Tsunami Bore Forces on Walls

2011 ◽  
Author(s):  
I. N. Robertson ◽  
K. Paczkowski ◽  
H. R. Riggs ◽  
A. Mohamed
Keyword(s):  
Phase Ii ◽  
Phase 1 ◽  
Vertical Wall ◽  
Lateral Loads ◽  
Flat Bottom ◽  
Large Wave ◽  
Wave Flume ◽  
Pressure Distributions ◽  
Wave Basin ◽  
Maximum Impact Force

A series of experiments have been carried out at Oregon State University to quantify tsunami bore forces on structures. Phase 1 of the tests was carried out in the Tsunami Wave Basin (TWB), while Phase II of the tests were carried out in the Large Wave Flume (LWF) at approximately twice the scale of the Phase I tests. These latter tests included ‘offshore’ solitary waves, with heights up to 1.3 m, that traveled over a flat bottom, up a sloping beach and breaking onto a flat ‘fringing reef’. Standing water depths on the reef varied from 0.05 m to 0.3 m. Resulting bores on the reef measured up to approximately 0.8 m. After propagating along the reef, the bores struck a vertical wall. The resulting forces and pressures on the wall were measured. The test setup for the Phase II tests in the LWF is described and the experimental results are reported. The results include forces and pressure distributions. Results show that the bores propagated with a Froude number of approximately 2, and that the forces follow Froude scaling. Finally, a design formula for the maximum impact force is given. The formula is shown to be an improvement over existing formulas found in the literature. The lateral forces are shown to be quite significant compared to traditional lateral loads on vertical wall elements.

Experimental Investigation of Tsunami Bore Forces on Vertical Walls

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
I. N. Robertson ◽  
K. Paczkowski ◽  
H. R. Riggs ◽  
A. Mohamed
Keyword(s):  
Vertical Wall ◽  
State University ◽  
Flat Bottom ◽  
Large Wave ◽  
Wave Flume ◽  
Pressure Distributions ◽  
Vertical Walls ◽  
Series Of Experiments ◽  
Maximum Impact Force ◽  
Sloping Beach

A series of experiments have been carried out in the large wave flume (LWF) at Oregon State University to quantify tsunami bore forces on structures. These tests included “offshore” solitary waves, with heights up to 1.3 m, that traveled over a flat bottom, up a sloping beach, and breaking onto a flat reef. Standing water depths on the reef varied from 0.05 m to 0.3 m. Resulting bores on the reef measured up to approximately 0.8 m. After propagating along the reef, the bores struck a vertical wall. The resulting forces and pressures on the wall were measured. The test setup in the LWF is described, and the experimental results are reported. The results include forces and pressure distributions. Results show that the bores propagated with a Froude number of approximately 2 and that the forces follow Froude scaling. Finally, a design formula for the maximum impact force is given. The formula is shown to be an improvement over existing formulas found in the literature.

Reynolds Averaged Navier-Stokes Computational Solution for Experimentally Generated High Velocity Bore Impact on Vertical Walls

2014 ◽  
Author(s):  
K. W. Paczkowski ◽  
H. R. Riggs ◽  
I. N. Robertson ◽  
M. H. Kobayashi
Keyword(s):  
High Velocity ◽  
Vertical Wall ◽  
Experimental Tests ◽  
Navier Stokes ◽  
Computational Domain ◽  
Flat Bottom ◽  
Large Wave ◽  
Wave Flume ◽  
Constant Height ◽  
Wave Research

A set of computational model tests was carried out to simulate high velocity bore impact on a vertical wall. The results were compared to a series of experimental tests conducted at the O.H. Hinsdale Wave Research Laboratory, large wave flume (LWF) at Oregon State University (OSU) [1]. Experimental tests included scaled tsunami experimental bores that traveled over a flat bottom [2]. The experimental bores were generated by solitary waves propagating over a sloping beach and breaking onto a flat reef [3]. After traveling through the reef portion, the generated bore impacted a vertical wall. In the experiments the resulting forces and pressures on the wall were measured. The aim of the study was to computationally regenerate the experimental bore flow and its impact on the vertical wall. Two computational domain setups were tested: 1) a dam break [3–8,10–16] and 2) a new approach, in which constant height and velocity water inflow was defined at the inlet to the domain. The two numerical approaches were compared to the LWF experimental data [3].

