This dissertation has focused on the charateristics of bubbles generated by breaking waves and the feedback of wave-current interaction on the forcing mechanism of low frequency wave especially basin seiching wave. For the first study, Optical image capture observations of breaking waves in a laboratory surf zone are presented. The...
The U.S. Pacific Northwest is home to one of the most extreme wave climates in the world with waves of 10 m in height arriving to the coast approximately each year. With an average water temperature of 12℃, the beaches in the region are too cold to go on a...
This dissertation provides a comparison of statistical and econometric frameworks, using a previously unused freight data source, to study crash frequency by crash type and heavy-vehicle hard braking in Oregon. Hard braking can serve as a proxy for several factors, one of which is safety. Therefore, with the hard braking...
Deep foundations are necessary for the construction of many structures, such as bridges and buildings, located in areas unsuitable for shallow foundations. Owing to the inherent variability of soil and the complex changes that occur in the soil adjacent to deep foundations as they are installed, the ability to accurately...
The safety of coastal infrastructure has been a concern after the Indian Ocean Tsunami in 2004 and the Great East Japan Tsunami in 2011. The western coast of the United States is also exposed to tsunami hazards due to the Cascadia subduction zone. Therefore, it is critical to design coastal...
This dissertation examines tsunami and hurricane wave loads on bridge superstructures. Tsunamis have caused significant damage to coastal communities in recent years. For example, the 2011 Great East Japan Earthquake and resulting Tohoku Tsunami destroyed infrastructure along the east coast of Japan including bridge superstructures. Recent hurricanes have also caused...
While sophisticated plans have been adopted nationally and globally to increase bicycling’s share of daily commutes, safety concerns have negatively impacted targeted bicycling growth. Specifically, truck traffic plays a pivotal role in bicyclists’ perceptions of safety and comfort, because of the severe consequences of bicycle-truck collisions. Several types of engineering...
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...
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...
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...
Coastal hazards are the result of numerous physical processes cumulatively causing water levels to flood and erode the land. The waves, storm surges, tides, and run-off contributing to elevated water levels are each the product of chaotic and random weather patterns. These stochastic weather patterns dissipate energy in Earth's climate...
Small unmanned aircraft systems (UAS) carrying consumer-grade nonmetric cameras are increasingly utilized to generate high-resolution 3D geospatial data. Low cost, ease of operation, widespread availability and low altitude maneuvering capabilities of UAS, as well as the rapid development of technology and methods, make UAS-based photogrammetry applicable to many civil engineering...
In the field of civil infrastructure, bridge desks are typically constructed using high performance concrete (HPC). Concrete bridge decks demand qualities such as low permeability, high abrasion resistance, superior durability, and long design life. Over decades of field and laboratory experience, many HPC bridge decks have been found to be...
Discrete columns, such as stone and soil-cement columns, are often used to improve the liquefaction resistance of loose sandy ground. In particular, stone columns are considered to increase resistance potential by densification, drainage, and reinforcement mechanisms. For silty soil, the shear stress reduction resulting from the reinforcing effect of stiffer...
There are many aging bridges in service in the US and around the world that were not constructed to modern seismic design codes and standards. As a result, they are expected to perform poorly during intense earthquake ground shaking. Older reinforced concrete (RC) bridges, in particular, are often supported on...
A significant number of Unreinforced Masonry (URM) buildings exist in the Pacific Northwest region of the United States of America that is a region of high seismicity, which could be subjected to both crustal and subduction zone earthquakes. The catastrophic and brittle failures associated with URM buildings in the past...
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...
Traffic signal countdown timers (TSCT) are innovative, practical and cost effective technologies with the potential to improve efficiency and safety at signalized intersections. The purpose of these devices is to assist motorists in decision making at signalized intersections with real time signal change information. While successful implementation of these devices...
The capabilities of modern three-dimensional (3D) capture technology such as laser scanning and image-based 3D reconstruction are well suited to enhance the practice and research of civil engineering. However, given the often-overwhelming focus placed on the incredible capabilities of these tools and techniques, it is important to investigate the limitations...
A Right-hook (RH) crash is a common type of bicycle-motor vehicle crash that occurs between a right-turning vehicle and through-moving bicycle at an intersection. At signalized intersections, RH crashes can occur at the onset of the green or during the latter portion of the green phase. In spite of the...
Significant amounts of uncertainty owing to both modeling decisions and inherent randomness are present in simulating the material and geometric nonlinear response of structural systems to extreme loading. Computing the sensitivity of structural response with respect to model parameters indicates which parameters have the largest affect on the response, which...
The advancement of the cutting-edge technologies of advanced driver assistance systems (ADAS) hold promises to reshape the future of the transportation system. The concept of connected (CV) and connected automated vehicles (CAV) technologies are live examples of the future transportation. Vehicle communication technology is expected to impact conventional traffic conditions....
The construction industry is a key contributor to the Gross Domestic Product (GDP) of many countries around the world and is valued at more than $10 trillion globally. Schedule, cost and quality are the main performance measures of construction projects. The primary goal for project stakeholders in the construction industry...
Damage estimates to the built environment from tsunamis are important for disaster mitigation, including planning emergency response and recovery. This dissertation evaluates the damage states of buildings in a small urban coastal city, Seaside, Oregon, from tsunami hazards generated by a Cascadia Subduction Zone (CSZ) event. This study is separated...
Catastrophic earthquake and tsunami events that resulted in significant loss of life and property over the past two decades have raised the global awareness regarding the need to understand the response of communities and their built environment to multi-hazard extreme events. In recognition to this impending threat to the coastal...
