Understanding the past, present, and future behavior of our nation's shorelines is vital for sensible coastal management. Localized areas of erosion, termed "erosional hot spots", can shift the shoreline landward threatening coastal infrastructure (Kraus and Galgano, 2001; Stauble and Gravens, 2004; McNinch, 2004). One specific type of erosional hot spot...
The mouth of the Columbia River (MCR) has a longstanding reputation of hazardous navigational conditions. This reputation has been developing since the first ship, the Columbia, traversed through the inlet in 1792. The hazardous conditions are related to the large waves and strong tidal currents that are common in the...
With energy prices rising and increasing concern about the influence of fossil fuels on climate change, wave energy systems are on the verge of commercial implementation. These first generation wave energy converters utilize either pneumatics or hydraulics to convert the mechanical energy of waves into electricity. For the last several...
The experimental setup and data are presented for a laboratory experiment conducted to examine realistic wave forcing on a highway bridge superstructure. The experiments measure wave conditions along with the resulting forces, pressures, and structural response of a 1:5 scale, reinforced concrete model of a typical section of the I-10...
An experiment on solitary wave impact on a vertical cylinder was conducted in the three-dimensional wave basin at the Oregon State University Hinsdale Wave Research Laboratory. The cylinder was designed using mechanic principles and finite element analysis techniques to enable accurate measurement of horizontal force and overturning moment. Video data...
The acoustic signals produced by the Dungeness crab (Cancer
magister) were investigated. The signals were examined for duration times and frequency content. The signals were converted from analog to digital form, and the autocorrelation functions and the power density spectrums were determined.
The signals produced by Dungeness and Japanese red...
This thesis is comprised of two manuscripts based on a laboratory experiment conducted to examine realistic wave forcing on a vertical wall subjected to tsunami loading. The first manuscript examined tsunami force and pressure distributions on a rigid wall that was fronted by a small seawall. Six different seawall heights...
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...
Coastal foredunes protect lives, infrastructure, and ecosystems during severe winter storms. In the U.S. Pacific Northwest (PNW), coastal foredune geomorphology is determined by both physical and ecological mechanisms. Before the 1900's, the native plant Elymus mollis was the dominant dune grass and dune morphology was largely determined by sediment supply...
This thesis presents the details of a large-scale laboratory experiment to study the
turbulence generated by waves breaking on a fixed barred beach. The data set includes
comprehensive measurements of free surface displacement and fluid velocity for one
random and one regular wave case.
Observations of the time-averaged turbulent kinetic...
This thesis is comprised of a manuscript based on a laboratory experiment run in the Tsunami Wave Basin as part of a research project funded by the Network for Earthquake Engineering Simulation called Housesmash. The purpose of the experiment was to better understand the role of the urban environment, represented...
Knowledge of wave conditions in nearshore regions supports the development of
ocean wave energy technology by providing wave climatology for device design
considerations, and power output estimates. By modeling wave transformation
over the continental shelf, wave conditions were predicted in nearshore regions
where potential wave energy conversion sites are located....
In the northwestern Gulf of Mexico there is a need for reliable water level forecasts to facilitate safe commercial navigation, marine construction, and emergency management. Though the low amplitude tides of the region can be predicted with conventional harmonic techniques, frequent strong storms make accurate forecasts of water levels difficult....
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...
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...
Successful prediction of nearshore sediment migration is important in determining the vulnerability of a coastline. During energetic wave climates (storm events) sediment rapidly erodes from beaches and is deposited offshore. In subsequent milder wave conditions, the sediment migrates shoreward, accreting on the beach and helping to protect the coastline. It...
Strong tidal currents experienced at Keystone Harbor, WA, have caused navigational hazards and disrupted ferry service in the area. This thesis presents details of the design, construction and implementation of a large scale physical model of Keystone Harbor used to evaluate the effectiveness of proposed jetty design alternatives to improve...
