TY - CONF A1 - Schneider, Ronald A1 - Rogge, Andreas A1 - Thöns, S. A1 - Bismut, E. A1 - Straub, D. ED - Caspeele, Robby ED - Taerwe, Luc ED - Frangopol, Dan M. T1 - A sampling-based approach to identifying optimal inspection and repair strategies for offshore jacket structures T2 - Proceedings of the sixth international symposium on life-cycle civil engineering (IALCCE 2018) N2 - Identifying optimal inspection and repair strategies for offshore jacket structures is a challenging task. We pre-sent an approach, which is based on recent developments in the field of risk-based operation and maintenance planning at the structural system level. The approach utilizes heuristics to define inspection and repair strate-gies at the system level and to reduce the search space of possible strategies. For each defined strategy, the expected service life cost of inspection, repair and failure is evaluated based on simulated inspection and re-pair histories. Subset simulation is applied to compute the conditional repair and failure probabilities required for this analysis. It also forms the basis for simulating inspection and repair histories. The strategy that mini-mizes the expected service life cost is the optimal one in the set of pre-selected strategies. The underlying condition and performance model accounts for the stochastic dependence among the deterioration states of the different structural elements and the structural redundancy. The approach is demonstrated in a case study considering a jacket-type frame. In this study, we essentially vary the inspection interval, the minimum num-ber of inspected components and the target reliability, and identify the combination that minimizes the ex-pected total service life cost. T2 - The sixth international symposium on life-cycle civil engineering (IALCCE 2018) CY - Ghent, Belgien DA - 28.10.2018 KW - Offshore steel structures KW - Fatigue KW - Reliability KW - Risk KW - Inspection planning PY - 2019 SN - 978-1-138-62633-1 SN - 978-1-315-22891-4 SP - 1081 EP - 1088 PB - Taylor & Francis Group CY - London AN - OPUS4-46434 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Berchtold, Florian A1 - Knaust, Christian A1 - Thöns, S. A1 - Rogge, Andreas T1 - Risk analysis in road tunnels – most important risk indicators T2 - Proceedings from the Seventh International Symposium on Tunnel Safety and Security N2 - Methodologies on fire risk analysis in road tunnels consider numerous factors affecting risks (risk indicators) and express the results by risk measures. But only few comprehensive studies on effects of risk indicators on risk measures are available. For this reason, this study quantifies the effects and highlights the most important risk indicators with the aim to Support further developments in risk analysis. Therefore, a system model of a road tunnel was developed to determine the risk measures. The system model can be divided into three parts: the fire part connected to the fire model Fire Dynamics Simulator (FDS); the evacuation part connected to the evacuation model FDS+Evac; and the frequency part connected to a model to calculate the frequency of fires. This study shows that the parts of the system model (and their most important risk indicators) affect the risk measures in the following order: first, fire part (maximum heat release rate); second, evacuation part (maximum preevacuation time); and, third, frequency part (specific frequency of fire). The plausibility of These results is discussed with view to experiences from experimental studies and past fire incidents. Conclusively, further research can focus on these most important risk indicators with the aim to optimise risk analysis. T2 - Seventh International Symposium on Tunnel Safety and Security CY - Boras, Sweden DA - 16.03.2016 KW - Fire KW - Risk KW - Road KW - Tunnel KW - Analysis PY - 2016 SN - 978-91-88349-11-8 SN - 0284-5172 SP - 637 EP - 648 CY - Boras, Sweden AN - OPUS4-37689 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -