The main objective of this research study is to incorporate construction worker safety and health into sustainable design and construction practices. This can be fulfilled by the development of an innovative construction worker safety and health planning tool, called Sustainable Construction Safety and Health (SCSH) Rating System that will:
•...
Metal and hydrogen ion acidity and extreme nitrate concentrations typical of
Department of Energy (DOE) legacy waste sites pose formidable challenges to
successful implementation of in situ bio-immobilization. Intermediate-scale (~ 2.5 m),
flow through models of an in situ bio-barrier were constructed to investigate U and Tc
removal from groundwater...
Forest roads produce fine sediment with traffic during wet weather. If the forest road is connected to a stream it can be a source of turbidity and fine sediment that may be detrimental to aquatic organisms especially salmonids.
The goal of this work was to investigate turbid runoff during wet-weather...
More than 65,000 organic chemicals are currently in commercial production with
approximately 1000 added each year. Many chemicals are released into the environment as organic mixtures derived from complex hazardous or solid wastes. Of these, more than 1000 chemicals are of environmental concern because of their production quantities, toxicity, persistence,...
Despite recent efforts to improve site safety, construction still accounts for a disproportionate injury and illness rate. According to the 2007 injury and illness data released by the National Safety Council, the construction industry has a fatality and disabling injury rate that is approximately three times higher than the all-industry...
Many conventionally reinforced concrete deck girder (RCDG) bridges were built in the US during the 1950s, throughout the expansion of the Interstate System. Designs followed the AASHO standard of the time, which permitted higher shear stress in concrete and reduced detailing requirements than permitted by current specifications. Many of these...
Sediment transport in a gravel-bottomed stream located in the Oregon Coast Range was studied to determine the effects of a single
layer of large particles (the armour layer) located at the surface of the bed material. The bed load transport system was studied jointly with suspended sediment transport to understand...
Two hilislope sites in the central Oregon Coast Range were instrumented and monitored for winter precipitation and saturated and unsaturated subsurface conditions. The study sites were near-ridge depressions typically known as headwalls. Based on results of the monitoring, two existing mathematical models
were adapted to predict piezometric levels in headwalls...
This thesis explores the factors limiting the alkene substrate range of the vinyl chloride (VC)-utilizing bacteria, and describes a method for measuring VC transformation in situ. Vinyl fluoride (VF) was evaluated as a surrogate for monitoring aerobic VC-transformation utilizing three isolates, Mycobacterium EE13a, Mycobacterium JS60 and Nocardioides JS614. JS614 grew...
Initially, a small experimental study was undertaken to examine the influence of incline on the frequency of taut cables. The experiments consisted of exciting a short cable at angles of incline from zero to 90 degrees and at various tensions. The results from these experiments shows a small effect due...
Wave breaking in the surf zone is an important forcing
mechanism on the generation of nearshore currents and in the driving
of sediment transport. At the same time, wave breaking can have
significant spatial and temporal variability that needs to be
accounted for in the description of nearshore processes. Remote...
This research focused on anaerobic transformation of trichloroethene (TCE), a
groundwater contaminant. The mixed anaerobic Evanite culture (EV) was studied to determine community behavior and composition responses to different electron donors and chloroethene electron acceptors. The potential toxicity from high concentrations of TCE and its daughter product cis-1,2-dichloroethene (cDCE) was...
This research analyzes the effects of islands on river process and the effects river processes have on island formation. A fluvial island is defined herein as a land mass within a river channel that is separated from the floodplain by water on all sides, exhibits some stability, and remains exposed...
Hydrodynamic models are used as a diagnostic tool to understand the temporal variability of shallow-water processes that are difficult to completely resolve with traditional field measurements. For all simulations, modeled quantities are qualitatively or quantitatively compared with available measurements to gain confidence in conclusions derived from the modeled results. In...
Many conventionally reinforced concrete deck girder bridges (RCDG) and their intermediate supporting bent caps were designed during the Eisenhower interstate era of the 1950’s with the AASHO design equations at the time, which subsequently place higher demand on the concrete. The referenced components may exhibit diagonal cracking due to the...