scholarly journals LOADING OF VERTICAL WALLS BY OVERTOPPING BORES USING PRESSURE AND FORCE SENSORS - A LARGE SCALE MODEL STUDY

2012 ◽  
Vol 1 (33) ◽  
pp. 44 ◽  
Author(s):  
Karunya Ramachandran ◽  
Rebeca Roldan Genzalez ◽  
Hocine Oumeraci ◽  
Stefan Schimmels ◽  
Matthias Kudella ◽  
...  
Keyword(s):  
Large Scale ◽  
Vertical Wall ◽  
Pressure Sensors ◽  
Scale Model ◽  
Force Sensors ◽  
Research Project ◽  
Joint Research ◽  
Large Wave ◽  
Wave Flume ◽  
Joint Research Project

This study is based on the data obtained from tests carried out in the Large Wave Flume (Grosser Wellenkanal (GWK)) in Hannover in the frame of a joint research project of Ghent University (Belgium) and Forschungszentrum Küste (FZK, Germany). The goal of the research project is to determine the wave induced loads on vertical storm walls located at the end of overtopped dike, which are designed to protect coastal cities from overtopping and floods. The loads resulting from waves overtopping the dike and impacting the vertical wall as a bore are measured by means of both force and pressure sensors. This paper describes the results of pressure and force records at the vertical wall, including a comparative analysis of the overall forces obtained by pressure integration and force sensors for two different wall setups: Fully blocked wall and partially blocked wall.

scholarly journals FULL SCALE IMPACT TESTS OF AN OVERTOPPING BORE ON A VERTICAL WALL IN THE LARGE WAVE FLUME (GWK) IN HANNOVER

2012 ◽  
Vol 1 (33) ◽  
pp. 62 ◽  
Author(s):  
Julien De Rouck ◽  
Koen Van Doorslaer ◽  
Tom Versluys ◽  
Karunya Ramachandran ◽  
Stefan Schimmels ◽  
...  
Keyword(s):  
Return Period ◽  
Structural Design ◽  
Vertical Wall ◽  
Full Scale ◽  
Impact Loads ◽  
Flow Depth ◽  
Large Wave ◽  
Wave Flume ◽  
Hydraulic Process ◽  
The Impact

To meet up with the requirements of the Flemish Government, the Belgian coastline needs a protection to a storm with a return period of 1000 years. At well-chosen locations, storm walls will be built, and for the structural design of these walls the impact loadings need to be known. Tests have been carried out at full scale in the Grosser Wellen Kanal, to determine the impact loads by overtopping bores. Wave overtopping over the crest of the dike occurs, and the overtopping bore progresses along the horizontal crest of the dike before impacting the storm wall. It is of major importance that such a wall can withstand the impacts. This paper describes the hydraulic process on the crest of the dike, expressed with parameters such as flow depth and flow velocity, and links them to the impact measured on the storm wall. Both pressures and forces are measured, and compared to each other.

Green Water on a Fixed Model in a Large Wave Basin: Flow Velocity, Void Fraction, and Impact Pressure Distributions

2017 ◽  
Author(s):  
Wei-Liang Chuang ◽  
Kuang-An Chang ◽  
Richard Mercier
Keyword(s):  
Flow Velocity ◽  
Void Fraction ◽  
Vertical Wall ◽  
Pressure Sensors ◽  
Impact Pressure ◽  
Green Water ◽  
Breaking Wave ◽  
Large Wave ◽  
Wave Basin ◽  
The Impact

