Base Plate Rigidity

[iv63]

I have read (and used) that adequate base plate rigidity is most likely assured if the base plate thickness is equal or greater than 1/4 of distance from the face of the column to the edge of the base plate m (tp >= m/4). Do you know where this number come from?
Thanks,
iv

 

[epitome1170]

I would anticipate this is a guideline and not necessarily accurate for all instances.

I would suggest designing your base plate for the uplift or moment using the AISC guidelines (i.e. tp = (6.67*M/Fy*b)^1/2)

That equation is for ASD loads and accounts for the moment in the baseplate by utilizing the force in the anchor rods at the distance from face of column.