Dynamic Properties of Long-Span Steel-Concrete Composite Bridges with External Tendons

Abstract

The dynamic performance of large-span steel-concrete composite bridges with external tendons is investigated by deriving the formula of equivalent damping ratio of composite bridges, and by analyzing the influence of shear connectors stiffness of composite girders, interlace slip, external tendons, and pile-soil dynamic interactions on the dynamic properties of steel-concrete composite bridge. Finite element calculations indicate that the equivalent damping ratio has significant influence on the dynamic response while the shear stiffness of grouped stud shear connectors and the prestressed levels of external tendons have different but relatively smaller influence on the free vibration frequency of long-span composite bridges; the influence of pile-soil interaction on the structural dynamic response of the composite bridge is clear.