Seismic Performance of a Cable-stayed Footbridge Using a Concrete Damage Plasticity Model

In this paper, a non-linear dynamic analysis of a cable-stayed footbridge to an earthquake is presented. The investigation was performed for an existing pedestrian bridge located in Czestochowa, Southern Poland. The total length of the structure is 46.90 m. The suspended structure consists of two spans (21.10 m and 25.80 m). The deck of the footbridge is made of a steel-concrete composite and is connected to the steel pylon by cables. The structure is equipped with elastomeric bearings as linking elements between the deck and the pillars. A three-dimensional FE model of the footbridge was created with the ABAQUS software program. For the verification of numerical model the modal assurance criterion (MAC) was applied. The acceleration time history of the registered shock was used as seismic excitation acting in three directions. The peak ground acceleration (PGA) of the shock was 0.4 g. To represent the inelastic behavior of the footbridges' deck under the earthquake, a concrete damage plasticity model was assumed as a constitutive model for the concrete. It turned out that the analyzed shock was strong enough to cause severe destruction in the reinforced concrete deck of the footbridge.