Engineering Commons^™

Heavy Truck Collision With Bridge Piers, Ran Cao

Dissertations and Theses

Based on bridge failure data compiled by the New York State Department of Transportation, collision, both caused by vessels and vehicles, is the second leading cause of bridge failures after hydraulic. The current AASHTO-LRFD (2017) specification recommends designing a bridge pier vulnerable to vehicular impacts for an equivalent static force of 2,670-kN (600 kips) applied in a horizontal plane at a distance of 1.5 m (5.0 feet) above the ground level. The vast majority of research studies on vehicular collision with bridge piers have been carried out with single-unit trucks, which are typically classified as medium-duty vehicles weighing about 89 …

Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi

Dissertations and Theses

Our preliminary survey showed that most of the recent flood-related studies did not formally explain the physical mechanisms of long-duration and large-peak flood events that can evoke substantial damages to properties and infrastructure systems. These studies also fell short of fully assessing the interactions of coupled ocean-atmosphere and land dynamics which are capable of forcing substantial changes to the flood attributes by governing the exceeding surface flow regimes and moisture source-sink relationships at the spatiotemporal scales important for risk management. This dissertation advances the understanding of the variability in flood duration, peak, volume, and timing at the regional to the …

An Analytical System For Determining Disciplinary Vocabulary For Data-Driven Learning: An Example From Civil Engineering, Philippa Jean Otto

Dissertations and Theses

Data-driven learning (DDL), an inductive teaching approach in which students learn through corpus interaction, has gained recent traction as way to teach specialized vocabulary in English for Specific Purposes (ESP) classes. There is little research, however, that addresses how to choose specialized vocabulary for teaching with DDL.

This study addressed this gap in research by exploring the potential of a three-part analytical, corpus-based system for determining vocabulary to teach with DDL for a specific context of language use. This system included (1) identifying words that were significantly more frequent in a specialized expert corpus than in a corpus of general …

Experimental Investigation Of Cfrp Wrapped Square Non-Ductile Reinforced Concrete Columns, Hayder Lateef Al-Khafaji

Dissertations and Theses

The use of fiber-reinforced polymers (FRP) for retrofitting or strengthening deficient concrete columns noticeably increased in the past few decades. Plenty of research has been conducted on the behavior of FRP-strengthened circular concrete columns, but far less research has dealt with non-circular columns. In the current study, the focus was to investigate the behavior of square columns with low to medium grade concrete and low steel reinforcement that were strengthened using carbon fiber reinforced polymer (CFRP) wrap. In the experimental portion of this investigation, twelve short square reinforced concrete columns (5" x 5" in cross section and 12" high) were …

An Assessment Of Post-Encroachment Times For Bicycle-Vehicle Interactions Observed In The Field, A Driving Simulator, And In Traffic Simulation Models, Ali Razmpa

Dissertations and Theses

Most safety analysis is conducted using crash data. Surrogate safety measures, such as various time-based measures of time-to-collision can be related to crash potential and used to gain insight into the frequency and severity of crashes at a specific location. One of the most common and acknowledged measures is post-encroachment time (PET) which defines the time between vehicles occupying a conflicting space. While commonly used in studies of motor vehicle interactions, studies of PET for bicycle-vehicle interactions are few. In this research, the PET of bicycle-vehicle interactions measured in the field, a driving simulator, and in a micro-simulation are compared. …

Behavior Of Prestressed Concrete Beams With Cfrp Strands, Yasir Matloob Saeed

Dissertations and Theses

The high cost of repairing reinforced or prestressed concrete structures due to steel corrosion has driven engineers to look for solutions. Much research has been conducted over the last two decades to evaluate the use of Fiber Reinforced Polymers (FRPs) in concrete structures. Structural engineering researchers have been testing FRP to determine their usability instead of steel for strengthening existing reinforced concrete structures, reinforcing new concrete members, and for prestressed concrete applications. The high strength-to-weight ratio of FRP materials, especially Carbon FRP (CFRP), and their non-corrosive nature are probably the most attractive features of FRPs.