The Horsetail Creek (HC) bridge is an example of an Oregon bridge that was classified as structurally deficient and was not designed to withstand earthquake (EQ) excitations. A fiber-reinforced polymer (FRP) rehabilitation was performed on the HC bridge to increase flexural and shear capacities for traffic loads. However, a seismic...
Recently, the concept of performance based design has become popular for many types of structures, including port facilities under seismic loading. For the case of pile-supported wharves, the level of performance is generally estimated using the displacement capacity of the structure. Therefore, understanding soil-pile interaction is one of the most...
A new set of data from a large-scale sand bar migration experiment is presented. During this experiment, two sandbars were generated. One of the bar was generated by the action of undertow, and sediment moved offshore. The other bar was generated by the shoreward movement of sediment coming from the...
Due to age, original design that is deficient by modern standards, inadequate maintenance, environmental conditions, and increasing loads, large numbers of bridges in United States and elsewhere are classified as deficient and in need of rehabilitation or replacement. According to a national bridge inventory established by the Federal Highway Administration,...
Non-destructive testing methods and applications have become of increasing interest due to the worldwide aging and deteriorating infrastructure network. In the field of Civil Engineering, bridges and bridge components as well as non-structural elements such as roadway pavements for example, are affected. In particular, the Acoustic Emission (AE) technique offers...
The evaluation of pavement condition is an important part of pavement
management. To evaluate a pavement, a distress survey has been performed mainly by
manual field inspections. Several automatic pavement evaluation systems have been
developed to overcome the drawbacks of field inspections. Automated evaluation
systems, however, imply their own limitations...
This work furthers the understanding of processes occurring in catchments that affect stream nitrate concentrations using two different approaches: a temporally intensive case study of three headwater catchments with varying land use (through storm event monitoring) and a spatially intensive study on the regional scale (through statistical modeling) of 1st-4th...
The rural two-lane highway in the southeastern United States is frequently associated with a disproportionate number of serious and fatal crashes. The major research objectives are to investigate the relations between probabilities of fatal crash type occurrence and potential contributing factors from road geometric design characteristics and roadside, environmental features....
Probability-based reliability methods have placed an increased emphasis on realistic simulation of structural behavior in bridge engineering. Uncertainty is present in every aspect of structural analysis. Aleatory uncertainties in the loading and load-carrying capacities, and epistemic uncertainties in mathematical idealization of bridge systems are the major contributors to uncertain structural...
Different specimen preparation methods such as moist tamping, dry funnel deposition, slurry deposition, dry air pluviation have been reported in the literature to investigate the undrained behavior of silty sands. Similarly, different means have been used to densify the soils prepared with such methods. However, the influence of the densification...
This research focused on the enhanced reductive dechlorination of trichloroethene (TCE) and its surrogate, trichlorofluoroethene (TCFE), using two bioremediation methods in anaerobic conditions. Two anaerobic bioremediation studies were conducted to investigate the effects of microbial communities in the presence of different electron acceptors and donors during anaerobic reductive dechlorination of...
A commercially available, three-dimensional (3-D) finite-element (FE) analysis
program was used to model metal-plate-connected (MPC) joints in wooden trusses.
The model's features included consideration of material properties, teeth-to-grain-to-direction-
of-force orientation, and wood-to-wood contact. Non-linear spring elements,
placed on the wood surface between wood and plate, were used to represent wood-to-teeth...
Fluid-structure interaction (FSI) is an interesting and challenging interdisciplinary area comprised of fields such as engineering- fluids/structures/solids, computational science, and mathematics. FSI has several practical engineering applications such as the design of coastal infrastructure (such as bridges, levees) subjected to harsh environments from natural forces such as tsunamis, storm surges,...
This dissertation presents the results of a research effort conducted to better understand the stress-strain, volume change, shear band formation, and strength characteristics of normally consolidated anisotropic clay under fully three-dimensional stress states. A series of consolidated drained true triaxial tests with a constant mean effective stress and constant Lode...
This study investigated complete reductive dechlorination of chlorinated aliphatic hydrocarbons (CAHs) over a broad range of concentrations. Tetrabutoxysilane (TBOS), as a slow-release anaerobic substrate, was studied for enhanced reductive dechlorination of tetrachioroethylene (PCE) present as a dense non-aqueous liquid (DNAPL). Four different site-mixed cultures were used in the study: Site-300...
