Civil and Environmental Engineering Commons^™

The Influence Of Sea-Level Rise On Salinity In The Lower St. Johns River And The Associated Physics, Teddy Mulamba

UNF Graduate Theses and Dissertations

The lower St Johns River is a low-gradient coastal river with tidal hydrodynamics that remain active from the Atlantic Ocean through to the upstream end of Lake George (river km 200). Salinity in the lower St Johns River is spatially and temporally variable, whereby the salinity distribution is driven primarily by the combination of ocean processes of tides and storm surges and hydrological processes of watershed runoff. This study examines the probability distributions and modes of behavior of salinity for present-day conditions using data, numerical modeling and eigen-analysis. The hypothesis is that long-term changes (decadal scale) in the ocean processes …

Safety Implications Of Transit Operator Schedule Policies, Hung Hoang

UNF Graduate Theses and Dissertations

In the bus transit community, driving long hours or spending extra hours at work are very common. This is true in the State of Florida, where bus transit is a very popular mode of public transportation. Although the correlation between a bus driver’s schedule and a crash event appears intuitive, further study regarding the effects of operator driving schedules on accident rates is needed to evaluate safety measures. The focus of this research is on the examination of bus driver schedules, and the effects of scheduling on accident rates in Florida. Data were collected at five bus transit agencies including …

Modeling Older Driver Behavior On Freeway Merging Ramps, Lina Lwambagaza

UNF Graduate Theses and Dissertations

Merging from on-ramps to mainline traffic is one of the most challenging driving maneuvers on freeways. The challenges are further heightened for older drivers, as they are known to have longer perception-reaction times, larger acceptance gaps, and slower acceleration rates. In this research, VISSIM, a microscopic traffic simulation software, was used to evaluate the influence of the aging drivers on the operations of a typical diamond interchange. First, drivers were recorded on video cameras as they negotiated joining the mainline traffic from an on-ramp acceleration lane at two sites along I-75 in Southwest Florida. Several measures of effectiveness were collected …

Composite Confinement Systems For Rc Column Repair And Construction Under Seismic Loads: Concept, Characterization And Performance, Mostafa Fakharifar

Doctoral Dissertations

"This study aims at developing, characterizing and validating an integrated composite confinement system of conventional jackets for: (1) repair and retrofit of existing bridge columns; and (2) construction of new bridge columns, subjected to earthquake excitations.

A new composite steel confinement jacket was proposed by combining a thin steel sheet and prestressing strands as a hybrid jacket, incorporating active and passive confining pressure on damaged RC columns. Both experimental and analytical studies were conducted to understand the performance and effectiveness of the proposed repair method. The experimental study involved two 1/2-scale lap-spliced deficient RC bridge columns originally tested to failure …

Rehabilitation And Strengthening Of Reinforced Concrete Members Using A Fiber Reinforced Cementitious Matrix Composite, Zena Riyadh Aljazaeri

Doctoral Dissertations

“Externally bonded fiber reinforced cementitious matrix (FRCM) for structural members was tested and evaluated as a new class of composite material for repairing and strengthening infrastructures. In comparison with fiber reinforced polymer (FRP) composites, FRCM composite has a superior high temperature resistance and great compatibility with concrete substrates. Experimental investigation is ongoing in the United States to evaluate the structural and durability performance of FRCM composite to be implemented in field applications. This experimental program consisted of testing 12 strengthened reinforced concrete (RC) beams to study the fatigue and flexure performance under environmental exposure and sustained stress, 10 strengthened RC …

Innovative Techniques For Seismic-Resistant Bridge Columns Under Ground Motion Excitations, Ayman A. Moustafa

Doctoral Dissertations

“This dissertation provides innovative alternative solutions for replacing conventional reinforced concrete columns. The proposed columns displayed enhanced seismic resistance and properties compared to their counterpart conventional columns. Two main techniques were followed and proposed to develop seismic-resistant columns. The first technique utilized rubberized concrete to internally enhance energy dissipation and damping. Materials testing of rubberized concrete with scrap tire replacement of fine aggregates were performed to evaluate its dynamic properties. Shaking table testing of a rubberized concrete column was performed and the behavior was compared to that of the conventional one. The rubberized column showed an increase of 16% in …

