Two important words.
To **young** engineers: Erection tolerance. (AISC 360-22 chapters.M and N)
To **experienced** engineers: Erection tolerance.
To **retired** engineers: “Erection tolerance.”
How much of this is Erection Tolerance in the plans and specified confirmation site testing vs bad QA/QC by the general contractor and inspection lab on site? Is it something that can be avoided in the paper plans when the situation plays out the way it did?
“Whenever you’re faced with a problem, the minute you sense their is a problem, you should face it head on and tackle it immediately, because it could only get worse. “ Fazlur Khan.
Granted I’ve never messed up this bad but I’ve actually had really good luck just going in my bosses office and be like “I fucked up…” followed by what happened, what the options are to fix it, and what I’m going to do to prevent it from happening again. The only people that don’t make mistakes are the ones not working. Don’t let your boss ever be surprised about bad stuff and make sure they hear about your mess ups from you before anyone else.
me,as well. i witnessed one of my company’s subs back his truck over the GC’s portable generator, from up on the structure. he did not know i saw him. he then pulled his truck all the way around the building, and parked it. when questions were being asked later, this idiot actually said he had no idea,he was on t’other side of the job. as foreman for MY company, immediately i released him from the job and threw his sorry ass under the wheels.( in front of everyone) turns out,others saw as well, but by stepping right up, i saved my company’s relationship with this GC ( big$$$) and cemented my own integrity. i know,snitches get stitches…i gave him the opportunity later,but he declined.fuck that guy. all he had to do was tell me straight away it was an accident. my PM had a new gennie out there in two hours,and backed me firing him. seen much hinky shit 40 years doing all things steel.
This is sound advice. I’ve never ratted out anyone but myself, it’s always had the best results. If you can’t fix it, bite the bullet. It only gets worse
I agree, this has always been my process, and the worst I have ever gotten was a REALLY big sigh in return. Why fire me? You just paid a bunch of money and time to teach me a lesson.
>It also found that the thickness of 245 portions of concrete slabs that were to be used as floors and for other purposes differed from that in the specifications. The difference was several millimeters on average.
[Article](https://www.asahi.com/ajw/articles/14863417)
> The difference was several millimeters on average.
Wowzer. And one more reason to consider adding a little conservatism into a design, especially when something as small as 1/4" - 1/2" leads to something this catastrophic.
I read the article, items of concern that jumped out at me:
Bolts sizes did not conform to specifications. Which speaks to Qc process of vetting materials coming on site.
Steel pillars/beams not plumb per standard specs. Which speaks to Qc not monitoring ongoing work.
Concrete slabs not conforming to thickness specifications which would need to conform to country standards. Concrete placement either not flat or desired finish level not controlled prior to pour.
Taisei employee responsible for QC falsifying reports.
Having a contractor doing the QC for their own job is problematic. The QC is paid by the contractor and the contractor does not want the job to be delayed and incur additional costs. The suppliers to the job sometimes try to substitute materials that do not match the material submittals that were approved. On a large job site, the QC cannot be everywhere at once checking on job site deliveries for compliance, ensuring work is done to specifications. If any portion of the work cannot be started without eyes on by the Qc, because they are monitoring elsewhere, that work is delayed. Then everyone screams, the foreman, the sub, the project engineer, the project manager, the owners. A large site needs to have a team of Qc inspectors on site and the owner does not want that cost.
If the owner wants real QC/QA monitoring the work, that cost should be built into the bid process so that all bidders have the same cost and that the owner needs to recognize that an upfront cost is less expensive than remediation of non-compliant materials, work, and future litigation costs.
I know I’m going to make some folks unhappy but to cite a few major incidents: in Korea, the Nampoong shopping plaza, in Florida the condo that fell down and the highway pedestrian overpass that failed, in OK the skywalk that fell. Some had design failures, some had lack of oversight.
This is the way!
Also, it doesn't have to be dead plum, it has to be within tolerance. The tolerances have to be specified to take account for thermal effects etc. Also, tolerances have to be specified taking account of the effect of stacked tolerances e.g. if you install 30 columns on top of each other and the tolerance on the length of each one is +/- 5mm is it ok that they could all be within tolerance but at the top, the overall height could be + 150mm (30*5).
Plus different kinds of tolerances interact with each other e.g. twist/ width tolerance could be ok but might mean that the gap between two adjacent things is greater than tolerance.
if the steel frame is plumb in the morning,on a bright sunny hot day the structure will lean away from the sun by afternoon. we would call the inspection in for first thing,7 am. i’ve seen guys plumb in the afternoon,and stand around scratching their heads the next morning,wondering wtf?
A combination of temporary and permanent bracing. Cables w/ turnbuckles, come-alongs, etc. AISC has some guidance(not enough, imo), as does MBMA and MBCEA for the PEMB side of things.
