Seismic-Damper Robust-Design for Protection of Isolated Bridges against Near-Fault Excitations

摘要

This work investigates the robust design of supplemental dampers for multi-span bridge systems supported on abutments and intermediate piers through isolation bearings. The adopted bridge model explicitly addressed nonlinear characteristics of the isolators and the dampers, the dynamic behaviour of the abutments and the effect of pounding between the neighbouring spans to each other as well as to the abutments. A probabilistic framework is used to address the various sources of structural and excitation uncertainties and characterize the overall performance. Stochastic simulation is used to evaluate this stochastic performance and perform the associated optimization for selecting the most favourable values for the damper characteristics. An efficient probabilistic sensitivity analysis is also established for the uncertain model parameters. An illustrative example is presented that considers the design of nonlinear viscous dampers for protection of a two-span bridge.