Evolution of Design Method Against Random Waves Statistical Properties and Spectral of Sea Waves Transformation and Deformation of Random Sea Waves Design of Breakwaters Design of Coastal Dikes and Seawalls Probabilistic Design of Harbor Facilities Harbor Tranquility and Vessel Mooring Hydraulic Model Tests with Random Waves Theoretical Description of Random Sea Waves Statistical Theory of Irregular Waves Techniques of Random Wave Analysis 2D Computation of Wave Transformation with Random Breaking and Nearshore Currents Statistical Analysis of Extreme Waves Prediction and Control of Beach Deformation Processes.

Random seas and design of maritime structures

[1] Tsunamis generated by deformable granular landslides are physically modeled in a three-dimensional tsunami wave basin based on the generalized Froude similarity. The dynamic landslide impact characteristics were controlled by means of a novel pneumatic landslide generator. The wave amplitudes, periods, and wavelengths are related to the landslide parameters at impact with the landslide Froude number being a dominant parameter. Between 1 and 15% of the landslide kinetic energy at impact is converted into the wave train energy. The wave amplitudes decay in radial and angular directions from the landslide axis. The first wave crest mostly travels with speeds close to the theoretical approximation of the solitary wave speed. The measured tsunami wave profiles were either of the nonlinear oscillatory or nonlinear transition type depending primarily on the landslide Froude number and relative slide thickness at impact. The generated waves range from shallow to deep water depth regimes, with the majority being in the intermediate water depth regime. Wave characteristics are compared with other two- and three-dimensional landslide tsunami studies and the results are discussed.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2011JC007850

Physical modeling of tsunamis generated by three-dimensional deformable granular landslides

[1] Subaerial landslides falling into reservoirs or open seas generate impulsive water waves, that are usually referred to as a class of tsunami waves It is important to study landslide-generated waves occurring both in closed water basins, where the waves interact with the shorelines and eventually the dam, and in open seas, where the generated waves can travel and deliver devastating damages hundreds of kilometers away In order to gain insight on subaerial landslide generated waves, the Italian National Dam Office recently funded an experimental and numerical research program geared to better understand and forecast tsunamis waves This paper introduces the experimental work which has been carried out in order to define empirical formulations able to forecast the principal features of the generated waves in a three-dimensional water body, as a function of the landslide movement Wave types observed during the experiments are here characterized using a wavelet analysis approach; new forecasting formulations (named RID formulas) are defined on the basis of the experimental study and tested using an artificial neural network model Results are finally compared to those presented in past experimental studies

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2004JC002778

Forecasting impulse waves generated by subaerial landslides

Landslide-generated waves (LGWs) are among natural hazards that have stimulated attentions and concerns of engineers and researchers during the past decades. At the same period, the application of numerical modeling has been progressively increased to assess, control, and manage the risks of such hazards. This paper represents an overview of numerical studies on LGWs to explore associated recent advances and future challenges. In this review, the main landslide events followed by an LGW hazard are scrutinized. The uncertainty regarding landslide characteristics and the lack of data concerning generated tsunami properties highlights the necessity of probabilistic analysis and numerical modeling. More than 53 % of landslides show the slide length larger than about 20 times of the slide thickness. This fact justifies the popular application of depth-averaged equations (DAEs) for landslides’ motion simulations. Such models are reviewed and tabulated based on their mathematical, numerical, and conceptual approaches. A landslide is generally treated as a homogeneous, mixture, or a multi-phase fluid with different rheologies. The Coulomb type rheology is the most-used rheology applied in more than 70 % of landslide models. Some of the recent studies are considering the effects of multi-phase nature, dynamic changes of rheological parameters, and grain-size segregation of the landslide on its deformations. The numerical tools that model LGWs are also reviewed, categorized, and examined. These models conceptualize a landslide as a general rigid LGW (R-LGW) or deformable LGW (D-LGW) mass. The rigid slide assumption is mainly applied in the LGW models with a focus on the accurate simulation of the wave propagation stage, particularly by means of higher order Boussinesq-type wave equations (BWEs). The majority of D-LGW models solve either the Navier–Stokes equations (NSEs) for a multi-phase (landslide material, water, and air) flow or the shallow water equations (SWEs) for a two-layer (a layer of granular material moving beneath a layer of water) flow. NSEs are more comprehensive models but less robust than DAEs. The key effect of dispersion in LGWs, which are typically important in intermediate and even deep water wave domains, challenges researchers to apply higher order BWEs instead of SWEs in two-layer models. Regarding numerical approaches, Lagrangian’s are more robust than Eulerian’s, but they have been rarely applied due to their high computational demands for real cases. The remaining challenges are reviewed as the necessity of probabilistic analysis to assess the risk of the related hazards more accurately for both past and potential LGW hazards; further thorough laboratory-scale experiments and field data measurements to have accurate and detailed benchmark data; providing RS/GIS-based worldwide hazard map for potential LGWs and compiled database for occurred events; extending BWEs for granular flows and DAEs with non-hydrostatic corrections; and economizing the computational costs of models by advanced techniques like parallel processing and GPU accelerators.

