Application of the Εxtended KDamper to the Seismic Protection of Bridges: Design Optimization, Nonlinear Response, SSI and Pounding Effects

The paper investigates the seismic performance of a novel passive vibration isolation and damping device termed Extended KDamper (EKD). concept is applied to representative two-span highway bridge, initially designed on conventional (CSI) bearings. An optimization process developed executed design EKDs, underscoring importance accounting for motion variability. Compared CSI, incorporation EKDs leads 40% 70% reduction in deck drifts. In contrast CSI which may sustain excessive bearing shear strains when subjected most adverse motions within examined set, bearings EKD bridge never exceed 200% threshold. Through use nonlinear 3D time-history analyses, it demonstrated that nonlinearity elements result residual exhibit variation maximum drifts accelerations order ±20% compared preliminary (linear elastic) set spectrum-compatible motions. increased from stiffening negative stiffness (NSEs), being more pronounced entail large displacement demands. With aid fully model entire soil – foundation structure system, effects soil-structure interaction (SSI) are explored shown significantly influence response system. Deck collision with abutments restricts movement pier; however, compromises substantial increase accelerations. Overall, facilitate economical enhanced performance, particularly displacement-sensitive structures like rail bridges.