/sci/ - Science & Math

>>9593357
Americans tried to cross it

>>9593357
It went plop.

Probably something to do with imperial measurements.

>>9593357
RUSSIA

Affirmative action

They were supposed to get some nice, competent asian ubermen to build it, until HR forced them to make some hiring changes.

>>9593438
Seriously this.

Why are all the people in the image fat?

https://twitter.com/FIU/status/972529770683564033
lol

Civil engineering

>>9593468
So....I'm looking at this thing as it is being installed and I'm thinking to myself, "there's actually nothing properly supporting it". I don't think the people hired to design or oversee it were part of a meritocracy form of hiring.

>$14.2 million
>concrete and rebar

There's been 1000s of concrete-rear bridges and overpasses collapse all over the work. you'd think people would learn that cheap does not equal best.

>>9593362
Evidently it was still under construction:

> One of the companies that constructed the bridge, Munilla Construction Management, said in a statement that it will conduct a "full investigation to determine exactly what went wrong" and that it will cooperate with investigators on the scene "in every way."

>"The new UniversityCity Bridge, which was under construction, experienced a catastrophic collapse causing injuries and loss of life," the company said.

>>9593357
Two possibilities:
1) (less probable) the project was flawed, whoever designed it is going to face trial
2) (more probable) the project was sound but there were mistakes in its realization

>>9593563
i agree, the odds of the engineers designing it wrong are much higher than some mexican laborer pouring “reasonable” amounts of concrete rather than exactly how it needs to be.

>>9593462
it's called usa

>>9593468
>Rosenberg

>>9593462
Terrorist detected.

>>9593568
No live footage, but it looks like a "karate chop" kinda failure so the bridge was too heavy to support itself.
I'm thinking that they used pre-stressed concrete and it stays flat at rest by design as opposed to slightly bucking upwards and as soon as any kinda force is applied it deflected downwards.

>>9593357
Holy fuck I've gone to this school

jet fuel for sure

>>9593607
A witness said it started to collapse on the "left" then in the middle.

>bridge weights 950 tons
>dropped several meters
How come it's not doing the same damage as a kiloton bomb?

>>9593623
probably not stressed at all then, just a shitty linkage component.

>>9593357
>What happened?
Shitty Infrastructure... IT KILLS!!!

>stress testing a bridge with the roadway underneath open

>>9593635
kek

>stress test a bridge that doesn't even have its support cables attached yet

>>9593357
bridge fall down

>>9593362
Kek

>>9593626
slow accelerations allow for safe energy dispersion. If the power is low, the damage is low. Filling a dam with billions of liters of water adds megatons of tnt equivalent to the potential energy of the structure, but does not rip it apart like a megaton bomb would.

>>9593357
Bridge made out of magnets, attracted by first set of cars passing through, breaks.

>>9593790
This is the only possibility.

>>9593357
lateral torsional buckling of bridge deck due to fiddling with post-tension cables improperly, or something more benign like shear yielding

>>9593607
That's not what pre-stressed concrete does.

>>9593661
>>9593526
You simply can't make up shit like this. No one would ever believe you with such proof.

>>9593357
It was obviously nanothermite.

Clearly the engies didn't do their sig figs right.

>>9593526
>I don't think the people hired to design or oversee it were part of a meritocracy form of hiring.
this. a bunch of rich whites put their friends and sons on the job

>>9593941
>Miami
probably a bunch of rich cubanos

>>9593661
Was it really supposed to have support cables? By the looks of things they didn't have much in the way of temporary supports under the of the span which you would expect if a large part of the load bearing structure wasn't in place yet..

>>9594003
yes


some GC is shitting their pants right now

>>9593362
HAHAHAHAHAHA

>>9593438
I bet it was white people who ruined it.

>decide to build a suspension bridge
>build the deck before the tower

>>9593952
the engineering firm is owned by 5 Cuban family members

Which 3rd world Europoor country did this happen in?

Infrastructure under Drumph

>>9594045
It wasn't in Europe it did happen in the 3rd world country known as Florida, located in North America.

>>9593934
>sig figs in civil engineering

>>9594055
It's a joke about how every professor in my 1st year classes said if we didn't know our sig figs, bridges would collapse and stuff. I know a lot of people prolly heard their professors say the same.

Apparently lawyers are already preparing lawsuits, claiming that the builders used concrete that they knew was stressed before it was even installed. A secretary from one of the firms leaked a memo to the press in which engineers refer to the materials as “pre-stressed.” Pretty damning.

>>9594003

>>9593357
The failure stresses were reached.

the span was maxxed out without support. concrete failed. like using a 2x4 at its ax span but the 2x4 has a flaw so the max span is less than engineering spec.IMO the site engineer fugged up

>>9594066
Pre-stressed concrete is great for bridges. Lighter weight, withstands the same amount if not more. It's essentially the next innovation after reinforcing.

>>9593438
Asians are incompetent engineers.

>>9593462
Welcome to America

>>9593357
Look at the fucking "before" picture: It has no support in the middle. It just fucking snapped, in two places. What an absolute critical failure, 0/100, complete failure, never try again, go directly to prison.

Holy shit imagine that was your family member, or friend, or you. Un-fucking-believable.

Stupidity and incompetence are moral sins.

>>9593626
not enough momentum

>>9593941
>rich whites
>in a Jewish community
>working for a company owned by 7 Cuban brothers
I thought /sci/ was supposed to have intelligent posters

>>9593357
>what happened?

They didn't support the bridge at all in the first place. You have to attach these areas to the cables that go to a big tower, which was not done, and they never supported it underneath before that could be done.

>>9594055
thank you. my profs got pissed over too many sig figs

>>9594066
bruh are you for real

>>9594066
Someone redpill me on "pre-stressed" concrete. Is it another kike trick?

>>9594210
no, damn near every typical highway bridge built these days is a prestressed concrete bridge

reminds me of something one of my engineering prof's used to say "There's more money when something falls down than putting it up."
He was an engineering expert witness and made quite a bit of money whenever something fell down.
>>9593357
Just wait until someone does a proper failure analysis. You think the goddamn armchairs here are gonna find anything worthwhile without CAD files, engineering data, and bits of bridge still wet with blood? Shit I haven't seen a goddamn calculation in this entire thread. I've read conspiracy theories with more calculations than this thread.

