Crownwall Failure Analysis through Finite Element Method

Abstract

Several failures of recurved concrete crownwalls have been observed in recent years. This work aims to get a better insight within the processes underlying the loading phase of these structures due to non-breaking wave impulsive loading conditions and to identify the dominant failure modes. The investigation is carried out through an offline one-way coupling of computational fluid dynamics (CFD) generated wave pressure time series and a time-varying structural Finite Element Analysis. The recent failure of the Civitavecchia (Italy) recurved parapet is adopted as an explanatory case study. Modal analysis aimed to identify the main modal parameters such as natural frequencies, modal masses and modal shapes is firstly performed to comprehensively describe the dynamic response of the investigated structure. Following, the CFD generated pressure field time-series is applied to linear and non-linear finite element model, the developed maximum stresses and the development of cracks are properly captured in both models. Three non-linear analyses are performed in order to investigate the performance of the crownwall concrete class. Starting with higher quality concrete class, it is decreased until the formation of cracks is reached under the action of the same regular wave condition. It is indeed shown that the concrete quality plays a dominant role for the survivability of the structure, even allowing the design of a recurved concrete parapet without reinforcing steel bars.

Structural Optimisation and Behaviour of the Breakwater Integrated Oscillating Water Column Device

“…Similar to the displacements, the dynamic aspects are not expected to largely affect the developed internal stress. It is highlighted that a similar crownwall has been recently investigated in Dermentzoglou et al (2021), where the dynamic response was found to be relevant for the overall structural integrity under the Confined Crest Impact, (Castellino et al, 2021;Castellino et al, 2018). However, the crownwall investigated by (Dermentzoglou et al, 2021) was only supported by a slender concrete element, whereas in the proposed case the combined effect of the elements of the rear chamber produces a stiffer and more resilient structure.…”

Numerical Experiments on Overhanging Parapets Under Non-Breaking Wave Conditions

“…Even for non-breaking wave conditions, these structures are subjected to large impulsive pressure that has been recently described and named as Confined-Crest impact, (C-CI, Castellino et al, 2018). The C-CI has been the cause of recent failures such as in the Civitavecchia harbour (Italy, Castellino et al, 2021 andDermentzoglou et al, 2020). Accordingly, this phenomenon raised the attention of researchers and professionals who require an additional tool to design these curvilinear structures by considering the overtopping reduction performance, the structure complexity and the C-CI.…”

A numerical investigation of tsunamis impacting dams

“…generated by earthquakes, landslides, and icebergs. Computational fluid dynamics (CFD) shows a great potential in modelling tsunamis (Yavari-Ramshe and Ataie-Ashtiani, 2016), waves impacting walls (He and Kashiwagi, 2012;Chen et al, 2014;Didier et al, 2014;Hu et al, 2016), and impulsive wave forces acting on recurved parapets (Castellino et al, 2018;Martinelli et al, 2018;Castellino et al, 2021;Dermentzoglou et al, 2021). Mesh-based methods, e.g.…”