Green water impact due to extreme waves impinging on a fixed, rectangular shaped model structure was investigated experimentally. The experiment was carried out in the large wave basin of the Offshore Technology Research Center at Texas A&M University. In the study, two wave conditions were considered: a plunging breaking wave impinging on the frontal vertical wall (referred as wall impingement) and a breaking wave directly impinging on the deck surface (referred as deck impingement). The aerated flow velocity was measured by employing the bubble image velocimetry (BIV) technique with high speed cameras. The pressure distribution on the deck surface was measured by four differential pressure sensors. The fiber optic reflectometer (FOR) technique was employed to measure the void fraction in front of each pressure sensor end face. The flow velocity, void fraction, and impact pressure, were synchronized and simultaneously measured. Comparisons between an earlier study by Ryu et al. (2007) and the present study were performed to examine the scale effect. Results between Song et al. (2015) and the present results were also compared to investigate the influence of structure geometry on green water flow and impact pressure. To examine the role of air bubbles during the impact, the velocity, pressure, and void fraction were correlated. Correlation between the peak pressure and the aeration level shows a negative trend before the wave impingement but a positive linear relationship after the impingement.

scholarly journals Large-Scale Laboratory Experiments on Mussel Dropper Lines in Ocean Surface Waves

2020 ◽  
Vol 9 (1) ◽  
pp. 29
Author(s):  
Rebekka Gieschen ◽  
Christian Schwartpaul ◽  
Jannis Landmann ◽  
Lukas Fröhling ◽  
Arndt Hildebrandt ◽  
...  
Keyword(s):  
Large Scale ◽  
Laboratory Experiments ◽  
Blue Mussel ◽  
Farming Systems ◽  
Quality Parameter ◽  
Large Wave ◽  
Marine Aquaculture ◽  
Ocean Surface Waves ◽  
Wave Flume ◽  
Waves And Currents

The rapid growth of marine aquaculture around the world accentuates issues of sustainability and environmental impacts of large-scale farming systems. One potential mitigation strategy is to relocate to more energetic offshore locations. However, research regarding the forces which waves and currents impose on aquaculture structures in such conditions is still scarce. The present study aimed at extending the knowledge related to live blue mussels (Mytilus edulis), cultivated on dropper lines, by unique, large-scale laboratory experiments in the Large Wave Flume of the Coastal Research Center in Hannover, Germany. Nine-months-old live dropper lines and a surrogate of 2.0 m length each are exposed to regular waves with wave heights between 0.2 and 1.0 m and periods between 1.5 and 8.0 s. Force time histories are recorded to investigate the inertia and drag characteristics of live mussel and surrogate dropper lines. The surrogate dropper line was developed from 3D scans of blue mussel dropper lines, using the surface descriptor Abbott–Firestone Curve as quality parameter. Pull-off tests of individual mussels are conducted that reveal maximum attachment strength ranges of 0.48 to 10.55 N for mussels that had medium 3.04 cm length, 1.60 cm height and 1.25 cm width. Mean drag coefficients of CD = 3.9 were found for live blue mussel lines and CD = 3.4 for the surrogate model, for conditions of Keulegan–Carpenter number (KC) 10 to 380, using regular wave tests.

scholarly journals EXPERIMENTS ON BEACH PROFILE CHANGE WITH A LARGE WAVE FLUME

1982 ◽  
Vol 1 (18) ◽  
pp. 85 ◽  
Author(s):  
Ryoichi Kajima ◽  
Takao Shimizu ◽  
Kohki Maruyama ◽  
Shozo Saito
Keyword(s):  
Simple Model ◽  
Transport Rate ◽  
Sand Transport ◽  
Two Dimensional ◽  
Beach Profile ◽  
Large Wave ◽  
Wave Flume ◽  
Grain Sizes ◽  
Profile Changes ◽  
Profile Change

Two-dimensional beach profile changes were investigated with a newly constructed prototype-scale wave flume. The flume is 205 m long, 3.4 m wide and 6 m deep. Sand of two grain sizes was used in the experiments. Analysis of the results was made through use of the parameter C, introduced by Sunamura and Horikawa (1974) to classify beaches as either erosional and accretionary. Beach profile changes obtained in the flume were similar to those in the prototype (field). Net sand transport rate distributions were classified into five types, two of which do not seem to have been observed in laboratory (smallscale) experiments. A simple model describing the five types was developed for evaluating two-dimensional beach profile changes.

Sign in / Sign up

Export Citation Format

Share Document