Performance of a damage protected highway bridge pier subjected to bi-directional earthquake attack
Recent earthquakes have demonstrated a need for a new design philosophy that avoids damage in order to ensure immediate functionality and reduced economic loss after an earthquake. Damage Avoidance Design (DAD) is one such philosophy that meets these demands. In this design approach, damage avoidance is obtained by special detailing of the joints, eliminating the formation of a plastic hinge and dissipating energy by rocking and supplemental dissipation devices. Quasi-static and pseudodynamic tests are performed on a scaled specimen to investigate the seismic behaviour of concrete bridge piers designed for damage avoidance. Input earthquake records are selected based on 50 and 90 percent survival probability as determined from an Incremental Dynamic Analysis (IDA). A 30% scaled circular pier designed to rock on a square steel-steel armoured interface is subjected to bi-directional lateral loading and axial load. Damage limit states are defined and confirmed by physical testing, which also verifies the bi-linear elastic, selfcentring characteristics of the rocking DAD system.