Seismic retrofit of steel deck-truss bridges: Experimental investigation

Alternative seismic retrofit strategies for steel deck-truss bridges are investigated in this study. Various modified tension-only bracing configurations, which consist of tendon elements with or without supplemental systems are introduced within the end-sway frames. The effectiveness of the retrofit configurations is demonstrated experimentally and analytically on a one-third scale model of an existing steel end-sway frame tested on the shaking table at the State University of New York at Buffalo. It is concluded that proposed alternatives can efficiently improve the lateral strength and stiffness characteristics. Moreover, the load path within the end-sway frame is modified to bypass the existing nonductile steel bearings. A stable energy dissipation mechanism is provided by means of re-centering elastomeric spring dampers along with fuse elements, thus reducing the overall seismic demand on the structural systems.