Also I must note it is quite strange that the organization investigating the bridge collapse is the National TRANSPORTATION Safety Board. It's a goddamn footbridge, does this mean the NTSB considers fucking walking transportation? Fuck if they ever get the chance to regulate shoes, no one will ever trip again. The NTSB is gonna fucking ream whoever was behind this.

>>9593357
>Alright /sci/, what happened?
CivilE fags btfo

>>9593411
this of course
blame putin, it's always him

>>9594229
There's nothing odd about the NTSB investigating it. It was a bridge over a busy road. That counts as transportation infrastructure and is thus the domain of the NTSB. It fell and crushed cars, which are another thing that falls under the domain of the NTSB. I'm not sure who you think should be investigating this if not the NTSB.

>>9593357
aaaaaaaaaa

>cubans
why am I not surprised? have you not seen the kind of people cuban-americans are?
why do US people still trust these fucks?

Doing PhD in structural engineering

You have to wonder what the purpose of the central tower/cables was if the main span of it was supposed to be installed separately. Either the span was designed to support itself, in which case maybe the cable stayed design was mainly aesthetic? Or the cables were a part of the design and someone figured it could be installed as a separate span and then the cables installed later? It doesn’t really add up.

For a concrete pedestrian bridge like that, the weight of the bridge itself is probably close to 90% of the vertical load it’s designed to sustain once you include people etc.

My guess is it was supposed to be temporarily supported in the middle of the span until the cables were attached, and there was a sudden shear failure at one of the truss joints. So probably the fault of the builders.

>>9593357
Mafia/RNC sold them shit quality concrete.

>>9594283
considering how utterly obliterated the bridge is with not visible steel structure, it could only have been designed to include additional support. there was first person video of someone driving under it a couple days ago and it looked seriously scary stretched across all the lanes.

>>9594066

>A suspension bridge
>Being stress tested before it has its cables installed
>And nothing supporting it
Surely the Mexican overseeing the construction saw where this would lead to.

>>9594229
>Shit I haven't seen a goddamn calculation in this entire thread.

see: >>9594183

>>9593661
o fugg

>>9594229
Bro the bridge was being stressed without having any of its supports installed, it doesn't take a lot of math to see what went wrong.

>the video filmed right after the collapse where you can see blood pouring out of the cars onto the road

Nope! Hope someone goes to jail for this but knowing CorpMerica its unlikely

>>9594350
Link fagget

nice ghetto country you retarded fat mongrels lol

>>9594354
>He says as Denmark builds an island with factory waste

>>9594357
>he says as america feeds it's population with factory waste

>>9594359
>he says as I feed his mom with cum

>>9594138
Well, there are a lot of things that all need to go wrong for this type of thing to happen. Think about everyone that worked on the project. Not to mention the checkers involved, and the fact that it might not have been constructed up to the plan specifications.

>>9593626
>>9594158
Not necessarily, It's not not 'dropped' exactly. There is a shit ton of steel in bridges that will yield and deform to take a whole heck of a lot of energy out of the system. Not to mention that it is supported and the cracking concrete will also release energy before hitting the ground.

>>9594183
Good catch and MS paint skills. You figured it out. I'm sure they just forgot to install them.

>>9594210
Just about every bridge you see concrete on is pre-stressed/precast/post-tensioned. It's a very efficient way to build something that spans long distances. Just about every parking structure is too, it's just not as common in buildings. They might have it in their slabs or piles only.
See >>9594101

>>9594229
What is there to calculate? The design company would have all their calculates that will be looked over.

>>9594283
Time to go back to school.

>>9594339
There would be no live loads on the bridge, only dead weight. The accelerated construction allowed them to not block the street while installing the supports.

>>9594349
Yea, they just forgot to put them. It's not like the concrete in the supports would need a while to harden. It was obviously designed to withstand self-weight.

>>9593357
That's Florida Cuban-Amerimutt Civil Engineering at it's finest

>>9594475
wow. now that is a real amerimutt face.

>>9594456
>It was obviously designed to withstand self-weight.

Obviously it was not. It was "intended" to do so, but was simply not done to such a design.

>>9594487
Looks like pure fat Cuban to me. Probably 3rd gen.

>>9594229
>armchairs
well no shit buddy, we're just spit balling here

>>9594487 >>9594475 >>9594494
That Goblina (Emma Gonzales) led SJW to force strict anti-gun laws in Florida

A CNN puppet (crisis actress)

https://www.youtube.com/watch?v=ZxD3o-9H1lY
https://www.youtube.com/watch?v=Sr1oyK5lvqQ
https://www.youtube.com/watch?v=4AtOU0dDXv8

>>9594491
Designed - The company made structural calculations and submitted them to a governing body to check over. Also most likely checked by an independent company.

So obviously it was designed to do so.

Or are you saying that the contractor made such a mistake that the plans had written on them to have the supports and not allow it to stand freely? You would be wrong again because the design firm needs to check the steps in the process and make sure the contractor was doing their job. They would have seen that they fucked up and closed the road.

>>9594501
>average american in 20 years

>>9594318
>bridge is with not visible steel structure,
Concrete without Steel rebars!? wtf!

>https://en.wikipedia.org/wiki/Rebar
>https://en.wikipedia.org/wiki/Reinforced_concrete

>>9594503
It was not designed to be used in the manner in which they used it.

>>9594521
What was the manner in which they used it?

>>9594521
It was used as ... a bridge. right?

>>9594503
>"so like this chef dude designed and made this cake and everyone says it is awesome. so i'm going to bake it"
>"did i mention i'm vegan?"
>*swaps out the cows milk for soymilk*
>"I'm also anti-grain."
>*swaps out wheat flour for potato flour*
>"I've ascended past sugar"
>*swaps out the sugar for aspartame*
>"Hmmm....says here to pour the patter into 3 separate short pans for baking..."
>*pours batter into one tall pan equal to all the other pans combined*
>"Great, now bake at 350F for 25mins or until brown. I just don't have that kind of time."
>*bakes cake on 500F for 5 mins*
>"WALLA!!"