Engineers, in practice, are often faced with the challenge of evaluating a fire-damaged structure and developing a rehabilitation and retrofit plan. In order to decide on a rehabilitation and retrofit plan, information on thermal degradation of building materials and connections are vital. A critical knowledge gap exists in terms of...
Pile supported bridges are typically constructed near or in a natural or man-made
slope and are subjected to lateral loading. The current design method for laterally loaded
piles involves the use of Winkler's spring concept with the standard nonlinear p-y curves.
The available p-y curves were developed based on results...
Aerial photography provides a method of analyzing dispersion
of wastes that are discharged into the ocean. This method is more
comprehensive than conventional boat sampling in dispersion studies.
The photographic technique permits waste concentrations to be
measured throughout the plume in one instant; thereby allowing the
diffusion analysis to be...
In this dissertation the interactions between hydrodynamics, sediment suspension and transport, and morphological evolution in the surf zone was investigated with a large-scale laboratory experiment data, CROss-Shore Sediment Transport Experiment (CROSSTEX). The data set included comprehensive measurements of water surface elevation, fluid velocity, sediment concentration, and morphology for irregular waves...
Halogenated organic compounds have had widespread and massive applications in industry, agriculture, and private households, for example, as degreasing solvents, flame retardants and in polymer production. They are released to the environment through both anthropogenic and natural sources. The most common chlorinated solvents present as contaminants include tetrachloroethene (PCE, perchloroethene)...
A numerical model for the simulation of fully-coupled fluid-structure
interaction is developed in this study. In modeling the fluid, the Reynolds
Averaged Navier-Stokes equations are solved for an incompressible viscous
fluid field and a k-ε model is employed for turbulence computations.
Hydrodynamic forces obtained by the integration of the fluid...
Laboratory data of free surface elevations and fluid velocities were
obtained using a laser-Doppler velocimeter for the case of a periodic wave
plunging over an impermeable, steep (1:10) slope with a fixed bottom roughness.
The measurements were conducted over 15 cross-shore locations from the outer
surf zone to the swash...
The cyclic resistance of predominantly fine-grained soils has received considerable attention following ground and foundation failures at sites underlain by silt-rich soils during recent earthquakes. In several cases substantial ground deformation and reduced bearing capacity of silt soils has been attributed to excess pore pressure generation during cyclic loading. These...
Posting advisory speed signs at sharp horizontal curve sites is a practice well established in the United States. The purpose of these signs is to provide the driving public with a safe speed to negotiate such curves; however, the link between these signs and safety has not yet been clearly...
A theoretical argument is presented to suggest that engineering curriculum be
designed to develop social capital. Additionally, the value of social capital in the
retention of students in the College of Engineering, and the development, role, and value
of social capital in an electrical engineering laboratory is evaluated. Data collected...
The Asphalt Pavement Analyzer (APA) device was used to characterize the impact of various mix factors on the development of permanent deformation in dense-graded mixes given a standard compactive effort. Factors included two aggregate sizes, three VMA levels, two fines contents, three binder contents and four binder types. All specimens...
Complex oscillations including chaotic motions have been identified in off-shore and submerged mooring systems characterized by nonlinear fluid-structure interactions and restoring forces. In this paper, a means of controlling these nonlinear oscillations is addressed. When applied, the controller is able to drive the system to periodic oscillations of arbitrary periodicity....
Large numbers of 1950's vintage conventionally reinforced concrete (CRC) bridges remain in-service in the national bridge inventory. Many of these bridges are lightly reinforced for shear. Evaluation of these bridges to prevent unnecessary and costly repairs requires refined analytical techniques. This dissertation presents finite element (FE) modeling and comparisons of...
During the past several decades, earthquakes have caused extensive damage to
buildings, including wood-frame, single-family dwellings, in the United States. In
order to mitigate future losses, existing buildings in earthquake prone areas should be
evaluated for their seismic safety. This is also an important issue for buildings in
Oregon due...
