The estimation of seismic performances of reinforced concrete girder bridges using nonlinear dynamic analysis

varijantama konstrukcija grede mosta jeste kontinuirni nosač sa četiri polja (35 m + 50 m + 50 m + 35 m) i zglobno je oslonjena na vrhove stubova i krajnje oporce. Stubovi su potpuno uklješteni u tlo sa dužinama 7 m, 14 m i 21 m, tj. analizirano je 18 različitih kombinacija dužina stubova. Geometrijska nelinearnost se obuhvaća preko P–Δ efekta, a materijalna nelinearnost se uključuje u analize kroz vlaknaste modele plastičnih zglobova. Procjena seizmičkih performansi je izračunata na osnovu zahtijevane lokalne duktilnosti i kapaciteta lokalne duktilnosti koje posjeduju kritični poprečni presjeci u stubovima analiziranih varijanti mostova. Za nelinearne dinamičke analize upotrebljeni su umjetno (sintetički) generirani i realni zapisi zemljotresa.The paper applies nonlinear dynamic analysis to estimate seismic performances of reinforced concrete girder bridges. In all analysed variations, the structure of the beam implies the continual girder with four fields (35 m + 50 m + 50 m + 35 m) hinged to the pier tops and the abutments. The piers are completely fixed to the ground with the lengths of 7 m, 14 m and 21 m; hence, 18 diverse combinations of pier lengths have been analysed. Geometric nonlinearity is included via the P–Δ effect, while the material nonlinearity is included into the analyses using the fibre models of plastic hinges. The estimation of seismic performances has been calculated on the basis of the demanded local ductility and the local ductile capacity of the critical cross-sections in the piers of all bridge analysed variations. Artificially (synthetically) generated and recorded earthquake accelerograms have been utilized for nonlinear dynamic analyses