>>9593357
some fat fucker bald american giant donut asshole came on the TV feed at the mic speaking
" we have a NATIONAL tragedy"

he actually said twice just sentence or two apart - I AM SO SICK OF EVERY LITTLE FUCKING THING MEANING THE WHOLE GOD DAMNED NATION....

Yeah it wouldn't be yer jerkass miami shithole, it's the whole nations fault, and by golly the NATION is mourning....at it's failure...

god I fucking hate that shit

>>9594545
>>9594527
They put part of a bridge into the function of a fully working bridge.

>>9594560
There's no other news in the world right now or something.

>>9594564
Yea, It was Designed that way.

You don't need to close down a street for a month, and can do all the finishing during the night.

>>9593357
Its Miami, so embezzlement and Corruption

>>9593462
Its a part of the USA that has lots of Hispanics
Do the math

>>9594491
kek

>>9594570
>Yea, It was Designed that way.

Then it was designed to fail.

>>9594559
Well, it's not always the contractor's fault, it may have been designed incorrectly (like faulty calculations/ incorrect assumptions) or the materials they received may have not been up to par. And also they can't just swap out stuff like a baker. Every single thing they do is monitored, and so they have to go back to the designer for every little thing they want to change. It happens all the time. For example, the concrete they use to make the bridge is put in little cylinders and tested in a machine that compresses it and tests it's strength.The contractor knows how to do something cheaper, and so they can ask the designer to change it (Depending on if it is Design/Build, Design/Bid/Build, etc...) and they have to redo all their calculations.

>>9594587
If a plane crashes was it designed to fail? If one of the steps of your staircase creaks was it intentionally made to do so by the person who designed it, and nails were methodically placed in such a way to ensure it creaks?

>>9593357
the fat fuck fireman buzzcut came on the tube and : " Yes, were using 7 ways to find people, we are calling out ... we have 14 branches of government ... blah blah... "

I'm thinking to myself they're all dead for sure... they got the fatfuck skinhead assuring the press they are doing everything they can so the 8 crushed vehicles under there are filled with certain dead as a doornail victims ... they'll be at it for 3 days before someone gets enough courage to get those tons of cement off the cars

>>9594598
Dude, you are being delusional and have no clue how civil engineering works.

>>9594603
Oh yea?

I guess the armed forces and the federal engineer core built the walkway

>>9594611
ahh... national tragedy....

Just realized how many cars were actually under the bridge. Holy shit.

Florida isn't even part of the USA. It is little Cuba and has been for 40 years or more. No one really gives a flying shit what goes on in Florida.

>>9594617
>actually under the notbridge

fixed for you

>>9594623
>It is little Cuba and has been for 40 years
well, a good deal of the urban areas and coasts are

>>9593357
watch it collapse from 45 degree angle
http://www.miamiherald.com/news/local/community/miami-dade/article205443304.html
5 secs vid
http://www.miamiherald.com/latest-news/article205442624.html

>>9593357
They let women build a bridge

>>9594640
>http://www.miamiherald.com/news/local/community/miami-dade/article205443304.html
It starts to fail right near the support on the right hand side.

>>9593661
>>9594003
The span was designed to stand without the cable stays.

pg 125

https://facilities.fiu.edu/projects/BT_904/MCM_FIGG_Proposal_for_FIU_Pedestrian_Bridge_9-30-2015.pdf

>>9594940
>Under our safety program,
MCM has, over the past four years,
performed over 2.5 million staff-hours
of work with no loss time accidents.
Gonna have to remove that now, aren't they?

>>9593563

From experience I can tell you that 1) is always the more probable error.

>>9593357
Mutts.

>Select all images with bridges

Why did they build the bridge before the tower? Are they retarded?

>>9594283
>For a concrete pedestrian bridge like that, the weight of the bridge itself is probably close to 90% of the vertical load it’s designed to sustain once you include people etc.

According to the PR it was supposed withstand cat 5 hurricanes. The cables might have been for that.

cable-stay =/= suspension

>>9595009
Wtf. Are those pipe things for aesthetics only?

>>9595030
I don't think so, they're lined up with those support beams.
Thing is, as many people have pointed out, bridges tend to be well overbuilt, so that they don't just collapse when the load is a little higher than expected.
It's quite likely that, by design, it could have been adequate to service the loads they were expecting without the tower and pipes but by putting the tower and pipes in it would be able to service much higher loads than expected.

Obviously something went wrong, probably in the construction of the main span that caused it to fuck right off.

>>9595030
>The stay cable pipes increase bridge stiffness for pedestrian loads.
According to the plans.

>>9594623
>Florida isn't even part of the USA. It is little Cuba and has been for 40 years or more. No one really gives a flying shit what goes on in Florida.
by that logic no one gives a shit what goes on in texas either since it's just little mexico

>>9593357
>be engineer
>can't even design a fucking bridge

These classes will be gutted next year, right?

>>9593357
From what I hear they tried to do a stress test before they had finished building it.
As in no center support beam and no suspension stuff.

>>9595048
Much more likely it was the construction and not the design.

>>9593568

I mean that's what happened at Hyatt Regency, so...

>>9594183
/thread

>>9593357
>what happened
The bridge colapsed

>>9595064
can you prove that?

Women happened...

>>9594041
>Them stress test without either of those things.

>>9595071
What's your hypothesis for why a pile of bridge shaped rubble appeared right under where there used to be a bridge.

>>9595072
Take the first quote and place it next to the crashed bridge. Maybe do something funky with the phrase "artistic touch".

>>9595071
see >>9594640

>>9594361
your country sucks get over it, you and your parents let it go to waste. TOO BAD! nothing is forever anyways it would have happened eventually

>>9594501
>the moment when you realize cubanomutts are more civilized than pure breed amerimutts

>>9595072
>they promote the idea that knowledge can be ascertained through reason. This is a masculine concept that hurts women's feelings

can't believe someone seriously wrote this trying to be in defense of women, so fucking pathetic

>>9595215
That whole image is cancer.

