Nonlinear Response Of Steel Girder Bridges Under Various Directions And Intensities Of Earthquake Motions

Abstract

This paper presents an investigation into the behavior of reinforced concrete slabs, steel girders, and concrete columns of a two span steel girder bridge under the influence of different combination of earthquake directions and intensities. The beam-column elements were used to represent the composite bridge deck (concrete slab and steel girder) and also the concrete columns. This element type has the nonlinear material capability. The free vibration analysis was performed to detect the first four mode shapes of the bridge models. Time history analysis was implemented on the bridge when subject to San Fernando Earthquake, 1971. Various failure patterns were detected by examming the maximum displacement patterns, and the maximum forces (or stresses) of the bridge components. Significant amplification of the bridge response occured in all directions, longitudinally, transversely, and vertically as a result of the combination effect of earthquake in the other directions.