Influence of seismic wave angle of incidence over the response of long curved bridges considering soil-structure interaction

Abstract

Scientific research has shown that soil-structure interaction (SSI) should be investigated especially in the case of bridges with great importance or specific soil and structural characteristics. The most efficient way available nowadays to account for this phenomenon is by modeling the performance of soil, structure and foundation as a whole in the time domain. On the other hand, especially for the case of long, curved bridges, the issue of deciding a ‘reasonable’ incoming wavefield angle of incidence has not yet been scrutinized. Along these lines, the scope of this paper is to investigate the influence of the excitation direction of seismic motion in the case of long, curved bridges, using the most refined finite element model practically affordable in terms of computational cost. For this purpose, the long (640 m) and curved (R = 488 m) Krystallopigi Bridge was modeled using the finite element program ANSYS accounting for SSI both at the location of piers and abutments. The parametric study of different ground motion scenarios performed, highlights the complexity of the phenomenon and the difficulty in determining a ‘critical’ angle of excitation for all response quantities and all piers at the same time especially when soil-structure interaction is considered. Moreover, the dispersion of the results obtained indicates that the impact of ignoring that phenomenon and the role played by SSI effects may be significant under certain circumstances.