Application of stress test concepts for port infrastructures against natural hazards. The case of Thessaloniki port in Greece

An engineering risk-based methodology for stress testing critical infrastructures is introduced and applied to the port of Thessaloniki in Greece exposed to seismic, geotechnical and tsunami hazards. The methodology workflow consists of four phases: Pre-Assessment, Assessment, Decision and Report phase. In the pre-assessment phase, all the necessary information is collected and archived. For the pilot study, the inventory includes the main port components namely buildings, waterfronts, cranes and the electric power system. Generic or site-specific fragility models are used for all exposed elements and considered hazards. Risk metrics and objectives are defined related to the functionality of the system and the structural losses. In the first level of the assessment phase, the performance of each component is evaluated using a risk-based approach. Then, a system level probabilistic risk analysis is conducted separately for earthquake and tsunami hazards. A complementary scenario-based risk analysis is carried out aiming to investigate the impact of site-specific response and extreme seismic events to the performance of the port. In the Decision phase, the results are compared with predefined objectives to decide whether the infrastructure passes, partly passes or fails the test. Guidelines and strategies to improve the performance and resilience of the port are summarized.