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RE: Architect cheating on structural calculations - where's the building depa...

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Chris, while I agree that some checkers do not do the thorough job they are supposed to do, my experience with design checking is very different from your conclusion that "most such requirements are nonsense".  I started my career working on structural designs for nuclear power plants, as well as fossil, geothermal, and hydro.  I was told that the company started requiring detailed design checking of calculations for all projects after they were initially required to do so only for nuclear projects.  It was found that too many errors were being encountered and corrected during checking, such that all designs warranted such checking.  It is true that nuclear projects have a lot of red tape, but in general the design checking that is required is well justified.  

I later moved to work on water and wastewater treatment plants and my new employer again required checking of design calculations.  In over 30 years of having my designs checked and checking other's designs, I have concluded that design checking is an essential aspect of structural engineering.  I am not sure I could comfortably place my PE seal on a set of drawings that are not backed up by checked calculations, as well as drawings that have been coordinated with the calculations and other contract documents.  The drawings and calculations produced are still not perfect, but they are superior to what would otherwise be used for construction. 

Our checking guidelines state that in addition to the mathematical accuracy, the following must be checked: code compliance, criteria, assumptions, methodology, and conclusions.  Does checking always fulfill all of these requirements?  No, but at least an attempt is made, and errors in each of those categories are often discovered and corrected. 

I'm not sure what you meant by your statement "For cultural value, the meaning of checking and reviewing is universal."  Certainly engineers do not have a universal understanding of these words.  "Review" is not the same as "checking".  I once had a submittal from another engineer who told me that the design had been checked - but we found an error in code interpretation, an error in analysis methods, and an error in mathematics for seismic design of a single structure.  The design may have been "reviewed" but it was not "checked". 

Establishing better QA/QC requirements in our industry for the engineering and design work would be a major improvement - but there likely will be much resistance.  That is unfortunate, as it likely would increase chargeable work and reduce liability costs for the engineer, as well as improve the quality of the product for the constructor and for the owner. 


William C. Sherman, PE
(Bill Sherman)
CDM, Denver, CO
Phone: 303-298-1311
Fax: 303-293-8236
email: shermanwc(--nospam--at)cdm.com

-----Original Message-----
From: Christopher Wright [mailto:chrisw(--nospam--at)skypoint.com] 
Sent: Wednesday, December 07, 2005 11:58 AM
To: seaint(--nospam--at)seaint.org
Subject: Re: Architect cheating on structural calculations - where's the building depa...


On Dec 7, 2005, at 10:41 AM, Paul Feather wrote:

> A plan checker cannot be expected to catch errors on a complex project 
> in a few short hours when that project has taken months to design, 
> unless those errors are blatant.  If a jurisdiction truly wants to 
> have a structural plan check, anything less than peer review by 
> competent equally licensed individuals will be flawed.  A system where 
> authority is given without accountability is prone to abuse.

For cultural value, the meaning of checking and reviewing is universal. 
I don't think anyone these days really knows what it's supposed to do. 
At one time it meant looking over design drawings for things like tolerance stack-up and dimensioning errors. Later when design incorporated a significant amount of math analysis it included someone to check arithmetic. It really should incorporate a run-through of the design rationale from assumptions about service conditions to the use of sound practice and prudent assumptions.

In 40+ years of engineering practice, I've never seen a design review that really did that. I've seen a lot of so-called reviews that amounted to checking arithmetic--checking that Mc/I was calculated correctly but not whether the assumption that the item really behaved like a cantilever beam was accurate or prudent. God knows how many reports I've submitted where I was gigged for word usage but got no questions whatever on my approach. The charming part is that most of the comments on word usage were mis-informed and I ended up finding numerical errors like mis-placed tabular data on my own when I was fixing an incorrect subscript.

My own experience in the nuclear power business, where a lot of attention is paid to checking and verification, is that most such requirements are nonsense. Most are procedural: fill out the right forms or include enough signature blocks and you pass the audit. Verify FEA software with a couple of trivial problems and you're good to go for non-linear seismic response. I had a guy 'audit' an analysis by spending two days leafing through a stack of computer print-out without the slightest expression of interest in how I'd set up the analysis. 
Same for aerospace projects. I had one reviewer demand that material for a platinum-iridium sensor element be covered by an ASTM spec. At the other end of the spectrum comes fracture reviews by people who can't interpret analysis results--they just make sure the box is checked off.

Oddly enough it's the little things and the fundamentals that always get you--the stuff that never gets checked because it's too simple or too obvious. The best plan checking system I've ever seen has come from drafters or shop people with experience on similar projects and the initiative to ask me about something that doesn't look familiar. For a sprog engineer, answering a lot of questions that might be obvious seems like a big pain in the ass, until one day someone bails you out big-time by finding something you forgot.

Christopher Wright P.E. |"They couldn't hit an elephant at
chrisw(--nospam--at)skypoint.com     | this distance" (last words of Gen.
........................| John Sedgwick, Spotsylvania 1864)

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