A considerable amount of research has focused on load-sharing and system effects in repetitive-member wood floor systems subject to transverse loading. However, relatively few studies have been conducted to investigate load-sharing and system effects in repetitive-member wall systems which may be subject to combined transverse and gravity (vertical) loading, and...
The fractal dimension of measured ocean wave profiles is found to be in the range of 1.5-1.8. This non-integer dimension indicates the fractal nature of the waves. Standard formulations to analyze waves are based on a differential approach. Since fractals are non-differentiable, this formulation fails for waves with fractal characteristics....
This dissertation presents the results of a research effort conducted to better understand the seismic performance and analysis of pile-supported wharves. Given the limited number of well-documented field case histories, the seismic performance of pile-supported wharves has been poorly quantified, and the analysis methods commonly employed in engineering practice have...
Performance-based design has gained interest in recent years among structural designers and researchers. Performance-based design includes selection of appropriate building sites, structural systems and configurations, as well as analytical procedures used in the design process, to confirm that the structure has adequate strength, stiffness and energy dissipation capacity to respond...
Two interesting challenges have been created in the traditional transportation planning process through recent adoption of more interactive roles by Federal, State and local transportation agencies and of those representing the communities being impacted by proposed transportation projects. First, the decision-making groups that formerly included solely transportation and related professionals...
The aerobic transformation of TCE and cis-DCE by a tetrabutoxysilane-grown microorganism (Vancheeswaran et al., 1999) led to the investigation of novel substrates, including benzyl alcohol, for promoting cometabolism. The culture grew on carboxylic compounds and alcohols, but did not grow on formate, methanol, methane, propane, butane, ethylene, benzene, toluene, or...
On August 31, 1992, Quality Printing Circuits, a circuit board manufacturing plant in Phoenix, Arizona, burned to the ground. The fire lasted approximately eight hours, creating a thick, black smoke that blew into the surrounding community. Emergency evacuation was erratic and since no air samples were taken during the fire,...
Laboratory and modeling studies were performed with a mixed-anaerobic-culture obtained from the Evanite site in Corvallis, Oregon. The culture completely transforms trichloroethene (TCE) to cis-dichloroethene (c-DCE), vinyl chloride (VC), and finally to ethene. Acetylene inhibition studies were used to examine the culture's microbial activities. Kinetic studies determined the half-saturated constant...
The present research investigates nonlinear barge motions through analyses of coupled multi-degree-of-freedom (MDOF) deterministic and stochastic models. Roll-Heave-Sway and other lower-ordered models are developed to predict the nonlinear motions and analyze the stability of a class of ship-to-shore cargo barges. The governing equations of motion contain coupled rigid body Roll-Heave-Sway...
This study investigated the use of radon-222 as an in situ partitioning tracer for quantifying nonaqueous phase liquid (NAPL) saturations in the subsurface. Laboratory physical aquifer models (PAMs), field experiments, and numerical simulations were used to investigate radon partitioning in static (no-flow) experiments and in single-well, 'push-pull' tests conducted in...
A one-dimensional, implicit, finite-difference model is
developed, calibrated and verified for three estuaries along
the central Oregon coast. The model is used to generate controlled
data for a large number of hypothetical estuaries.
Two non-dimensional coefficients, K[subscript F], and. K[subscript I], are developed
incorporating physical characteristics of the estuary which...
Mycobacterium vaccae JOB5 and Graphium sp. were studied to evaluate their ability to cometabolize methyl tert-butyl ether (MTBE) and its metabolites after growth on two different alkanes, propane and iso-pentane. Both cultures were capable of cometabolizing MTBE and the metabolites, tert-butyl formate (TBF) and tert-butyl alcohol (TBA). MTBE, TBF, and...
The mixed metal compound, Chromated Copper Arsenate, or CCA, has been widely used as a wood preservative. The metal ions in CCA, CrO²⁻₄, Cu²⁺, and AsO³⁻₄, have been found in contaminated surface and subsurface soils and groundwater nearby some wood preservative facilities and nearby wood structures. Iron oxides are a...
This study consists of three parts: 1) Part A: Limiting Height Evaluation for
Composite Wall Tests, 2) Part B: Mid-Span Deflection Evaluation for Composite Wall
Tests, and 3) Part C: Nominal Axial Strength Evaluation for Wall-Braced Wall Stud
Columns.