>>9595225
I'm not a woman hater, don't believe I'm on your side.

>>9595231
i'm a stupid hater, and the shit wrote there is fucking stupid

>>9595231
To be free, to be wrong, is important for those who want to be something more.

>>9595231
when they removed the gender box on job applications, woman started getting fewer jobs because the people hiring started interviewing applicants who had actual merit shown on their application instead of being swayed by tits. Of course women are still outraged by this for some reason.

Regardless, what it means is that only meritocracy matters, not gender.

I don't get it. why use such a heavy bridge for pedestrians in the first place?

>>9594640
>http://www.miamiherald.com/latest-news/article205442624.html
dr6lcqo3bxtwa.cloudfront.net/binary/2018/3/16/13/1437580321678-6bjrso/Bridge_Edit-1521208359394.mp4

>>9595311
Here.

>>9594174
ya thot wrong kiddie

>>9595322
still not as fast as the twin towers.

clearly propaganda to get people to forget about the killings

>>9595357
Which killings? There's been like 10k+ in the past week alone.

>"One person commits suicide about every 40 seconds, one person is murdered every 60 seconds and one person dies in armed conflict every 100 seconds" - World Health Organization

>>9595311
they need it to be fairly wide because university foot traffic can be pretty extreme, so the overall size seems right, but there is a noticeable lack of steel involved. google images shows how it shouldve been

>>9595389
wouldn't a steel bridge had been more compact and lighter? I ask because I have no idea, but it seems that way to me

Bridges should be neutrally buoyant to mitigate the danger of collapse upon failure.

>>9595393

steel bridge =/= artistic touch

>>9595393
if it was mostly steel, yes. but steel beams and prefab concrete are often combined, which could lead to very heavy structures. it all depends on the conceptual and functional needs. yet the weird thing here is they wanted the entire structure to be prefab concrete. i guess they had patents around this new 'Accelerated Bridge Construction' process, but there's probably a reason why no one else did it this way up until now.

>>9595412
You're kidding right? Theer's a shitload of artistic steel bridges out there already.

>>9595421

he was referring to this >>9595072

>>9595424
Then he should have also quoted that post.

>>9595418
guess I'm not wrong when I say the bridge was overly heavy for no reason whatsoever
also, who the fuck does stress testing at work hours? these people must be really stupid...

>>9595432
pure autism

>>9595412
but they wanted hammocks and panther benches and and and....

>>9595454

>>9595432

i know this is /sci/ but goddamn autismo

>>9595461

>>9595464
Pic from the same document.
FIGG had bridges of theirs collapse in the past years. And MCM wasn't approved by the state of Florida to do that kind of work.

>>9595311
Heavy bridge for heavy pedestrians.

>Rosenberg

>>9593952
>>9594042
Hire 3rd world people you get 3rd world results

>>9595503
Kinda hard to not hire 3rd world people in a 3rd world country

>>9595450
pretty sure stress tests aren't supposed to make whatever's being tested collapse, just check if everything within acceptable parameters. doing it during work hours is perfectly normal.

>>9594174
Jews are white.

>>9595251
meritocracy is the liberal cancer that allows these hostile sorts to infiltrate and take over
They certainly don't give a shit about meritocracy, and you crying about "hurr why are they so feminism" doesn't stop them from putting their own kind in positions ofpower.

>>9595470
beaners and feminists huh
doubt any of the guilty party will face the death penalty as they deserve.

>>9595389
Bridge clearly supported its own weight,

>>9595322
imagine being in those two cars just leaving before it collapses

>>9595545
(you)

What happened? t. Doesn't browse news

>>9595545
¿Que?

>>9595626
t. Doesn't read the thread

>>9595450
>>9595462
Actually reading the absolute horse shit that is in >>9595072 when it wasn't quoted and it wasn't even part of that line of conversation.

How fucking new are you to 4chan, kid?

>>9595584
>Bridge clearly supported its own weight,

Only it didn't. lol

>>9595626
>What happened? t. Doesn't browse news
A pedestrian walkway collapsed in front of

Florida International University's Campus
(QS #751-800 meme tier university)

It was built by Cuban-americans, in just 1 day (hmmm) with a faster (but not safer) construction method.

For more details watch these news
https://www.youtube.com/watch?v=eY3TtNrZS-w
https://www.youtube.com/watch?v=MjN_iY164uw

>>9595578
>meritocracy is the liberal cancer

Meritocracy is hiring people who are qualified, not people based on gender, race, or family/friend ties.

>>9595657
>https://www.youtube.com/watch?v=MjN_iY164uw

Eh, they said they were removing cables and tightening cables but there's 0 cables anywhere at all during the entire time. lol

>>9593357
>Alright /sci/, what happened?
>/sci/
Well, gravity doesn't real, just like time and free will.
So it must have been that the engineers were too gay.

>>9595657
>built by Cuban-americans, in just 1 day (hmmm)
go hmmmm yourself. IT was pre-fabbed elsewhere, and INSTALLED in just one day.

>>9595322
Yup, as I suspected. Concrete is great at sustaining longitudinal force, but when you apply transversal force to a relatively think layer without >>9594518, it just snaps in half.

>>9595072
>women have a different perspective
>We're able to put in an artistic touch and we're able to build too.

in other words:
>men can't art
never mind the other racist and sexist nonsense in the other comments.

>>9595651
it was a fucking joke, of the type you and any other 4chan regular should be used to, calm down

>>9595540
yeah, well, weren't they promoting this as a new type of design, construction or some shit? should have thought a bit before testing things

>>9595670
this

>>9595668
The cables are in the concrete

https://en.wikipedia.org/wiki/Prestressed_concrete

>>9593357
women happened

>>9595677
You can clearly see the steel in the broken bridge. I mean the steel will be ~1% by volume, and that's all in thin strands so it might be hard to spot by an uneducated person.

You clearly have no idea what you are talking about, concrete doesn't care about 'longitudinal' or 'transverse'. Flexural forces are usually much higher than shear sure, but reinforcement is used in both directions to support the bridge with factors of safety. If there was no mild steel in that bridge I guarantee it would not be able to support itself over a 170' span over a week.