Age-Related Differences In Vehicle Control And Eye Movement Patterns At Intersections: Older And Middle-Aged Drivers, Yusuke Yamani, William J. Horrey, Yulan Liang, Donald L. Fisher

Psychology Faculty Publications

Older drivers are at increased risk of intersection crashes. Previous work found that older drivers execute less frequent glances for detecting potential threats at intersections than middle-aged drivers. Yet, earlier work has also shown that an active training program doubled the frequency of these glances among older drivers, suggesting that these effects are not necessarily due to age-related functional declines. In light of findings, the current study sought to explore the ability of older drivers to coordinate their head and eye movements while simultaneously steering the vehicle as well as their glance behavior at intersections. In a driving simulator, older …

Water Resources Systems Analysis: A Bright Past And A Challenging But Promising Future, David E. Rosenberg, Kaveh Madani

Civil and Environmental Engineering Faculty Publications

Our field of water resources systems analysis is now experiencing one of its most exciting eras where scientists, decision makers, and funding agencies want to apply systems approaches to solve varied, complex, uncertain, and interdisciplinary resource management problems. Solving these problems presents great opportunities for us to engage in complex, real-world decision-making and make positive changes. However, to capitalize on these opportunities, we as a field must also overcome several large challenges related to problem identification, integration, blind use of systems tools, a focus on optimality, and harnessing big data. To overcome, we must look back to find what we …

Shear Testing Of Precast Concrete Sandwich Wall Panel Composite Shear Connectors, Jaiden Olsen, Marc Maguire

Civil and Environmental Engineering Faculty Publications

As energy codes become more stringent, thermal efficiency of Precast Concrete Sandwich Panel Walls has become more important. This paper addresses the problem of predicting the behavior of full scale precast concrete sandwich panel walls, using data collected from small, inexpensive push-off specimens. Several fiber reinforced polymer (FRP) connectors being used today underwent shear testing performed on component scale push-off specimens. Each specimen contained several of the FRP connectors and the variables studied were wythe thickness, insulation type and insulation bond. A simplified beam spring model was created which uses beams to represent the concrete wythes and shear springs to …

Evaluation Of Concrete Degradation Using Acoustic Emission: Data Filtering And Damage Detection, Marwa A. Abdelrahman

Theses and Dissertations

The prevalence of aging and deteriorating infrastructure in the U.S. has raised concerns regarding its level of serviceability, reliability, and vulnerability to natural disasters. This issue has gained attention recently and efforts are being conducted to accelerate the delivery of enhanced nondestructive testing (NDT) and structural health monitoring (SHM) methods. Acoustic emission (AE) is a strong candidate for these applications due to its high sensitivity and potential for damage detection in different materials. However, several challenges associated with the technique hinder the development of automated, reliable, real-time SHM using AE.

This study aims to advance the use of AE for …

Improved Assessment Of The Magnitude And Acceleration Of Prehistoric Earthquakes In The South Carolina Coastal Plain, Emad Gheibi

Theses and Dissertations

Seismically-induced soil liquefaction is one the most hazardous geotechnical phenomenon that can cause loss of life and devastating damage to infrastructure. Proper estimation of critical ground motion parameters (e.g. peak ground acceleration and earthquake magnitude) is vital for seismic design of new structures and retrofit of existing structures, especially in regions such as the South Carolina Coastal Plain (SCCP) where the frequency of re-occurrence of large earthquakes is low (studies of paleoliquefaction features have revealed seven, large, prehistoric earthquakes occurring within the last 6000 years) and the locations of potential sources are not exactly known. Moreover, due to mechanical and …

Java Based Visualization And Animation For Teaching The Dijkstra Shortest Path Algorithm In Transportation Networks, Ivan Makohon, Duc T. Nguyen, Masha Sosonkina, Yuzhong Shen, Manwo Ng

Civil & Environmental Engineering Faculty Publications

Shortest path (SP) algorithms, such as the popular Dijkstra algorithm has been considered as the "basic building blocks" for many advanced transportation network models. Dijkstra algorithm will find the shortest time (ST) and the corresponding SP to travel from a source node to a destination node. Applications of SP algorithms include real-time GPS and the Frank-Wolfe network equilibrium.

