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Full-Text Articles in Civil Engineering

Investigating Changes In Trends Of Traffic Crashes Due To Covid-19 Pandemic In Florida’S Freeways, Ntagwanko Kisabanzira Jan 2022

Investigating Changes In Trends Of Traffic Crashes Due To Covid-19 Pandemic In Florida’S Freeways, Ntagwanko Kisabanzira

UNF Graduate Theses and Dissertations

The COVID-19 pandemic outbreak caused a shift in traffic patterns that have in turn influenced a change in traffic accident trends. Due to stay-at-home orders that were issued across the United States, transportation agencies reported low traffic demands on highways after the pandemic outbreak. Low traffic volumes are associated with relatively higher speeds that are linked to increased severity of crashes. Several states reported an increase in fatal crashes after the outbreak of the COVID-19 pandemic. This paper evaluates the traffic crash trends on three interstates in Florida (I-10, I-75, and I-95) and sheds light on what happened before, during, …


Crystalline Analysis Of Geomicrobially-Induced Calcium Carbonate Precipitation In Sands Using A Surface Percolation Treatment Technique, Justin Edward Mulloney Jan 2022

Crystalline Analysis Of Geomicrobially-Induced Calcium Carbonate Precipitation In Sands Using A Surface Percolation Treatment Technique, Justin Edward Mulloney

UNF Graduate Theses and Dissertations

Ottawa 50/70 sand specimens and natural beach sand samples were treated using bio-augmented geomicrobies via a surface percolation technique. Testing was conducted on these specimens to determine how resultant calcium carbonate precipitation changed as a function of temperature, depth from the surface, and in the presence of magnesium. Specifically, x-ray Diffraction (XRD), a Scanning Electron Microscope (SEM), and Energy Dispersive X-ray Spectroscopy (EDS) were used to determine and quantify the presence of calcium carbonate and its associated phase. Results showed a direct relationship between temperature and precipitated calcium carbonate. In addition, as an unintended consequence associated with the treatment, ammonium …


Linear Generators In Wave Energy Conversion: Performance, Feasibility, And Location Study, Luis Fernandez De Valderrama Jan 2021

Linear Generators In Wave Energy Conversion: Performance, Feasibility, And Location Study, Luis Fernandez De Valderrama

UNF Graduate Theses and Dissertations

As the energy demand increases and climate change becomes a major problem, the solution to decrease greenhouse gas emissions and mitigate the effects of climate change involves increasing the use of sustainable and renewable sources to generate electricity. However, developed renewable sources have inconveniences that make them incapable of generating the totality of the electricity that a country demands. Wave energy is an alternative renewable energy source that can help mitigate the inconveniences of other renewable sources and decrease the emission of greenhouse gases.

This study aims to find the potential of linear generators in wave energy by analyzing the …


Exploring The Use Of Drones For Conducting Traffic Mobility And Safety Studies, Abdallah N. Kinero Jan 2021

Exploring The Use Of Drones For Conducting Traffic Mobility And Safety Studies, Abdallah N. Kinero

UNF Graduate Theses and Dissertations

ABSTRACT

Advanced traffic data collection methods, including the application of aerial sensors (drones) as traffic data collectors, can provide real-time traffic information more efficiently, effectively, and safely than traditional methods. Traffic trajectory data like vehicles’ coordinates and point timestamps are challenging to obtain at intersections using traditional field survey methods. The coordinates and timestamps crucial in calculating trajectories can be obtained using drones and their particular integrated software. Thus, this study explores the use of unmanned aerial systems (UAS), particularly tethered drones, to obtain traffic parameters for traffic mobility and safety studies at an unsignalized intersection in Tallahassee, Florida. Tethered …


Predicting Anthropogenic Underwater Pile Driving Noise Using Pile Driving Analyzer (Pda) Data, Brandon Alfredo Rivera Jan 2021

Predicting Anthropogenic Underwater Pile Driving Noise Using Pile Driving Analyzer (Pda) Data, Brandon Alfredo Rivera

UNF Graduate Theses and Dissertations

In the past several years, there has been increasing concern about anthropogenic noise generated during marine pile driving. This concern is expected to increase concomitantly with increases in waterfront construction efforts associated with aging infrastructure and sea level rise. Several guidelines are available to help predict underwater noise transmission due to pile driving, but the issue with all these methods is that they require one to measure sound pressure levels at one locus or more from the driven pile. In the context of marine construction, adding specifications for underwater noise collection may be expensive or difficult because contractors typically have …


