This　paper　discusses　the　seismic　behavior　of　reinforced　concrete　(RC)　bridge　structures,　focusing　on　the　shear-flexure　interaction　phenomena.　The　assessment　of　reinforced　concrete　bridges　under　seismic　action　needs　the　ability　to　model　the　effective　non-linear　response　in　order　to　identify　the　relevant　failure　modes　of　the　structure.　Existing　RC　bridges　have　been　conceived　according　to　old　engineering　practices　and　codes,　lacking　the　implementation　of　capacity　design　principles,　and　therefore　can　exhibit　premature　shear　failures　with　a　reduction　of　available　strength　and　ductility.　In　particular,　recent　studies　have　shown　that　the　shear　strength　can　decrease　with　the　increase　of　flexural　damage　after　the　development　of　plastic　hinges　and,　in　some　cases,　this　can　cause　unexpected　shear　failures　in　the　plastic　branch　with　a　consequent　reduction　of　ductility.　The　aim　of　the　research　is　to　implement　those　phenomena　in　a　finite-element　analysis.　The　proposed　model　consists　of　a　flexure　fiber　element　coupled　with　a　shear　and　a　rotational　slip　spring.　The　model　has　been　implemented　in　the　OpenSEES　framework　and　calibrated　against　experimental　data,　showing　a　good　ability　to　capture　the　overall　response.