder how they got 13" cores out of a 9" slab.

 

[Eufalconimorph]

From what I understand (pretty much entirely from watching climbing bolt break testing) concrete won't start to crack until well over 35kN if properly set. A 5000lbf (22.2kN) test shouldn't do a damn thing to it. Of course if the concrete is already heavily corroded it could fail sooner, but I wouldn't call a 22kN test load "much too high a force" since that's the normal MBS (Minimum Breaking Strength) range for the less-strong parts of a (non-trad) climbing fall protection system (carabiners, slings, etc). Bolts are usually 40kN+ MBS.

 

[Roga50]

NBC6 (one of our local stations here) just did an investigative segment where they were showing new documents indicating that the planters had severe drainage issues and drainage pipes (related to the planters) were replaced (I think last year) and it was also stated that the planters had no waterproofing at all.

I tried to find the video online, but so far it's only on local TV down here.

 

[lucky555]

Isn't the Generator Room above the garage entrance, it was going to be replaced and the slab reinforced. Over the collapsed section in tiktok video? I wonder if the weight was accounted for in the original design.

What's the weight of the new roofing materials? I see one pallet still there on the remaining portion. Tarco is 72lbs/roll, 28 rolls/pallet for 2,016lbs, good for 3,024 sq. ft. plus barrels of bitumen or adhesive etc.
Were the roof anchors used that day when getting the roofing materials up there?

 

[Roga50]

Generator: yes. It was located behind the louvers in the entranceway video with the broken pipe. (Fire pump and domestic water pumps in the same room per the plans) Leading me to believe that the broken pipe was the water main, which would have been in that vicinity.

I did see info on the replacement and apparently it was going to be replaced with a Kohler of a specific model, but no docs on what the original one was, so no info on weight comparisons. The plans did note upgrading the slab under the generator room to handle the new weight but did not detail what exactly would be done. I *ASSUME* that work had not begun because of no permits issued...

 

[Awestruc]

Here is a link to a news story regarding the Maison Grande Condominium.

Records show there have been five inspections that determined the building is an “unsafe structure.” The building envelope is among the list of concerns. There were also warnings that the two-story parking garage and pool deck “have reached the end of their useful life and require repair, replacement,” or “a combination thereof.”

Apparently building has been deemed "unsafe" due to structural deterioration 5 times. The building has a red placard that says "Unsafe Structure" placed there by the code enforcement department and a spokeswoman for the city says this:

“We use a red placard when a building violation is posted, which provides the language ‘unsafe structure’ per the County Code. This does not necessarily mean the building is unsafe or in imminent danger,” Melissa Berthier, a spokeswoman for the city, wrote in an e-mail on Tuesday. -

https://www.local10.com/news/local/...s-fear-outcome-of-surfside-building-collapse/

 

[Roga50]

Sounds like a cover-up as to why an evacuation was not immediately ordered. I was always under the impression that an "Unsafe Structure" notice down here basically suspended your Certificate of Occupancy and the building must immediately be closed down for normal use. I was really surprised a when I saw that story about Maison Grande a few day ago. I wonder how many more there are? As I posted above, as we speak the city ordered the evacuation of YET ANOTHER complex due to them revisiting an inspection report and deciding it was unsafe. Wonder if it was red-tagged before today?

I'm getting the feeling it's gonna be really hard to find hotel rooms in Dade county for a while with all the condo's that are gonna be closed down...

 

[spinspecdrt]

https://www.youtube.com/watch?v=hynHiWE818c[/URL]

This engineer is going with the idea that the pool/patio deck collapsed pulling the beams toward the deck causing the main sections of the condo to come down.

Looks plausible but not exactly sure what caused the deck to collapse first]

This was posted in old thread after part 3 was started. Posting here in case anybody missed it.

 

[lucky555]

250kW diesel generator estimate 6,000-7,000lbs plus fuel tank size. A heavy load and I see the slab and columns are ordinary. The collapsed beam looked under that room.
I wonder if the diesel was the stubborn fire. Generator uses about 64 gal/hr. and not sure of spec on how long they need to run.

 

[Roga50]

I thought I read they were pulling out the underground tanks and replacing with natural gas...