AGREED 2000%

I'll go with that as well !

Yes yes he is I'm not in his field either but I've worked around people like that over the years he has my respect

Literally the first comment on every video. Couldn’t be more true. Thanks guy

I agree...he makes you think you could be an engineer after watching and listening to his videos

... or a HOA board member? :-)

This is a prime motivation for me. I know I may not create meaningful change in the current fields of construction and engineering in my lifetime, but if I can help the next generation, I will die happy.

@@BuildingIntegrity There were times when collapse was not an option. These are times of Egyptian pyramids construction. They are still with us 3500-4000 years later. The rest of humans history is buildings construction optimization for cost. Sometimes this optimization cause collapse. Optimization level of Structural Engineering shall either do step back or find that particular construction/materials error that violated optimization rules of Structural Engineering. IMHO this building had to have more concrete walls between columns, so that they prevent swing of the building part that contains only columns and slabs. Buyers want more open space without walls. But this weakens the building structure against swing (due to wind load in Florida) and consequent cracks where load became excessive for materials. In the collapse video collapsed part 3 was swinging like jelly. This caused its collapse due to exponentially increasing number of cracks appeared those several seconds through all joints between columns and slabs. Such building shall either be built with steel columns or shall be built with lot of concrete walls inside.

and old alike💃

Forget young people - I am 46 and after these lectures want to get a masters in engineering (getting a MA in urban planning right now).

His ability to effectively and efficiently communicate is masterful. This could be called "Basic Engineering for Dummies," because even I can understand what he's talking about. This is very well-done.

You are absolutely correct! I’m a current elementary special-education teacher, and his ability to teach these engineering concepts is exceptional. I always comment on every single video of his that he should be a professor in a college of civil engineering. The college would be so lucky to have him!

@@jamieleightee *A simple exercise:* For _each_ 100 pounds of _horizontal_ component of wind force directed against a north wall, each of the east and west outside walls that are at right angles to it takes up 50 pounds of force. If a third interior wall is added parallel to the east and west walls then each wall will take up 33.3 pounds of force. The floors that also transmit this horizontal component of force to the outside walls prevent concave deflection of the north wall. Horizontal force transmitted by the floors that is taken up by the footings of the columns and rear wall may be ignored for this analysis. Is a third interior wall of solid concrete required? (Referred to in some discussions as a shear wall). After calculating the force that the east and west walls must accommodate it is a matter of design choice. It is likely that the minimum thickness and strength of the east and west walls already greatly exceeds the horizontal force that these must hold back. Thus, for each 50 pounds exerted horizontally, the walls as a result of their strength to function as a wall supporting the vertical downward load from weight, are already capable of sustaining a horizontal component several times that amount, which is why the contribution of the footings was ignored. An interior wall of solid concrete that is not connected by rebar to the adjacent part of the building is in effect an _exterior_ wall to which an abutting structure has been added that encloses it making the whole thing appear to be a single building. Pre-construction-sales enabled raising capital for a much larger structure. The reason behind this two-phase design is _finance,_ not engineering.

Thank you, that means a lot.

Agree 100 %

I agree!

I could not have said that any better. He has my attention and my respect.

Very well said... he brings total respect, sound reasoning and dignity to this whole situation.

I agree

I'm gonna agree with that as well.

Right?? It's like seeing the world with new eyes because I am scrutinizing everything now!

I don't like rebar at this point. I'm going to lean towards the old I beam stuff that's still standing. The Empire state got smacked twice by military planes in the 40s. Still standing and the repairs are still holding 70 years later. I beams it is.

Honestly, my eyes have been opened, aware of details. Just walking inside a 4 story parking garage has me noticing column widths. I’m just a little old retired lady.

@@windsofmarchjourneyperrytr2823 Steel-skeleton (I-beam) structures are great for OFFICE buildings, but NOT for residential units, because... they SWAY in the wind! Peeps can handle that when working, but when relaxing or SLEEPING?... nay way. (That said, when you're *right on the beach,* you still have to maintain/coat your I-beams... ;')

Who knew that same audience would be waiting in anticipation for the next instalment. Good morning from the U.K.

