ACI 318-08 Appendix D-Shear Breakout

[palves]

I have a question regarding Section D6.2.4 of Appendix D. This provision tells what to do when anchors are influenced by 3 or more edges, but says nothing about when they are influenced by less than 3 edges. Im working with a program called DSAnchor, and have detailed a bolt arrangement that is in the middle of a wall. Ive made the edge distances (Ca1 and Ca2) large enough (~100") so that no edges should be affected, yet the program seems to still be calculating Ca1 based on provision D6.2.4. In order to make sure that the program is running correctly I want to make sure I understand how Ca1 is calculated, but cant find it in the code. Does anybody know how Provision D6.2.4 should read if the anchors are affected by less than 3 edges? Thanks.

 

[civilperson]

Calculating by hand, a pyramid or right angle cone with 35 degree slope will intersect the side wall and the surface. The area of this cone will give the breakout strength of the anchor.

 

[JedClampett]

This is a miserably written section. Ca1 is defined in section 2.1-Notation and Definitions. I don't blame the program for calculating the capacity for large edge distances, but they shouldn't control. If you look at the commentary, Section RD6.2.1, this is stated.

 

[Diquan]

I dont have it right here, but did you search in the PCA Notes of ACI318-05, maybe in that section they have explames of how to calculate it.

Diquan

 

[palves]

Well, after much work I finally understand what is going on. Thanks for your replies.