Strength and Deformability of Steel Column Footing

Abstract

The hysteretic loops of the embedded‐type column‐to‐footing connection, subjected to seismic loading, can be classified into three types, namely (1) Elastic‐plastic with sufficient deformability; (2) pinching type with large deformability; and (3) pinching type with poor deformability. Fracture modes of the types are: type A, where a plastic hinge is formed in the steel column at the top surface of the footing; type C, where punching shear failure of the footing concrete occurs, in which the side wall breaks out laterally at the girder‐free side of the footing, preceding the yielding of the column member; or type B, which is a combined mode of types A and C. The maximum strength of the connections of type C is analyzed theoretically based on the test results hitherto reported in Japan. And, to ensure avoiding failure in type C, a design guide for details of the connection is presented, together with a parametric study.