טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentAkrish Gal
SubjectInteraction between a Deformable Wall and Water Waves
DepartmentDepartment of Civil and Environmental Engineering
Supervisors Professor Oded Rabinovitch
Professor Yehuda Agnon
Full Thesis textFull thesis text - English Version


Abstract

This study deals with the interaction between non-breaking water waves and a vertical wall. In particular, the study concerns two cases of interaction. The first case deals with the interaction between water waves and a vertical rigid wall. The second case focuses on the interaction between water waves and a vertical elastic wall. In both cases, the influence of certain effects, which are not taken into account by the common design practice, is examined. To this end, three numerical models are developed. These models are based on the high order spectral (HOS) method and aim to simulate a two-dimensional wave flume with a constant depth. The additional potential concept is used to treat the non-periodic kinematic conditions on the lateral flume boundaries. Finally, a new numerical approach that extends the HOS method to treat the interaction between water waves and an elastic wall is developed.

The study of the interaction between water waves and a vertical rigid wall shows that the effect of nonlinear evolution may cause extreme values of run-up and wave force that cannot be obtained through the design practice. Two mechanisms for extreme non-breaking run-up and wave force values are revealed. The first is the waves’ amplification during the group propagation towards the wall. The second mechanism is the nonlinear reflection of the waves from the wall. In shallow water, the amplification occurs due to the formation of an undular bore. In deep water, wave group amplification occurs during the disintegration process into envelope solitons.

Considering the interaction with an elastic wall, the study focuses on the influence of the dynamic parameters of the wall on the hydrodynamic values and on the structural response. The importance of the hydroelastic analysis is examined by a comparison to uncoupled analysis for several wave loading conditions. The study reveals the relaxation phenomenon for relatively flexible walls. For such cases, the importance of hydroelastic analysis is also demonstrated. In contrast to the perception of the common design practice, the study suggests that the hydroelastic analysis is also essential when considering relatively stiff walls under extreme loading situations. Altogether, the study points at the hydroelastic interaction between the wave and the wall and provides a spectrum of analytical and numerical tools for its quantitative assessment.