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Transient waves generated by a box falling into water are analytically and experimentally investigated (Scott Russell wave generator). Within the frame of linear theory, a new analytical solution for the leading wave is proposed. It is shown that both the impulse pressure of the box's impact on the free surface and the velocity field generated during the underwater phase (wave generator type boundary condition) have to be taken into account when predicting wave amplitude and period. The analytical solution, in satisfactory agreement with experiments performed in a two-dimensional flume, can be used for validating numerical models and for estimating the order of magnitude of landslide-generated waves. DOI: 10.1061/(ASCE)0733-950X(2008)134:1(53) CE Database subject headings: Water waves; Transient flow; Landslides; Tsunamis.

The complex dynamics of the Venice tidal barrier subjected to broadbanded wave spectra are investigated by applying empirical orthogonal function (EOF) analysis to experimental data sets. Space and frequency patterns of the natural modes of the barrier are reconstructed and satisfactorily compared with the recent theory of Li and Mei. The results indicate that when broadbanded wave spectra are considered, natural modes with the longest spatial wavelengths seem more likely to be excited than those with shorter wavelengths. CE Database subject headings: Italy; Barriers; Tides; Tidal effects; Gates.

This paper looks at the iterative techniques and the convergence criteria that are necessary to deal with two difficulties in the integration of the full elliptic mild-slope equation, by means of an FEM model. The first difficulty is the nonlinearity due to the inclusion of a wave breaking dissipation factor. This paper gives an overall description of an iterative technique and presents an effective convergence criterion. It shows that this technique, although fully reliable, is time-consuming. Therefore the present paper also sets out to present an accelerated method, which is shown to be up to five times faster than the standard one. The second difficulty arises from the generally adopted boundary reflection condition, which depends on the angle--not known a priori--between the incident wave direction and the normal vector to the reflective boundary. A suitable iterative method and an efficient convergence criterion are presented here, along with validation tests aimed at simulating total absorption. Both nonlinear wave breaking and total absorption are important for coastal-morphology applications. A test on a domain reproducing a sloping beach has therefore been carried out in order to investigate the behavior of both these iterative techniques when used simultaneously.