In this study, an experimental …

Mechanistic-Empirical Pavement Design Guide (Mepdg) Method Implemented To Estimate Damage In Flexible And Rigid Pavements, Tenzin Gusto

Dissertations and Theses

The implementation of the Empirical-Mechanistic Pavement Design Guide (MEPDG) method for flexible and rigid pavements requires numerous input parameters. Most of these parameters can be easily determined while some require best estimates that are usually extracted from available literature. This thesis identifies the most critical input parameters in terms of their effects on the damage of pavements and their influence on the determination of the number of corrective maintenance cycles to be performed during the design life of pavements. It was found that for flexible pavement, change in the average monthly temperature by as little as results in large differences …

Evaluating The Effects Of A Congestion And Weather Responsive Advisory Variable Speed Limit System In Portland, Oregon, Matthew Blake Downey

Dissertations and Theses

Safety and congestion are ever present and increasingly severe transportation problems in urban areas throughout the nation and world. These phenomena can have wide-ranging consequences relating to safety, the economy, and the environment. Adverse weather conditions represent another significant challenge to safety and mobility on highways. Oregon is not immune from either of these global issues. Oregon Route (OR) 217, to the southwest of the downtown Portland, is one of the worst freeways for congestion in the state and is also subject to the Pacific Northwest's frequently inclement and unpredictable climate. High crash rates, severe recurrent bottlenecks and highly unreliable …

Responses Of Underground Structures Subjected To Blast Loading, Soufiane Nezilli

Dissertations and Theses

Terrorism against American citizens and assets is real and growing. The number and intensity of domestic and international terrorist events, along with the September 11, 2001, attacks, change the way Americans think and live. According to the Blue Ribbon Panel (BRP) on Bridge and Tunnel Security assigned by AASHTO, the US transportation system consists of 337 highway tunnels and 211 transit tunnels in 2003. The number is expected to grow in the near future. These tunnels are subjected to the threats of internal explosion, either accidental or maliciously intentional. Explosions inside transportation tunnels would result in direct casualties; and the …

Understanding Travel Modes To Non-Work Destinations: Analysis Of An Establishment Survey In Portland, Oregon, Christopher D. Muhs

Dissertations and Theses

During the past three decades, research in travel behavior has generally proceeded from broad-level, aggregate analysis of mode share--the proportions of walking, bicycling, transit, and vehicle travel occurring in traffic analysis zones, census tracts, neighborhood, or other geographical units--to fine-grained, disaggregate analysis of mode choices and other trip-making attributes at the individual level. One potential issue is whether there are differences in the types of conclusions drawn from results of analyses performed at these different levels, as these results directly inform transportation planning and policy.

This thesis aims in part to confirm whether the types of conclusions drawn from different …

Reliability Analysis Of The Hec-18 Scour Equation And Aashto Deep Foundation Design Codes, Jun Yan

Dissertations and Theses

This research project studied the reliability of driven pile foundations subjected to scour, gravity loads including dead loads and live loads, and their combinations. The design of the foundation followed the procedures of the AASHTO LRFD Bridge Design Specification. The design methods were the HEC-18 pier scour equation used to determine the scour depth, and the α-Method and Nordlund-Thurman Method used to design the driven pile. The limit state considered was the axial bearing resistance of the piles in the soil. The reliability indexes for bridges subjected to maximum expected scour depth and gravity loads were found through Monte Carlo …

Real-Time Atmospheric Compensation And Surface Temperature Estimates From Satellite Using Neural Networks, Gary Bouton

Dissertations and Theses

Military satellites are being used to determine potential security threats using accurate high sensitivity measurements from defense satellites. These systems focus much more on sensitivity and Signal/Noise Ratio (SNR) than on multispectral capability. Therefore, these systems are highly vulnerable to thermal absorption and reemission that can affect the thermal signature prior to launch. In particular, there is a need to use additional assets to estimate the atmospheric temperature and water vapor profile so that an estimate of the atmospheric processes can be obtained and a correction developed to improve the thermal detection. In particular, the use of existing meteorological geostationary …

Application Of Multi-Hazard Seismic-Blast Detailing For Highway Bridges, Dominique Morton Torres

Dissertations and Theses

The increase of worldwide terrorist attacks on public transportation has heightened our concerns of protecting the nation’s transportation infrastructure. Highway bridges are an attractive target for terrorist attacks due to ease of accessibility and their overall importance to society. The primary objective of this research is to investigate multi-hazard seismic-blast correlations of blast-induced bridge components through numerical simulations of a high-precision finite element model of a typical highway bridge in New York. Seismic-detailing for blast loading on bridges has been investigated to study the correlations between seismic design for blast load effects. High-precision 3D Finite Element models of bridges detailed …

Towards A Better Monitoring Of Soil Moisture Using A Combination Of Estimates From Passive Of Microwave And Infrared Observations, Zulamet Z. Vega-Martinez

Dissertations and Theses

No abstract provided.

Evaluation Of Quikscat Data For Monitoring Vegetation Phenology, Doralee Pellot

Dissertations and Theses

No abstract provided.