Modeling Coastal Vulnerability Of The St. Johns River And Northeastern Florida Shorelines, Madison E. Heppe Jan 2021

Modeling Coastal Vulnerability Of The St. Johns River And Northeastern Florida Shorelines, Madison E. Heppe

UNF Graduate Theses and Dissertations

Coastal and riverine communities, with anthropogenic congestion and natural and economic resources, are vulnerable to climate change impacts including rising sea levels and increasing severity and frequency of storms. Coastal habitats are being increasingly recognized as natural infrastructure that provides resiliency against these stressors. However, few studies have analyzed coastal vulnerability at landscape scale with finely resolved spatial data that account for habitats and demographics. The purpose of this study is to map the coastal vulnerability of the St. Johns River and adjacent Northeastern Florida Atlantic shoreline within the St. Johns River Water Management District. Unique to this study is …


Determination Of Extreme Flood Events In The Black Creek, Julington Creek, Dubin Creek, Big Davis Creek, Ortega River, And Pablo Creek Sub-Basins Of The Lower St. Johns River Basin, Florida, Usa, Samantha Kovalenko Jan 2021

Determination Of Extreme Flood Events In The Black Creek, Julington Creek, Dubin Creek, Big Davis Creek, Ortega River, And Pablo Creek Sub-Basins Of The Lower St. Johns River Basin, Florida, Usa, Samantha Kovalenko

UNF Graduate Theses and Dissertations

Extreme flood estimation is a continuously developing field of research. Economic and community well-being are dependent on flood risk preventative planning, which can only be successfully implemented through sound flood estimating methods. Without the execution of proper flood prevention measures, many communities remain at risk. In addition to a new extreme flood estimation methodology, this research presents a new approach to establish flood estimates. Traditionally, more than one flood estimate per return frequency storm does not exist. This research produced a set of 10-, 25-, 50-, and 100-year flood estimates for the Black Creek, Julington Creek, Durbin Creek, Big Davis …


Estimating A Range Of Flow Rates Resulting From Extreme Storm Events Within The Wekiva River Watershed Through Statistical Testing And Modeling, Wesley K. Koning Jan 2021

Estimating A Range Of Flow Rates Resulting From Extreme Storm Events Within The Wekiva River Watershed Through Statistical Testing And Modeling, Wesley K. Koning

UNF Graduate Theses and Dissertations

The middle portion of the St. Johns River is located in East-Central Florida, USA. This region of the St. Johns River is increasingly subject to urbanization and conversion of forest areas to agricultural land. Overall, these changes mean that future flood events in the area could adversely impact local citizens. Therefore, the examination of extreme flood events and resiliency to such events is critical. The purpose of this preliminary study is to explore a range of practical applications to estimate extreme flood flows at watercourses within the Middle St. Johns River Basin, focusing specifically upon the Wekiva River sub-basin. The …


Preliminary Design And Analysis Of A Wave Energy Converter With Electromagnetic Induction, Laura Fernandez De Valderrama Jan 2020

Preliminary Design And Analysis Of A Wave Energy Converter With Electromagnetic Induction, Laura Fernandez De Valderrama

UNF Graduate Theses and Dissertations

As the energy demand increases with the constantly increasing population, as well as the effort to replace conventional fossil fuels with cleaner sources of energy, ocean energy has emerged as a potential global resource. The ocean contains an enormous amount of energy that has not been exploited yet, although efforts have augmented during the past decades.

The overall purpose of this research is to design, model, and analyze, a wave energy converter (WEC) prototype to contribute to the current research in this field. This particular work represents the first stage of the research process in which the ultimate goal is …


Synthesis And Characterization Of Carbon Sequestering Calcium Carbonate Cement, Mohammad Jobaer Uddin Jan 2020

Synthesis And Characterization Of Carbon Sequestering Calcium Carbonate Cement, Mohammad Jobaer Uddin

UNF Graduate Theses and Dissertations

The cement industry is the second-largest manufacturing emitter of CO2, and the manufacture and placement of concrete accounts for 7-8% of anthropogenic CO2 emissions. There is increasing pressure on the cement industry to develop a sustainable cement to support rapid global urban development without the associated emissions of cement production. The calcination reaction required to manufacture Portland cement is the prime source of emissions, so eliminating the release of CO2 liberated during calcination of limestone provides an excellent opportunity to produce a more sustainable cement. Calcium carbonate (CaCO3) cement is a novel alternative, which can …


