Steel column to concrete foundation connection

[PostFrameSE]

Where can I find information on using a nut/washer as opposed to a hooked anchor when embedding in concrete? Can I use the basic development length and the reduction factors as though my anchor rod with nut & washer was a standard hooked bar? Is there any specific criteria that I need to use when specifying size of washer? I'd appreciate any thoughts.

Thanks.

 

[prsconsultant]

AISC Design guide #1 has the info you may need.

 

[PMR06]

Try ACI 318-02 Appendix D

 

[Lion06]

Use the second edition of the AISC Design Guide #1. Appendix D of ACI is also a good resource.
If you have any tension on these anchor bolts, do not use hooked bars. They have a tendency to straighten and pull out. AISC recommends against them for anything other than gravity only columns.

 

[PostFrameSE]

If I may continue this thread, I've since updated my ACI and I have access now to Appendix D, Anchoring to Concrete. I have several questions:

1. I'm assuming that anchorage to grout-filled CMU walls is applicable here. Is that correct?

2. Using equation D-4, I come up with a concrete break-out strength of 7,642lbs with my effective "h" = 5" and using 2,500psi grout. Does this seem realistic?

3. It appears that I also need to make a check of Np, which is basically a crushing failure. Does A(brg) refer to the area of the washer or head LESS the area of the bolt? I couldn't find a definition of that, but it only makes sense that that would be the case.

If I could be assured that I'm looking at this correctly, I'd appreciate it.

Thanks you.

 

[Lion06]

1.) Not sure

2.) If the answer to 1.) is that you are correct, then it doesn't seem unreasonable (without knowing your edge distance constraints).

3.) You are correct.

 

[twinnell]

You should be looking at ACI 530 for masonry design. They have a section on anchoring to cmu walls.

ACI 318 Appendix D is for concrete and really for concrete with edges far away from the bolt locations. Once you have close edge distances, they sort of leave you hanging.

 

[UcfSE]

1. Use ACI 530.

2. Not unreasonable for breakout only necessarily, but sounds high by the time you account for the lost area and edge distance in a masonry wall (mathematically only, see 1).

3. Yup. This seldom controls in my experience.