scholarly journals NUMERICAL STUDY OF WAVE RUN-UP AT PERMEABLE FIXED REVETMENT SLOPE

2017 ◽  
pp. 32
Author(s):  
Izmail Kantarzhi ◽  
Sergii Kivva ◽  
Natalia V Shunko
Keyword(s):  
Porous Medium ◽  
Numerical Model ◽  
Large Scale ◽  
Numerical Study ◽  
Water Filtration ◽  
Wave Surface ◽  
Natural Conditions ◽  
Wave Flume ◽  
Run Up ◽  
Large Scale Tests

The numerical model of wave surface elevation and water filtration in the saturated-unsaturated porous medium is developed. The model uses to define the parameters of the wave run-up at the slope protected by the permeable fixed layer. The model shows the wave surface in the different times, including the wave run-up height at the slope and wave run-down. Also, the velocities in the upper protected layer as well in the soil body of the slope are defined. Model is verified with using of the published large-scale tests with the slopes protected by Elastocoast technology layers. The tests were carried out in the wave flume of Technical University Braunschweig. The numerical model may be applied to calculate the maximal waves run-up at the protected engineering and beach slopes in natural conditions.

scholarly journals WAVE RUN-UP AT SEA DIKES UNDER OBLIQUE WAVE APPROACH

1982 ◽  
Vol 1 (18) ◽  
pp. 50
Author(s):  
E. Tautenhain ◽  
S. Kohlhase ◽  
H.W. Partenscky
Keyword(s):  
Irregular Waves ◽  
Wave Direction ◽  
Wave Runup ◽  
Natural Conditions ◽  
Wave Impact ◽  
Oblique Wave ◽  
Wave Flume ◽  
Wave Approach ◽  
Impact Forces ◽  
Run Up

Besides wave impact forces, erosion of the inner side of a sea dike is a serious cause of destruction. Therefore, wave run-up and overtopping effects have to be considered with respect to the safety of a dike. Strong relations were found between both these influences (TAUTENHAIN et.al., 1980, 1981, 1982), based on experiments in a wave flume and using an energy conservation concept. However, under natural conditions, an oblique wave approach has to be considered. This paper deals with the influence of wave direction on wave runup on a smooth dike slope in order to provide a basis for calculating the overtopping rates for both regular and irregular waves.

scholarly journals BREAKING AND WASH UP OF SOLITARY WAVES ON A COMPOSITE BEACH

2020 ◽  
pp. 29
Author(s):  
Hajo von Hafen ◽  
Jacob Stolle ◽  
Nils Goseberg ◽  
Ioan Nistor
Keyword(s):  
Solitary Waves ◽  
Horizontal Plane ◽  
Large Scale ◽  
Propagation Path ◽  
Rock Falls ◽  
Damage Potential ◽  
Large Wave ◽  
Beach Slope ◽  
Wave Flume ◽  
Run Up

Hazardous events, such as landslides, rock slides, rock falls or avalanches often generate extreme, impulsive waves when entering water bodies (Fuchs & Hager, 2015). These waves are approximated by solitary waves and researchers investigate their damage potential when inundating built environment. Deepening the understanding of solitary waves running up a uniform beach slope and propagating over a subsequent horizontal plane can help to reduce and mitigate damage and the number of casualties caused by such a hazardous event. So far, few authors addressed this specific setting near-shore (Fuchs & Hager, 2015; Zelt & Raichlen, 1991). In this study, large scale solitary waves propagate about 200 m in in the Large-Wave Flume (GWK, 307 m 5 m 7 m) at the Coastal Research Center in Hannover, Germany then they run up a beach slope and subsequently break, generating a bore which advances onto a subsequent, initially dry, horizontal surface. Unlike previous studies, the generated solitary waves broke close to the edge between the beach slope and the horizontal plane section. The overall aim of this study is to investigate the characteristics of the broken waves' dynamics. In addition, their surge profile and front celerity are compared to those of the non-breaking solitary waves. Subsequently, the differences between the velocity regimes along the bore propagation path are presented and linked to the fundamental physical processes behind.

scholarly journals Interaction between Crustal-Scale Darcy and Hydrofracture Fluid Transport: A Numerical Study

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Tamara de Riese ◽  
Paul D. Bons ◽  
Enrique Gomez-Rivas ◽  
Till Sachau
Keyword(s):  
Fluid Flow ◽  
Numerical Model ◽  
Transport Mechanism ◽  
Large Scale ◽  
Fluid Transport ◽  
Numerical Study ◽  
Ballistic Transport ◽  
Accretionary Prism ◽  
Small Scale ◽  
Porous Flow

