Recent Engineering Debacles 7

[hidalgoe]

HellO:

What have been the results of recent engineering debacles, like Boston's Big Dig concrete section that fell and killed some folks in a car or Katrina meant for PE's as far as liability and ethics are concerned?

 

[Tomfh]

The failure was due to intermittent vortex shedding due to a constant wind speed that incited a primary torsional resonant frequency in the structure

It wasn't forced resonance due to vortex shedding, it was aeroelastic flutter.

 

[jorton]

The Brooklyn Bridge is accepted as the first modern suspension bridge. It was designed by Roebling. According to Niels J Gimsing in Cable Supported Bridges – Concept and Design, 1983,

“During the period when Roebling worked as a bridge designer in the United States, a fatal bridge disaster took place when the suspension bridge across the Ohio River at Wheeling was destroyed by the wind in 1854. This accident made a strong impression on Roebling and inspired him to take several measures to increase the stiffness of suspension bridges beyond what is obtained by the cable itself. In his bridges, following the Wheeling disaster, he therefore introduced stiffening trusses with a considerable bending stiffness and stays to supplement the pure suspension system.”

As quoted on the website

http://www.gribblenation.com/swparoads/essays/nationalrd/wheeling.html

, here is a description of the Wheeling Bridge failure. It sounds remarkably similar to the Tacoma Narrows Bridge failure.

"For a few moments we watched it with breathless anxiety, lunging like a ship in the storm; at one time it rose to nearly the heighth of the towers then fell, and twisted and writhed, and was dashed almost bottom upward. At last there seemed to be a determined twist along the entire span, about one half of the flooring being nearly reversed, and down went the immense structure from its dizzy heighth to the stream below, with an appalling crash and roar. Nearly the entire structure struck the water at the same instant dashing up an unbroken column of foam across the river, to the heighth of at least forty feet! "

 

[ImminentCollapse]

The three gorges dam is supposed to silt up in less than 20 years.....

 

[Ron]

The issue about wind loads is correct. I have seen several failures of buildings that were designed and constructed (reasonably) well, that did not adequately consider uplift. These buildings were in south Florida, built prior to 1975. Hurricane Andrew (1992) showed their deficiencies.

We found masonry structures with tie beams and joist "pockets" (a common technique) that had no uplift restraint other than dead load. Not good enough when the wind speed is 140 mph+. Codes at the time required nothing like that...for instance, the 1969 version of the Standard Building Code required a design pressure of 25 psf for any building up to 30 feet in height. That same building today, in South Florida, would require an uplift pressure of up to about 40 psf...a 60 percent increase in pressure.

 

[ACtrafficengr]

A few years ago, a partial collapse of a freeway ramp occurred in Albany NY. Review of the bridge inspection reports showed the expansion rocker bearings had been overextended for years, but no one really did anything about it.

https://www.nysdot.gov/divisions/en...ository/manuals/dunn_failure_report_10-05.pdf

On the other hand, the Department's response and forensic engineering report did not try to obfuscate things, which was not an ethical failure.


Poughkeepsie Galleria parking deck collapse:

http://en.wikipedia.org/wiki/Poughkeepsie_Galleria#Parking_garage_collapse

"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928

"I'm searching for the questions, so my answers will make sense." - Stephen Brust

 

[photoengineer]

I just got an e-mail tody about 12 story building that fell over in China. The construction crew excavated dirt from one side of the building, put it on the other. It rained, which allowed the soil to act like a fluid. The imbalance of dirt created a shear load in the dirt pushing the building over.

You can find this on teh internet with a Google search. Very interesting.

 

[hokie66]

The Shanghai building collapse was discussed here.

thread507-248426

Not sure whether there were any ethical considerations, probably just stupidity.

 

[unclesyd]

Where dos this incident fit?

thread507-261822

 

[plasgears]

A recent debacle in my company was when our plastic gear supplier sourced the material in China as a cost reduction. The material was offspec Acetal, the source not certified, and the stuff hit the fan. All this in an ISO9000 company.

The company was sold twice after losing the contract; a premium line of cars suffered widespread infant mortality.

DO NOT SOURCE CHINA!

 

[patprimmer]

plasgears

And how was this an engineering debacle.

Are such problems restricted only to China.

Is this type of problem guaranteed when dealing with China.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

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[brandoncdg]

Doesn't ISO9000 mean almost nothing?

