Reinforcement for anchor bolt groups

[3doorsdwn]

A while back I remember seeing a reference that dealt with reinforcing for anchor bolt groups where the loads exceeded the capacities given by ACI 318 (appendix D). Has anyone seen something like this? (Thanks in advance)

 

[Lion06]

Here is a paper that deals with it.

 

[WillisV]

The practice has also been better codified in ACI 318-08 - see D.5.2.9 and associated commentary figures.

 

[asixth]

I usually provide some additional longitudinal reinforcement slotted through the u-bars to provide some additional pull-out capacity if that is what you are referring to.