Miami Beach, Champlain Towers South apartment building collapse, Part 02 151

[dik]

thread815-484587


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

-Dik

 

[Zroge]

https://www.cnn.com/us/live-news/miami-florida-building-collapse-06-29-21/index.html

Watch the video under "A nearby condo complex is working to repair similar damage. Here's what it looks like inside."

 

[Spartan5]

With all of the talk about the need for more inspections, this building had been scrutinized for several years by a licensed structural engineer and it still fell down. If anyone should know how/why the building collapsed it is them.

What is/was their responsibility in this instance?

What should they have done that they didn’t do? (As it pertains to major defects that require immediate attention.)

Should the municipality be the structural engineering firm that completes the inspections, reports, and recertifications? How large would that staff have to be in a place like Miami Beach?

 

[bradw1128]

I've never thought much about this until this happened, but it's bothering me. Coming from a bridge guy, I see a huge disconnect in the near-constant engineering eyes watching over our bridges but the opposite for buildings. Bridges are inspected typically every two years, in some states every year for fracture critical members. For slower-developing problems like scour it might be five years. This is done in a systematic way in a consistent format. Some level of data is public. Problems are prioritized and fixed. The impetus for all of this was the Silver Bridge collapse in 1967 that killed 46 people (and that bridge was just shy of 40 years old I might add).

As we see from this tragedy, the life safety impact of a building structural failure can be as serious or worse than a bridge collapse. Yet the formal scrutiny of these structures ends with a certificate of occupancy at the time they are built until recertification four decades later? The in-between is left to disclosures between buyers and sellers of the properties. How does that protect public safety?

I'm hoping this opens eyes to the need for engineers to evaluate the safety of our entire built environment. We talk a lot about "crumbling infrastructure" but take for granted that buildings are safe indefinitely. Surely that can't continue after this.



Bradley Wilder, P.E.
Construction P.E. (KY), MBA
Bridge Rehab, Coatings, Structural Repair

 

[bones206]

This is from the preliminary repair drawings showing test probe results in the pool deck area:

I interpret this to mean there was a second layer of patio pavers added to the pool area at some point in time after original construction. Can anyone confirm?

 

[ash060]

I would imangine that this is because bridges are public and buildings are private. Housing payments are already high and to require building owners in this case an assoication of owners to pay for inspections ever year or two would be difficult. It appears that people in the building have known about some of the issues for at least a few years, but they couldn't come to an agreement on how to fund the repairs. How would you expect someone to react if they were told that they need to come up with a $10,000 special assesment to fix something they aren't familar with? I am guessing most would say they couldn't afford it.

 

[dold]

@JStructsteel
The talk about the pool is mainly regarding the "pool deck". Essentially the elevated slab the covers the entire property at ground level and forms the roof of the underground parking garage. At least that's what I'm talking about. The pool itself probably has nothing to do with any of it as it is supported directly by the foundation, other than being a source of corrosion for surrounding areas perhaps.

 

[JStructsteel]

Thanks. I have seen stories of the pool equipment area and how bad it was deteriorated, and from the plans, it seems its near the pool, not the building. Just trying to figure out why that story is being pushed to the top, perhaps just because its new info and has pictures?

 

[JStructsteel]

Spartan5, If I condemned every building that had rebar issues or cracks, i would be out of business. Yes, the engineer did say its critical, but no engineer could predict this type of failure at the time of inspection. Who knows what happened even since April?

It would have to be a State wide agency, and then again, who is going to pay for it? $$$ matter, even in a disaster.

 

[FoxSE14]

Should engineers be speaking up?

I said it in the first Champlain Towers thread, and I'll say it again....yes, emphatically, yes. And we're shooting ourselves in the foot as a profession when we do not. Thankfully some are starting to speak up as I've now seen on CNN, even saw an SE assoc president on local news in Midwest US, and they have found ways to do so without speculation. Or if a speculation-type statement was issued, they've prefaced it as such. I'll spare my first draft rant which got longer than I intended, as I do not wish to hijack this thread. It's good to see engineers starting to share their thoughts now, but I do think we should be among the first out there when such events occur...with careful statements.

 

[DavPc]

The photos of the spalling around the pool equipment from the Miami Herald article linked above are now making the rounds on local and national TV news. I'm skeptical, however, that spalling on the "skimmer" part of the pool shell in an isolated corner of the property would be a factor in the building's collapse. That spalling is most likely caused by 40 years of moisture from the pool itself and not the failed waterproofing on the deck. Furthermore, the deck around the pool and spa is one of the few places where it didn't collapse.

Now, as has been pointed out above, if this spalling was the current state of the structure throughout the entire garage area, then that's something to be concerned about.

The more interesting aspect of the Herald article is the report from this pool maintenance personnel that 36 hours before the collapse, the garage, 21 years later after the last reported sighting, was still having issues with significant standing water at the base of the parking ramp. It is suspicious the location of the water is at ground zero where the deck collapsed and close to where the building collapse started.

 

[OHIOMatt]

"It would have to be a State wide agency, and then again, who is going to pay for it? $$$ matter, even in a disaster."

Another statewide agency with individuals immune from civil liability is not the answer. The main driving factors in these decisions are economic. Remove liability caps from the insurance companies and have the inspections done by people with a lot to lose. Perhaps the building codes could be adopted to provide guidance to engineers on what level of damage is acceptable. Just spit balling, but a statement saying that any damaged element with less than 85% of original capacity must be monitored on some timeframe. Anything less than 75% of original capacity must be replaced immediately. If any element is found to have a 50% reduction in capacity, the entire structure must be vacated until repairs are made.

