Re: CBC 2007 Revisions to Appendix D

Howard:

 

The failure is always brittle. Can't get around that!

Thank you,

Farzin S. Rahbar, SE
David C. Weiss Structural Engineer & Associates, Inc.
(818) 227-8040 Ex. 13 Fax: (818) 227-8041

 

In a message dated 10/2/2009 10:39:24 A.M. Pacific Daylight Time, coengineer@aim.com writes:

I believe that you do have to use the 0.75 redcution factor as well.  Can you use a smaller diameter anchor, deeper embedment, or a lower grade steel to ensure ductility?

 

Howard Silverman, PE

Anchoring Systems & Field Engineer Manager

USP Structural Connectors/Covert Operations

www.USPconnectors.com


-----Original Message-----
From: FSRahbar@aol.com
To: seaint@seaint.org
Sent: Fri, Oct 2, 2009 10:14 am
Subject: CBC 2007 Revisions to Appendix D

List:

 

CBC 2007, Section 1908.1.16, Modification to D.3.3.3, requires use of a reduction factor of 0.75 factor in calculating the Design Strength of Anchors. Modification to Section D.3.3.5, requires a ductile connection or" the minimum design strength of the anchors shall be at least 2.5 times the factored forces transmitted by the attachment".

 

Question: When we multiply the factored forces by 2.5, do we still have to use the 0.75 reduction factor in calculating the design strength?

 

Thank you,

Farzin S. Rahbar, SE
David C. Weiss Structural Engineer & Associates, Inc.
(818) 227-8040 Ex. 13 Fax: (818) 227-8041