Shear Breakout Modification Factor in Appendix D

[JAX91]

ACI 318-08 Section D.6.2.6 requires an edge effect modification factor to be placed on the shear breakout strength of a single anchor or group of anchors. The factor is dependent on ca1 and ca2 values. When a set of anchors is on a pedestal and has two ca2 values, do we need to use the modification factor twice (one for each ca2)? The tension edge effect factor allows you to use only one modification factor calculated using the minimum edge distance. In the past, I have used only one shear breakout modification factor calculated using the minimum ca2 value. Is this correct?

 

[Lion06]

That's what I've typically done. And that's the way I wrote my spreadsheet.