? in solving base plate ex. prob from AISC 13ed

[NearBeer]

Was working on an example problem on base plates from the collection of problems on a CD that came with the 13ed of the AISC.

Example J.7 Base plate bearing on concrete; after an initial guess at base plate area and dimension, the next step says: "Check base plate dimensions"

"Verify N greater than or equal to d + 2 and B greater than or equal to b(sub)f + 2."

This part of the prob references Table 14-2 but when I look at the table, table 14-2 (pg.14-21) lists information pertaining to "recommended max sizes for anchor rod holes in base plates>"

Feel free to call me a dunce if appropriate but I am not figuring out where it says that "N must be greater than or equal to d + 2..." etc etc.

Thanks for the help!

/R,
NearBeer

 

[nutte]

They're making sure N > d+2*3" and B > bf+2*3". They're just trying to maintain 3" of plate around all four sides of the column. This is not a specification-mandated value, just what they are providing so that there is room for the anchor rods.

I don't know why the example references Table 14-2. That just guides you to what size hole you need for a given anchor rod diameter.