Boulder transport models have been used to develop a historical record of hydrodynamic events. This is done by evaluating the size, location, and composition of boulders that have been removed from their region of formation. Boulder transport is difficult to predict, even under laboratory conditions.
Experiments were conducted to evaluate...
An understanding of natural coastal hazards is essential for improving resilience of coastal communities. Effective management of coastal hazards relies on prediction tools and mitigation structures that have been designed to handle the dynamic coastal system. This dissertation is a collection of manuscripts that cover a diverse range of fundamental...
The use of data extracted from particle image velocimetry (PIV) along with vector and tensor visualization techniques provides a valuable tool for understanding a complex flow field. By studying a simple geometric structure such as a cylinder under a simple transient waveform, fundamental mechanisms of wake development under solitary wave...
To better understand the extreme local amplification of tsunami, the experimental investigation on counter-propagating solitary wave collisions over a horizontal bottom was conducted using the optical measurement techniques: Particle Image Velocimetry (PIV), and Laser Induced Fluoresce (LIF). Head-on collisions and oblique collisions of equal-amplitude as well as unequal-amplitude waves were...
A series of laboratory experiments were conducted to study the wave field in the inner lagoon excited by ‘long’ incident waves. Three cases were considered: Cases A, B and C presenting incident waves of wavelength with factors of 1, 2 and 2.5 times the width of the reef respectively. The...
Most tsunami studies have been conducted based on the incompressible fluid theory. However water compressibility must be considered for the process of tsunami generation by bottom displacements during submarine earthquakes. During the 2003 Tokachi-Oki earthquake, the ocean-bottom pressure variations were registered by the pressure gauges PG1 and PG2 located right...
Soil instability from tsunami hazards causes substantial damage to coastal infrastructure (e.g., the damage caused by the 2011 Great East Japan Tsunami, or the Heisei Tsunami). Tsunamis are unpredictable, so it is difficult to obtain field-scale measurements. Simulating tsunamis in a laboratory setting is therefore important to further understanding of...
Reflection of an obliquely incident solitary wave at a vertical wall is studied experimentally in the laboratory wave tank. Precision measurements of water-surface variations are achieved with the aid of laser-induced fluorescent (LIF) technique and detailed temporal and spatial features of the
Mach reflection are captured. During the development stage...
Numerical results are presented using a higher-order pseudo-spectral method in order to solve the Zakharov-Craig-Sulem formulation of the Euler model. We study the effects of variable bathymetry on weakly-dispersive, weakly-nonlinear, shallow water waves. Improved predictions on wave amplitude and shoaling behavior are developed by analytical means in the context of...
In recent years, tsunami events have caused great devastation and loss of life around the globe. The coast of Oregon is highly vulnerable to a nearfield tsunami event caused by a Cascadia Subduction Zone earthquake, yet lacks a clear plan for evacuation and disaster mitigation. Vertical evacuation is a proposed...
With the use of a higher-order Euler formulation, we numerically study the reflection of an obliquely incident solitary wave at a vertical wall and compare results with the higher-order Kadomtsev-Petviashvili theory. A maximum amplification of 3.91 is achieved along the wall, nearly realizing the fourfold prediction by Miles (J. Fluid...
Collisions of counter-propagating solitary waves are investigated experimentally.
Precision measurements of water-surface profiles are made with the use of the laser
induced fluorescence (LIF) technique. During the collision, the maximum wave
amplitude exceeds that calculated by the superposition of the incident solitary waves,
and agrees well with both the asymptotic...
Tsunamis have the potential to inflict severe damage and loss of life in coastal communities. Structures known as vertical evacuation buildings provide an alternative evacuation site for communities living in relatively flat, coastal regions with inadequate sources of high ground for evacuation. Design of these structures balances risk and economy,...
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Andre R. Barbosa Harry H. Yeh
Tsunamis have the potential to inflict severe damage and
The 2004 Indian Ocean and 2011 Tohoku tsunami events have shown the destructive power of tsunami inundation to the constructed environment in addition to the tragic loss of life. A comparable event is expected for the Cascadia Subduction Zone (CSZ) which will impact the west coast of North America. Research...
The characterization of bathymetry and its time evolution is very important for both oceanographic science applications, and for societal reasons relating to coastal engineering
and development. Historically, the process of depth surveying has been costly and labor-intensive.
This is especially true in nearshore regions, hence a method that is both...
In the companion paper (Chen & Yeh, J. Fluid Mech., vol. 749, 2014, pp. 577–596), collisions of counter-propagating solitary waves were studied experimentally by analysing the measured water-surface variations. Here we study the flow fields associated with the collisions. With the resolved velocity data obtained in the laboratory, the flow...
The 11 March 2011 East Japan Earthquake and Tsunami caused unprecedented
damage to well-engineered buildings and coastal structures. This report presents some notable
field observations of structural damage based on our surveys conducted along the Sanriku coast
in April and June 2011. Engineered reinforced concrete buildings failed by rotation due...
Impulsive forces on a box-shaped structure due to bore impact are investigated experimentally. Experiments are conducted in the laboratory by generating a Gaussian-shaped wave onto a step before impacting structures of three different cross-shore to long-shore length ratios. The relationship between measurements of the splash-up flow on the structure wall...
Over the last decade the world has seen three major tsunamis strike the coasts of
Indonesia, Samoa, and Chile. These tsunamis have caused significant losses of life and
property on the coastal cities of these and nearby countries. The NEES (Network for
Earthquake Engineering Simulation) Housesmash project was created to...
The near-surface region of a coastal sediment bed is complex and dynamic. At some sites, near-surface sediment deposits are susceptible to extreme events, such as tsunamis or other large overflows, which induce high shear stresses on the sediment bed. The specific properties of sediment beds subjected to such extreme loading...