Ground failures, in particular landsliding, liquefaction and lateral spreading can be triggered by seismic sources. The frequency, magnitude, and impact of these ground failures are highly dependent on the topography and geology of the site including its slope, depositional environment, and geotechnical properties as well as the proximity of the...
Tsunami loading can cause sediment instability, which can compromise the structural integrity of coastal buildings and infrastructure. To understand the process by which a tsunami can cause sediment instability, it is necessary to understand how the pore water pressure in the soil changes during tsunami loading. Tsunami run-up causes the...
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...
Former industrial or commercial sites that have been left unused are typically referred to as brownfield sites, or simply, brownfields. Many communities have such properties that are abandoned, idle or underused. Despite public efforts to facilitate brownfields revitalization projects, the rate of remediation remains unexpectedly slow. Efforts to resolve this...
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...
Modern geospatial data are frequently represented in some type of three-dimensional (3D) coordinate system, for example geodetic latitude, longitude, and ellipsoid height (φ, λ, h) derived from Global Navigation Satellite Systems (GNSS). But for engineering and surveying work, φ, λ, h coordinates are usually converted to a topocentric system consisting...
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...
Anchoring systems are used to hold floating offshore devices (e.g., energy devices, oil platforms) to keep them on their stations. Anchors are embedded into the seabed soils. In some cases, the interface shear between anchor and seabed soils together with anchor self-weight provide the holding capacity of the anchoring systems....
This dissertation studies the coupled fluid-structure interaction (FSI) of a wave energy converter (WEC) and evaluates the design of a WEC mooring system. The research is conducted in support of conceptual development, field test and performance evaluation of WECs as part of the mission of the Northwest National Marine Renewable...
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 challenge for municipal authorities of growing urban areas is to provide larger and faster transportation and utility networks that are safe and resilient to significant disruptions after an earthquake event and other disasters. Urban regions, like the San Francisco Bay or the Los Angeles area, are situated in seismically...
A sewer geyser is a series of ejecting air-water mixture eruptions through vertical shafts of drainage systems. In field observed geyser incidents, manhole covers were blown into the air and they were followed by ejecting air-water mixture eruptions that lasted for several seconds at a time. Trapped air in sewer...
Transportation systems are facing safety and operational challenges with a cost of billions of dollars annually in lost production time and wasted fuel. Infrastructure expansion, previously held as a panacea to most transportation challenges has lost its appeal due to financial, land-use and environmental constraints. Interest is surging in intelligent...
Cross-Laminated Timber (CLT) is one of the latest engineered wood products to show promising structural features for a variety of structural purposes including resisting lateral loads. For CLT to be widely adopted, its modal behavior needs to be fully evaluated through experimental and numerical methods. It is important to the...
Optimization of reservoir operation is involves various competing objectives for a scarce resource (water). To find the optimal operation of reservoirs, it is essential to consider multiple objectives simultaneously. There are various sources of uncertainty associated with the reservoir operation problem that should be considered as well.
The overarching goal...
Over the past two decades, the Lean Construction academic and practicing engineering community has used lean practices and tools to help improve the performance of the Architecture, Engineering, and Construction (AEC) industry. Lean practices have led to improved competitiveness of construction companies that have adopted them, by focusing on ways...
Recent statistics regarding large truck crashes reveal that fatality rates of large trucks per 100 million vehicle miles traveled (VMT) and fatality rates per 1,000 registered vehicles are higher than those for passenger vehicles. These statistics underscore the need for greater efforts by safety professionals to help mitigate the impacts...
Despite numerous techniques for measuring and estimating water depth, bathymetry in the nearshore zone is notoriously difficult to map. Dangerous sea states, noisy environmental conditions, and expensive survey operations, particularly in remote areas, contribute to the difficulties of obtaining data along the coast. Global datasets, derived mainly from satellite altimetry...
It is expected that information taught in the context of school will ultimately transfer to workplace settings. To support this transition, educators and researchers advocate for organizing foundational ideas, or concepts, in specific domains of knowing. In the domain of transportation engineering, knowing of concepts, which include "big ideas" such...
Cementitious materials are often characterized through the use of advanced analytical techniques to understand the macro-, micro-, and nano-scale properties, including phase formation during hydration, and subsequent potential deterioration mechanisms which can affect service life. A major limitation with using such analytical techniques to quantify solid phases in cementitious systems...
The corrosion and passivity of iron (and carbon steel) in media with different alkalinity as well as iron depassivation have been studied extensively using electrochemical methods and nano-scale surface characterization studies. The electrochemical techniques provide valuable information about the average electrochemical behavior of relatively large metal surfaces, typically in centimeter-square...
Drilled shaft foundations provide significant geotechnical resistance for support of structures, such as highway bridges, traffic sign, and signal pole structures, and are used widely to meet their structural foundation requirements. The amount of steel reinforcement in drilled shaft foundations has increased over the past several decades to account for...
A construction project is considered to be unique due to the process of delivering a customer-designed product, diverse stakeholders involved, the unique location and timeframe of construction, and specific social, economic, and environmental constraints attached to it. The uniqueness of construction projects brought great challenges to the construction industry professionals...
Degradation of watersheds is a major concern in areas where adverse climate effects and unsustainable use of the natural resources have caused extensive stresses to watershed systems (e.g., increased floods, increased droughts, worsened in-stream water quality) through the years. While considerable efforts are being made to generate technical solutions that...
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...