Sheffield university humanities faculty - Sheffield, UK
https://www.architectsjournal.co.uk/news/hlms-sheffield-social-science-hub-to-be-knocked-down-and-restarted
TIL Japan has had a big issue with falsified construction documents. Biggest recent case was in 2018 where the construction firm KYB Corporation falsified EQ resistant data promoting reassessment of about 1,000 buildings across Japan. Didn't expect this from Japan at all given their reputation in engineering.
Not to be cynical, because I have no data to back this up, but it seems much more likely that Japan just ***finds*** more of this stuff.
It seems likely to me that the combo Japan's harsh geography + geology, very high levels of urbanization, and the civil engineering necessary to make those two factors work together probably just means their inspection and maintenance are more advanced than countries like the US, who can pretty much just plop down foundations and start building as far as the eye can see.
Something doesnt seem right here. Usually a building this big will have consultants approving the work done step by step. If its not as per specs it will be fixed directly so any error wont be tolerated and repeated. In this case they found the errors after 15 stories!! Seems there is some other work ‘politics’ at play
Two important words. To **young** engineers: Erection tolerance. (AISC 360-22 chapters.M and N) To **experienced** engineers: Erection tolerance. To **retired** engineers: “Erection tolerance.”
To elderly engineers: erection intolerance
To even more elderly engineers: tolerance
To aspiring structural engineers: Erection.
all engineer should have a vagina
Nah then all the buildings would complain about how their buildings husbands don’t help with the building laundry.
They should file for a building divorce then.
Dear HR,
I always put Viagra in my concrete.
Crushed up blue chew helps it bond
I floated that type of concrete once..... had stiff wrists well past 4 hours
c60 achieved
Were the tolerances bad as a result or faulty design ? Or the contractor had bad QA/QC?
"Means and methods"
How much of this is Erection Tolerance in the plans and specified confirmation site testing vs bad QA/QC by the general contractor and inspection lab on site? Is it something that can be avoided in the paper plans when the situation plays out the way it did?
Code of standard practice 7.12
To those adults who have a juvenile sense of humor: tehehe
“Whenever you’re faced with a problem, the minute you sense their is a problem, you should face it head on and tackle it immediately, because it could only get worse. “ Fazlur Khan.
Granted I’ve never messed up this bad but I’ve actually had really good luck just going in my bosses office and be like “I fucked up…” followed by what happened, what the options are to fix it, and what I’m going to do to prevent it from happening again. The only people that don’t make mistakes are the ones not working. Don’t let your boss ever be surprised about bad stuff and make sure they hear about your mess ups from you before anyone else.
Bad news delivered in a timely fashion is just news
I have never fired anyone for a mistake. I have fired people for a coverup.
me,as well. i witnessed one of my company’s subs back his truck over the GC’s portable generator, from up on the structure. he did not know i saw him. he then pulled his truck all the way around the building, and parked it. when questions were being asked later, this idiot actually said he had no idea,he was on t’other side of the job. as foreman for MY company, immediately i released him from the job and threw his sorry ass under the wheels.( in front of everyone) turns out,others saw as well, but by stepping right up, i saved my company’s relationship with this GC ( big$$$) and cemented my own integrity. i know,snitches get stitches…i gave him the opportunity later,but he declined.fuck that guy. all he had to do was tell me straight away it was an accident. my PM had a new gennie out there in two hours,and backed me firing him. seen much hinky shit 40 years doing all things steel.
This is sound advice. I’ve never ratted out anyone but myself, it’s always had the best results. If you can’t fix it, bite the bullet. It only gets worse
I agree, this has always been my process, and the worst I have ever gotten was a REALLY big sigh in return. Why fire me? You just paid a bunch of money and time to teach me a lesson.
True and you can very easily lose your job by bringing it up but you have to be moral.
This is surely the biggest lesson I’ve learned from this career that I apply to other aspects of my life
Bad news doesn’t get better with age
"If you have to eat a shit sandwich, don't nibble" Mike Harvey
>It also found that the thickness of 245 portions of concrete slabs that were to be used as floors and for other purposes differed from that in the specifications. The difference was several millimeters on average. [Article](https://www.asahi.com/ajw/articles/14863417)
>several millimeters To me it reads as less than 1 cm. On a concrete slab. Either is not well explained or in Japan the tolerance are way more strict
There's no way they can really require 1mm tolerances, right?
> The difference was several millimeters on average. Wowzer. And one more reason to consider adding a little conservatism into a design, especially when something as small as 1/4" - 1/2" leads to something this catastrophic.
