Column Base Connections for Hollow Steel Sections: Seismic Performance and Strength Models

Abstract

AbstractThe seismic response of exposed hollow steel section columns to base plate connections is examined through a series of eight experiments. The prototype-scale tests investigate a range of variables including base plate size and thickness, column size, and anchor rod layout (four rods in two rows, and eight rods in three rows). The specimens were subjected to cyclic flexural loading and instrumented to provide direct (rather than inferred) measurement of tension forces in the anchor rods. All the specimens showed excellent deformation capacity, with a stable hysteretic response for base rotations as large as 0.057–0.13 rad. Three specimens failed by fracture of the weld between the column and the plate, whereas five did not fracture. Evaluation of the test data against the current design approach prevalent in the United States suggests that (1) the design approach is reasonably conservative but (2) does not address the effect of the third (i.e., central) row of anchor rods; as a result, it cannot be...