Validation Of Noaa Interactive Snow Maps In The North American Region With National Climatic Data Center Ground-Based Data, Christine Chen

Dissertations and Theses

"Both the areal coverage of snow and the volume of water in its subsequent melt are of concern for the creation and maintenance of both hydroelectric power and local water supply. The interactive multisensor snow and ice mapping system (IMS) is a geographic interactive system that allows for both the viewing of various sensor data and the mapping daily both snow and sea ice extent by an analyst on one platform. This thesis investigates the agreement between the National Oceanic and Atmospheric Administration’s (NOAA) interactive multisensor snow and ice mapping system (IMS) and snow depth values obtained from the National …

High-Resolution Numerical Simulation Of Tidal Enegry Distribution Along The New Jersey Coastline And Influence Of Sea-Level Rise, Simon Kraatz

Dissertations and Theses

No abstract provided.

Coupling The Hydrodynamic And Water Quality Model Ce-Qual-W2 With A Multi-Trophic Fish Bio-Energetics Model For Lake Roosevelt, Washington, Michael Lee Mckillip

Dissertations and Theses

Grand Coulee Dam created Franklin D. Roosevelt Lake as part of the Columbia Basin Project. Located in northeastern Washington State, the Project provides economically important hydropower (19 billion kilowatt hours per year), irrigation (225,000 ha), flood control, and sport fishing ($5 to 20 million annually). A good system understanding aids in balancing these beneficial uses for the 230 km long reservoir. The reservoir's atypical 45-day mean residence time is much shorter than a typical lake, and much longer than for a riverine dam. The spring freshet requires drawdowns of 15 to 20 m for flood control—the driving characteristic of reservoir …

Improved Regression-Based Streamflow Forecasting Considering Large-Scale Climate Variability, Austin R. Fisher

Dissertations and Theses

The Natural Resources Conservation Service (NRCS) produces water supply forecasts for most of the streams in the western United States. The NRCS produces forecasts starting in January, when snow course measurements of snow water equivalent were available. Although the seasonal streamflow volume forecasts made by the NRCS are useful, many water supply managers need information at the beginning of the water year in October and would like to see forecasts in the form of a monthly hydrograph.

An investigation into the effect of decadal scale variability, as reflected by the Pacific Decadal Oscillation (PDO), show important relationships that may be …

Modeling Improvements For Water Supply Forecasting In The Columbia River Basin, Daniel Albert Buller

Dissertations and Theses

The purposes of this study were twofold. The first was to explore possible improvements that could be made over existing methods by applying alternative modeling approaches, including the one developed by Garen to forecast runoff volumes in the Columbia River at The Dalles, Oregon. The second was to use the Southern Oscillation as one of the variables to forecast spring and summer runoff and to evaluate whether this variable adds significant information early in the season before any snow has accumulated. The Columbia River basin's mountainous topography and northern latitude are ideally suited for water supply forecasting because much of …

Settlements Due To Arid Collapsible Soils, Heather L. Devine

Dissertations and Theses

The arid alluvial deposits common to the western United States frequently undergo moderate to severe collapse when wetted that can threaten or destroy the stability of structures that are founded on such soils. Additionally, in some areas collapse has been known to occur due to overburden stresses alone. As development expands in these areas a method to estimate the degree of this collapse is essential. Current settlement methods are reviewed and evaluated as they apply to collapsible soils, providing a basis for the development of a proposed settlement method for determining collapse. To aid in the determining the basis for …

Numerical Simulation Of Contaminated Sediment Transport In The Upper Columbia Slough System, Binghong Wu

Dissertations and Theses

An integrated modeling system has been developed to simulate sediment and contaminated sediment transport in the Upper Columbia Slough System during the Flood of 1996. The modeling system consists of a hydrodynamic model, a sediment transport model, and a contaminant transport model. The hydrodynamic model predicts the Slough flow dynamics and sediment transporting power; the sediment transport model predicts flow-induced sediment transport; and the contaminant transport model predicts the migration of contaminated sediments in the Slough system.

The Upper Columbia Slough modeling system is characterized by its recognition of the complex interplay of Slough hydrology, hydrodynamics, sediment transport, contaminant transport. …

A Telescopic Approach To Modeling Leachate Dynamics And Migration At The St. Johns Landfill, Portland, Oregon, Thomas Stephen Lowry

Dissertations and Theses

The St. Johns Landfill is a 225-acre site that lies near the confluence of the Columbia and Willamette Rivers, in the North Portland Industrial District of Portland, Oregon. A slough system surrounds the landfill on three sides with the fourth side adjacent to a shallow lake. The landfill first opened in 1930 when it was operated as an open dump. It operated as an open dump until 1969 when it was converted to a sanitary landfill, employing daily cover and compaction. The landfill was closed in 1991.

