The revision foreseen in this project is aimed at the improvement of Eurocode 8, whose application will be widespread in the next years within the Mediterranean countries, and the up-dating of seismic codes of eastern Europe.
During the recent earthquakes of Northridge and Kobe an unexpected brittle failure of connections and, in same cases, of members occurred. This means that something new happened, which was not foreseen in the current engineering practice. For this reason, the international scientific community and, in particular, the earthquake prone countries of the Mediterranean area and of the eastern Europe are aware of the urgent need to review the current seismic provisions. They feel the need to investigate new topics such as the influence of the strain rate on the cyclic behavior of beam-to-column joints. In addition, the whole background of modern seismic codes deserves to be completely reviewed in order to grasp the design rules which failed during the last terrible seismic events.
The aim of the joint research programme, here proposed, is to provide an answer to the above questions. This task will be accomplished through the following objectives :
* analysis and synthesis of research results, including Code Provisions, in relation with the evidence of Northridge and Kobe earthquakes. Particular attention will be devoted also to those research results which have not accounted for in preparing the provision of modern seismic codes.
* assessment of new criteria for selecting the behavior factor for different structural typologies and definition of the corresponding range of validity. In particular, in this field, the need to provide simplified methods for evaluating the q-factor is felt more and more urgent. The aim is to provide the designer with an operative tool which allows him to be aware of the inelastic performances of the designed structure.
* identification and evaluation of the structural characteristics of connections influencing the seismic response of steel buildings. Therefore, the research will be devoted to the strength and stiffness evaluation of moment resistant connections and to the prediction of their degradation under cyclic loads. Low cycle fatigue will also be investigated.
* definition of criteria for designing and detailing beam-to-column connections for seismic resistant structures, considering also the seismicity of the site.
These objectives will be accomplished through the following tasks : analysis of design criteria and seismic hazard, evaluation of the material behavior in extreme conditions, ductility demand of members and connections, evaluation of the behavior factor, reliable models for the cyclic behavior of connections, interaction between local and global ductility, failure mode and ductility control, preparation of an Application Document.
Funding SchemeCSC - Cost-sharing contracts