Is helix reinforcement considered a closed fitment?

[Uprising]

I'm currently designing a bored pier for a cantilevered overhead sign structure (VMS) and would be very grateful if someone could please provide some advise in regards to the questions below.

Clause 8.3.8 of AS 3600-2009 requires that torsional reinforcement consist of both closed fitments and longitudinal reinforcement. Would helix (spiral) reinforcement be considered a closed fitment? And is anyone aware if the calculations in AS 3600-2009 for Tus and Vus (perpendicular shear reinforcement) be applicable to helix reinforcement?

Cheers,
Luke

 

[hokie66]

Yes, helical reinforcement is closed. It is customary to provide an extra turn or two at the top and bottom. And I see no reason why shear calculations for helical reinforcement would be different than for closed ties.

 

[Uprising]

Thanks hokie66