CDG, Los Angeles Civil Engineering specializing in Hillside Grading

http://cdg-ca.com

 

[GregLocock]

ISO9000 means as much or as little as you want. It can be summarised as "Document what you do, do what you document".

So if you have a sourcing procedure that says "Source material from the cheapest supplier, do not verify its quality".

Then you have complied with ISO9000.



Cheers

Greg Locock

I rarely exceed 1.79 x 10^12 furlongs per fortnight

 

[IRstuff]

Greg's take is absolutely correct.

Our previous certification for ISO9000 was hung up because our process-oriented procedures were so complex that we had trouble documenting that we were following the process. The process was then changed to a two-page thing, and we got certified the following year.

TTFN

FAQ731-376

 

[drawoh]

A recent debacle in my company was when our plastic gear supplier sourced the material in China as a cost reduction.

You have brought this up in thread16-221050 and in thread769-227602. Your customer demanded a 10% price reduction, and your company passed it on to your supplier. You all got the quality you deserved, and by the sound of it, the customer feedback you deserved.

This is more of a management screwup than an engineering one, unless safety was involved.

JHG

 

[brandoncdg]

drawoh: Don't engineers have a bit of say regarding the cost reduction? I wouldn't cheap out on parts on our Civil plans based on a client wanting to be cheap on the project.

I am curious about the Vegas City Center and who was cheaping out when they built the Harmon. Probably no one will ever know.

CDG, Los Angeles Civil Engineering specializing in Hillside Grading

http://cdg-ca.com

 

[patprimmer]

I have at times had some very good quality out of China and some junk out of the USA

Not typical I admit, but it depends on who you deal with and how you deal with them no matter where you are.

I have seen two toolmakers in Aus within a few blocks of each other, one made absolute junk, like worse than anything I ever saw out of China and the other made as good as the best from Switzerland.

I also recently rewrote quality manuals etc for a company who repeatedly got major non conformances and were on probation with one more chance to not lose their accreditation. I rewrote the manual to change the emphasis from we will be the world leader in everything to we will identify business that best matches our resources and competitive advantages and work with the identified customer for best fit to optimise profits and business development.

We now have one minor non conformance which has been fixed. I guess he will tick that off and find another in the next audit.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

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[JLSeagull]

This thread has drifted a bit - from attempting to control the Mississippi River on one end and manufacturing quality control on the other end of the spectrum. One of our inspectors often complains about the lack of suitable manufacturing processes at our primary control valve suppliers manufacturing shop. Second rate quality control is bad but isn't really an engineering debacle.

OTOH, our society chooses to control things like the MS River among the pork projects initiated by our elected officials. Upon the next "New Madrid" earthquake the Mississippi River may choose a different course. Rivers do this without earthquakes but something like the New Madrid event are likely causes of significant change. When the Mississippi River changes course it will likely destroy millions of acres of rural land and cause some significant changes for the industrialized areas along the current route. Only then will anyone ask why the Corp of Engineers did not prevent this. Stay tuned.

 

[brandoncdg]

I think this topic can drift very easily because engineers basically create everything there is, and a lot of those creations can destroy people's lives pretty quickly.

Civil Development Group, LLC
Los Angeles Civil Engineering specializing in Hillside Grading

http://cdg-ca.com

 

[patprimmer]

Opps

I missed my point on the quality comments.

The point was, we constantly basically failed QC audits. I rewrote the manual, did no changes to procedures and specifications nor conformance to specification, but got a good pass on the next audit.

The point is for ISO9000 you can specify where you want to draw the quality line.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[PriamEngineering]

As the topic has seemed to drift into non recent engineering debacles here's a European angle on some horrendous incidents.

1. Tay bridge disaster 1879 (75 people killed). Cause- low quality Cast iron used in construction.

2. Allenader Keilland - 1980 -123 people killed. Cause poor weld caused fatigue crack and failure of one part of the structure causing collapse.

3. Eschede train disaster 1998. 101 dead. Cause. Fatigue of the composite wheels which were fitted at the insistence of the management to improve ride handling.

Funny enough when I list these (and other failures) in my fatigue course for practicing engineers hardly any of them have heard of any of these incidents. Which brings to my mind the phrase… Those who don’t learn from history are doomed to repeat it!

http://www.priamengineering.co.uk