Risk-Based Optimal Design of Seismic Protective Devices for a Multicomponent Bridge System Using Parameterized Annual Repair Cost Ratio

Base isolators and fluid viscous dampers are viable protective devices that have been commonly considered in the seismic protection of civil engineering structures. However, optimal design these remains a tedious iterative undertaking due to uncertainty ground motions, nonlinear behavior structure, its change dynamic characteristics (i.e., effective stiffness damping ratio) under each new design. The problem becomes more challenging concerning multiresponse bridge system where conflicting damage potential is often expected among multiple components (e.g., column, bearing, shear key, deck unseating, foundation). In this respect, study develops risk-based optimization strategy directly links annual repair cost ratio (ARCR) parameters base dampers. This achieved by devising multistep workflow integrates hazard model, experiment for bearings dampers, logistic regression towards parameterized component-level fragility models, system-level loss assessment. developed ARCR as convex function influential devices. As such, bearing damper designs can be pinpointed visualizing global minimum surface. carried out against typical reinforced concrete highway California installed with three types widely-used isolation bearings—the elastomeric lead-rubber friction pendulum system. It shown obtained significantly reduce bridge, whereas combining optimally designed provide risk.