Neat! Please provide a link to your evidence that any single person watched even 1/2 of the video. I will wait here.

@@eriklarson9137 I did. Why would you want such evidence?

I’ve watch all his videos, some more than once

@@eriklarson9137 I have watched the video all the way through, and have done so more than once because it is complex information.

Yes, this realistic approach will make the final report easier to understand and accept as it’s unlikely that just one cause will be cited.

Me too and I really appreciate it!

Me too

No, he isn't. Engineering involves a lot of math and physics, not entertainment videos. They're nice to watch and get the general idea, but you're still light years away from being an engineer after watching it

THIS!!!

*A simple exercise:* For _each_ 100 pounds of _horizontal_ component of wind force directed against a north wall, each of the east and west outside walls that are at right angles to it takes up 50 pounds of force. If a third interior wall is added parallel to the east and west walls then each wall will take up 33.3 pounds of force. The floors that also transmit this horizontal component of force to the outside walls prevent concave deflection of the north wall. Is a third interior wall required? (Referred to in some discussions as a shear wall). After calculating the force that the east and west walls must meet it is a matter of design choice. It is likely that the minimum thickness of the east and west walls already greatly exceeds the force against which it must hold up to horizontally. Thus, for each 50 pounds exerted horizontally, the walls as a result of their thickness to function as a wall bearing up the vertical downward force from weight, are already capable of sustaining a horizontal component several times that amount. An interior wall of solid concrete that is not connected by rebar to the adjacent part of the building is in effect an _exterior_ wall to which an abutting building has been added that encloses it making it appear to be a single building. The reason behind this is _finance,_ not engineering.

Ed Zachary, muito bem.

I agree 100% with your comment. The few times I have clicked on other videos, I would get so mad. I went to comments and in the kindest way told them to come and watch this channel.

Thank you very much! We are working hard to keep improving this channel.

@@BuildingIntegrity I love your channel and have watched many of your videos twice to grasp the concept. Your explanations are very detailed and yet make the topic easily understood. THANK YOU for doing this for us! I know your time is precious with a family and a business to run. You are very much appreciated! Wish I could have you oversee anything I should live in! Your integrity has gained my 100% trust! Well done!

*A simple exercise:* For _each_ 100 pounds of _horizontal_ component of wind force directed against a north wall, each of the east and west outside walls that are at right angles to it takes up 50 pounds of force. If a third interior wall is added parallel to the east and west walls then each wall will take up 33.3 pounds of force. The floors that also transmit this horizontal component of force to the outside walls prevent concave deflection of the north wall. Horizontal force transmitted by the floors that is taken up by the footings of the columns and rear wall may be ignored for this analysis. Is a third interior wall of solid concrete required? (Referred to in some discussions as a shear wall). After calculating the force that the east and west walls must accommodate it is a matter of design choice. It is likely that the minimum thickness and strength of the east and west walls already greatly exceeds the horizontal force that these must hold back. Thus, for each 50 pounds exerted horizontally, the walls as a result of their strength to function as a wall supporting the vertical downward load from weight, are already capable of sustaining a horizontal component several times that amount, which is why the contribution of the footings was ignored. A building is designed so that the entire structure remains standing. That a collapse is only partial appeals to emotions, not logic. An interior wall of solid concrete that is not connected by rebar to the adjacent part of the building is in effect an _exterior_ wall to which an abutting structure has been added that encloses it making the whole thing appear to be a single building. Pre-construction-sales enabled raising capital for a much larger structure. The reason behind this two-phase approach is _finance,_ not engineering.

In complete agreement with you!

Being a woman or black has little bearing on your curiosity. I'm glad you are mentally stimulated but don't let labels hold you back.

What does your race or sex have to do with your personal interest in engineering?

Take a look at highway bridges when you drive under them too. You can clearly see damaged concrete and rusted steel rebar from salt being used to melt snow and ice. It's just a matter of time before they fail also. Stay safe my friend.

