PSI - Issue 78

Yazdan Almasi et al. / Procedia Structural Integrity 78 (2026) 433–440

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1. Introduction Industrial facilities located in coastal seismic regions are increasingly exposed to compound natural hazards, particularly earthquake-tsunami sequences. Events such as the 2011 Great East Japan Earthquake and Tsunami (GEJET) have demonstrated how these cascading hazards can overwhelm structural defenses and trigger major technological accidents, including fires, explosions, and large-scale releases of hazardous materials (Krausmann et al., 2017). Such events, referred to as Na-Tech (Natural Hazard Triggering Technological) scenarios, underscore the critical need for multi-hazard risk assessments that consider the dynamic and interconnected nature of hazard impacts on industrial systems (He et al., 2022; Krausmann et al., 2017). Earthquake-tsunami scenarios represent a particularly destructive form of Na-Tech events, where industrial equipment is subjected to sequential and compounding loads (He et al., 2022; Nishino et al., 2024). These dual hazards can result in severe consequences, including buckling, structural failure, and the release of hazardous materials. Equipment such as atmospheric storage tanks (ASTs) and pressure vessels are particularly vulnerable due to their exposure to both ground shaking and subsequent hydrodynamic forces (Nishino et al., 2024). Capturing these complex interactions requires the development of specific fragility models and risk indicators that reflect cascading effects, evolving structural conditions, and the time-dependent nature of damage progression. Moreover, past disasters have demonstrated that these events can lead to extensive environmental contamination and long-term operational disruptions, particularly when hazardous materials are released from compromised equipment (Krausmann et al., 2017, 2019; Nishino et al., 2024). For example, tsunami-induced fires and tank displacements have exposed significant weaknesses in Na-Tech-specific safeguards and emergency preparedness. Despite increasing awareness, many industrial facilities remain under-designed for multi-hazard conditions, and risk assessments continue to treat earthquake and tsunami hazards in isolation. This lack of integration limits the ability to predict real-world compound effects and delays the implementation of effective mitigation strategies. This paper presents a state-of-the-art review of existing methodologies for assessing the multi-hazard risk to industrial equipment exposed to earthquake-tsunami sequence scenarios. The objective is to synthesize recent advancements in fragility modeling, hazard interaction, and consequence analysis, identify persistent methodological gaps, and propose future directions for integrated, dynamic, and realistic risk assessment approaches. In this regard, investigation and analysis of seismic-tsunami Na-Tech impacts, structural vulnerabilities, and multi-risk approaches are needed to promote safer design and improve mitigation strategies for critical infrastructure in tsunami-prone seismic areas. 2. Earthquake and Tsunami in the Na-Tech context Earthquakes generate intense ground shaking, ground deformation, and inertial forces that can compromise the structural and operational integrity of industrial facilities (Caprinozzi et al., 2020; Caputo et al., 2019; Corritore et al., 2021; Paolacci et al., 2015). Observed damages include anchorage failures of storage tanks, collapse of pipe racks, shell buckling, malfunctioning of safety-critical systems, etc (Caputo et al., 2019; Corritore et al., 2021; Paolacci et al., 2015). For instance, the 2023 Turkey Earthquakes caused widespread disruption in industrial zones near Gaziantep and Hatay, where several chemical storage tanks experienced settlement and structural instability due to ground motion amplification and soil failures. Similarly, during the 2011 Great East Japan Earthquake, the Cosmo Oil Refinery in Chiba suffered large-scale fires and tank failures primarily due to unanchored equipment, sloshing-induced roof displacement, and the failure of pipe systems, which were exacerbated by inadequate seismic isolation and foundation instability (Krausmann & Cruz, 2013). Tsunamis introduce a second hazard layer, characterized by high-velocity water flow, impulsive hydrodynamic forces, debris impact, and prolonged inundation (Mebarki et al., 2016; Nishino et al., 2024; Vitale, Ricci, et al., 2024). These effects can damage previously weakened structures and trigger secondary Na-Tech consequences. The 2011 Tōhoku Earthquake and Tsunami remain the most studied example, with severe tsunami-induced damage to oil storage tanks, power plants, and chemical industries in the Sendai and Chiba regions. Fires erupted due to tank flotation and ruptures, while inundation disabled critical lifelines such as power and water supplies, significantly delaying emergency response (Araki et al., 2017; Krausmann & Cruz, 2013; Mebarki et al., 2016; Nishino et al., 2024). Tsunami-induced damage to industrial facilities was also observed during the 2004 Indian Ocean Tsunami, particularly in coastal areas of Sumatra and India, where unanchored steel storage tanks floated and were displaced over long