>>9595696
I mean, that type of construction has been done hundreds of times before, so it's not too new.

>>9595736
Just about every company wants to promote diversity. One company fucks up.
>See? Look at that! Diversity is bad.

/sci/
Complains that engineering is too easy. Can't even google some small facts and has to make up reasons to hate women.
>B-but my pure maths and my 3B1B videos! I could have designed that bridge in under an hour!

>>9595736
>diversity is encouraged and supported
At least one thing got supported hey

>>9595736
Hispanic Women

La Goblina. La Ogra de los Estados Unidos. La Creatura. La Oscuridad. La abominacion. La luz extinguido. La aberracion

https://www.youtube.com/watch?v=TZ77xBgIA9s

>>9595503 >>9595184 >>9594516 >>9594501 >>9594494 >>9594475

>>9595776
>One company fucks up
He's showing a different fuck up that OP

>>9595804
GomeZ eyebrows look like painted on a cat

>>9595806
So what? We've had companies fuck up constructions since forever, pinning this catastrophe on diversity or some other boogeyman is just intellectually dishonest.

>>9595845
Fair enough
I was just pointing out the mistake in saying one company
That being said, I'm of the opinion that this Miami thing is a building flaw not a design one if I had to guess

>>9593462
Pfft. That's not fat.

>>9595418

ah, yes, great pic. that bridge you posted is essentially an overdimensioned two-part steel frame that "locks" by mounting the prefab concrete parts onto it. good oscillation dampening and virtually indestructible (also cheap), i wonder why they chose their concept over existing and tested ones, it can`t be because they wanted their dumb, little roof, right?

>>9593357
Firstly, what kind of state builds a bridge and lets other people pass under it while it's being built???

>>9593357
civil engineer here
to me it looks like a Problem with shear forces, since it happened suddenly and the first breaks were right next to the base.

further Analysis leads my Attention to the to Joints next to the base. the lower one is more suspectable.
designing the rebars in nodes like These really requires a huge amount of skill, especially when pre stressed members are next to it.
the design of the rebaring rods tend to be really complicated, with a number of things considers with each rod.
These many and complicated rods then have to be ALL at the right place before the concrete is poured. the concrete has to be poured with extra passion and skill.
but usually all These steps are supervised closely.


however, from personal experience I know that most critical mistakes occur on the construction site, because the construction company decided it has to make something 'easier'.

the Company had another Bridge collapse a couple of years ago. another brigde usually means other engineers.

So my guess is: the Company fucked it up because they fucked with the falsework or the did not give the concrete enough time to harden up, usually between 28 and 56 days.

If anyone can find out, if the pouring of the upper deck was less then four weeks ago, we migth have gotten to the core of it.
on the Suspension: the Joints don't really look that strong to me, so it really might only have been for Show. (idiotic).

>>9595890
uni mannheim?

>>9595902
gibs da überhaupt bauings?

>>9595882
>dumb, little roof
That's one of the more confusing bits of the design. If you wanted a covered bridge why would you pick one that only covers 53% of the walkway? On top of that 1/4 of the covered area in the center is wasted by the trusses. You could have put on a full size roof any number of ways and it still would have been lighter than the half size one they used.

From what I'm seeing about weather in the area it rains on over 1/3 of the days of the year.

>>9595908
klar, nur kein diplom

>>9595890
nice analysis, anon

>>9595912
I think they designed the roof to provide as much structural support as possible without adding unnecessary weight. The obsession with prestressed concrete would limit what they could reasonably achieve (and obviously, it did).

>>9595882
Steel is not cheap. Nobody wants to work with it because it is seen as expensive. A bridge like the picture also sucks at spanning large distances. Everything sucks compared to PS/PT.

>>9595888
Well, if there wasn't a problem it would have saved them from closing a main street for a month. It was designed in such a way to cause the least amount of delays, then the final construction is for it to hold service loads over its lifetime.

>>9595890
What are you, a first year? Your pic sucks, you can't just pretend it's one piece. You would only do that to find the support reactions. If anything, you would treat it like a truss with compression on top and tension on bottom. It would actually break in the deck, as concrete sucks in tension. That's why there would be PS in the deck. Also, what is SAP? It's not that complicated. If you knew anything, you would know the most complicated part comes from staging of the construction. And no, you never wait 28-56 days for it to cure, the contractor wants 7day strength considerations so they don't throw away money. Main staging calcs are based on 7day. Also there is no falsework because it was not needed. There is nothing to fuck up.

>>9595969
>steel is not cheap
wat. maybe not in burgerland, what with the severely reduced steel production in that country.

>>9595969
if I want to clarify that the maximum shear forces occur at the supports, I sure can pretend it's just a one piece beam.
Also if I wanted to calculate the forces in the middle section (top and bottom parts), I could just divide the Moment by the height of the truss and be done.
I think it is you who got no idea.
>what is SAP?
yes, what is it?

over here in germany we usally wait 14 days for normal buildings like houses and such. however, bridges are complicated and need special attention. I really think this is where they fucked up.
7 days really only gives you 70..80% of strength, pic related. risk of deformations is high too

they had falsework on wheels btw

>>9596014
Well, you see our country is very large, and there are steel mills scattered around. Large=Long Distances=High price to ship. Same goes with precast plants, in that you would need to ship it. Nobody wants to ship a 40'-150' long thing thousands of miles. Even with precasting they want to splice it. That's why there is an appeal to make it right next to the place you want in and just move it into place.

I'm sorry we don't have factories on every street corner like your country seems to.

>>9596025
It won't break in shear at the supports. You would need a fucking huge section for it to even be a consideration. Obviously with PC It's going to break with flexure because it's so slender and its section modulus is so low. AKA the deck.

Have you ever used any Structural Analysis Program?

With houses you build up, and so the stuff at the bottom needs to be strong to support the stuff on top, so obviously you need to wait. However, this isn't a building or CIP. The only CIP section was over the channel. 75% strength is all you need, you're not adding full service loads, you only have selfweight with PS/PT stresses and losses. You also use high strength, ~7ksi. Your pic obviously says something about super-plasticisers, which are used so you don't need to wait as long, strengthening my point that you only need 7day cure.