@@justinhaase8825 the structural engineering field is predominately men. Hence look at most of the comments and a Google search. That is why I said what I said and stand by it. My experience and perspective as a black woman won't be dictated by a man or anyone else who is non-Black. I was simply pointing out this channel brings people from diverse backgrounds to a white male-dominated field. I also don't hold myself back. I'm a business owner and doing well in my life.

Same. NIST's hopefully too.

Yes. I will be eagerly awaiting NIST's findings.

After these series of vids, we are never going to look the same way to a building, instead now we are going to look through walls and into the structure as a whole.

Dont underestimate a papercut

Absolutely. Great way to get that point across. So good.

Sheared along the shear wall line !

Not just the headboard but also the hinged wood flooring in one of the x09 units but also the closet organizer in the closet to the right of bedroom and artwork on bathroom wall to right of that.

I think I know what you're talking about! I was looking at it and wondering "what the heck is that?" As soon as I read "headboard," that question was answered - but I'm still going to go back and look. I'm gonna look for the wood flooring, closet organizer, and artwork, too...

I think the headboard was in 710 and the floor & bathroom art were in 910

I've seen even crazier after a tornado. Whole house destroyed, cars thrown all over the place, and 2x4s speared through concrete curbs, and yet where a house once stood you might find a cabinet with all the china still inside it without even a crack on it.

Where do you see that ?

In my building all 8 apartments on each level abut either the fire-stairs (as mine does) or the elevator shafts. I am very pleased that our building is particularly strong as a result. However, those who abut the elevator core experience noise from the elevators with those on the top two levels getting the worst noise due to proximity to the elevator motor room above them. So there can be downsides to living by the elevator shafts. But being by the stairs is brilliant. My building has two separate fire-stairs that entwine like DNA meaning that there is always a second stair with separate exit in case there is fire in one of the stairwells. This double-stair design made of 12 inch thick concrete is particularly strong, and with 10 inch thick floor slabs and 8 inch thick concrete walls I get the feeling that this building would survive a nuclear attack. It is unfortunate that not all buildings are built to this same standard. The building is over 40 years old and unlikely to be demolished any time in the next century, but when it does need to come down one day, I feel sorry for any demolition company that would have to tackle it. When looking at footage of Champlain Tower it amazes me that people paid top dollar to buy into a building that even if it was well waterproofed and well maintained, still looked like it had a very flimsy structure. They might think it makes the place look “light and airy” to have such small columns and wide slabs, but I prefer the stronger, more rigid construction of my building. I also prefer the way my building is built directly on sandstone bedrock and no soil-retaining walls in the basement levels, just solid rock walls. It helps me sleep at night.

nowhere is going to be 100% safe. Being on a hill will expose you to structures trying to slide down the hill, with all the potential for differential shifting of the structure. If your structure is significantly reinforced, it’s possible the original design was meant to allow for a less than fully rigid foundation. (saying this as I look out the window from the third floor of a condo on a hill/mountain). I approach it as a case of seeking moderation in all things, and also realizing that the world has been and continues to be a dynamic thing. We may try to freeze parts of it, or pretend that parts of it won’t ever change, but there are limits to what man can achieve. It’s important to recognize those limits where they occur, and either push back against them, or accept them as they are, and in all cases, respect them.

@@artistjoh WHERE exactly are you located, that the Engineers won out over the Accountants, and built to that high standard? Also, how many storeys high is your building?

@@Relkond ...OH, well, I really didnt mean it was safest in all... I should have said, home in clouds close to heaven with God overlooking with Pearly gates on the driveway

@@MajorCaliber 18 stories high, and in the Sydney CBD. Of course there is a twist - construction standards were so expensive that the builder went broke before construction was complete and another builder completed the job. It was built in 1980. It helps that the entire Sydney CBD is a sandstone ridge with little soil overlay. It means all building foundations are excavated into bedrock. The downside is all underground rail and tunnels are expensive due to rock excavation. It also helps that earthquake risk is as low as it gets.

