Seismic assessment of earthquake‐resilient tall pier bridges using rocking foundation retrofitted with various energy dissipation devices

Abstract

While conventional seismic isolation bearings are usually inefficient for bridges with tall piers, rocking foundation is a promising approach mitigating their seismic demands and improving post-earthquake resilience. However, excessive tilt angle might occur at rocking interface and lead to overturning during strong earthquake excitations. This paper investigates the efficiency of various energy dissipation devices in improving the seismic performance of rocking foundations employed in tall pier bridge systems. The devices considered in this study include yielding steel cable (YSCs), viscous dampers (VDs), and super-elastic shape memory alloy cables (SMAs), and they are implemented out of the pier columns for convenience of replacing if damaged during earthquakes. The results of nonlinear time history analysis show that all these devices are capable of suppressing the seismic responses of tilt angle at rocking interface; however, the seismic vulnerability of piers is increased as well, since these devices impose extra demands on columns. Consequently, the parameters of energy dissipation devices should be carefully determined in engineering practice, achieving balance between the seismic performance of tilt angle at rocking interface and nonlinear demand of pier columns. Note that the maximum demands of columns are determined by the design parameters of devices, which could improve the seismic resilience of tall pier bridges and facilitate the post-earthquake rescue operations.