For transportation engineering students, the Dijkstra algorithm is not easily understood. This paper discusses the design and development of a software that will help the students to fully understand the key components involved in the Dijkstra SP algorithm. The software presents an …

Java Computer Animation For Effective Learning Of The Cholesky Algorithm With Transportation Engineering Applications, Ivan Makohon, Duc T. Nguyen, Mecit Cetin

Civil & Environmental Engineering Faculty Publications

In this paper, the well-known Cholesky Algorithm (for solving simultaneous linear equations, or SLE) is re-visited, with the ultimate goal of developing a simple, user-friendly, attractive, and useful Java Visualization and Animation Graphical User Inter-face (GUI) software as an additional teaching tool for students to learn the Cholesky factorization in a step-by-step fashion with computer voice and animation. A demo video of the Cholesky Decomposition (or factorization) animation and result can be viewed online from the website: http://www.lions.odu.edu/~imako001/cholesky/demo/index.html. The software tool developed from this work can be used for both students and their instructors not only to master this technical …

Numerical Model Water Quality For Hidalgo County, Texas; Main Drainage System, Jose Orvyl Gonzalez, Grimaldo Carrillo, Jungseok Ho

Civil Engineering Faculty Publications

Increasing urbanization, water intake, and human water interaction of drainage canals of the Hidalgo County watershed seals the drainage basin and expands floodplains along the canal-side. Incremental use of drainage systems affects the amounts of nutrients that can cause an exposure to residues of agriculture chemicals, water related parasitic diseases, and fecal diseases. Proper water quality management is crucial for pollutant transport detection, estimation of non-point source discharge, and prediction of pollutant discharge at water endpoints. This research seeks to improve the understanding stormwater quality and quantity that is influenced by the frequency of human-water contacts and associated with treatment …

Suspended Sediment And Nutrient Concentrations And Loads In Two Irish Rivers, Sean T. Harrington

Theses

This thesis presents the results of new and original research on suspended sediment (SS) and nutrient concentrations and loads on the Rivers Bandon and Owenabue in the south of Ireland. It addresses the knowledge gap in SS and nutrient concentration data and in particular SS load/yield estimation methods. A comprehensive database of SS and nutrient concentrations has been established. An investigation into the relationship between water discharge and sediment and nutrient transport is presented and new original relationships between turbidity and suspended sediment concentration (SSC) and nutrients are developed. Turbidity-based suspended sediment loads (SSL) are estimated from the continuous turbidity …

Urban Resilience: The Regeneration Of The Dublin Docklands, Aoife Doyle

Conference papers

Resilience, and more specifically ‘urban resilience’, is a ‘fuzzy’ concept, which has gained increasing public, political and academic interest over the past two decades; particularly in the context of the global financial crisis of the late 2000s. This paper adopts an understanding of resilience as the ability of cities to change, adapt and, crucially, transform in response to stresses and strains. Yet how have cities – and urban planning – responded to the recent economic crisis; and how can one examine this in practice? This paper investigates the case of Dublin, Ireland. In particular, it utilises the resilience concept to …

Do Characteristics Of Walkable Environments Support Bicycling? Toward A Definition Of Bicycle-Supported Development, Christopher D. Muhs, Kelly Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

Does walkability equate with bikeability? Through a comprehensive review of studies of the built environment and bicycling, including mode choice, route choice, safety, and urban design literature, this paper addresses this question. Previous work has raised the issue that the two modes are functionally different, despite them often being combined into a nonmotorized category, and has highlighted research challenges. Existing studies of bikeability have largely focused on infrastructure. This paper contributes to the literature on bicycling and the built environment by providing a thorough review of past research with a focus on the relationships between land use, urban form, and …

Bio-Physical Closure Criteria Without Reference Sites: Realistic Targets In Modified Rivers, Melanie L. Blanchette, Mark Lund, Robyn Stoney, Digby Short, Colm Harkin

Research outputs 2014 to 2021

The use of reference sites for establishing closure criteria in areas disturbed by mining activities is common practice. ‘Reference’ sites are those considered to be largely unimpacted by anthropogenic activity (retaining desirable natural characteristics), and occurring near disturbed sites. Sites are considered rehabilitated when their biophysical condition approximates that of the reference site. However, this approach often creates impossible or unrealistic targets for miners seeking to close rehabilitated lands. For example, reference sites are often limited in availability (or non-existent) due to impacts by other land uses. Further, any available reference sites might not be realistic matches for the rehabilitated …

Polychlorinated Biphenyl Compound And Metal Contamination And Remediation In Torch Lake, Houghton County, Mi, Ankita Mandelia

Dissertations, Master's Theses and Master's Reports

Torch Lake was subject to approximately 100 years of industrial pollution due to the dumping of waste associated with copper mining in the Keweenaw Peninsula, which lasted from approximately the 1860s through the 1960s. It is well-known that this waste included copper-containing mine tailings. What was less understood are the impacts of polychlorinated biphenyls (PCBs) and heavy metals besides copper on the lake system.

