Lateral-Load Response of a Reinforced Concrete Bridge

Abstract

Cyclic, transverse loads were applied to the bents of a three-span reinforced concrete bridge. At a load equal to 45% of the bridge's weight, the bent drift ratio was 0.5%. The bridge's high stiffness was attributed to its continuous superstructure and stiff abutments, which resisted approximately 80% of the applied load. After the soil surrounding the abutments had been excavated, the bridge's stiffness was 15% of the initial stiffness. After the researchers had isolated the bridge superstructure from the abutments, the stiffness was 9% of the initial stiffness. Despite the bents' poor details, damage was limited to yielding of the wingwalls and column cracking; similar bridges should resist likely transverse seismic motions with little damage. The tests provided estimates of the abutment and bent resistances that can be used to evaluate modeling procedures. Following existing modeling procedures, the researchers assembled a model that reflected the measured nonlinear properties of the concrete, steel, soil, bearing pads and polystyrene. The model reproduced the measured response well.