Hollow bridge-pier properties for response spectrum analysis

The present paper proposes equivalent stiffness and energy dissipation properties of reinforced concrete hollow bridge piers to be used in the context of response spectrum performance based assessment and design. The work is carried out by performing parametric numerical analysis using a 2D fibre model calibrated against experimental results and by varying the longitudinal steel reinforcement ratio, height over width ratio, normalised axial force, level of confinement and concrete class of a rectangular hollow section reinforced with Tempcore B500C steel. The results of the analysis are given in the form of charts and closed form expressions for the yield curvature and moment, ultimate ductility, post yielding stiffness ratio and energy dissipated of the section, and are translated to the member level through the plastic hinge length approach. Likewise, the parameters of a Takeda model derived from the parametric analysis are given for use in nonlinear time history analysis.