The objectives of this thesis are to summarize the status of contamination and remediation activities in Torch Lake and to estimate the magnitude of potential sources of PCBs to Torch Lake. First, a brief overview of …

Risk-Based Assessment And Strengthening Of Electric Power Systems Subjected To Natural Hazards, Abdullahi Salman

Dissertations, Master's Theses and Master's Reports

Modern economic and social activities are dependent on a complex network of infrastructure systems that are highly interdependent. Electric power systems form the backbone of such complex network as most civil infrastructure systems cannot function properly without reliable power supply. Electric power systems are vulnerable to extensive damage due to natural hazards, as evident in recent hazard events. Hurricanes, earthquakes, floods, tornados and other natural hazards have caused billions of dollars in direct losses due to damage to power systems and indirect losses due to power outages, as well as social disruption. There is, therefore, a need for a comprehensive …

Property Analysis Of The Asphalt Materials Using Molecular Dynamics (Md) Method, Hui Yao

Dissertations, Master's Theses and Master's Reports

The main objectives of this dissertation are to build the Molecular Dynamics (MD) model for the asphalt binders with three components, asphaltenes, aromatics and saturates, and analyze the properties of the asphalt models to discover the interactions and mechanisms of asphalt-aggregate and asphalt-modifier. The contributions of this dissertation are summarized as follows: (1) the Amber Cornell Extension Force Field (ACEFF) was assigned to each component, and most of the parameters of the force field were obtained from the General Amber Force Field (GAFF). Electrostatic Potential (ESP) charges were assigned to each atom with the NWChem calculation; (2) the modified asphalt …

Evaluation Of Self-Healing Of Asphalt Concrete Through Induction Heating And Metallic Fibers, Yashwanth Pamulapati

LSU Master's Theses

Healing by means of induction heating is promising, however the effectiveness of this technology is yet to be demonstrated due to limited studies on cracking damage and fracture resistance property recoveries after healing. The objective of this study was to test the hypothesis that a new generation of asphaltic materials could be artificially healed while in-service by embedding metallic fibers in the mix and by applying a magnetic field at the surface. To achieve this objective, an open-graded friction course (OGFC) was successfully designed and prepared to incorporate up to 5% steel and aluminum fibers by weight of the mix. …

A Characterization Of The Water Quality Conditions And Pollutant Loads In Surface Waters Near The Northeast Ohio Regional Sewer District’S Combined Sewer System In Cleveland, Ohio, Nathan Zgnilec

Dissertations, Master's Theses and Master's Reports

The Northeast Ohio Regional Sewer District (NEORSD, Cleveland, OH) serves over one million citizens through the operation of three waste water treatment plants. NEORSD provides this service through combined and separated sewer systems, which, during rainfall events, are known to deliver large volumes of untreated wastewater containing high concentrations of Escherichia coli (E.coli), ammonia nitrogen, and phosphorus. NEORSD is currently investing $3 billion over the next 25 years to mitigate its combined sewer overflows and plans to allocate additional funds to improve remaining pollutant sources related to its system, e.g. separated sewers. A suite of PC-SWMM pollutant loading models have …

Assessing The Impacts Of Climate Change On The Surface Temperature Of Inland Lakes In Michigan, Kaitlin Reinl

Dissertations, Master's Theses and Master's Reports

The aim of this study was to validate and apply a lake model for predicting the susceptibility of small inland lakes in Michigan to changes in thermal regime and increased cyanobacteria growth as a result of future climate conditions. The Freshwater Lake Model was selected, tested for sensitivity to various inputs, and validated through comparison to observed conditions. The sensitivity analysis showed that the lake model was most sensitive to solar radiation, air temperature, and air humidity. Comparison of predicted climate data with observed conditions revealed highly variable climate model error. The lake model validation was conducted using 10 lakes …

