Tuesday, August 5, 2008

RE: more aci 318

To deal with ACI Appendix D, I am using CMU stem walls and installing anchor bolts to the requirements of  Chapter 2 of ACI 530.

 

Bob Garner, S.E.


From: Mark D. Baker [mailto:shake4bake@earthlink.net]
Sent: Tuesday, August 05, 2008 9:10 AM
To: seaint@seaint.org
Subject: more aci 318

 

This bolt thing is becoming more frustrating.

 

I have been doing anchor bolt shear/tension calc for a 1000# piece of electrical equipment mounted on a pad with ½” dia. anchor bolts (manufacturers frame provides holes for ½” dia bolts). The pad is 8’ by 8’.

 

I have found that a 14” deep concrete pad with cast in place bolts embedded 8” is required for ductile failure, my closest edge distance is 18”. I cannot have brittle failure due to seismic category D.

 

What used to be a 30 minute calc for loading and bolt design has turned into hours of *&^$%#@ and a pad design that is embarrassing to provide the client and contractor.

 

Aaaargh !!

 

Mark D. Baker

Baker Engineering