] [Thread] [Date] [Author]

[Mark Gilligan <MarkKGilligan(--nospam--at)compuserve.com>]

It has been stated that :

>Is it standard engineering practice to adjust the design for the worst
way that things could be built in the field if the builder in the
field doesn't pay attention to the design?<

This approach is questionable.   It is based on the assumption that we know
enough about "the worst way that things could be built" to quantify the
impact, thus allowing us to compensate for poor construction.  This denies
the ability  people have  to screw things up in unique ways.  In many
situations it is not possible to quantify, ahead of time, the consequences
of the failure to read the construction documents.  In other situations the
failure to follow the documents can result in failure without externally
applied loads.

There is no problem with accomodating contractors preferences for box or
casing nails nor is there a problem in adopting practices that are less
sensitive to workmanship issues.  The problem is in acquiescing to
noncomplience.  If you adopt this approach how does the Contractor know
that you really want him to do something in a certain way.

In response to Mr. Wright's comment:

"In that vein, I wonder how many of the infamous welded moment connection 
cracking problems were really problems with a deskbound designer not 
knowing how welders were actually doing the work."

A significant factor in the performance of the pre-Northridge moment
connection was the failure of the welders to follow the  welding
procedures.  The engineers not only did not know what the welders were
doing,  in most cases the engineer had no idea why it was important to
follow the welding procedures.  This lack of attention to welding quality
resulted in a situation where many welding inspectors were accepting work
that was not in compliance with the basic welding codes.

Because of these issues I believe that we should expect that there should
be reasonable compliance with our designs.

I  wonder if the real reason that we adopt the attitude of  compensating
for contractors non-compliance is the recognition that in many instances
there is no support from Clients to pay for inspections and to reject the
work.


Mark Gilligan