A numerical study of the run-up generated by three-dimensional landslides

A large set of numerical experiments are designed to examine the maximum run-up generated by three-dimensional (3-D) submerged and subaerial, solid body landslides. A depth-integrated numerical model is utilized, allowing for the efficient simulation of landslides in shallow and intermediate water. Six dimensionless parameters are introduced: the slide thickness, the slide wave number, a slide shape parameter, the horizontal aspect ratio of the slide, the specific gravity of the slide mass, and the slope of the beach. Six sets of simulations are first presented, wherein one of the six dimensionless parameters are singularly varied. This allows for the identification of parameter dependence on maximum run-up. After combining the dependencies a number of relationships appear. Most notably, a very clear division between the near and far field is observed, where here the far field is defined as the region displaced from the projection of the landslide, on the nearby beach, where edge waves may dominate the wave pattern. For submerged slides a nondimensional estimation of the maximum run-up just landward of the slide is found as well as the location and magnitude of the secondary run-up peak. This secondary peak is due to the propagation of edge waves and is in some cases larger than the peak immediately landward of the slide. The results presented in this paper may be useful for preliminary hazard assessment, where a simple and quick estimation of the maximum run-up height and locations are required. Additionally, the formulas developed will be particularly beneficial to those developing 3-D landslide experiments.