Experimental Evaluation of a Rocking Damage-Free Steel Column Base with Friction Devices

Abstract

This paper presents the experimental evaluation of an earthquake-resilient rocking damage-free steel column base, previously proposed and numerically investigated by the authors. The column base uses post-tensioned high-strength steel bars to control its rocking behavior, and friction devices to dissipate seismic energy. It is equipped with a circular steel plate with rounded edges, which is used as a rocking base. The rounded edges prevent stress concentration and damage of the contact surfaces, whereas the circular shape allows rocking toward all plan directions. In contrast to conventional steel column bases, the proposed column base exhibits monotonic and cyclic moment–rotation behaviors that are easily described by analytical equations. This allows the definition of a step-by-step design procedure which ensures damage-free behavior, self-centering capability, and energy dissipation capacity for a target design base rotation. The experimental tests, presented in this study, were conducted under monotonic and cyclic loads demonstrating the damage-free behavior even under large rotations. The experimental results were used to validate the design procedure and to calibrate refined three-dimensional (3D) nonlinear finite-element models that will allow further investigations.