Crustal-scale fluid flow can be regarded as a bimodal transport mechanism. At low hydraulic head gradients, fluid flow through rock porosity is slow and can be described as diffusional. Structures such as hydraulic breccias and hydrothermal veins both form when fluid velocities and pressures are high, which can be achieved by localized fluid transport in space and time, via hydrofractures. Hydrofracture propagation and simultaneous fluid flow can be regarded as a “ballistic” transport mechanism, which is activated when transport by diffusion alone is insufficient to release the local fluid overpressure. The activation of a ballistic system locally reduces the driving force, through allowing the escape of fluid. We use a numerical model to investigate the properties of the two transport modes in general and the transition between them in particular. We developed a numerical model in order to study patterns that result from bimodal transport. When hydrofractures are activated due to low permeability relative to fluid flux, many hydrofractures form that do not extend through the whole system. These abundant hydrofractures follow a power-law size distribution. A Hurst factor of ~0.9 indicates that the system self-organizes. The abundant small-scale hydrofractures organize the formation of large-scale hydrofractures that ascend through the whole system and drain fluids in large bursts. As the relative contribution of porous flow increases, escaping fluid bursts become less frequent, but more regular in time and larger in volume. We propose that metamorphic rocks with abundant veins, such as in the Kodiak accretionary prism (Alaska) and Otago schists (New Zealand), represent regions with abundant hydrofractures near the fluid source, while hydrothermal breccias are formed by the large fluid bursts that can ascend the crust to shallower levels.

Runup of solitary waves on a circular Island

1995 ◽  
Vol 302 ◽  
pp. 259-285 ◽  
Author(s):  
Philip L. -F. Liu ◽  
Yong-Sik Cho ◽  
Michael J. Briggs ◽  
Utku Kanoglu ◽  
Costas Emmanuel Synolakis
Keyword(s):  
Numerical Model ◽  
Solitary Waves ◽  
Large Scale ◽  
Wave Equations ◽  
Laboratory Data ◽  
Two Dimensional ◽  
Wave Trapping ◽  
Shallow Water Wave Equations ◽  
Circular Island ◽  
Run Up

This is a study of the interactions of solitary waves climbing up a circular island. A series of large-scale laboratory experiments with waves of different incident height-to-depth ratios and different crest lengths is described. Detailed two-dimensional run-up height measurements and time histories of surface elevations around the island are presented. A numerical model based on the two-dimensional shallow-water wave equations including runup calculations was developed. Numerical model predictions agreed very well with the laboratory data and the model was used to study wave trapping and the effect of slope. Under certain conditions, enhanced runup and wave trapping on the lee side of the island were observed, suggesting a possible explanation for the devastation reported by field surveys in Babi Island off Flores, Indonesia, and in Okushiri Island, Japan.

Experimental and numerical study of CFRP reinforced steel beams

2020 ◽  
pp. 147509022096026
Author(s):  
Minos E Kypriadis ◽  
Elias P Bilalis ◽  
Nicholas G Tsouvalis
Keyword(s):  
Large Scale ◽  
Numerical Study ◽  
Load Capacity ◽  
Steel Structures ◽  
High Strength ◽  
Maximum Load ◽  
Steel Beams ◽  
High Fatigue ◽  
Reinforced Steel ◽  
Large Scale Tests

The use of composite materials patches for the reinforcement of steel structures attracts particular interest. Due to their high strength, light weight, and high fatigue and corrosion resistance, composite patches represent a versatile reinforcement solution. In this paper, the reinforcement of steel beams with CFRP patches is examined. Large scale tests of “H” and “square hollow” cross section steel beams are conducted. The beams are reinforced with CFRP patches, investigating the effect of the thickness and the length of the patch, and the type of the cohesive joint. All reinforced specimens showed increase of their stiffness and their maximum load capacity. Furthermore, advanced finite element models are developed for the simulation of the mechanical behavior of the reinforced steel beams. FE results relate very well to the experimental ones for most of the measured magnitudes, thus verifying the reliability of the developed models in estimating stiffness, yield load and maximum load capacity of the beams.

scholarly journals LARGE SCALE TESTS ON FORESHORE EVOLUTION DURING STORM SEQUENCES AND THE PERFORMANCE OF A NEARLY VERTICAL STRUCTURE

2018 ◽  
pp. 13 ◽  
Author(s):  
Riccardo Briganti ◽  
Rosaria Ester Musumeci ◽  
Jentsje Van der Meer ◽  
Alessandro Romano ◽  
Laura Maria Stancanelli ◽  
...  
Keyword(s):  
Large Scale ◽  
Water Levels ◽  
Beach Sand ◽  
Swash Zone ◽  
The European Union ◽  
Large Wave ◽  
Wave Flume ◽  
Wave Conditions ◽  
Almost All ◽  
Large Scale Tests