The purpose of Part A is to develop experimentally-based limiting heights...
The addition of exogenously supplied hydrogen stimulates PCP reductive
dechlorination and increases bacterial growth. While research focuses mainly on
pure cultures, few exist capable of aryl reductive dechlorination, and few markers
exist to identify reductively dechlorinating bacteria within mixed cultures.
Furthermore, most active bioremediation projects stimulate mixed cultures of native...
Recent experience demonstrates that waterfront structures are vulnerable to
earthquake damage. The poor seismic performance of these facilities has been
primarily due to liquefaction of backfill and/or foundation soils and the lack of
seismic design standards for waterfront structures. The seismic performance of
waterfront structures is a key issue in...
A pilot scale demonstration of a biological permeable barrier was conducted in a pentachlorophenol-contaminated aquifer at a wood preserving facility. A permeable reactor was constructed to fit within a
large diameter well. Arranged in series, a cylindrical reactor 24" x 36" (0.61 x 0.91m) (diameter x height)
was partitioned to...
The Wiggins-Holmes extension of the generalized
Melnikov method (GMM) is applied to weakly damped
parametrically excited cross waves with surface tension in
a long rectangular wave channel in order to determine if
these cross waves are chaotic. The Lagrangian density
function for surface waves with surface tension is
simplified by...
Response behavior of a nonlinear structural system subject to environmental loadings
is investigated in this study. The system contains a nonlinear restoring force due to large
geometric displacement. The external excitation is modeled as a narrowband stochastic
process possessing dynamic characteristics of typical environmental loadings.
A semi-analytical method is developed...
Base isolation is an alternative seismic design strategy in which the primary structures
and their internal components are uncoupled from the potentially damaging horizontal
components of an earthquake by base isolators which attenuate the transmission of
horizontal acceleration into the system. Rotating machines are among the key internal
components of...
Cometabolic biodegradation processes are potentially useful for the
bioremediation of hazardous waste sites. In this study the potential application of phenol-oxidizing
and nitrifying bacteria as "priming biocatalysts" was examined in the
degradation of polycyclic aromatic hydrocarbons (PAHs), aryl ethers, and aromatic
ethers. We observed that a phenol-oxidizing Pseudomonas strain cometabolically...
Environmental factors and physical properties of latex modified concrete (LMC)
are hypothesized to contribute to early age cracking in bridge deck overlays. Cracking
permits the ingress of moisture and aggressive solutions into the substrate and may
contribute to other subsequent distresses. Understanding the material properties and
mechanisms involved is necessary...
The composite FRP rebars research at Oregon State University was initiated in
1993 principally to develop a non-metallic hollow reinforcement. It was recognized that
the tensile properties of such reinforcement are unquestionably superior to steel, but its
performance in concrete could be problematic. The bond between FRP rebars and
concrete...
This thesis presents an examination of the nearshore wave bottom boundary layer
under conditions of significant sediment response. Using both field observations and
simple models, the response of the bottom boundary layer to random waves is shown to
have a complex behavior. First, the linearized wave bottom boundary layer governing...
Time-domain models were developed to predict the response of a tethered buoy
subject to hydrodynamic loadings. A coupled analysis of the interaction of a buoy and
its mooring is included and three-dimensional response is assumed. External loadings
include hydrodynamic forces, tethers tensions, wind loadings and the weight of both
cable...
The dissertation uses state-of-the-art structural engineering theories, in parallel with the modern and still-developing control theory of electrical engineering to mitigate the vibratory responses of a double-stayed bridge subjected to strong earthquake ground motions.
First, a nonlinear finite element model of the double-stayed bridge subjected to non-uniform (multi-support) earthquake excitations...
Cometabolic biodegradation processes, important for bioremediation of hazardous waste sites, are not well understood and have not been modeled thoroughly. Toxic effects and bacterial responses to toxicity may change intracellular enzyme levels, rendering traditional enzyme kinetics models inappropriate. This document presents a novel cometabolic enzyme kinetics model that incorporates enzyme...