Numerical modeling of subaerial and submarine landslide-generated tsunami waves—recent advances and future challenges

Routine navigational dredging generates huge quantities of marine sediment, posing significant environmental and economic burden. This research intended to explore the efficacy of wood waste biochar as a green admixture and assess the influence of different physico-chemical properties of dredged sediments on the mechanical performance of cement-based sediment products. X-ray diffraction and porosimetry analysis reflected that particle size distribution of sediments determined the pore structure formation and strength development. Thermal and calorimetry analyses showed that biochar incorporation slightly enhanced the cement hydration reaction, while its relatively large and brittle particles induced microcracks and weakened the strength of sediment products. Nevertheless, biochar addition enhanced immobilization of potentially toxic elements and organic contaminants, rendering the sediment products more environmentally acceptable. Hence, the innovative approach of this study can recycle dredged sediment and waste wood biochar to produce eco-friendly construction materials such as fill material and paving blocks.

The roles of biochar as green admixture for sediment-based construction products

Three-dimensional experiments on landslide generated waves at a sloping coast

Application of wavelet transform analysis to landslide generated waves

An experiment on harbour resonance induced by incident regular waves and irregular short waves

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...

Treatment of Wave Breaking and Total Absorption in a Mild-Slope Equation FEM Model

When earthquakes occur, suddenly bottom deformations will induce water response that is almost instantaneous. Then, bottom displacements affect wide areas and generate transient waves (tsunamis) usually characterized by a relatively small heightwith respect to their length, i.e. by a small steepness. Indeed, just after the earthquake, the water free surface mimics the final bottom deformations, that can be of the order of some meters, and small amplitude long waves start to propagate resulting in a potential transoceanic devastation (Synolakis et al., 2002). When either subaerial or submerged landslides occur, thedisplacementswill takeplace onboth larger temporal-, and smaller spatial-scale. The deformations are of the order of hundreds of meters and the generated waves are quite different from those induced by submarine earthquakes. Hence, landslide tsunamis tend to be a local phenomenon, although extreme. Since two centuries ago, submarine failures were related to “sea waves without earthquake” when great waves were observed without any account of earthquakes (e.g. Mallet & Mallet, 1858; Milne, 1898; Montessus de Ballore, 1907). In an illuminating reasoning Mallet & Mallet (1858) argued that “great underwater slippage takes place [...] the effect upon the surface of the sea is at the same moment to originate a positive and a negative wave. [...] The magnitude of the wave raised is dependent upon that of the mass of solid material that has suddenly changed its place, upon the depth of water in which the slippage has occurred, upon the rapidity of the transposition, and in minor degree upon the form and material of the portion of the bank that has slipped.” One of the more meaningful event occurred at Lituya Bay (Alaska, July 9, 1958), when a subaerial landslide triggered by an earthquake entered the water at the Gilbert Inlet and generated an impulse wave (Miller, 1960). The induced run-up was the highest known: the water rose up to 524m at the slope in front of the landslide, then thewaves propagated into the Bay and eventually radiated offshore through the Bay inlet with minimum effects outside the Bay itself. Another example, related to submarine failures, is the well documented tsunami generated by an underwater slump triggered by a magnitude 7 earthquake on July 17, 1998 close to the Sissano Lagoon, Sandaun Province, Papua NewGuinea (see Synolakis et al., 2002). The tsunami struck about 30 km wide area, i.e. rather small, by inducing a maximum run-up of about 15 m and killing over 2100 people. Landslide generated impulse waves can occur not only at the sea boundaries, but also in enclosed basins (i.e. reservoirs and lakes). The event that took place at the Vajont Valley (Italy) on October 9, 1963 is perhaps the more sorrowful one. A subaerial landslide of about 6

/pdf/forecasting-landslide-generated-tsunamis-a-review-5bcuano91a.pdf

Paolo De Girolamo

Papers

Three-dimensional experiments on landslide generated waves at a sloping coast

Application of wavelet transform analysis to landslide generated waves

An experiment on harbour resonance induced by incident regular waves and irregular short waves

Treatment of Wave Breaking and Total Absorption in a Mild-Slope Equation FEM Model

Forecasting Landslide Generated Tsunamis: a Review