Also, that's not falsework, that was the thing that put it in place that was removed. If it was falsework then it would need to be there the entire time supporting the bridge while it cures.

yes, that falsework was probably fairly typical, then with some of it removed, the transporter could come in under it.

>>9596079
>Have you ever used any Structural Analysis Program?
ah, yeah sure. I use them every day actually. dlubal und such.

>It won't break in shear at the supports.
well, I'm pretty sure it did

>Your pic obviously says something about super-plasticisers
it doesn't, you just don't know any german

>you're not adding full service loads,
full service load in this case is just a bunch of pedestrians +snow +wind

>the stuff at the bottom needs to be strong to support the stuff on top, so obviously you need to wait.
nope, it's the most slender parts that need the best concrete. also if you don't wait enough the ceilings will be concave.

>Also, that's not falsework, [..]
thx for the clarification

>>9594283
The centre span and cables were apperently for vibration control, not for strucutral support.

>>9594961
Better question is, why only four years?

>>9596109

here my friend, read this again HA!
>>9594283
>shear
>90% dead weight
>builders fucking up probable

>>9596127
meant you

>>9596079

>>9594318
>considering how utterly obliterated the bridge is with not visible steel structure, it could only have been designed to include additional support.
that's what I thought too, on the other hand, the connecters on top are fucking tiny

>>9596109
What I'm saying is it's way more likely for the deck to break after something like steel relaxation/ bad anchorage/ or anything to do with stresses due to PS/PT than break in shear. It's a 170’ span bridge. It would probably break in shear right away, rather than waiting a week. I agree that shear is more sudden, but is unlikely to be controlling.

Ceilings are cambered for this very reason. When you put wet concrete on steel sheeting it will deflect in the center, but it is super easy to calculate what it is and how to adjust for it so you don't need any falsework. Falsework in buildings is hella expensive because it takes so damn long.

>>9596127
I don't even know what to say to this.

>>9593357

America vs. civic design:

Build a 6 lane freeway between your campus and the housing unit

>or the other way around

>>9596148
well, let's wait and see see what the official reports say
have a nice weekend

>>9596162
You too.
:)

>>9595238
Oh ok, so women are stupid now, ok.

>>9596390
Don't be absurd.
Women were always stupid.

>>9595072
God damn it they fuck up everything... except me..

>>9595091
Quantum physics

>>9595421
>What kind of bridge you want
>Just spin me in a web of lies

>>9595657
>browse the news
One news outlet I read said it was opened on Saturday when it was only the main span that was installed on Saturday and it didn't even have the stairs constructed for the span yet.

>>9595655
it was being stressed tested

Why didn't they just build an underpass? A tunnel under the road instead of a dinky bridge over it.

Sounds like they wanted to get fancy. The renders show ceiling fans in the fuckin thing.

>>9595659
It's important to do both
How do you think institutions, nations, businesses, etc survive the test of time?

>>9593362

>>9596079
>there are steel mills scattered around
...but only a fraction of the number that existed a few decades ago.

Women

Just look at the length, height of the bridge and the distance between the supports
Even a 10 year old kid would know that he shouldnt stack more than two cards between two supportive card pillars

>>9593635
Wait that was a stress test? Well then.. I'd call that successfully stressed

>>9596877
A for effort

>>9596726

100111100

>>9596691
Because there's a canal right next to the road, that the bridge was supposed to go over too.

>>9597023
But it didn't have to go over the canal. It was just convenient for the bridge to.
The main issue was removing pedestrian traffic from the intersection, which a tunnel could have done.

>>9596877
I think some people are confusing stress testing the overall bridge structure with testing the stress on the post tensioning cables. These are the cables that run inside the beam, and not the 'cables' held up by the pylon.

>>9593357
elon musk was contracted to build it

>>9597027
yeah that blue thing hanging out was probably a hydraulic post tension jack

>>9596914
You need some error correction codes or something. It's 100111000

>>9595061
The Hyatt Regency catwalk was designed just fine. It was a change requested by the GC that fucked things up. Don't remember off hand if the engineering approved the change or the GC did it on his own but I do know it was safe as designed but obviously not as implemented.

>>9597080
A post-tension jack doesn't get ejected like that without a brittle failure of the tensioning rod.

https://www.youtube.com/watch?v=KtiTm2dKLgU

quick rundown

>>9593661
>Stress testing during live traffic when the bridge isn't even completed yet on the assumption that the test won't fail.

Wtf were they thinking?

>>9596691
It's Florida, there were probably ground water concerns. It's also a city so you'd also have to worry about dealing with unmarked cable and pipe lines. Plus digging holes is expensive.

>>9595383
>There's been like 10k+ in the past week alone
And 10% of those were in 'murica

>>9596750
Not to mention concrete is very brittle. The rebar doesn't help when the span between the supports is so huge. The people who designed it probably didn't consider the environmental factors (rumbling from vehicles, wind, sun etc.)

>>9595383
Why should I give a shit about suicides again?

>>9597183
See >>9597127

It's probably the best public speculation as to why it failed.

>>9594106
t. jealous chink mad at Nipponese superiority

>>9594174
>>in a Jewish community
are you actually fucking retarded enough to think Sweetwater is a jewish community?

>>9593462
miami is one of the most obese cities in the US

>>9596390
>now

>>9596693
by having sensible immigration policies and then implementing meritocracies
that is the only way forward, faggot
unless you want to regress our technology to the middle ages so that aristocratic monarchism would work

>>9596726
me in the back

>>9597127
Wow, I expected this to be full of conspiracy theories, but he actually knows what he is talking about.
I could elaborate if anyone is interested, but it's all explained if you watch the whole video.

>>9596726
young women
only one is even average sorry don't kill me

The problem wasn't the bridge design or the designer, it was the construction. The bridge was being built using an expedited process that favored putting it up quickly over doing so safely. They built most of the bridge offsite and moved it into place, planning to build the supports once it was there. But without the proper supports, the section fell down almost immediately.

