This paper investigates the dynamic performance of a concrete bridge under a sequence of earthquakes. The PGA of the mainshock and the aftershock were comparable. The concrete damage plasticity model of material was assumed to represent the plastic behaviour of the bridge. Firstly, the mainshock was applied to the bridge, then the aftershock was imposed on the structure which had already been weakened by the first shock. The analysis of plastic and damage measures revealed that the aftershock had a considerable effect upon the structure in terms of enlarging zones affected by irreversible strains or additional damage evolution.

This paper investigates the dynamic performance of a concrete bridge under a sequence of earthquakes. The PGA of the mainshock and the aftershock were comparable. The concrete damage plasticity model of material was assumed to represent the plastic behaviour of the bridge. Firstly, the mainshock was applied to the bridge, then the aftershock was imposed on the structure which had already been weakened by the first shock. The analysis of plastic and damage measures revealed that the aftershock had a considerable effect upon the structure in terms of enlarging zones affected by irreversible strains or additional damage evolution.