CHANGE OF HORIZONTAL WAVE PRESSURES ON A CAISSON DEPENDING ON THE CREST LEVEL OF ARMOR LAYERS ON THE RUBBLE MOUNTED CORE

This study reports physical experiment campaign to measure horizontal wave pressure acting on a solid caisson that is protected with double-layer Tetrapods and core-layer of rubble stones. The main focus of this study was to evaluate the effects of crest level of the armor layers on the measured wave pressures. The measurements were conducted with four different models in terms of the coverage of the front face of the caisson: no coverage, full coverage up to the crest of the caisson, and two different partial coverages where the crest level of the armor layers were lower than the crest of the caisson. The wave pressures above the still water level showed significant discrepancy depending on different armor coverages, especially for the caisson that are partially protected by armor blocks. It seemed that impulsive loadings acted at times on the top exposed part of the caisson if the caisson is imperfectly protected by armor blocks.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/e8oNZrmiTjo

Vibration Suppression in Two-Dimensional Oscillation Dynamical Systems

During the past few decades, significant interest in applying linear and nonlinear dynamical vibration absorbers for energy transfer and dissipation has significantly arisen. The existing studies of employing dynamical absorbers with small and large-scale dynamical structures have been mostly focusing on suppressing the oscillations for structures that move in one direction only. However, most of these structures are vulnerable to different sources and types of excitations that could induce two-dimensional oscillations into these structures. Consequently, this paper presents an application of a vibration absorber to suppress the two-dimensional vibration induced into the structure caused by a two-dimensional impulsive loading. The system description and the governing equations are firstly introduced and then followed by an optimization process to maximize vibration suppression. The response of the system under various combinations of longitudinal and lateral impulsive loadings is presented and the capability of the proposed absorber to suppress the induced vibration is evaluated.

A CFD STUDY ON THE STRUCTURAL RESPONSE OF A SLOPING TOP CAISSON

The paper discusses preliminary results of a CFD study on the structural response of a Sloping Top Breakwater subject to wave overtopping. The analysis showed that the transmitted wave field act to increase both the landward and the seaward forces and that the conventional design methods may be not adequate to guarantee an appropriate degree of safety to the structure. The study also confirmed the previous finding by Walkden et al. (2001), which noticed the existence of strong impulsive loadings on the inner face of the wall, due to violent overtopping events.