Seismic Behavior of Hollow Stiffened Steel Bridge Columns

Rectangular columns constructed from steel plates are widely used to support highway bridges in Japan. Columns of this type, designed without special consideration for ductility, sustained damage during the 1995 Hyogo-ken Nanbu earthquake. This paper describes tests of 24 large-scale models of hollow and concrete-filled stiffened rectangular columns in order to investigate their seismic performance. Testing under constant axial loading and cyclic bending as well as on the shaking table was carried out. It was found that columns partially filled with concrete had a larger strength than did hollow columns, but their displacement capacity was sometimes smaller. Bridge column models tested on the shaking table tended to sustain increasing displacements in only one direction, and columns tested by reverse cyclic loading possessed member displacement ductility capacities between 2.6 and 6.1, even though the columns had not been designed specifically for ductility. A rational and simple empirical method for estimating the deformation capacity of hollow columns subjected to reverse cyclic loading that considers the different modes of buckling is proposed and a design example is provided.