COMPOSITE STEEL-CONCRETE JOINTS DESIGN AND MODELLING GUIDELINES

The behaviour of steel and steel-concrete composite joints has been thoroughly studied in the last decades, with particular focus on their influence on the global response of framed structures. Nev-ertheless, especially as far as composite steel-concrete structures are concerned, there are no well-established design guidelines to optimize choices and adequately design composite joints. For this purpose, this paper highlights the main issues that need to be addressed with regards to the seismic design of the beam to column joints belonging to steel-concrete structures, discussing rules reported within codes, as well as modelling approaches. The contents are covered in the “Linee guida per la progettazione sismica di strutture intelaiate composte acciaio-calcestruzzo e l’analisi non lineare” (Guidelines for the seismic design of steel-concrete composite framed structures and the non-linear analysis), a set of guidelines being developed within the RELUIS 2015 project, financed by the ‘Dipartimento di Protezione Civile’ (Department of Civil Protection). The provisions that are re-ferred to throughout this paper are the ‘Norme Tecniche per le Costruzioni’ (NTC2008) and the Eurocode 4 [EN 1994-1-1:2004] as far as the general rules to be applied to the design of a composite structure are concerned, and the Eurocode 8 [EN 1998-1:2004] as regards the specific rules to be applied to a seismic areas. For the single steel components of the joint, reference are made to EC3 part 1-8.