This work presents the results of an experimental investigation on the effects of a sequence of storms on wave overtopping at a nearly vertical battered seawall at the back of a sandy foreshore. The experiments were carried out in the Large Wave Flume (GWK) at Leibniz Universität Hannover (Germany), as part of the research project ICODEP (Impact of Changing fOreshore on flood DEfence Performance), within the European Union programme Hydralab+. The layout consisted of a 10/1 battered seawall and a natural sandy foreshore with an initial 1:15 slope. The beach sand had a nominal diameter of 0.30 mm. Three storm sequences were simulated, where each consisted of three individual storms. Each storm was divided into six steps in which the wave conditions and still water level were varied to represent the peak of an actual storm. The six sea states were based on a JONSWAP spectral shape, with wave heights roughly between 0.6 m and 0.8 m. Two still water levels were tested. For the central two steps the level was such that the freeboard was only 0.14 m and almost all waves were overtopping. In the remaining steps low still water levels were employed, leaving a narrow swash zone. Two storm profiles were considered, the first one with a lower level of energy and the second one with a higher one. These were combined in the three different sequences. All the tested wave conditions were designed to be erosive for the beach, with no recovery in between. Each sequence started from a plain beach configuration and the beach was not restored in between storms. The measurements included waves, pressure and forces, sediment concentrations and flow velocity together with overtopping. The profile of the beach was measured after each sea state tested.

Re-Analysis of Run-Up Levels for Slender Monopiles

2019 ◽  
Vol 02 (01n02) ◽  
pp. 1950002
Author(s):  
Karsten Garborg ◽  
Thomas Lykke Andersen ◽  
Jesper Skourup ◽  
Peter Bak Frigaard
Keyword(s):  
Experimental Data ◽  
Nonlinear Waves ◽  
Large Scale ◽  
Bandpass Filter ◽  
Analysis Method ◽  
Post Processing ◽  
Wave Analysis ◽  
Highly Nonlinear ◽  
Run Up ◽  
Large Scale Tests

In the present paper, the experimental data on wave run-up on slender monopiles from recently published small and large scale tests are reanalyzed using different methods for the wave analysis. The hypothesis is that the post processing has an impact on the results, due to depth limited and highly nonlinear waves in many of the tests. Thus, the identified maximum waves by a zero-down crossing analysis are highly influenced by the reflection analysis method as well as by bandpass filtering. The stagnation head theory with the run-up coefficient is adopted and new coefficients are presented. The hypothesis is verified, and the applied bandpass filter is identified as a large contributor to conservatism in previous studies, as the steep, nonlinear waves that produce the highest run-up can be heavily distorted by the bandpass filter.

scholarly journals Numerical Study of Violent Impact Flow Using a CIP-Based Model

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Qiao-ling Ji ◽  
Xi-zeng Zhao ◽  
Sheng Dong
Keyword(s):  
Free Surface ◽  
Numerical Model ◽  
Large Scale ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Small Scale ◽  
Surface Boundary ◽  
Two Phase ◽  
Constrained Interpolation

A two-phase flow model is developed to study violent impact flow problem. The model governed by the Navier-Stokes equations with free surface boundary conditions is solved by a Constrained Interpolation Profile (CIP)-based high-order finite difference method on a fixed Cartesian grid system. The free surface is immersed in the computation domain and expressed by a one-fluid density function. An accurate Volume of Fluid (VOF)-type scheme, the Tangent of Hyperbola for Interface Capturing (THINC), is combined for the free surface treatment. Results of another two free surface capturing methods, the original VOF and CIP, are also presented for comparison. The validity and utility of the numerical model are demonstrated by applying it to two dam-break problems: a small-scale two-dimensional (2D) and three-dimensional (3D) full scale simulations and a large-scale 2D simulation. Main attention is paid to the water elevations and impact pressure, and the numerical results show relatively good agreement with available experimental measurements. It is shown that the present numerical model can give a satisfactory prediction for violent impact flow.

scholarly journals Cyclic Behavior of Hollow Section Beam–Column Moment Connection: Experimental and Numerical Study

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1608
Author(s):  
Eduardo Nuñez ◽  
Nwar Boainy ◽  
Freddy González ◽  
Ronald Torres ◽  
Ricardo Picón ◽  
...  
Keyword(s):  
Numerical Model ◽  
Large Scale ◽  
Numerical Study ◽  
Local Buckling ◽  
Cyclic Behavior ◽  
Steel Buildings ◽  
Moment Connections ◽  
Hollow Section ◽  
Moment Connection ◽  
Ductile Behavior

Steel buildings with tubular columns showed a satisfactory performance during the Honshu (2011) earthquake, unlike steel buildings in the 1994 Northridge and 1995 Kobe earthquakes, where welded moment connections showed damage in their joints. In this research, a lateral joint using a hollow structural section (HSS)-beam and HSS-column subjected to cyclic displacement was performed. Three large-scale specimens were tested and a numerical model was calibrated, reaching a good adjustment. Later, several configurations of beams and columns were evaluated using finite element (FE) models from the numerical model previously calibrated. A flexural resistance higher 0.80 Mp at 0.04 [rad] was obtained for all cases studied. The ductility factor in the 3 specimens was lower than 2.5, therefore a non-ductile behavior was controlled in the connection. This aspect is very important although a 0.8 Mp at 0.04 [rad] was achieved. Finally, the typical welded moment connection can be improved using the bolted moment connection, which allows the concentration of inelastic incursion in the beam compared with the welded solution. However, a non-ductile behavior derived from local buckling in flanges of a tubular beam can affect the seismic performance.

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