Then take whatever math course you did poorly at again.

Get some tutoring with the math. Once you get it, you will GET it. You may just need some extra help at first.

@@denverdubois5835 I appreciate that. At 53 years old I think it’s a little too late.

@@JSSTyger Definitely appreciate the sentiment. I’m 53. I’m probably past my prime. 🤣🤣

Architects don't use much math other than adding up what to charge for your bill. Structural Engineers live and breathe math and it's integral to their work. One is a more of an artist, the other is a serious profession. Don't conflate the two.

Is it possible they should not be building on man made islands that are actually former landfills?

Why no photos of that? Should be several of them, yes?

Thank you! I appreciate you taking the time to comment.

Wow! Thank you for the referrals and kind words!

The other building did have larger columns from level 2 on down due to the column offsets at level 2 to clear parking layout in the basement. Those columns were larger than necessary for the load which is a bit odd considering that nothing else in the building seems to be that much larger than it needed to be. That would definitely give the west part of the building more resistance to lateral loads.

I want to know if they ever find Mrs Stratton? I haven’t heard anyone say do.

@@gracieg7601 Yes. Around July 12 she was identified. She seemed like a beautiful soul.

Thank you for the kind comment! Ciao!

John ... while the steel in the elevator offers some strength, it's the concrete box like structure around the elevator / stairs that gives the most strength. If you think about it, this giant box beam is basically 4 support columns that are interconnected and spreading the load in an area that's around 10 x 20 ft and that's more support than any of the other columns because of the solid walls all the way to the roof. If you watch any construction you will notice this part is first in the process and they are free standing before the rest goes into place. It's the strongest part of the building.

Thanks!

@Charles Allen you talking to me?

@Charles Allen oh I see! Yes, I totally agree with you. I thought you were referring to my comment. They are def covering their asses.

@Charles Allen Can’t disagree with you!

Go for it dearest child !

Go for it!

Yeah, I don't understand that either. I asked that question above. The engineer replied that he thinks they simply "snapped cleanly". I'm finding that hard to swallow, but he is an engineer!

look how few rebar are sticking out from the wall

Crazy isn’t it? My guess for not having rebar sticking through the shear walls is that it just so happened to tear in between 2 bedroom walls. Maybe they weren’t load bearing walls and therefore only had wood and no rebar in it but that’s just my guess. I am not an engineer

@@kyber7503 My guess is cutting corners

I'd want to see photos taken close to the shear wall, to see if the rebar sheared off more cleanly there, as opposed to the tangles we see from where the slab tore on a more diagonal path. What does appear to have been the case is that a combination of factors overwhelmed the building structure, pointing out that the building codes in effect in 1981 did not provide adequate margins, especially when potentially substandard construction and excessively deferred maintenance came into play.

Me too! I tell everyone that I am a forensic structural engineer now!!

I like this comment !

Interesting! Thanks for the knowledge!

A good point. I find that handmade paper made in a frame by the sheet doesn't show the same directional alignment as Fourdrinier or similarly roll-made paper, so that might be an option if a similar experiment was to be done again some other time.

@@alisonwilson9749 An equally good point! In our printshop, we used to process Tyvek paper that was untearable. It was made of plastic fibers, but these were also randomly aligned as to prevent any easy tear propagation if a tear should ever occur.

I like this comment !

I’d sign up!

I heard it briefly mentioned on another channel.

You're bucking a lot of closely-held Flori-duh traditions there... like how even the most expensive single-family residences in FL do NOT have a basement (due to the water table), while virtually every high-rise condo--even right on the ocean--have one, and sometimes TWO sub-basements devoted to parking... cuz poofty awkitects say cars be "yucky", and must be hidden away... _smh_

The same is true of aviation accidents. There may be an initial cause, but it rarely stands alone. A causes B causes C and so forth. Several may be necessary before disaster follows.

Lack of support & no sense of urgency to condemn the building in 2018 !