The use of high strength steel reinforcement has the potential to provide economic and constructability benefits when used in reinforced concrete structures. However, more research is needed to justify and confidently allow its use. Current design provisions limit the nominal yield strength of reinforcing steel bars to 60 ksi (420...
Cross-Laminated Timber (CLT) is a prefabricated building material that is relatively new to the United States and North America. It consists of no less than three layers of graded, dimensional lumber glued in alternating longitudinal and transverse layers to create a panel that can be used for various building applications...
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...
Coastal communities in the U.S. Pacific Northwest (PNW) are rapidly engaging with the idea that hazards and environmental pressures are changing and may be characteristically different in the near future. This has led to a need for scientific knowledge and tools that can help coastal communities prepare and build resilience...
Bio-cementation is a promising method for the liquefiable mitigation of loose saturated sands. In the improvement process a bacterium that can be found naturally in soil deposits is fed urea. The bacterium consumes and breaks down the urea to form ammonium and carbonate. In the presence of calcium, calcium carbonate...
In the presence of strong winds, ocean surface waves dissipate significant amounts of energy by breaking. Here, breaking rates and wave-following turbulent dissipation rate measurements are compared with numerical WAVEWATCH III estimates of bulk energy dissipation. At high winds, the measurements suggest that turbulent dissipation becomes saturated, however the modeled...
3D laser scanning has been used extensively in engineering reconnaissance surveys to capture perishable data in an efficient, reliable, and precise manner. Many insights on damage can be obtained from the data through various methods of post-processing; however, many of these techniques are often labor intensive. This delay reduces the...
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...
Lidar (LIght Detection And Ranging) is a remote sensing technology using light in the form of a pulsed laser, which enables efficient, accurate, 3-D data acquisition of a scene. Depending on the mounting platform, lidar data acquisition can be categorized into Airborne Laser Scanning (ALS, or airborne lidar), Terrestrial Laser...
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...
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 logarithmic-spiral (log-spiral) limit equilibrium procedure for slope stability analysis rigorously satisfies both force and moment equilibrium with a failure surface geometry formulated as a function of the soil’s angle of internal friction. Within the framework of limit equilibrium, this procedure has, in the past, been primarily limited to homogeneous...
Bridge inspection is a critical task needed to monitor bridge quality and serviceability. In the U.S., 40% of bridges are more than 50 years old while most bridges are typically designed for a lifespan of 50 years. 9.1% of the 614,387 bridges across the U.S are considered structurally deficient. These...
Fire hazards threaten human life and property safety. Since it is unrealistic to study human behavior during a real fire hazard, computational tools are a better choice to computational tools are a better choice to simulate fire growth and human behavior for predicting evacuation performance in chaotic emergency situations. Although...
As ecoroofs have become more widespread throughout the U.S., it has become increasingly important to understand their structural behavior. The purpose of this research was to investigate the load effects exerted on a roof structure with an ecoroof during rain events and the subsequent drainage period, with the intention of...
Decreases in pavement program funding levels have encouraged paving agencies to adopt higher levels of recycled materials into their asphalt mixes. In order to fully evaluate the effects of recycled asphalt pavement (RAP) in Hot Mix Asphalt (HMA) mixes, the level of blending between the RAP and virgin binders in...
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 construction industry is infamously recognized for having jobsites identified as hazardous working environments due to workers-on-foot commonly functioning at dangerous heights and in close proximity to other construction entities, among other reasons. These hazardous operations result in an increased risk of worker injuries and fatalities caused by fall hazards...
Aggregate piers have been used for centuries, with increasing occurrence in the last few decades. Their usage has been driven by land development demand and enabled through equipment and engineering improvements. Understanding the principles controlling bearing capacities and serviceability performance has been an ongoing area of interest for structures supported...
Left turn movements are considered to be the highest risk movements through an intersection, and can result in head on, angle, or side impact crashes. The flashing yellow arrow (FYA) for use as a permissive left turn phasing indication is relatively recent, first appearing in the 2009 edition Manual on...
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...
Recent statistics suggest that the construction industry continues to experience poor project performance. Specifically, construction productivity has witnessed a meager annual growth of 1% over the past 20 years while the industry constantly records both a high number of fatalities and a high fatality rates relative to other industries. The...
Autonomous vehicles (AVs) may have the potential to mitigate a significant proportion of serious crashes which are due to human error or poor decision making behind the wheel. However, there are still many concerns associated with SAE Level 3 AVs that require intervention by a human driver after a take-over...