Investigation Of Expedient, Cost Effective And Sustainable Soil Stabilization For Tactical Vehicles Using Surfactant-Induced Soil Stabilization (Siss), Joshua Sasser Jan 2020

Investigation Of Expedient, Cost Effective And Sustainable Soil Stabilization For Tactical Vehicles Using Surfactant-Induced Soil Stabilization (Siss), Joshua Sasser

UNF Graduate Theses and Dissertations

Surfactant-induced soil stabilization (SISS) is a new method for soil stabilization whereby anionic surfactants and alkaline earth metals are introduced to a soil matrix. This research served as a preliminary study into SISS’ suitability as a temporary soil stabilization method that could be used to improve wheeled vehicle traction during amphibious type naval operations conducted on a beach head.

Beach sand specimens were treated with sodium dodecyl sulfate (SDS; aka sodium lauryl sulfate) and calcium chloride using two methods: hand mixing in testing cylinders and surface percolation in bench scale sandboxes. Treated cylinders were tested for unconfined compressive strength (UCS) …


Evaluating The Mobility And Safety Benefits Of Adaptive Signal Control Technology (Asct), John Herman Kodi Jan 2019

Evaluating The Mobility And Safety Benefits Of Adaptive Signal Control Technology (Asct), John Herman Kodi

UNF Graduate Theses and Dissertations

The Adaptive Signal Control Technology (ASCT) is a traffic management strategy that optimizes signal timing based on real-time traffic demand. This thesis proposes a comprehensive methodology of quantifying the mobility and safety benefits of the ASCT deployed in the state of Florida. A Bayesian switch-point regression model was proposed to evaluate the mobility benefits of ASCT. The analysis was based on a 3.3-mile corridor along Mayport Road from Atlantic Boulevard to Wonderwood Drive in Jacksonville, Florida. The proposed analysis was used to estimate the possible dates that separate the two operating characteristics, i.e., with and without ASCT. Also, the posterior …


Simulation Exploration Of The Potential Of Connected Vehicles In Mitigating Secondary Crashes, Mike Alvin Soloka Jan 2019

Simulation Exploration Of The Potential Of Connected Vehicles In Mitigating Secondary Crashes, Mike Alvin Soloka

UNF Graduate Theses and Dissertations

Secondary crashes (SCs) on freeways are a major concern for traffic incident management systems. Studies have shown that their occurrence is significant and can lead to deterioration of traffic flow conditions on freeways in addition to injury and fatalities, albeit their magnitudes are relatively low when compared to primary crashes. Due to the limited nature of crash data in analyzing freeway SCs, surrogate measures provide an alternative for safety analysis for freeway analysis using conflict analysis. Connected Vehicles (CVs) have seen compelling technological advancements since the concept was introduced in the 1990s. In recent years, CVs have emerged as a …


Operational Effectiveness Of Connected Vehicle Smartphone Technology On A Signalized Corridor, Festo Mjogolo Jan 2019

Operational Effectiveness Of Connected Vehicle Smartphone Technology On A Signalized Corridor, Festo Mjogolo

UNF Graduate Theses and Dissertations

Over the last decade, extensive research efforts have been placed on performance evaluation and the benefits of innovative CV applications. Findings indicate that CV technology can effectively mitigate the safety, mobility, and environmental challenges experienced on transportation networks. Most of research evaluated CV technology through simulation studies. However, a field study provides a more ideal method of assessing CV technology effectiveness. Therefore, a field study to obtain the actual effectiveness of CV technology was warranted, to validate previous findings, and to add to the body of knowledge surrounding this topic. This thesis presents both a field study and simulation evaluation …


The Operational And Safety Effects Of Heavy Duty Vehicles Platooning, Ahmed Alzahrani Jan 2019

The Operational And Safety Effects Of Heavy Duty Vehicles Platooning, Ahmed Alzahrani

UNF Graduate Theses and Dissertations

Abstract

Although researchers have studied the effects of platooning, most of the work done so far has focused on fuel consumption. There are a few studies that have targeted the impact of platooning on the highway operations and safety. This thesis focuses on the impact of heavy-duty vehicles (HDVs) platooning on highway characteristics. Specifically, this study aims at evaluating the effects of platooning of HDVs on capacity, safety, and CO2 emissions.

