Circular Tie Lap Lenght

[JAE]

We cannot seem to find explicit requirements for the lap length on a circular tie in a circular column. In past projects I have used 12" or 16" depending on the column diameter. Chapter 7 doesn't seem to address the lateral tie splice (although "circular ties" are mentioned) and Chapter 12 doesn't seem to address it.

I am not talking about spirals, but inidividual circular ties.

I seem to remember seeing some recommendation in an ACI detailing manual but we don't have it right now.

What do you all typically specify?

 

[Taro]

The requirement is not clearly defined in the body of the code. However, fairly clear guidance is given in the commentary. Individual circular ties would be treated similar to the ends of continuous circular ties. R7.10.5 says anchorage "should be a standard hook as for separate bars or by one additional turn of the tie pattern".

 

[jrmack]

I would use 7.10.4.5 for splicing spiral reinforcement, which I feel is similar. The minimum is 12" or 48db.

 

[JAE]

Thanks you two - appreciate it.

 

[mrengineer]

CRSI Design Handbook shows 48db for drilled piers, "Class A Lap" for columns.