000004867 001__ 4867 000004867 005__ 20141119144600.0 000004867 04107 $$aeng 000004867 046__ $$k2002-06-02 000004867 100__ $$aArena, Felice 000004867 24500 $$aNON-LINEAR WIND-GENERATED WAVES FORCES ON A VERTICAL WALL 000004867 24630 $$n15.$$pProceedings of the 15th ASCE Engineering Mechanics Division Conference 000004867 260__ $$bColumbia University in the City of New York 000004867 506__ $$arestricted 000004867 520__ $$2eng$$aThe statistical properties of some narrow-band second-order processes in the mechanics of sea waves in front of a vertical wall are investigated. Arena & Fedele (2002) have shown that the asymmetry between the crest and the trough distributions on a vertical wall is markedly greater than the asymmetry crest-trough in an undisturbed field, either for the free surface displacement or for the fluctuating wave pressure at a fixed depth. In this paper the narrow-band second-order wave force and overturning moment on the vertical wall are derived by analytical integration of the wave pressure. It is obtained that for a fixed threshold of the probability of exceedance, if kd is smaller than 1.38 (being k the wave number and d the bottom depth), positive peaks of the wave force process (that occur with the wave crests of free surface displacement on the wall) are greater than absolute value of negative peaks (that occur with the wave trough). The wave force is a quasi-symmetric process for kd=1.38: the non-linearities are weak and both the positive peak distribution and the negative peak (in absolute value) distribution are given by the Rayleigh law with good approximation. Finally it is noteworthy that for kd>1.38 we find that the wave troughs of surface displacement at wall produce negative peaks of the wave force that are (in absolute value) greater than positive peaks produced by wave crests. The predictions are in good agreement with the data of a small-scale field experiment (Boccotti, 2000). 000004867 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb. 000004867 653__ $$aNarrow-band process, non-linear process, non-linear random force, crest distribution, trough distribution, vertical wall 000004867 7112_ $$a15th ASCE Engineering Mechanics Division Conference$$cNew York (US)$$d2002-06-02 / 2002-06-05$$gEM2002 000004867 720__ $$aArena, Felice$$iFedele, Francesco 000004867 8560_ $$ffischerc@itam.cas.cz 000004867 8564_ $$s96939$$uhttps://invenio.itam.cas.cz/record/4867/files/456.pdf$$yOriginal version of the author's contribution as presented on CD, . 000004867 962__ $$r4594 000004867 980__ $$aPAPER