This paper aims at giving an overview of the main findings and a summary of the results obtained within the framework of the International Benchmark SMART 2013, jointly organized by the CEA, EDF under the supervision of the IAEA. The benchmark, devoted to the Seismic design and best-estimate Methods Assessment for Reinforced concrete buildings subjected to Torsion and nonlinear effect, was split into four stages. The first stage allowed characterizing the nonlinear constitutive laws used in the best-estimate approaches. The second stage aimed at calibrating the numerical models. As for the third stage, it was devoted to blind nonlinear dynamic computations when a RC mock-up, representing a 1:4 scaled part of a typical nuclear electrical building, is subjected to strong input ground motions. In the last stage, the influence of both the material nonlinearities and the methodologies used to compute the fragility curves were analysed. From the analysis of the results obtained by all the participants, the following conclusions have been drawn: (i) significant improvements have been made on the way of controlling the boundary conditions when simulating high intensity shaking table tests involving a complex RC specimen, (ii) the numerical models were able to capture the peak frequency shifts, (iii) within the framework of the considered seismic scenario, the aftershock did not lead to additional damage, (iv) a satisfactory level of available seismic margin is confirmed with respect to the design of such building. Finally, it appears that SMART 2013 research program has succeeded not only in showing the robustness of a complex nuclear RC structure designed according to the current French practices but also in assessing the improvements made for in terms of best-estimate approaches and description of uncertainties when dealing with probabilistic vulnerability analysis.
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