Tuesday, August 5, 2008

Re: more aci 318

Mark,
 
        Why does the bolt itself have to fail in ductile failure?  Why can't a plate or similar detail that is connected to the bolt be used to provide the ductile failure?
 
Regards,
 
H. Daryl Richardson
----- Original Message -----
Sent: Tuesday, August 05, 2008 10:09 AM
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

 

 

 

 

 

 

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