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This study examined the dynamic behavior of two-column bents used to support box-girder bridges. Three 0.3-scale specimens were subjected to earthquake records from the 1994 Northridge Earthquake using a large shake table (4.3 x 4.4 m [14 ft × 14 ft 6 in.] in plan) at the University of Nevada, Reno. Details in the bents were based on the 1999 California Department of Transportation design standards. The specimens were identical except for the column aspect ratios, which were 2.5, 4.5, and 6.64. Experimental data were collected at the critical sections in each specimen. The three specimens successfully resisted high levels of seismic loadings and achieved sufficient ductilities. The observed and measured results of the three specimens were helpful in understanding dynamic behavior and are documented in this paper. [ABSTRACT FROM AUTHOR]

A quarter scale model of a two-span RC bridge was tested using the Network for Earthquake Engineering Simulation (NEES) multiple shake table system at the University of Nevada, Reno, Nev. The project was funded through a National Science Foundation-NEES demonstration grant. The bridge system was tested from a preyield state until column failure. In depth analytical modeling was conducted to determine the effectiveness of current structural analysis software and methodology in predicting the bridge model response. Both SAP2000 v.9 and Drain-3DX were used for this purpose. Both models produced reasonable results up to column failure, however, the Drain-3DX model was determined to be most effective to predict the nonlinear bridge model response. Parametric studies were conducted to investigate optimal element discretization and integration parameters. Existing equations for pre and postyield column shear stiffness showed good correlation when compared with the measured data. [ABSTRACT FROM AUTHOR]