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Re: Non Professionals doing Engineering

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I must give the individual who wrote the original post, credit for wanting to know more and certainly would encourage it, be he professional or non-professional. I do believe, unfortunately, that he may be the exception rather than the rule.

We write our specifications to require that the actual design of wood trusses be supervised and stamped by a P. E. registered in the state that the project is being constructed. This is all well and fine but in reality what happens is that there is no professional directly supervising the non-professional at the lumber yard who inputs the data into the computer. He sends his calcs to some out of state P.E. who has a license in the particular state our project is located in and it gets rubber stamped. This is not what I call direct supervision as required by many codes.

It is not unusual for us to find mistakes in loadings, support assumptions, etc. while reviewing shop drawings. We always draw loading diagrams when we have drifted snow conditions. In Wisconsin, the state cracked down several years ago on those architects who were leaving drifted snow determination up to the truss designer.

We usually receive the shop drawings after the trusses are built or even erected (not an ideal time to try to fix things). Sometimes even getting any shop drawings or calculations is like pulling teeth. The contractor, who may be used to building residential, says that he never submits truss drawings and we respond by saying that this building requires submittals by the governing building code and the specifications. When we do red mark the drawings and/or require resubmittals, we are accused of holding up the project. And the beat goes on...............

I agree with you Dennis that the solution lies with the building officials. The project manager also needs to get tough with the contractors who are not providing submittals. If they don't submit shop drawings or fix the things that are substandard, then I have no recourse but to list those incomplete items on my  Statement of Substantial Completion to the State. The State will then not allow the Owner to occupy the building.
 

Jim Kestner, P.E.
Green Bay, Wi.
 

Dennis S. Wish PE wrote:

 Jim, this is a great questions. Personally, I think it comes down to what the building official will accept. Architects have been designing structural members for a long time. IMO, those architects who I had the opportunity to plan check where quite deficient in their understanding of structures and load paths. They believed that the few static's courses they took in college, combined with a few books (mostly the Parker series) place them in positions of liability more times than not. However, this can not be controlled unless the building official is willing to mandate that the calculations submitted are reviewed by a licensed (and hopefully competent) engineer.Many states don't require engineering on certain types of structures (most notably residential). I think that many are starting to see that historic problems which have occurred may have been reduced (I doubt that they would be totally resolved) had the elements been designed by someone with more in depth understanding of the materials.In California, wood trusses must be designed under the supervision of a licensed Civil or Structural Engineer. This does not guarantee that the person using the computer program understands how a truss works. I don't believe that anyone can force responsibility on a professional - and this, unfortunately, is where litigation takes over.The Computer Applications Committee of SEA of California is addressing the issue of control of computer programs. In this case it is an issue of submitting and accepting the reliability of a program. It was discussed that there may need to be a typical problem assigned to each category of design problem and any program which is submitted for this type of design should be able to submit calculation which proves that it can reliably solve the problem. This does not resolve potential bugs, but places the reliability of a program on a level platform so that those who create software in their own offices can assure the building official that the results are as accurate as the programs commercially sold. Commercial programs "generally" have better User's manuals and sample programs to support their programs abilities. This is not typically the case with proprietary software used by one or a few people.As we discussed in the past, the only assurance for reliability is the basic understanding of the materials and physics involved in solving the problem. Identifying a mistake is not easy unless the person reviewing it has solved enough problems (experience) to identify when a result appears to be out of order. Personally, I don't think that this needs to be done manually as a pre-requisite. The designer MUST have an understanding of the process, but with this understanding he or she should be able to evaluate the output - as would be expected of a plan check technician. I, too, am interested in the opinions of others on this issue.Dennis S. Wish PE
-----Original Message-----
From: Jim Kestner [mailto:jkestner(--nospam--at)somervilleinc.com]
Sent: Saturday, January 23, 1999 7:12 AM
To: Structural Engineers Association International
Subject: Non Professionals doing Engineering
I recently ran across this message on another newsgroup and it made me wonder if we are slowly losing control of our profession to non-professionals, especially with the advent of computer programs:

Hello, I design wood roof trusses and sometimes I need to know how big of a
drift will form on the trusses when there are two different roof elevations
next to each other. Up till now I had the design program do this for me. Now
I would like to know how to do it myself, and I can't seem to be able to
find a formula to do this. Any help would be greately appreciated, thanks.

This posting made me think about where our profession is going and the affect the computer will have on it. Are these trends good or bad? Is the EOR the Supervising Professional in this case? Does the EOR really have direct supervision as many codes require? I am sure a number of us have a few stories to tell about why this process does not always work well. All comments are welcome.

Jim Kestner, P.E.
Green Bay, Wi.
 

 

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