Wave-structure interaction I

Hydraulic structures are essential for flood protection, water management and navigation in coastal, delta and lake regions. Their importance will continue to grow in the coming years, because of two main factors. Firstly, because of the consequences of climate change and sea level rise. Secondly, because of the continuous development and urbanization of coastal, delta and lake regions, with an increase in the value of the assets and activities in those locations combined with more strict safety requirements. Those factors will lead to the construction of a series of new hydraulic structures and the renovation of several existing structures.
Wave loads acting on such hydraulic structures are crucial for their design and safety assessment. This study addresses two different types of wave loads on hydraulic structures: confined wave impact loads and bimodal wave loads. To this end, a series of laboratory experimental test campaigns were carried out in a wave flume.

The GPMDLR has requested to ARTELIA the preliminary design studies for the enlargement of the containers terminal in Port East (La Réunion). In the frame of the studies, the laboratory of ARTELIA has carried out in 2D physical model testing to evaluate the behavior of caissons exposed to cyclonic waves. 
Main objectives of the study were: the evaluation of overtopping rates, the verification of stability of foot protection, and the recording of wave pressures (sensors) and loads (scale).
Given the fact that most of the waves broke violently upon the caisson, the nature of efforts was impulsive and the scaling to prototype by classical Froude similarity principles was not appropriate. Results were therefore amended following Cuomo's correction factors for the Froude scaling law (Cuomo et al. 2010).
Times series of efforts were intended to feed numerical models (static and dynamic) to assess caissons' geotechnical stability and the design of concrete parts.

Comprehensive design guidelines and literature on wave impacts at stepped revetments are lacking. Laboratory experiments are essential for establishing design recommendations, yet prior small-scale studies are likely to be subjected to scale effects. This study quantifies scale effects of wave impact characteristics by conducting full-scale flume experiments with two step heights. Results show that small-scale tests underestimate design wave impacts up to a factor of 7.7. Impact loadings occur considerably faster at full scale, with peak rising times decreasing by up to 5.6 times. Prediction formulae are dervied for the vertical distribution of maximum horizontal impact pressures as well as for temporal characteristics of these pressures at stepped revetments.

Composite vertical breakwaters are structures often used to protect port basins, especially in deep-water conditions. One of the technical solution to optimize the performance of these structures consists in placing the crown wall at a retreated position, aiming at inducing a time lag between the loads acting on the trunk and on the crown wall. In the literature there is a lack of guidelines to consider the effects of crown wall retreat in terms of wave actions and hydraulic performance of the structure. Recently, Romano & Bellotti (2023), based on physical model experiments, provided a first experimental insight on the increase/reduction of the wave loads acting on deep water vertical breakwaters with retreated crown wall placed. The paper presents a physical model study of wave induced forces on a composite vertical breakwater, where the crown wave wall is retreated with respect to the front face of the caisson.

The results of an experimental investigation to analyze the water flow, the stability of the pieces and the reflection
coefficient of a slope of concrete cubes placed in an organized way, paving stone style, together with larger blocks to increase
its overall roughness, are presented.
The experiment was conducted at the wave flume of the University of Costa Rica and tested wave ranges typical of the
Pacific coasts of Central America with long swell periods.