Steel Column Base Plate Design Moment

The couple of forces of bearing on the concrete and tension in anchor bolts resists to the external bending moment resulted by fixing the column base in foundation.

Steel column base plate design moment.

Whether each t stub is in tension or compression depends on the magnitudes of the axial force and bending moment. Base plates with both axial loads and moments are not covered in the aisc specification or the manual of steel construction. Steel column base plates are one of the most ndamental parts of a steel structure yet the design of base plates is commonly not given the attention that it should by engineers. Two general approaches exist for design one based on the elastic behavior and one based on the ultimate.

The example shows a column base with an unstiffened base plate. Engineers must refer to textbooks for design information though not all texts cover this case. Distribution of forces at the column base the design moment resistance of the base plate depends on the resistances of two t stubs one for each flange of the column. The column base connection is one of the critical connections in a steel structure.

The design forces for each situation are therefore determined first. Stiffened base plate connections and column bases cast in pockets are other options available. Column bases for instance moment frames which resist wind or earthquake forces.