Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Dynamic design of machine foundation

[Subject Prev][Subject Next][Thread Prev][Thread Next]


The best guide book for rotating equipment at grade is "Design of Structures and Foundations for Vibrating Machines", by Arya/O'Neill/Pincus however it is out of print and hard to find.  It is a very tedious procedure with lots of small numbers but in essence you develop springs and damping ratios for six degrees of freedom then calculate the deflection from the out-of-balance forces generated by the rotor shaft.  This is an ideal situation for a program or spread sheet but if you are doing this for the first time note you will spend a lot of time debugging and trying to get it right.

Thomas Hunt, S.E.
ABS Consulting

"Rich Lewis" <sea(--nospam--at)>

12/13/2004 12:49 PM

Please respond to

Dynamic design of machine foundation

I am designing a foundation for a 130,000 lb compressor with dynamic
loads.  The foot print of the equipment is over a 30X40 ft. area.  It
will have a separate mat foundation below it.

I have done some research and it appears to me a dynamic load such as
this requires a special analysis to calculate the deflections based on
the dynamics.  I found several references on this, one in particular by
Bowles in the 5th ed., chapter 20.  He has a program to calculate the
vertical, horizontal and rocking deflections due to the machine
dynamics.  Is the method he describes in his book what is commonly used
in practice today?  Is there an easier way to do this?

Bowles method requires the dynamic shear modulus.  Are there some tables
with typical values for clay soil other than what he has in his text?
Bowles uses primarily metric in this chapter and doesn't have an
equation for English dynamic modulus.

I would appreciate any suggestion I can get for foundation design of
dynamic equipment loads.

Richard Lewis
Lewis Engineering

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at:
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*   Questions to seaint-ad(--nospam--at) Remember, any email you
*   send to the list is public domain and may be re-posted
*   without your permission. Make sure you visit our web
*   site at:
******* ****** ****** ****** ******* ****** ****** ********