>>9593357
The bridge fell down

>>9597482
It looks more like on site changes in how they transported the span resulted in much higher than expected strain on one of the tension bars which pushed it beyond the tensile strength of the bar.
From measurements of the tension on the bar they would have seen it was below the required tension and so they decided to jack it up, but the problem was that the bar was already beyond its limits, so increasing the tension on it was just pulling it apart.
And then it snapped, ejected the rod >>9597080 and now you had a truss that was being supported solely by the concrete and it couldn't take it.

>>9593635
Jesus Florida get it together

>>9595421
That's fucking sweet
Guessing Dubai

>>9597596
Nah it’s singapore. The ship building is a giveaway

It is pretty sweet

>>9593661
Hmmmm
Wonder why it collapsed

>>9597212
I hope your mom commits suicide, maybe that'll give you some perspective.

>>9595421
Architecture went to shit.

>>9594183
How fucking awkward is that.

>>9595072
>>9595115

s͚͙̳͙͎̫̙̓ͣ́ͩ̓ͧ͗̿p̶͈̜ͭͣ̑̀e̜̬͚̩͙̽̐͋ͣ̿̊ͣc̯̦͍̭͆ͬ̀̎̀̓ͨ͑͑ͅi̦̬͓̥ͬ͆̇͛ͤ̃ͭa̹͔̰͔̞͚̪̝̰ͫ̎̋l͔̩̖̫̫̙̝͍͖ͧ̍ͭ̊̈̚ ̸͕̗̥͚̙͆̂͐͘ţ̸̺̼͍̺̜͆̒̊͆ö̢͔͙̖̟͕͚́͆̌̀ͩ̿u̸͍̮͌̉c̪̯̒̉͋ͩḩ̵̸͍̗̣̮͎̘̪͆̑̇ͧ̍ͧ̍͋̔

>>9597704
Sorry to break your circlejerk but she wasn't involved with working on this bridge.

>>9594183
Smaller arrows would be sufficient. But good observation.

>>9597741
And it's looking even more like design wasn't the issue.
Rather that the span wasn't transported and supported as designed which caused a section to be over stressed.

>>9593526
So the engineer will be taking full responsibility for all these deaths and'll be locked up for manslaughter right?

>>9593357
1. it wasn't finished and the supports weren't added yet (concrete pylons attached to a central pillar)

2. they were apparently weight testing it in the middle of the day with traffic going under and that's what caused the failure

6 people ded

>>9597774
No. You and >>9597796 watch >>9597127

>>9597812
Fuck off. You should read >>9595072
It's plain as day what happened. Feminists put "diversity" ahead of competence and people died for it, as usual.

>>9597796
>weight testing whilst trafficking is on going
I'm sure that's a breach of safety regulations and is punishable in court.
Apparently it was management that was rushing them but in the end whomever was in charge and gave the go ahead

>>9595545
Jews themselves will tell you they aren't

>>9597819
Fuck off, mate, stop ignoring evidence because it doesn't fit your narrative.

>>9597819
Why should I read that? It has nothing directly to do with the bridge collapse.

>>9593357
As someone that works in construction and more directly in the cities I can confirm that 65% of construction budgets are going to cocaine.

The corruption in this city is insane. I hope those fuckers literally get sued to homelessness. Crackhead bitches with influence and contracts getting people killed

https://www.youtube.com/watch?v=KtiTm2dKLgU

>>9596693
>It's important to do both

You are a fucking moron. If someone can't do that job they get then it simply doesn't work.

>>9597832
>>9595545

Diversity hires

>>9597865
AvE, my man. very nice analysis

>>9594045
found the spastic

>>9595178
>tell you your mom drinks cum
>autistic rant about america instead of a comeback
Touched a nerve?

>>9593357
It's funny that Civil Engineering only get attention when it fails badly, killing people .

>>9593357
its just a promo for the new Tony Hawk Game

>>9593623
referring to Dems

>>9593661
> what is a risk assessment?

>>9593357
>>>/pol/164318071

>>9599086
Female-led Construction Company

Lmao

>>9593411 >>9594243
>Russian Hackers

>>9593661
The cables were decoration, they weren't designed to support it at all.

>>9593357
an artistic touch happened

>>9599128
She is a (Con) artist.

>>9599128
artistic touch in STEM
aka STE(((A)))M

>>9596726
>can hear them discussing engineering group projects and shouting LIKE I DON'T KNOW I JUST WANNA PASS THIS FUCKING CLASS in my head

>>9599155

>>9597852
Those are quotes directly from the people who designed the bridge, showcasing exactly why women shouldn't be designing out bridges. They don't give a shit about reality and the shit they produce falls down.

>>9599128 >>9599100 >>9597704
>>9599155 >>9599263 >>9596726
>>9595736 >>9595072 >>9599623
>Women in STEM

>>9599623
>english professor
>designing a bridge
sure thing, buddy

>>9593362
fpbp

>>9599623
But none of those things suggest they designed the bridge wrong.

>>9599699
Really though, the fact that a 175' span was built with unorthodox methods with no redundancy whatsoever means it is wrong by default. They designed a fake cable stay bridge in such a way as to invite total catastrophic failure. Concrete nodes are already unpredictable enough. There was no reason to totally rely on them in this structure unless there was a systemic dysfunctional mindset. It's not literally biological sex that caused all this, but the absurdity of the quotes is a nice reminder of how deluded certain people can be about STEM fields.

>>9599699
true, it looks more like procedures were not followed to the letter as AvE pointed out.
like the transport and lifting vehicles were not at their designated positions, damaging the bridge in transit from its staging area already

>>9599822
Yes.
They designed it to be constructed and transported in a certain way. We don't know who decided to change how it was transported or who signed off on it but the fact is that moving the lifting vehicles and not having the support plates completely changed the way stress was distributed across the span as it was transported.

If they had the tower up and attached the pipes, maybe it would have stayed up, but it still would have been considerably weakened in the same place, you can only speculate if part of it still would have collapsed at a later date.

This one's easy. The bridge was a shitty concrete/rebar hackjob and they put it into place and started stress testing it... without the load bearing pilons... on a busy street that they didn't shut down. Basically everything about this project, from the materials to the construction to the test procedure to the safety protocals, was doomed to fail from the begining.

