Τρωτότητα μεταλλικών κατασκευών λαμβάνοντας υπόψη την αλληλεπίδραση εδάφους-θεμελίωσης-κατασκευής

This diploma thesis aims to assess the influence of coupled soil-structure interaction (SSI) and site amplification effects on the seismic response of steel structures. In particular, an idealized moment resisting frame, as well as a concentrically braced frame are examined. Typical soil materials and profiles are selected according to Eurocode 8 and simulated with finite elements using OpenSees, to consider the nonlinear soil behavior. Then, incremental dynamic analyses are carried out using actual earthquake records of escalating intensity. The analysis of the steel frames is performed for two conditions of foundation: a) fixed-base considering soil characteristics and b) Beam-on-Nonlinear-Winkler-Foundation spring-type foundation elements. The results of the dynamic analyses are indicatively presented and discussed based on both the relative displacement of the floors and the moment-rotation at the ends of the beams and columns. The results' thorough analysis and comparison demonstrate the significant contribution of various subsoil configurations and SSI to the seismic behavior of steel frames. The above methodology will be used as a benchmark to further investigate the influence of site-effects and SSI on the seismic fragility and vulnerability of steel structures.