AS3600_Circular pile shear capacity

[benjaman]

Hi,

Has anyone done any circular piles shear capacity check using AS3600? Can anyone please shed any light?

 

[bugbus]

In our office, we refer to AASHTO to calculate the effective depth dv, where:

dv = 0.9 * (D/2 + Dr/pi)

where D = column diameter, Dr = diameter of a circle intercepting the main rebar. (I could have the subscripts wrong here).

The commentary in AASHTO states that the column diameter D should be used for the width 'b', the reasoning being that the bulk of the concrete component of the shear force occurs close enough to the mid-depth of the section that you can justify using the full diameter (something along those lines, I don't have the code in front of me).

I'm always surprised that the Australian code never discusses circular sections, especially for shear strength and how to (simply) deal with the rectangular stress block for bending.

 

[Retrograde]

Clause 8.2.1.5 states that for solid circular sections, bw may be taken as the section diameter.

Clause 8.2.1.9 states that the effective shear depth depth dv shall be taken as the greater of 0.72D or 0.9d.

I would just take it as 0.72D for a circular section.