The rip current field resulting from the transformation of surface gravity waves over offshore submarine canyons is studied. Employing a wave transformation model and a wave-induced circulation model over observed bathymetry we find that rip current circulation cells exist with alongshore spacing of O(1OOm) even though the nearshore bathymetry displayed...
This thesis presents the details of a large-scale laboratory experiment to study the runup velocity on a complex 3D bathymetry. The PIV measurements including the instrumental setup, the recording procedure, and the image processing are presented. Tsunami inundation directly affects the coastal population and is one of the most important...
Anchors resistant to tensile loads are commonly used in civil engineering practice. Anchors in the marine environment are most frequently used for the mooring of vessels. Only recently, with the expansion of the offshore industry, has the need to develop more reliable anchor systems become necessary. Embedded plate anchors are...
Two types of boundary element models are developed for the interaction of waves with trenches. The first type is for a two-dimensional domain in the horizontal plane and employs the linear long wave approximations. It is shown that appropriate selection of pit geometries leads to a significant reduction in wave...
The surf zone exhibits large energetic signals from wave shoaling and subsequent dissipation due to breaking, forcing circulation. The bathymetry responds to the wave and wave-induced circulation with the growth, transport, and destruction of large scale bathymetric features, such as mega ripples and sand bars. There is an obvious fluctuation...
Caissons are frequently used in the coastal environment for
breakwaters, jetties, seawalls, and piers. Because a satisfactory
analytical solution to a typical caisson installation has not been
developed, design of a caisson-style structure typically is either
based on physical model testing, which is expensive, or the
structure is designed as...
The reliability of ocean systems is dependent on organizational factors. It has been shown that low probability / high consequence system failures are overwhelmingly induced by organizational factors. However, no methodology is yet widely accepted for the evaluation of this phenomenon or its accurate quantification. A qualitative complementary approach is...
The purpose of this study was to ascertain the potential erosion
impacts associated with ship movements in confined waters. The flow
associated with a ship passage can be separated accordingly: (1) the
propeller wake, (2) flow about the hull, and (3) associated waves.
Each of these areas has been analyzed...
The overriding goal of this study was to provide first order estimates of dilution and tidal flushing of waste discharges released hypothetically into various Oregon estuaries during critical low flows and tides. Causal relationships between discharged wastes and subsequent estuarine response were studied. Various approaches to determine the assimilative capacity...
Two types of linear random wave simulation methods are investigated;
viz., (1) Deterministic Spectral Amplitude (DSA) and (2) Nondeterministic
Spectral Amplitude (NSA). These linear simulations are extended to
second-order in a perturbation expansion in the frequency domain by
utilizing a Fast Fourier Transform (FFT).
The nonlinear interaction matrix for waves...
Velocity measurements from drifter GPS records are assimilated and used in an ensemble-based inversion technique to extract the river bathymetry. The method is tested on a deep meandering reach and a shallow braided reach of the Kootenai River in Idaho, USA. The Regional Ocean Modeling System (ROMS) is used to...
The eventual deployment of wave energy converters (WECs) on a commercial scale will necessitate the grouping of devices into arrays or "wave farms," in order to minimize overhead costs of mooring, maintenance, installation, and electrical cabling for shoreward power delivery. Closely spaced WECs will interact hydrodynamically through diffracted and radiated...
During 1973 data was collected to analyze the seasonal variations of the tidal dynamics, water quality and sediments of the Alsea
Estuary. A summary of historical information with a list of all
known alterations to the estuary was made. A complete physical
description, including the geographical setting and mixing classification...
The objective of this study is the development and
verification of an analytical solution for an unsteady
flow field partially occupied by a permeable structure.
Flow is induced by a small amplitude incident wave
train and the permeable structure may contain multilayered
anisotropic but homogeneous material. The analytical
solution developed...
Directional wave spectra have been estimated in this study based
upon simultaneous subsurface measurements of current and pressure.
Two previously developed methods, the stochastic and deterministic
approaches, have been reviewed and restudied. It is demonstrated by
means of the Correlation Theorem that the stochastic and deterministic
approaches are, under certain...