>>9593635
>>9593661
>>9594339
>>9595056
>>9595088
>Stress testing a bridge after finding cracks in a key support point after people heard a loud cracking sound, and having a 2 hour meeting over it and declaring it a non-issue.

>>9593357
>>9593879
>>9595890

civil engineer student here.

as these two says. they messed with the tension wires inside the bridge.

pre tension = because concrete is stronger when compressed they put pre tension on it.

nothing wrong with the design, the installers(murica) where retards, didnt follow the installation sequence and fucked up the tension process (the steelrood lateral have been shot out of the concrete, the blue thingi. it broke before the bridge and all the strength went away).

to much tension and it broke.

the real case why it broke => big fatass americans. seriously, lobbism and obesity all over the country, fucking gross.

>>9600225
> implying women are capable of noticing why that's a bad idea

>>9600244
the student correcting myself a bit.

they got pre tension wires in the big horizontel slabs. then its more like big bults and nuts in the lateral pillars.

pre tension wires = tubes with wires that i put tension on, on site. then put concrete over it.

the bults are regulareable ? you can change the tension. they fucked up with these.

>>9600248
What's hilarious is they had this meeting and concluded it was safe literally only 4 hours before it collapsed.

>>9600248
Do you even have proof that women were involved in that process?
As far as I can determine the potential females involved were in the design, and they're in a different state.
They're not construction workers, so even if they were called by the company building the bridge and told that people heard cracking sounds they wouldn't be able to judge the situation. It would have been up to the contractor to assess.
The contractors definitely fucked up. They fucked up in modifying the design for transporting the plan to the pillars, and they fucked up assessing the bridge after the noises were heard.
I'm guessing they were also under pressure to keep the road open which affected their decision.

>>9600244
Change fields before you kill someone.

That member they were working on was already under compression (see this pic >>9595890
for example as that has the trusses labeled), if you pre-stress it i.e apply more compression to it, it doesn't miraculously become more strong with that.
>it broke before the bridge and all the strength went away
If the pre-stressing bar/cable had broken before the bridge the bridge would still be standing.

>>9600325
Watch >>9597127

>>9600316
> Do you even have proof that women were involved in that process?
See >>9595072

>>9600336
You and this yt-show off >>9597127 are missing the point here. That member is already under compression, this is basic knowledge if you know anything about structural engineering and truss bridges. The work crew could have cut that rod inside #11 with an angle grinder and it wouldn't have caused it to collapse.

What they did instead was tighten it (for whatever reason) which propably caused a failure in the joint area where that bar was anchored which in turn caused the collapse

>>9600359
That's not proof they were involved in the process to determine the bridge was still fine.

>>9600397
The video says why they decided to increase the tension on it. They would have had readings on all the tension bars and it would have been below the expected value, so they tried to bring it up to tension.

>>9600405
> That's not proof they were involved in the process to determine the bridge was still fine.
They were literally in charge of the project you mong.

>>9599115
Are you implying Russia has no interest in meddling in other countries' internal affairs?

>>9600325
i think that member was under bending moment, and so they needed tension to stabilize it. the fact that people had already heard snapping and whipping, and a manager called in about cracks, the structure was likely already ruined. anything they were doing with the tendon was like treating the symptoms of a fatal disease. in this case it just happened to cause sudden multiple organ failure.

>>9600405
There would have been two sets of expected values one for the move during which the span was supported at different points and one for when in place. Your video had a clip in it which a crew member said they would be destressing two bars before opening the road to public (that would be 2 and 11). Clearly that information didn't reach everyone since someone decided 5 days later to try to retighten it back to the pre-stress levels that were needed for the move (but harmful now since the weight of the bridge was already compressing that member)

Rough in-place expected values can be seen in the 2015 draft plan: zero pre-stressing for member #11 (same for both move and in-place as the movers were closer to the right spots in that plan)

>>9600316
>I'm guessing they were also under pressure to keep the road open which affected their decision.
1000times this
Everyone with a brain knows this is the case,and that's because America is a retarded backward country where if you close one road the whole city (and beyond) goes into lock down mode that's because American have too much freedumb for silly things such as public transport and a functioning reliable passenger railway network
>tfw too free to not have to drive to get anywhere

>>9600359
Are /pol/ tards that gullible or are you just pretending?

>>9600421
Link to your source

>>9600454
And ironically now the road will remain closed way longer than if the did things properly.

>>9600481
That's pretty much the irony whenever something like this happens.

>>9600425
> vaginas given jobs for the sake of "diversity"
> can't design a bridge that can stand up longer than a week
> blame the Russians when it falls down
You can't make this shit up, liberals are just that delusional.

>>9593357
Work in PT and used to work for the company doing the PT work on this bridge. I've done jobs like this, where members are pre-stressed and then detensioned afterwards. From the pics, it looks like they used Williams bars with nut lockoffs. I've never seen or heard of a Willams bar of that diameter failing. The problem with detensioning Williams bars is that you have to put some stress on the bar with the ram to detension it. The reason, it's done this way instead of loosening the nut is for instrumentation of the tension in the bar. I've used turn of the nut method for small loads but these bars were probably at 200+ kips. In any case, the PT crew was probably detensioning the member and one of the end anchorages in the nodes failed causing a complete failure of the structure. When it comes to PT, everyone I work with are extremely cognizant of the dangers of screwing up and we conduct ourselves accordingly. If one tendon failure can cause the entire structure to collapse, it's a shit bridge design, plain and simple.

>>9600626
Nobody ever mentioned Russia in this bridge story except for you... You're literally arguing against your own delusions

>>9600454
I'll add that I've never been to miami, but every city in florida i've been to has fucking retarded road planning. Sometimes there's literally one main road that goes to everything and traffic shuts their entire economy down

>>9600804
>cognizant
Don't take this personally, but I'm really curious as to why Americans create convoluted synonyms of existing English words. It seems like the symptom of a mental illness.

Take personally the fact that your engineering speak is gay as fuck.

>>9601635
Are you trolling or genuinely retarded? Not even American or the guy you're replying to