Seismic analysis of long multiple‐span highway bridges

Abstract

AbstractMathematical models and three‐dimensional non‐linear dynamic analysis procedures are described for determining the seismic response of long, curved (or straight), multiple‐span, reinforced concrete highway bridges. Under the action of strong earthquakes, the columns (or piers) of such structures may experience large cyclic inelastic deformations of a coupled form. Also, cyclic slippage of the Coulomb type can take place in the expansion joints of the deck causing multiple impacts and separations to occur. These separations may be sufficiently large to cause tensile yielding of the longitudinal expansion joint restrainer bars (or cables) and, if not controlled, can permit deck spans to fall off their supports resulting in partial or total collapse of the structure. In this paper, a three‐dimensional elasto‐plastic mathematical model suitable for representing the coupled inelastic flexural behaviour of reinforced concrete columns under cyclic deformations is presented along with a non‐linear mathematical model for simulating the non‐linear discontinuous behaviour of expansion joints. The procedures used for non‐linear seismic response analysis are described and a numerical example is given to illustrate the method.