A fuzzy approach in the seismic analysis of long span suspension bridge

This study deals with the treatments of uncertainties in the seismic analysis of complex structures. As a complex structure, one has considered a long span suspension bridge having the main span of 3300 m. This is, without doubt, a very complex structure for the nonlinearities, uncertainties and interactions involved in its behaviour. This paper focused the attention about the definition of the seismic input (artificial accelerograms) and the following dynamical analyses that are made in presence of uncertainties. In particular, one has considered the uncertainties involved in the seismic intensity and in the seismic direction. In order to treat these uncertainties one has developed an analysis based on the fuzzy theory. The procedure performed, in order to reproduce the fuzzy response of the bridge, it is exposed.