The landfill sits directly on top of a thick layer of silty overbank …

Water Quality Model For South Slough, Coos Bay, Oregon, Holly Kay Juza

Dissertations and Theses

The South Slough Estuary is located off Coos Bay along the southern coast of Oregon. It is divided into two channels that meet and continue to Coos Bay at the Charleston Harbor. There are six major contributing streams to South Slough. After rainfall events, the level of coliform bacteria in the slough increases because of stream bacteria loading. This is due to cattle grazing in the drainage areas, failed septic systems from private homes, and sewage sludge applied to the County landfill, which drains into the slough. The Oregon Health Division has enforced a Sanitation Management Plan for Commercial Shellfish …

Improved Finite Analytic Methods For Solving Advection-Dominated Transport Equation In Highly Variable Velocity Field, Wei Cuifeng

Dissertations and Theses

Solute transport studies frequently rely on numerical solutions of the classical advection-diffusion equation. Unfortunately, solutions obtained with traditional finite difference and finite element techniques typically exhibit excessive numerical diffusion or spurious oscillation when advection dominates, especially when velocity field is highly variable. One recently developed technique, the finite analytic method, offers an attractive alternative. Finite analytic methods utilize local analytic solutions in discrete elements to obtain the algebraic representations of the governing partial differential equations, thus eliminating the truncation error in the finite difference and the use of approximating functions in the finite element method. The finite analytic solutions have …

Predicting Solute Transport In Natural Streams - A Stochastic Approach, Xueqing Zhou

Dissertations and Theses

The existing theories for predicting longitudinal dispersion in straight open channels have long been recognized as inadequate when applied to natural rivers. These theories tend to grossly underestimate dispersion in real streams since an important mixing mechanism due to nonuniform river cross-section variations is not explicitly taken into account. Recognizing the important role of stream irregularities on solute transport and the analytical difficulties of classical deterministic analysis, we develop a stochastic approach for analyzing solute transport in natural streams. Variations in river width and bed elevation are conveniently represented as one-dimensional random fields, characterized by their autocorrelation functions. Advection and …

Two Dimensional Finite Element Modeling Of Swift Delta Soil Nail Wall By "Abaqus", Richard James Barrows

Dissertations and Theses

Soil nail walls are a form of mechanical earth stabilization for cut situations. They consist of the introduction of passive inclusions (nails) into soil cut lifts. These nailed lifts are then tied together with a structural facing (usually shotcrete) . The wall lifts are constructed incrementally from the top of cut down. Soil nail walls are being recognized as having potential for large cost savings over other alternatives. The increasing need to provide high capacity roadways in restricted rights of way under structures such as bridges will require increasing use of techniques such as combined soil nail and piling walls. …

Modeling Of Flow And Water Quality In Henry Hagg Lake Near Forest Grove, Oregon, Michael T. Knutson

Dissertations and Theses

Increased population growth in Washington County, Oregon, has helped cause the water quality of the Tualatin River to decline. Henry Hagg Lake is a storage reservoir which was built to augment summer low flows in the Tualatin River. Hagg Lake also supplies the Tualatin River Basin with both irrigation and municipal water in the summer. Using the U.S. Army Corps of Engineer's model CE-QUAL-W2 (a two-dimensional hydrodynamic and water quality model) , a model of Henry Hagg Lake was created. The model was calibrated using water quality and hydraulic data for 1990 at the Hagg Lake outflow in Scoggins Creek. …

Water Quality Modeling Of The Tualitin River, Christopher John Berger

Dissertations and Theses

Water quality problems related to excessive algal growth, high nutrient loading, and low flows have been occurring along Oregon's Tualatin River. The Tualatin River is 86 miles long and has a drainage basin of 711 square miles. The drainage basin incorporates forest, agricultural, and urban areas. Located in the Portland metropolitan area, these problems have been acerbated by the effects of urban growth. To help analyze pollution control alternatives, a river model study, funded by the Oregon Department of Environmental Quality (DEQ}, was undertaken. An in-stream model of hydraulics and water quality was developed. The Corps of Engineer's CE-QUAL-W2 model, …

Predicting Seepage Of Leachate From The St. Johns Landfill To Ground And Surface Water Systems, Kevin A. Schock

Dissertations and Theses

Determination of the vertical and horizontal groundwater hydraulic gradient within a landfill is the first step in determining the potential of groundwater contamination from the landfill leachate. The length of a study and the frequency at which measurements are recorded can greatly affect the description of the local groundwater environment. A more comprehensive analysis can be preformed for longer periods of study and greater measurement frequency. The intent of this study was to install a continuous groundwater level monitoring system around the st. Johns Landfill for a minimum study length of one year. This would allow a more thorough study …