Base plate + foundation

[lachinnur]

Hi, I am new to foundation design, There is UPN 200 has baseplate connection to foundation (attached picture). I need to design this foundation as per ACI 318. There are a lot of example for reinf concrete column footing connection, but not many for this type of connection, If anyone has a idea please share with me, Thanks in advance

 

[milkshakelake]

-The base plate itself is no different from a regular foundation, except that it has a smaller A1 or A2 bearing area (in the bearing stress formula). I think it might be A2, I can't remember off the top of my head.

-The concrete pier should be designed as a concrete column with axial load, and moment if there is any. Depends on your loading, but for most buildings up to 7 stories, nominal reinforcement of 1% should work.

-Concrete pier should have some nominal dowel reinforcement per ACI to tie it together. I just extend the same size bars as in the pier to make them dowels, but ACI allows for smaller dowels to be used.

-If your anchor bolts have uplift and/or shear, you need to check them for concrete breakout and a few other things with the correct edge distance. ACI has a section on anchor bolts. It's very tedious; you just run through it step by step. Or close your eyes like I do and use Hilti Profis to do it for you, though you should at least verify the results for one case.

-If there is uplift, I think the anchor bolts should have long enough development length to develop a tension splice with the concrete pier vertical rebar.

Hopefully I didn't miss anything, but that should cover it. The base plate and anchor bolt design is kind of like designing a connection to a small foundation.

 

[lachinnur]

Thank you so much for clarification