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Re: Q: "Percentage" of building or building component failures attributed to design

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Bill,

I?m of the opinion that building collapses are a lot
like airplane crashes. I?m told that there?s a saying
among pilots that it takes at least 3 mistakes to make
a plane crash. I suspect that it similarly takes at
least three mistakes to make a building fall down.
These mistakes can be grouped into the following broad
categories:

Design errors
Detailing errors
Assembly errors (i.e., fabrication errors (rare) or
field errors (common))
Errors due to miscommunication (failure to clearly
communicate design requirements onto the contract
documents)
Errors due to lack of communication (failure to
communicate with others when things change)
Errors due to lack of supervision (during design,
detailing or construction)

Lack of qualified inspection personnel on the jobsite
can also contribute to problems going un-noticed.

A number of years ago a Concorde jet crashed on
takeoff. All structural engineers should read the
accident report from this crash. If I remember
correctly, there were about 8 or 10 things that
contributed to the crash of this plane ? any one of
which by itself was not enough to make the plane go
down. Here?s a list of some of some of the problems
that led to the crash:

Plane too heavy (too much fuel)
Weight improperly distributed.
Took off with a tail wind (even my 4 year old grandson
knows that he has to toss his balsa glider into the
wind)
One of the landing gear wheels had a bad bearing that
made it lock up similar to when you get a bad shopping
cart at the grocery store with one bad wheel that?s
stuck 90 degrees from the way direction that you?re
pushing it.
Debris on runway cut a tire.

Building collapses work the same way. 

That's the way I see it (but I don't have any hard
statistics to back me up).

Cliff Schwinger


--- Bill Polhemus <bill(--nospam--at)polhemus.cc> wrote:

> Greetings.
> 
>  
> 
> I'd like some opinions-preferably backed up with
> facts-as to the percentage
> of building or building component failures that can
> be attributed to DESIGN,
> as opposed to construction flaws.
> 
>  
> 
> I suspect-though I don't know-that the number of
> failures that can be laid
> at the feet of the designer is probably quite
> low-maybe in the five percent
> range. In contrast, I suspect that the number of
> failures attributable to
> constructors not following the plans and specs,
> using the wrong materials,
> inadequate attention to detail, etc., is high.
> 
>  
> 
> I cannot prove this but it stands to reason. The
> goal of an engineer and
> that of a constructor are radically different, and
> the constructor actually
> has the hardest task, obviously.
> 
>  
> 
> I would like to establish some sort of documented
> criterion for my belief.
> Any comments would be most welcome.
> 
> 



		
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