Effective framework for seismic analysis of cable-stayed-bridges,Part 1: Modeling of the structure and of the seismic action

摘要

The spatial variability of the strong ground motion leads to significant aspects inrnthe structural response of long-plan structures, such as long-span and medium-span bridges. Inrnthis study the structural responses of a prestressed concrete cable-stayed-bridge, with mediumlength-rnspan of 300 m, under 30 different seismic events, in both cases of synchronous andrnasynchronous motion at the base of the structure have been compared. Although the studies arernprincipally conducted by a 3-D model of the structure, which one will call "frame model",rndeveloped using the finite element software Ansys, the structure has been studied using anotherrnmodel, which one will call "shell model", in order to evaluate how the differences in thernmodeling lead to different results. In the part 1 of the study, the authors put in evidence therndifferences among the models response in terms of modal characteristics of the principalsrnmodes. The comparison of the results obtained in both the models shows the similar behaviourrnof the two models, confirmed by the small differences in percentage of the values reached byrnmonitored static and kinematical.