Effective Length of Anchor in Concrete

[carnahanad]

I have a column with a large uplift and I'd like to use the D.5.2.9 part of appendix D. This lets us use the reinforcement in the pier to develop the tension. My issue is that D.5.2.3 has shortened my effective length for equations (D-4)- (D-11). Does this shortened effective length still apply when I'm calculating my development length for the reinforcement per D.5.2.9? The figure for D.5.2.9 shows the effective length to be from the top of the concrete to the head of the anchor. It seems a little muddled to me.

 

[amec2004]

The D.5.2.3 three edges hef shortening doesn't apply when anchor reinforcement is used as per D.5.2.9

The intent of D.5.2.9 is to use anchor reinforcement to replace concrete tensile breakout strength calculation completely, as such the the Eq (D-4) through (D-11) stated in D.5.2.3 is no longer in use once anchor reinforcement is used.

For the difference of using anchor reinforcement and without using anchor reinforcement, you can go to

http://www.civilbay.com

to download anchor bolt design spreadsheet and have a comparison.

 

[carnahanad]

Thanks,

It didn't make sense to have to use the shortened hef, it would be extremely difficult to get enough development to have any amount of extra strength.