By assuming the linear superposition principle to be valid, the
hydrodynamic forces on a horizontal cylinder under waves and current
are examined. In this study, towing a cylinder in waves is used to
simulate a cylinder under waves and current. The experimental
technique is proved valid through theoretical considerations and...
An analytical model is developed to examine the response and
efficiency of a vertical rigid, hinged, floating breakwater. The
boundary value problem describing the flow field yields a well-posed
Sturm-Liouville problem which is solved by separation of variables
for the velocity potentials. The equation of breakwater motion about
the breakwater...
The problem of a fixed rectangular structure of unit width in a
train of simple harmonic normally-incident waves is modeled. The solution
allows for variable (1) length and draft of structure, (2) differing
depths in the three (fore, aft, and beneath the structure) distinct
regions, and (3) wave period. The...
The stochastic and the Fourier theories for sand waves developed
by Lee(11) and Hino(6), respectively, for unidirectional flows are
extended in order to estimate the rate of sediment turnover (RST) under
oscillatory flows in the South Slough estuary, Coos Bay, Oregon. Data
were collected by a mechanical and a sonic...
Hydrodynamic forces on a cylinder oscillating horizontally
underwater with its axis perpendicular to the motion
were measured at the Oregon State University Wave Research
Facility. The cylinder had an outer diameter of 12 inches
and a length of 12 feet. For the data presented herein, the
maximum displacement of the...
An experimental study was conducted to determine the hydrodynamic
forces on smooth and roughened circular cylinders as
influenced by a nearby plane boundary. The ambient flow was perpendicular
to the cylinder and parallel to the boundary. Measurements
were taken in a water channel and a wind tunnel to obtain the...
This report presents the findings of a sediment analysis
program formulated to determine the flushing potential
of various shaped small boat marina basins. Chemical tests
regarding volatile solids, Kjeldahl nitrogen, grease and
oil, and sulfides were performed with the results compared
to established sediment quality criteria. These results
were used...
The purpose of this study was to provide an understanding of the
interrelationships between fresh and salt water Circulation, tidal transport
and flushing patterns in the Chetco River estuary and its boat
basins.
Field work and water quality measurements were conducted at the
entrance of the Chetco River during 1975...
The results of three hydraulic model tests to evaluate the stability
of a placed stone breakwater are presented and discussed. The prototype
breakwater was designed to protect offshore power and port facilities in
60 feet of water and was tested at scale ratios of 1:10, 1:20, and 1:100.
The armor...
Problems associated with quantification of deep water wave kinematics
and dynamics are examined. Summaries of Stokes' theory and Dean's
stream function theory are reported. A computer algorithm is developed
to solve the hydrodynamic characteristics for Stokes' fifth and third
order and linear theories. Tests are initiated to verify the results...
The dynamic response of an offshore structure to measured and simulated
stochastic wave forces is investigated. The theoretical nondeterministic
analysis is performed in the frequency domain for a two-dimensional
model. The ocean wave system is assumed to be a zero mean, stationary,
ergodic Gaussian process described by a one-dimensional wave...
This report describes the hydrodynamic testing and
evaluation of a one-tenth scale model of the FMC Wave
Attenuation Device. The purpose of the test was to quantify
the wave attenuation characteristics and structural loading
induced by a test program of monochromatic incident waves
on the submerged structure. The device was...
An experimental underwater acoustic imaging system has been
designed and built. Operating at 650 KHz, real time acoustic images
are obtainable. Using both geometrical optics and Fourier optics,
the theory of image formation and resolution is presented. Other
factors affecting image quality and system acuity are also discussed.
System components...
Aerial photography has become a valuable method of acquiring
information on estuarine current circulation patterns. The method
provides a comprehensive picture of nearly simultaneous surface
water movements. It represents a significant improvement over
conventional surface float and current meter methods because large
areas may be covered in great detail with...