Energy Dissipation Devices for Bridges with Steel Superstructures

摘要

Recent earthquakes have clearly demonstrated the seismic vulnerability of bridges constructed with steel superstructures. The relative flexibility of these bridges, especially in the transverse direction, may result in overstressing or even failure of components, including trusses, end diaphragms, beams, bearings, piers, and columns. For the case of slab-on-girder steel bridges, flexible end diaphragms may experience large deformations, leading to buckling or brittle fracture during seismic excitations. However, if the end diaphragms are too stiff, the forces transmitted through the diaphragms to the bearings and substructure may lead to damage or failure in the supporting system. Structural dampers and other energy dissipation techniques are viable options to enhance the ductility and energy dissipation capacity of the diaphragms, thereby increasing the safety and reliability of the bridges. Prior research has clearly shown that ductile end diaphragms can greatly improve the response of steel slab-on-girder bridges; however, only a limited number of the many available energy dissipation devices have been investigated.