Steel Base Plate to AISC 360

Get started with your design

The Steel Base Plate to AISC 360 calculator checks against concrete crushing from a column in compression and provides the minimum required baseplate thickness. There are three types of calculations for different columns types: wide flange, tube and pipe.

All calculations are performed in accordance with AISC 360-05 and AISC Steel Construction Manual 16th Edition.

What is the design approach in AISC 360 for base plates?

For the simple case of pure compression (no moments develop at the base plate), the column axial force is assumed to be distributed from the column end to the column base plate in direct bearing. The column base plate is then assumed to distribute the column axial force to the concrete or masonry as a uniform bearing pressure by cantilevered bending of the plate. There is therefore two main design requirements: to design against crushing of the concrete footing by calculation of the footing's allowable bearing strength, and to determine the minimum base plate thickness by calculation of the "critical base plate cantilever length".

What factors influence the required thickness of a base plate?

The minimum required thickness of a steel base plate is influenced by the base plate plan area, base plate yield strength, applied compression load and the "critical base plate cantilever length". The AISC Steel Construction Manual 14th Edition provides equations to calculate this cantilever length.

How do wide flange, tube, and pipe columns differ in their base plate requirements?

The type of column used—wide flange, tube, and pipe—results in slightly different values for the "critical base plate cantilever length", which therefore affects the minimum required base plate thickness.