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Re: Anchor Bolts

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> From: rlewis(--nospam--at) (Richard Lewis)

> I am design the anchor bolts for a pre-engineered metal building.  I have

>      I have designed buildings for almost 15 years now, including quite a few
> pre-engineered buildings.  I have always required the building supplier to

Do you mean that you do the structural design for the pre-eng building
or simply provide the system specifications and general building

> design the anchor bolts and never had much of a problem with that
> requirement.  This particular building supplier is making a big fuss about
> having to design the anchor bolts, which includes embedment, etc.  Have I

Typically, the pre-eng manufacturer/designer does not design the
foundation - especially the major pre-eng manufacturers. Past practice
has been to provide an A/B design (straight, with or without plate,
hooked, etc.) with the understanding and caveat that the foundation
designer should accomodate the assumptions for that selection. Many
foundation engineers dislike the restrictions that this can impose on
their designs and the most economical foundation may be precluded.

> been wrong to require the supplier to completely design the anchor bolts in
> the past?  Prior to getting the calcs, I do not have firm numbers on
> reactions to design the bolts myself.  Now, if I design the bolts and the
> contractor doesn't like it, does he have a legitimate claim for an extra?

What is the scope in your contract? Major pre-eng manufacturers will
explicitly state in their quote that they do not include design or
supply of A/Bs or foundations. Whether you should even consider
designing the A/Bs will depend on who pays for what. Why accept a
liability for which you have no obligation?

The project documents are incomplete without the reactions. Many pre-eng
suppliers will provide these in advance of the final design documents
for most buildings. The pre-eng quote software, that I have seen, does a
decent job developing reactions for basic buildings. Depending on
complexity, the manufacturer's engineering dept. probably prepares
reactions and A/B layouts in advance for most projects prior to complete
design - you just have to ask for it.

Growing use of pre-eng capable software by people not employed by or
contracted to the manufacturer is permitting the manufacturers to step
further away from the A/B design issue. This is partly to reduce
liability and partly to discard a service, in the name of efficiency,
that is not consistently required.

This leads into a REALLY scary discussion of the improper use of pre-eng
quote/design software by people not trained as professional engineers
(e.g. the bookkeeper, in one case I am familiar with). The pre-eng
industry is a primary example of the Build/Design direction of the
construction industry. I could rant ...

Paul Ransom, P.Eng.           |  Good at what I do
Civil/Structural/Project      |  Doing what I want
Burlington, Ontario, Canada   |  Learning
ad026(--nospam--at)                |  Growing