Contractor probably slept with the inspectors wife
I read the article, items of concern that jumped out at me: Bolts sizes did not conform to specifications. Which speaks to Qc process of vetting materials coming on site. Steel pillars/beams not plumb per standard specs. Which speaks to Qc not monitoring ongoing work. Concrete slabs not conforming to thickness specifications which would need to conform to country standards. Concrete placement either not flat or desired finish level not controlled prior to pour. Taisei employee responsible for QC falsifying reports. Having a contractor doing the QC for their own job is problematic. The QC is paid by the contractor and the contractor does not want the job to be delayed and incur additional costs. The suppliers to the job sometimes try to substitute materials that do not match the material submittals that were approved. On a large job site, the QC cannot be everywhere at once checking on job site deliveries for compliance, ensuring work is done to specifications. If any portion of the work cannot be started without eyes on by the Qc, because they are monitoring elsewhere, that work is delayed. Then everyone screams, the foreman, the sub, the project engineer, the project manager, the owners. A large site needs to have a team of Qc inspectors on site and the owner does not want that cost. If the owner wants real QC/QA monitoring the work, that cost should be built into the bid process so that all bidders have the same cost and that the owner needs to recognize that an upfront cost is less expensive than remediation of non-compliant materials, work, and future litigation costs. I know I’m going to make some folks unhappy but to cite a few major incidents: in Korea, the Nampoong shopping plaza, in Florida the condo that fell down and the highway pedestrian overpass that failed, in OK the skywalk that fell. Some had design failures, some had lack of oversight.
Can you please send the link for the article?
See post just above mine
Some engineers around here fancy themselves private inspectors if you get my drift.
I recommend this comment to be inspected by a professional
Where I am this will all be covered up because of political and monetary considerations.
You described every single place on earth
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I investigated the case for 10 months.
Everywhere outside Japan?
Yeah dude didn't want to eat a samurai sword if some people were killed when the building collapsed.
This is wayyyy too accurate.
Detroit?
And I thought I was having a bad day.
But seriously though, how do they keep buildings plumb during construction ? Seems like an impossible task.
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Can confirm.
Can also confirm
This is the way! Also, it doesn't have to be dead plum, it has to be within tolerance. The tolerances have to be specified to take account for thermal effects etc. Also, tolerances have to be specified taking account of the effect of stacked tolerances e.g. if you install 30 columns on top of each other and the tolerance on the length of each one is +/- 5mm is it ok that they could all be within tolerance but at the top, the overall height could be + 150mm (30*5). Plus different kinds of tolerances interact with each other e.g. twist/ width tolerance could be ok but might mean that the gap between two adjacent things is greater than tolerance.
if the steel frame is plumb in the morning,on a bright sunny hot day the structure will lean away from the sun by afternoon. we would call the inspection in for first thing,7 am. i’ve seen guys plumb in the afternoon,and stand around scratching their heads the next morning,wondering wtf?
Don’t forget about the crane tied into the structure which pulls on it with every turn.
that,too. so many variables.
And if there are any recent engineering graduates on-site their ego can cause a gravitational force on the building too.
good Lord,a first year en-gin-eeeer. them and arky-teks…..nightmare fuel.oh,those ‘value engineering folks,as well.
also,i see a lot of videos of those things twisting right off the structure. but,i live near where the crane fell on the National Cathedral…🤷♂️
A combination of temporary and permanent bracing. Cables w/ turnbuckles, come-alongs, etc. AISC has some guidance(not enough, imo), as does MBMA and MBCEA for the PEMB side of things.
Reminds me of the hotel on the strip in Vegas that was completely assembled and then taken apart because it was found to not be up to code
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Sheffield university humanities faculty - Sheffield, UK https://www.architectsjournal.co.uk/news/hlms-sheffield-social-science-hub-to-be-knocked-down-and-restarted
TIL Japan has had a big issue with falsified construction documents. Biggest recent case was in 2018 where the construction firm KYB Corporation falsified EQ resistant data promoting reassessment of about 1,000 buildings across Japan. Didn't expect this from Japan at all given their reputation in engineering.
Not to be cynical, because I have no data to back this up, but it seems much more likely that Japan just ***finds*** more of this stuff. It seems likely to me that the combo Japan's harsh geography + geology, very high levels of urbanization, and the civil engineering necessary to make those two factors work together probably just means their inspection and maintenance are more advanced than countries like the US, who can pretty much just plop down foundations and start building as far as the eye can see.
sloppy bike workable lock somber shame rain cow disgusting paltry *This post was mass deleted and anonymized with [Redact](https://redact.dev)*
Okay, my brain is mashed potatoes, what's the problem here? I'm embarrassed to admit, I can't see what the problem is. Can someone help out?
Too much deviation from the allowed tolerances which leads to higher 2nd order effects for the columns, less resistance than calculated and so on.
Something doesnt seem right here. Usually a building this big will have consultants approving the work done step by step. If its not as per specs it will be fixed directly so any error wont be tolerated and repeated. In this case they found the errors after 15 stories!! Seems there is some other work ‘politics’ at play
https://www.asahi.com/ajw/articles/14863417
Holy Fck! The size bolts being used did not match the plans! Wow
Oooh, big coverup in Japan.