Dust Susceptibility At Mine Tailings Impoundments: Thermal Remote Sensing For Dust Susceptibility Characterization And Biological Soil Crusts For Dust Susceptibility Reduction, Bonnie Zwissler

Dissertations, Master's Theses and Master's Reports

Mining operations produce massive volumes of mine tailings, which are deposited as slurry into permanent tailings impoundments. An important and heavily regulated environmental hazard associated with mine tailings impoundments is fugitive dust emissions. Wind erosion of mine tailings impoundments and the resulting dusting events, especially those caused by cold weather dusting, remain an on-going challenge for the mining industry. The overall goal of this research was to develop and evaluate effective, economical, and sustainable solutions to two major issues facing mine tailings impoundments with regards to dusting: (1) dust monitoring/detection and (2) dust reduction/prevention. Specifically, the research studied iron mine …

Extracting Physically Realistic Pore Network Features From Xct Data And Investigating The Impact Of Pore Topology On Flow In Porous Media, Godfrey Mills

LSU Doctoral Dissertations

Synchrotron XCT imaging approaches applied in this study provides crucial information on the impact of image voxel resolution on image based simulation results and the characteristic length scales that can be extracted from XCT image data sets. The methods and results in this work provides a holistic approach in generating reliable and representative porous media flow and transport properties via image processing and pore scale simulations through XCT image data sets of porous media. This study also shows how XCT imaging, coupled with pore topological and morphological measures can be utilized in quantifying the differences, and/or similarities between a 2.5D …

Effects Of Temperature Segregation On The Denisity And Mechanical Properties Of Asphalt Mixtures, Pranjal Pravin Phaltane

LSU Master's Theses

Temperature differentials (TD) between the target laydown and actual laydown temperatures of asphalt paving mixtures have been noticed and measured since the late 1990s. Since then, numerous research studies conducted on the phenomena found inconclusive conclusions regarding the effects of TD on the initial pavement quality and the long-term performance. The objective of this study was to evaluate the effects of different levels of TD on the initial quality and the long-term performance of asphalt pavements by evaluating the core density and laboratory measured performance characteristics, respectively. Through the evaluation, it was also aimed to ascertain and establish allowable TD …

Driver Engagement In Secondary Tasks: Behavioral Analysis And Crash Risk Assessment, Mengqiu Ye

LSU Master's Theses

Distracted driving has long been acknowledged as one of the leading causes of death or injury in roadway crashes. The focus of past research has been mainly on the change in driving performance due to distracted driving. However, only a few studies attempted to predict the type of distraction based on driving performance measures. In addition, past studies have proven that driving performance is influenced by the drivers’ socioeconomic characteristics, while not many studies have attempted to quantify that influence. In essence, this study utilizes the rich SHRP 2 Naturalistic Driving Study (NDS) database to (a) develop a model for …

Sulfate-Reducing Bacteria Community Analysis: Isco/Isb Coupled Remediation, Christopher K. Bartlett

Theses and Dissertations (Comprehensive)

Improved techniques for remediating groundwater systems are required for the more than 500,000 contaminated sites in North America. Many of these sites are the legacy of historical industrial operations, inappropriate disposal practices and accidental releases. The most widely observed contaminant at many of these sites is petroleum hydrocarbons (PHCs). Recently, remediation efforts that involve the sequential application of treatment technologies have gained widespread interest. One specific sequential technology application or treatment train employs the aggressive nature of a chemical oxidation followed by bioremediation for polishing. When persulfate is used as the chemical oxidant its natural degradation by-product is sulfate, an …

Numerical Modeling Of Wetland Hydrodynamics, Agnimitro Chakrabarti

LSU Doctoral Dissertations

Wave induced erosion accounts for as much as 26% of landloss in coastal Louisiana. This dissertation work, focuses on answering research questions relevant to the design of two shoreline protection methods (a) vegetated wetlands and (b) nearshore breakwaters. Two types of numerical models are used - the three-dimensional (3D) Navier Stokes Equation for small to medium scale experiments and a depth integrated, fully non-linear Boussinesq model for dispersive waves for larger, field scale studies. The former model provides insights into the 3D hydrodynamics of wave interaction with vegetation canopies and breakwaters, while the latter model focuses on the horizontal two …