The Astoria-Megler Bridge is a 6.6 kilometer (4.1 mile) long bridge, connecting Oregon and Washington on US 101, with a continuous steel truss main span of 376 m (1232 ft). It is the second longest main span bridge of this type in the world. Due to vortex shedding, some of...
Global climate change is expected to exaggerate the severity of floods and droughts and increase the frequency of extreme streamflow events in the Midwestern United States. Managing these projected impacts poses a major challenge for water resources, conservation, and land use management. Wetlands have been considered as a conservation strategy...
Wheeled mobility devices (WhMD) pose unique safety risks to users while riding public transportation. Unsecured or improperly secured WhMDs create safety concerns for other transit riders and operators. Tests using accelerometers and visual observations were conducted to understand how WhMD orientation and securement in articulated buses, streetcars, and light rail...
In this study, the effects of implementing different wind input or physics packages in a numerical wave model to recreate large wave conditions are explored. Three large wave events are simulated with WaveWatch III. The wind inputs which are compared are NCEP's Global Forecasting System (GFS) with 0.5 degree resolution...
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...
A wave-by-wave forecasting system is desired for optimization of wave energy conversion devices and for improving safety of vessel-based marine operations. This study outlines the first validation attempts of a recently developed forecasting system called Wavecast. The forecasting approach uses X-Band marine radar images for data assimilation, then reconstructs and...
Forecasting of ocean waves over a short duration on the order of tens of seconds was approached with the optimization of wave energy conversion in mind. This study outlines the development of an artificial neural network model, specifically the Nonlinear Autoregressive Network with Exogenous Input (NARX), to predict a wave-by-wave...
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...
As the second largest river in the U.S., the entrance to the Columbia River is home to some of the most extreme wave conditions on the Pacific Coast. Winter storms commonly generate waves 6-8 m in height, which in combination with strong tidal currents, can produce dangerous navigation conditions. 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...
An intersection, due to its vehicle and pedestrian conflict movements, experiences complex traffic situations that might contribute to crashes. In the city of Corvallis, OR, historically more than 80% of the total crashes have occurred within an intersection or have been designated as intersection-related. It is important to develop a...
Alkali-silica reaction (ASR) is one of the leading causes of concrete deterioration throughout the world, and affects both structural and non-structural elements. Despite strong research efforts since its discovery by Stanton in the late 1930s, this deteriorating reaction is still not clearly understood nor are proper preventative measures effectively applied...
Helical anchors are a type of deep foundation element that can be installed quickly in almost any location and can accept the immediate application of operational loads. The use of helical anchors has expanded in recent decades from its established application in the power transmission industry to more traditional civil...
This study presents the theoretical background necessary to model the bearing capacity of shallow and deep foundations in partially saturated soils. The conventional bearing capacity equations for shallow and deep foundations and the 𝛽-method for deep foundation side resistance have been modified to include the effects of matric suction and...
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...
Bridge inspections are vital for monitoring the health and serviceability of transportation infrastructure throughout the world. However, inspections can be logistically-challenging, expensive, and dangerous. For example, inspections may require climbing, as well as the use of scaffolding, ladders, rescue boats, bucket trucks, and/or under-bridge inspection vehicles. Small, multirotor unmanned aircraft...
Background
The National Science Foundation (NSF) has funded multiple research projects dedicated to the development of research and evidence based instructional strategies in an effort to improve the state of science, technology, engineering and math (STEM) education in the US. These efforts have led to an abundance of research based...
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...
Recent tsunami field surveys from the 2011 Great East Japan Earthquake and Tsunami have recorded numerous examples of tsunami-induced soil instability: significant scour around foundations, foundation failure of piles, and other damage caused by liquefaction. From the observations of soil instability leading to the failure of critical coastal structures, it...
The finite element software framework, OpenSees, has been used by researchers
to simulate the response of structural and geotechnical systems to earthquake loading. Implementation of the Particle Finite Element Method (PFEM) has made it possible to simulate hydrodynamic forces through fluid-structure interaction (FSI) in OpenSees. To validate the FSI implementation...