Distracted driving is an adverse driving behavior that is widely known to impair the safety of all roadway users and traffic flow. Despite the extensive research efforts on the prevalence and effects of distracted driving on roadway safety and performance, the number of vehicular crashes and fatalities resulting from distracted...
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....
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 research asserts that flood risk perception of individuals living in floodplains influences their preparedness for taking actions to protect themselves from flood hazards. The results of this research are backed up by quantitative analysis of survey responses of individuals living in floodplains of Corvallis, OR in the USA. The...
Chloride-induced corrosion is one of the primary causes of the degradation of reinforced steel in concrete structures. Currently, the rapid chloride permeability test (RCPT) is the most specified method to determine the concrete’s resistivity to chloride ingress, thus a determining factor in assessing the durability of concrete. While it is...
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...
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...
Any work of literature is a product of its time revealing truths about its culture. My thesis explores how pre-selected inspiration, personal experiences, and current events play a role in the devising process of a script. The inspiration for this particular devised play is Letters to a Young Poet by...
Total emissions from the US contribute 15% to the global emissions. The construction industry is a major source of the exhaust emissions produced. Use of light-duty vehicles and heavy-duty trucks for various construction activities contributes 83% to the total greenhouse gases produced. Construction equipment comprises of on-road and non-road equipment,...
Internal stability of Geosynthetic-Reinforced Soil (GRS) walls are conventionally assessed using lateral earth pressure methods. Determination of these pressures is a key component of limit state design as it enables determination of mobilized resisting forces in reinforcements needed to ensure stability and function of the GRS structure. However, conventional methods...
Measuring resistivity as a method to calculate formation factor is becoming a popular way to evaluate transport properties of concrete. Resistivity measurements are dependent on multiple factors including the resistivity of the pore solution, leaching effects, the degree of saturation of the specimen, the age of the specimen (degree of...
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...
Pin and hanger assemblies are a common type of connection used in past engineering practice for steel girder bridges. The connection consists of pins, hanger plates, and girder ends. The connection detail was used widely between 1930 and 1980. The connections are considered fracture critical and nonredundant because connection failure...
The work of engineering education researchers has resulted in the development of research-based instructional strategies (RBISs) aimed at providing educators with means to increase student learning. Research has shown that there is a disconnect between the development of RBISs and their use by educators. Means to make new practices more...
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...
Interest in performance specifications has been growing in the civil and construction industry in the past decade. One major focus area has been on understanding how to prolong the service life of concrete structures, since repair and rehabilitation of existing infrastructure have cost many trillions of dollars. Deterioration mechanisms such...
Steel Slit Panel Frames (SSPFs) are an innovative and resilient lateral force resisting system. Steel Slit Panels (SSPs) are bolted to the beams and act as replaceable seismic fuses, dissipating energy through flexural yielding in links between vertical rows of slits. SSPFs have shown promise as a lateral force resisting...
With all of the efforts that have been conducted over the past 100 years since the first accident causation theory was published, the Accident Proneness theory by Vernon (1918), the construction still trails among different industries in terms of fatal and nonfatal work injuries. Theories and models that have been...
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...
The role of ground motion duration on the seismic performance of civil engineering structures remains unclear. Thus, the role of earthquake strong ground motion duration is assessed in a three manuscript thesis, which includes: (1) assessment of the effects of ground motion duration on the seismic performance of a model...
Significant progress has been made over the past 20 years in developing models to estimate the service-life of reinforced concrete systems. The basic understandings of the mechanisms that control the transport of ions and moisture in concrete systems have been well researched and models for determining corrosion initiation, specifically chloride-induced...
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...
In the first quarter of the twentieth century, iron was commonly used to provide tensile resistance for preservation and restoration of historical buildings. A major factor contributing to increasing the deterioration and degradation of historic structures is corrosion of ferrous materials. One approach to avoid long-term degradation of iron and...
Liquefaction of saturated granular material due to cyclic loading can result in catastrophic damage to the built environment. The mechanics of liquefaction have been previously studied through field testing, physical modeling, laboratory experiments, and numerical simulations. However, significant questions remain with respect to the particle-scale behavior of granular materials during...
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...
There are over 130 million wood poles supporting electrical transmission and distribution lines in the U.S. The vast majority of these poles are preservative treated to prolong their useful life. In some cases, however, the depth of treatment is relatively shallow, leaving a deep zone of moderately durable, untreated heartwood....