There is going to be costs associated with any program, but based upon what I see in my day to day work, events like this will continue to happen.

 

[DavPc]

Huh, the spa was added sometime later. The drawings only show the main pool. I would really like to know when that was done.

The current pool and spa design and layout are in some 1980 revisions of the original plans on pages 204 and 264. It appears when the 13th floor penthouse was shoehorned in, the finalized pool area design was ready.

 

[StrucDesignPE]

I think, that the public has a vastly inflated view of the capabilities and responsibilities of the building department.

I think most building departments have a vastly inflated view of their own capabilities and responsibilities.

One of the most common sense things I have seen regarding the maintenance of this building is a suggestion that instead of 40 year recertification it would be evaluations at something like a 5-year interval (5, 10, 15) with each inspection becoming progressively more in-depth.

 

[Teguci]

You could have the most generous inspection plan for structures and still miss design flaws like the I35W bridge (or hire the De Soto bridge inspector). And, unless someone in a building department is going to take personal responsibility for an aged existing building, giving local building departments more power will ultimately just ensure that turtles can sleep on the beaches at night (do any of you talk to your local building inspectors?). At this point, I'm thinking about the pocket change Morabito got for the inspections, and being thankful that I'm not him. I've seen an entire top layer of rebar rusting and delaminating through a supported floor. Concrete chipping off the corner of columns - no big deal. Condemning a structure is a lose-lose (hidden win if you're right) proposition.

Pin pointing the failure is key (hint - not the D-rings on the roof). Maybe this failure has already been corrected by current building codes? Until we know the problem, we can't fix it. The deal as professionals, is that we hold our profession accountable (ah-hem New Orleans). In return, we should work to hold off the lynch mob who think plaster spalls are a sign of impending collapse.

 

[SFCharlie]

Would it be a problem if the rebar arrangement had not accounted for a lack of horizontal support at the midpoint of this "new" column height?

YES Several posts have said so, but, perhaps in technical jargon.

SF Charlie
Eng-Tips.com Forum Policies

 

[Rabbit12]

StrucDesignPE, I think the big issue is we can require all the inspections we want but someone has to have the authority to make sure the repairs are made. Right now there is literally no one with skin in the game (aka liability) that can force changes. Even us as engineers include statements (for good reason) that attempt to limit our exposure with inspections.

I'm guessing this Morabito firm will be included in litigation. A fair question is should they have done more in 2018? By all accounts they gave the report to the condo board which likely consisted of a bunch of people with no real knowledge of how critical these issues were except for a few sentences in a report. They see the cost to fix those and it's pretty easy to just kick the can down the road.

So when a condo sells in this complex does the seller have an obligation to disclose any correspondence about the repairs recommended in 2018?

 

[Murph 9000]

I'm curious about the lack of shear walls (isolated and composite) and the impact it may or may not have had on the collapse. If they had closed off the secondary stair with the red walls, would that have prevented the total collapse between Grid H - P, assuming the diaphragm were cut off from the blue shear walls if the initial collapse occurred around Grid H.

I'm pretty sure the collapse progression was initially halted by the eastern stairwell and increased column density in the N,O,P columns. That section might have remained standing if the stairwell had provided shear walls to resist its westward movement.

Under the general consensus that the failure of the upper levels started with I,K,L,M in row 9.1/10, it's not unreasonable to think that additional stability in that stairwell might have saved apartments in the north side of the collapse, potentially limiting it to the two pool-side stacks between the elevators and parking ramp.

 

[JStephen]

"Remove liability caps from the insurance companies "- let me know what your new infinite-liability auto insurance costs. I'd be curious who is qualified to underwrite it as well.

 

[OHIOMatt]

JSTephen, removing or drastically increasing the liability caps for the insurance carriers would force them to reduce their exposure in other ways. Primarily this could be done by periodic inspections and more stringent design requirements. FM Global takes this approach. We often joke in our office, that if you design to FM Globals standards, they will never have to pay a claim. This is done for manufacturing and warehousing, so why not take a similar approach to buildings with hundreds of occupants?

We must find a different approach to building safety. I have personally found that the building departments are ill equipped to handle any project of greater scale than a house. Look no further than New Orleans. An incomplete set of documents was approved by the building department. Any novice structural engineer and most contractors would have been able to see that, yet the city issued a permit.

 

[Seppe]

As Rabbit12 stated, there's a grey area between engineering recommendation and downstream stakeholder action.

Should Morabito have used stronger, more definitive language regarding concerns over impending structural failure? And if they had, is there anything preventing another engineer (and another, and another) from coming in and offering a second, more owner-palatable opinion to the contrary?

As we sit today, the engineering community can't really mandate another party's activity, nor the timeframe in which the activity is carried out. All they can do is present information as clearly (and educationally) as possible, with due consideration for "strong warning" when conditions warrant, and bring as many relevant stakeholders into the correspondence loop as possible (AHJ included). In the end, though, even if ten engineers opine that immediate repairs are critically important, they have no power to enforce.

I read the Morabito report. Only they can speak to observations made and the manner in which they present their resulting judgments and recommendations in a written summary. I personally didn't get the sense that a time sensitivity of remediation was expressed in the written word, nor was there any language regarding interim temporary measures that might be leveraged as a precautionary step prior to the start of a full repair. Again, though, that's one person's interpretation, and an interpretation made without the benefit of being privy to other supporting conversation and correspondence that accompanied the report.

It's a flawed system, as it relies heavily on the decisions and choices of flawed humans. You just have to hope that all stakeholders behave responsibly.