BREAKING WAVE CHARACTERISTICS FOR THE LOADING OF A SLENDER PILE

Large-scale model tests were carried out in the Large Wave Channel (GWK) with a slender cylindrical pile located at the end of a 1:10 slope. The test cylinder was subject to both regular and irregular waves. The paper deals with (i) the evaluation of the breaker characteristics at the breaking point for the test conditions, (ii) the comparison of the results with published data from small-scale experiments and (iii) the measured vertical distribution of horizontal particle velocities under a breaking wave. Additionally a new method of separating the measured force history into a slowly varying quasi-static and a dynamic part is presented by using the EMD (Empirical Mode Decomposition) for the analysis of breaking wave attack. INTRODUCTION The loading on a vertical slender pile is commonly calculated with the Morison equation. The total wave force F on the pile is described as a sum of a drag component FD and an inertia component FM as follows: dy u 4 D C dy u u C D F F F 2 M D M D 2 1 ∫ ∫ ⋅ ⋅ ⋅ ⋅ + ⋅ ⋅ ⋅ ⋅ ⋅ = + =