ABSTRACT
The mechanical behavior of bridge decks equipped with High Damping Rubber Bearings is strongly affected by the rubber shear modulus that governs their lateral stiffness. It is a random variable, which can be described by a normal distribution.
In this paper, the effects of the variability of the shear modulus are investigated in terms of displacements for both the isolators and the piers, with reference to a case-study RC bridge with continuous caisson deck over four spans. The bridge is modelled with minimal systems with a reduced number of degrees of freedom along the longitudinal and transversal directions. Linear time-history analyses have been carried out using 7 natural seismic records, by considering 10,000 samples for the shear modulus fitting the chosen distribution. A statistical analysis has been then developed on the numerical results in order to obtain percentile values. Finally, Upper and Lower Bounds are identified for design purposes.
