Optimal response of isolated multi span continous deck subjected to near fault and far field records

The present study analyses the optimal friction coefficient for the seismic isolation of bridges, equipped with single concave friction pendulum (FPS) devices. The bridge are modelled through a six-degree-of-freedom system while the FPS friction property is described through a model that accounts for the dependency on the velocity. By introducing a time scale and a length scale, a nondimensional analysis has been used to solve the equation of motion. In particular, the response is made independent from the peak ground acceleration-to-velocity ratio. Furthermore, two different sets of seismic records are considered: far field and near fault. Then, many bridge models are considered by changing different parameters (i.e., pier period, deck period, mass of the deck and of the pier and friction coefficient). By minimizing the substructure response, an optimum value of the friction coefficient is computed.