Experimental and numerical study on failure mechanism of steel cylindrical tanks subjected to earthquake-tsunami sequence

Abstract

In coastal areas, earthquakes are very likely to cause deformation of the seafloor crust, which in turn triggers large-scale water displacement and forms tsunamis. Structural damage caused by an earthquake may diminish the resistance of steel cylindrical tanks to tsunami impact, resulting in more pronounced failure behavior. In this study, a sequential loading experimental program and corresponding Coupled Eulerian Lagrangian-based numerical model are developed to investigate the failure mechanism of steel cylindrical tanks subjected to earthquake-tsunami sequence. To be specific, failure characteristics of tank models under isolated tsunami loading are examined through experiments with different solitary wave heights and water velocities. The damage amplification effect of seismic pre-damage on subsequent tsunami impact is compared by subjecting earthquake-damaged tanks to tsunami loading. Results indicate that seismic-damaged tanks exhibit more significant failure behavior due to factors such as geometric deformation, residual stress, and wave breaking. Specifically, the protruding edges caused by seismic pre-damage induce concentrated stress, leading to higher maximum stresses and more pronounced displacement changes in the tank walls. Compared with considering the individual tsunami hazard only, peak displacement failure amplification exhibits fluctuations ranging from 17.1% to 94.5%, while peak stress amplification factors varied between 4.5% and 158.3%. This work lays the groundwork for overcoming the limitations of traditional single-hazard fragility analyses.