Performance-based approaches for high strength tubular columns and connections under earthquake and fire loadings (ATTEL) : final report

The use of high strength steel (HSS) circular hollow sections (CHS) is still limited in the construction industry despite their excellent structural and architectural properties and the fast development of end-preparation machines. The lack of information about the design of HSS elements may however not be considered as a brake on innovation. Indeed, EC3-1-12 gives design recommendations allowing the extension of the scope of Eurocode 3 to steel grades up to S690/ S700MC. Nevertheless, it is widely recognised that the EC3-1-12 extended rules are not allowing full benefit from all the strength potentialities of the HSS elements. The project ATTEL intended to develop both analytical and experimental know-how in order to support new design criteria for the exploitation of HSS and steel-concrete composite circular hollow sections for columns and connections subjected to exceptional loads, like earthquakes and fire. Experimental, analytical and numerical investigations have been achieved in ATTEL so as to allow practitioners to make full use of high strength steels ranging from S500Q/S500MC to S690Q/S700MC which represents nowadays an upper limit for structural applications. The main achievement of the project is the proposal of design rules and design recommendations for structures using HSS tubular columns and for structural elements made of HSS such as steel/composite columns, beam-to-column joints and column bases in fire conditions and/or under moderate/strong seismic actions. Besides that, the field of economical application of HSS CHS solutions has also been identified for the various above-mentioned loading situations.