The (nonlinear) response behavior of a piecewise-linear system is investigated under
both deterministic and stochastic excitations in this study. A semi-analytical procedure is
developed to predict the system behavior by evaluating the joint probability density functions
of the Fokker-Planck equations of the stochastic piecewise-linear system under random
excitations via a...
A technique is developed and tested to analyze the interaction of flowing water,
bed topography, and bedload sediment transport in meandering channels where gravel
bars are removed. The method relates the local velocity distribution, bed shear stress and
sediment transport conditions to the local bed configuration in river bends before...
The incipient motion of sediment particles in gravel-bed
rivers is a very important process. It represents the
difference between bed stability and bed mobility. A field
study was conducted in Oak Creek, Oregon to investigate
incipient motion of individual particles in gravel-bed
streams. Investigation was also made of the incipient...
In 1987, Congress authorized a 5 year $150 million dollar research program called
the Strategic Highway Research Program (SHRP). SHRP was divided into four major
areas, including the asphalt research program. The asphalt research program was divided
into six major research contracts, one such contract, SHRP-003A was called Performance
Related...
Asphalt concrete pavement is subjected to several damaging actions from traffic
loads, water (from precipitation and/or groundwater sources), and temperature. The
durability of the asphalt-aggregate mixture, its ability to withstand these damaging
actions for long periods, is a very important engineering property. While the durability
of the asphalt-aggregates mixture depends...
Stochastic analysis procedures have been recently applied to analyze nonlinear
dynamical systems. In this study, nonlinear responses, stochastic and/or chaotic, are
examined and interpreted from a probabilistic perspective. A multi-point-moored
ocean structural system under regular and irregular wave excitations is analytically
examined via a generalized stochastic Melnikov function and Markov...
The Melnikov method is applied to a model of parametrically generated cross-waves in a long rectangular channel in order to determine if these cross-waves are chaotic. A great deal of preparation is involved in order to obtain a suitable form for the application of the Melnikov method. The Lagrangian for...
The Environmental Conditioning System (ECS) was designed to evaluate the
water sensitivity of asphalt concrete mixtures. The ECS subjects asphalt concrete specimens to a series of conditioning cycles including water flow, elevated and/or lowered temperature, and repeated axial loading. The purpose of this research was to: (1) evaluate the ECS...
Low temperature cracking is attributed to tensile stresses induced in an
asphalt concrete pavement that develop when the pavement is subjected to a cold
temperature. Cracking results in poor ride quality and a reduction in service life of
the pavement. Low temperature cracking has been predicted by regression
equations, mechanistic...
The success of civil engineering construction in cold regions often depends on the
assessment of the potential for frost heave. Over the past two decades two models have
been presented to the engineering community to identify the frost heave potential,
namely: (1) the segregation potential (SP), and (2) the discrete...
It has been suggested that projects in the construction industry are subject to risks more than other industries. However, there is often little parity in allocation of risks in the construction industry. Usually, project participants allocate risks by aversion where owners tend to shift risks to the primary contractor, who...
A time-domain model was developed to predict the fluid/structure
interaction of a three-dimensional deformable body in a fluid domain subject to
long-crested finite amplitude waves. These nonlinear waves induce transient
motion in the body. In turn, the interaction of the body with the waves modifies
the wave field, causing additional...
Statistically-based estimation techniques are presented
in this study. These techniques incorporate structural test
data to improve finite element models used for dynamic
analysis.
Methods are developed to identify optimum values of the
parameters of finite element models describing structures.
The parameters which may be identified are : element area,
mass...
Testing of asphalt binders and asphalt-aggregate mixtures using dynamic mechanical analysis is becoming popular with improvements in high-speed computers, precision equipment, and computer software. Researchers are trying to describe the behavior of asphalt binders and asphalt-aggregate mixtures in terms of their time- and temperature-dependent linear viscoelastic behavior. The objectives of...
Complex nonlinear and chaotic responses have been recently observed in various
compliant ocean systems. These systems are characterized by a nonlinear mooring
restoring force and a coupled fluid-structure interaction exciting force. A general class
of ocean mooring system models is formulated by incorporating a variable mooring
configuration and the exact...