Tension Reinforcement for anchor bolt 2

[DoubleStud]

Let's say ACI chapter 17 concrete breakout isn't strong enough to resist the tension force. I want to use the corner rebar to resist the tension. If B is the same length as ld, then I have full capacity of the vertical rebar? What if I am less than ld, can I ratio it?

I know I can also do U bar like Fig. R17.4.2.9, but I want to simplify the reinforcement. Let me know what you guys think.

 

[MacGruber22]

https://drive.google.com/file/d/13TNfWE-CQx54UHx0LCKIGxs_yJKqSHWo/view?usp=drive_link

I would not count on pedestal bars that are farther away from the anchor rods than 1/3 hef regardless of the theoretical ld from the intersection of the breakout cone. A lot of movement would need to occur to mobilize the stiffness of the bars farther away.

Keep in mind, code does not have provisions for Asreq/Asprov for hooks, only straight ld. I know some people do this anyways, especially with retaining wall bar hooks.

Avoid U-bars or other hooks when you can. If you need to, consider using smaller diameter bars and more quantity for verticals to limit required ld. You appear to have a lot of pedestal height to work with here to play with longer anchor rod lengths too.

You need confinement ties around your anchor rod bearing nuts/heads and the quantity/spacing of ties at the top of the pedestal do not graphically appear to meet code. Considering I see a PEMB frame column, make sure you check your pedestal for shear and don't assume minimum column/pedestal detailing ties works.

-Mac

 

[HTURKAK]

This fig. from Anchorage Design for Petrochemical Facilities (ASCE)

The reinf. should normally be straight dowels and if the anchor length is too long because of straight ld requirements, i would prefer to increase the no. of rebars with small dia. rather than 90-degree or 180-degree hooked bars because of constructability considerations.
Make sure to provide additional link ties to avoid side face blow out .

According to the grace of God which is given
unto me, as a wise masterbuilder, I have laid the foundation, and another buildeth thereon. . . .
I Corinthians 3:10

 

[DoubleStud]

HTURKAK, what is your opinion on using ratio for capacity if full ld is not achieved?

 

[HTURKAK]

My opinion is , If the available ld, is shorter than the required straight development length , the
maximum force that can be developed may be calculated with using ratio.

I would like to remind that the development length may be calculated in accordance with ACI 318. The links will also provide additional capacity. The reduction in development length shall not be applied in SDC C, D, and E.




According to the grace of God which is given
unto me, as a wise masterbuilder, I have laid the foundation, and another buildeth thereon. . . .
I Corinthians 3:10

 

[MacGruber22]

DoubleStud - Unless there is a seismic concern, I would have no issue reducing straight bar ld based on actual stress.

-Mac