The new service was developed for NEK, which subscribed fragility analysis of Bunkered Building 1 (BB1) as a part of the Safety Upgrade Program (SUP). The aim of the SUP is to upgrade the safety measures, which will help to prevent severe accidents and to improve mitigation of the consequences in the case of major seismic events. In this report preliminary results of fragility analysis of building BB1 are presented. The fragility analysis was performed according to modified methodology developed in USA. The background for the methodology for the fragility analysis of building BB1 is presented elsewhere (Dolšek et al. 2015). The study was conducted in two phases. In the first phase, the seismic response analysis was performed at PGA=0.6g. Since the outcome of the fragility analysis depends on the level of PGA used in seismic response analysis, the simple sensitivity analysis was performed in the second phase of the fragility analysis. In this phase, the seismic response analysis was repeated by scaling ground motions to PGA=0.4g and PGA=0.8g. Although the analysis was conducted in two phases, the results of the study are presented together for all three levels of PGA.
F.11 Development of a new service
COBISS.SI-ID: 7335009Young researcher Nuša Lazar Sinković has successfully completed her doctoral thesis entitled Risk-based seismic design of reinforced concrete frame buildings using simplified nonlinear models. In the thesis it is pointed out that seismic design of buildings according to current standards does not provide sufficiently clear information about the safety against collapse. For this reason a new procedure for the risk-based seismic design of buildings is proposed, which is iterative and based on the use of nonlinear methods of analysis. The proposed design procedure starts with the selection of an initial structure, which is gradually adjusted until the estimated seismic risk is lower than the target risk. Beside the simple guidelines for structural adjustments the concept of differentiation in the reliability of design is also implemented, so that less demanding analytical methods are used in the initial iterations, whereas more demanding, and usually more accurate methods, are used to verify the design results obtained by using simplified methods. Part of the research was aimed at improving the accuracy of seismic risk estimation, which is an important component of the proposed design procedure. New equations for seismic risk assessment, which take into account the physically defined limits of ground-motion intensity, have been derived. It was found that sometimes, if the lower and upper limits of the ground-motion intensity are insufficiently taken into account, overestimated values of the seismic risk may be obtained. The suitability of the proposed design procedure, which takes into account the newly developed equations for seismic risk assessment, was demonstrated on two examples of reinforced concrete frame buildings. The target risk was achieved after only three or four iterations. The proposed methodology for structural design provides additional information, which enables more informative decisions regarding the structural safety under seismic loading.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 7245409The invited lecture entitled Risk-informed engineering: From force-based design to loss assessment of buildings was given at University College London, on the invitation of Tiziana Rossetto, professor of earthquake engineering from University College London, who has managed to gain the ERC project on earthquake engineering. The emphasis was on the dissemination of the results obtained within the project sponsored by Slovenian Research Agency. We agreed that both research institution will try to prepare proposals for European projects and strengthen collaboration through the exchange of young researcher.
B.04 Guest lecture
COBISS.SI-ID: 7096417