Seismic Resilience Assessment of the Western Macedonia Highway Network in Greece

Abstract

Retis-Risk is a comprehensive framework recently developed for the assessment and management of the seismic resilience of interurban roadway networks. In this paper, this framework is applied for the road network of the prefecture of Western Macedonia in Greece. Refined data concerning real traffic conditions and network topology were collected and a detailed network mapping was performed in GIS. Utilizing an ad-hoc developed software for implementing the holistic methodology, the as-built road network was assessed and the network components with the highest vulnerability and consequence were identified. To improve the loss assessment reliability, bridge-specific fragility curves were employed based on the refined FE modeling. Structural and traffic cost due to earthquake scenarios of different return period were then predicted. To identify effective loss mitigation measures, the whole process was repeated assuming two different pre-earthquake risk management strategies. The first one concerns a retrofit program tailored to selected (i.e., the most critical) network components, while the second one focuses on the beneficial effect of a better recovery planning. Results indicate the significant contribution of an effective risk management to the loss mitigation and network resilience improvement. Moreover, a sustainable health monitoring system was installed on Polymylos bridge to ensure satellite data transmission during an earthquake event to update the postearthquake recovery model, nearly in real time, with the measured spectral acceleration of the superstructure. The results indicate that the road network is adequately resilient, primarily due to its newly constructed infrastructure and its compliance to modern seismic standards. However, it consists an interesting application case demonstrating the applicability of the methodology and the major potential benefits of a holistic resilience-based management for the case similar intercity highway networks.

Safety of buried steel natural gas pipelines under earthquake-induced ground shaking: A review

“…In this case, the problem is usually addressed by considering single seismic scenarios derived deterministically or from disaggregation of PSHA-generated seismic hazard maps. Another approach is proposed by Sextos et al [170], where seismic scenarios associated with specific return periods are produced by PSHA for each seismic source independently. Appropriate IMs for assessing pipeline network loss are discussed in Section 4.…”

“…(24) by using appropriate normal CDFs to model the recovery phase, depending on the damage state. In Sextos et al[170], where intercity networks are addressed, resilience-centered time-dependent qualitative loss indicators of binary form are introduced to track the over-time variation of direct and indirect losses not easily quantifiable in monetary terms (here: connectivity, accessibility, environment), and their effect on the functionality metric. The previous two approaches are examples of transportation networks linking structural, geotechnical with network and consequence analysis that can be potentially adapted to the case of pipeline networks after appropriate modifications.…”