This paper presents the results of the studies of tsunami waveform characteristics obtaiпed iп laboratory conditions duriпg propagation over а plane bed. Тhе dependences of the rise rate of the leadiпg wave front, the characteristics of the dispersive wave tail, the duration of the maiп wave impulse on its height for various water depths are iпvestigated. Usiпg the methods of the mathematical data processiпg, the maiпly liпear character of these dependences is shown. Тhе paper presents а comparison of the waveform profile recorded duriпg the experimental studies with the results of numerical calculations describiпg the process of wave generation Ьу а laboratory wavemaker. These calculations were performed usiпg mathematical models based on the potential theory of an ideal incompressiЫe fluid (the method of boundary elements) and on the theory of а viscous iпcompressiЫe two-component fluid (the method of finite differences ). Тhе obtaiпed results сап Ье used in engiпeeriпg calculations ofthe characteristics oftsunami wave impacts on hydraulic structures, for approbation of numerical models that describe the generation and propagation of tsunami waves, including in the laboratory conditions. This paper continues the research ofthe authors' team aimed at developing а mathematical model ofthe origin and propagation of solitary waves in а physical experiment.

In this paper, the calculation method is described that makes it possiЫe to determine the main characteristics of tsunami waves impact on marine hydrotechnical structures and objects located in the coastal zone. Taking into account the various forms of the objects makes the approach presented in the work useful for obtaining estimates for the solution ofvarious applied proЫems including the calculating the criteria of safety of structures and objects during the planning of construction in tsunami-prone areas. The paper presents а mathematical model that is used for the quantitative describlng of the process of tsunami waves interaction with marine structures and allows to determine the values of the pressure and force coefficients. Classification of offshore and coastal structures according to the degree of their permeaЬility for the water flow is given. This classification makes it possiЫe to identify different types of tsunami waves interaction with In this paper, the calculation method is described that makes it possiЫe to determine the main characteristics of tsunami waves impact on marine hydrotechnical structures and objects located in the coastal zone. Taking into account the various forms of the objects makes the approach presented in the work useful for obtaining estimates for the solution ofvarious applied proЫems including the calculating the criteria of safety of structures and objects during the planning of construction in tsunami-prone areas. The paper presents а mathematical model that is used for the quantitative describlng of the process of tsunami waves interaction with marine structures and allows to determine the values of the pressure and force coefficients. Classification of offshore and coastal structures according to the degree of their permeaЬility for the water flow is given. This classification makes it possiЫe to identify different types of tsunami waves interaction with them. Formulas and relationships are given that allow to calculate the values of the wave loads on the structures and objects depending on their characteristics. Expressions for well-permeaЫe objects are presented. Formulas are given for poorly permeaЫe objects for the situation of the impact of the flow formed Ьу the tsunami waves and for the stage of quasistationary flow around these objects.

То reduce the wave loads on floating marine stmctures (like platforms and pontoons), at present, protective barriers are used that are partially or completely impermeaЫe. This work is dedicated to the study ofthe interaction between long sea waves with constmctures f ormed bу а protected stmcture and а protective barrier that are located above а shallow slope. The paper presents the results of experimental and numerical investigations of runup values and force impacts on а semi-submerged body over а wide range of incident wave heights for different barriers types, for different ratios between body draft and local depths, for the different distances between the barrier and the body and for other characterisitcs. Experimental studies were performed in а hydrowave laboratory in а flume with an installed vacuum wavemaker that creates tsunami-type waves. For nшnerical studies, we used the nonlinear model of incompressiЫe fluid flows and а step-by-step computational algorithm using the moving grids that adapt to а moЬile free boundary and condense near the structures under study. Wave generation was perf ormed bу а numerical wavemaker that simulates а real vacuum wavemaker of an experimental setup. The paper presents the values of design parameters that allow the protective barrier to reduce the wave mnup values and force impacts on the floating body.

This work is dedicated to the studies of the soil structure changes near the marine hydrotechnical structures caused Ьу the tsunami waves impact. Тhе results of the experimental iпvestigations are presented for two types of structures: for а mariпe ice-resistant stationary gravitational-type platform and for а bank reiпforcement of the slopiпg type with а protective riprap layer. As the results of the experimental studies of the tsunami waves impact on the gravity-type offshore platform, the formed bed profiles were measured and their analysis was performed. Тhе quantitative iпformation was obtaiпed on the degree of the soil looseniпg near the base of the platform. Тhе obtaiпed data testify to the possiЫe iпdependence of the soil looseniпg degree from the Euler number that characterizes the iпtensity of the wave impact on the soil. Experimental studies ofthe tsunami waves impact on the bank reiпforcement structure ofthe slopiпg type shown that the filtration flows occurriпg iпside the iпcliпed facet of the structure as а result of the tsunami wave action lead to а change iп the structure ofthe rock riprap. This iпcreases the porosity ofthe soil that composes the structure. А qualitative similarity between the tsunami waves impact on the soil and on the embankment elements of the hydraulic engineering structure is noted.

In this paper, a brief review of theoretical and experimental studies on the effect of tsunami waves on elements of sloping structures is considered. Authors' results of experimental and theoretical studies, which were used as the basis for guiding documents for the design of marine protective hydraulic structures and the Code of Rules "Buildings and Structures in tsunami-prone areas. Rules of Design", published under the auspices of the Ministry of Construction and Housing and Communal Services of the Russian Federation in 2017. The influence of the roughness of structures on the magnitude of the solitary wave runup was investigated. The calculations were carried out using the long-wave model obtained by Professor Yu. Z. Aleshkov, realized by a difference scheme of the second order. In this paper, we consider protective structures in the form of a slope with a vertical wall and a slope with a berm and a vertical wall. Comparison of the calculated data with the experimental data for two relative wave heights is given. In the final part, new results obtained in the numerical modeling of tsunami based on the complete Euler equations are presented (the authors constructed a new, completely conservative second-order scheme for the numerical realization of these equations) and discusses the prospects for further study of the problem of tsunami interaction with protective structures.

Dynamical loads are estimated on underwater vertical cylindrical parts of offshore platforms from the forcing of fully nonlinear internal wave motions generated by multicomponent barotropic tidal flow over topography along a vertical section for the conditions of the Sea of Okhotsk (Aniva Bay, near the south-eastern part of the Sakhalin Island shelf). The evolution of this process is analysed using numerical model of Euler equations for incompressible density-stratified fluid in a vertical plane. The intensity of pressure on lateral underwater surface and the rate inertia moment are expressed according to Morison’s formula for a cylindrical pile of 2.5 m diameter and 42 m height and computed as functions of time. They can reach values of 2.3∙105 N and 4.8∙106 N∙m, respectively, during the tidal cycle. The frequency of the appearance of large peak values in the internal wave velocity field and the probabilities of the corresponding high loads are also calculated.