Research on Seismic Response Reduction of Self-Anchored Suspension Bridge

Because self-anchored suspension bridge is a floating system, some seismic reduction devices are installed between tower and stiffening girder to reduce the displacements and forces induced by longitudinal seismic wave. Using time history analysis method, the pounding process of a concrete self-anchored suspension bridge with main span of 180m is studied in detail. The influences of different stiffness, free gap, damping coefficient of the device and different frequency spectrum characteristics of seismic wave were considered in the analysis. The parameter analysis reveals that the pounding may increase or decrease the seismic response which is mainly depend on the free gap between the tower and the main girder. The frequency spectrum characteristics of seismic wave have great influence on the displacement, forces and times of pounding. Compared with pounding device, viscous dampers are also researched to reduce the seismic responses of self-anchored suspension bridge and the main influential factors are considered in detail. The conclusions of the study are useful for the practical design of self-anchored suspension.