This study is based on a hypothetical model that was created using the VISSIM software. VISSIM is a powerful simulation software designed to mimic the field traffic flow …


A Study On Erosion Resistance For Microbially Induced Calcite Treated Beach Sand, Abigail Chek Jan 2019

A Study On Erosion Resistance For Microbially Induced Calcite Treated Beach Sand, Abigail Chek

UNF Graduate Theses and Dissertations

Microbial induced calcite precipitation (MICP) was used to treat several sandboxes filled with naturally occurring beach sand collected from Atlantic Beach, FL. Unlike most previous MICP studies, a surface-spray technique was used to treat these sandboxes where relatively high-concentration bacteria solution and high concentration calcium chloride/urea solutions were applied directly to the boxes’ surfaces. Several different treatment combinations were tested whereby bacterial optical density, bacteria/urea/calcium chloride volume relative to void space, and bacteria/urea/calcium chloride ratio were manipulated. Treated sandboxes were tested for erodibility using a pocket erodometer and for calcification using a wash method. In addition, sandboxes were dissected after …


Evaluating The Performance Of Cooperative Merging Assistance System For Aging Drivers, Flavius Matata Jan 2019

Evaluating The Performance Of Cooperative Merging Assistance System For Aging Drivers, Flavius Matata

UNF Graduate Theses and Dissertations

Freeway merging maneuvers demand considerable attention by drivers and are among the more complex operations drivers must perform on freeways. Aging drivers, a growing population in the United States, face added challenges when merging. This study utilized Vissim models created in a previous study that modeled the behavior of aging drivers during freeway merging. An algorithm for Cooperative Merging Assistance System (CMAS) that utilizes Connected Vehicle (CV) technology was developed in this study. The Vissim models were created for two interchanges on I-75 in Fort Myers, Florida, each with different geometric characteristics. Acceleration lane lengths of 1000ft and 1500ft were …


An Analysis Of Hydroacoustic Transmission Loss Associated With Marine Pile Driving, Jonathan Paul Berube Jan 2019

An Analysis Of Hydroacoustic Transmission Loss Associated With Marine Pile Driving, Jonathan Paul Berube

UNF Graduate Theses and Dissertations

There has been a growing concern in recent years about the effects of anthropogenic noise due to marine pile driving on underwater wildlife. Current guidelines for mitigating hydroacoustic effects associated with these events are based upon relatively simple transmission loss formulations. The advantage to these guidelines is that computing transmission loss using their prescribed methods is not labor intensive, but their disadvantage is that they may not take all variables into account. Because of this, it may be possible to improve transmission loss computations. To better-characterize marine pile driving sound transmission loss, a unique in-water instrumentation system was developed. This …


Effect Of Vessel-Generated Waves In Near Low Tide Conditions On Shorelines In The Intracoastal Waterways, Mackenzie Lee Sanchez Jan 2018

Effect Of Vessel-Generated Waves In Near Low Tide Conditions On Shorelines In The Intracoastal Waterways, Mackenzie Lee Sanchez

UNF Graduate Theses and Dissertations

Erosion is caused when there is a net loss of sediment in a coastal system, i.e. when the amount of sediment leaving a system is more than the amount of sediment entering that same system. This investigation will focus on vessel-generated waves and their effect on the shorelines of the Jacksonville, Florida Intracoastal Waterways near low tide conditions. The investigation conducted herein examines variations in turbidity and pressure measurements in response to passing vessels at a single site location previously selected in 2016. The primary water/shoreline interaction recorded during this investigation is located below the visible scarp (near low tide …


An Integrated Closed Convergent System For Optimal Extraction Of Head-Driven Tidal Energy, Michelle Ann Vieira Jan 2018

An Integrated Closed Convergent System For Optimal Extraction Of Head-Driven Tidal Energy, Michelle Ann Vieira

UNF Graduate Theses and Dissertations

As the demands for energy increased with the global increase in population, there is a need to create and invest in more clean and renewable energy sources. Energy derived from the movement of the tides is an ancient concept that is currently being harnessed in a handful of large tidal range locations. However, the need to move from fossil fuel driven energy sources to those that are clean and non-polluting is a priority for a sustainable future. Globally, hydropower potential is estimated to be more than 16,400-Terawatt hours annually. Given that the electricity consumption worldwide was at 15,068-Terawatt hours in …


Development Of Forward And Inversion Schemes For Cross-Borehole Ground Penetrating Radar, Donald Jones Jan 2018

Development Of Forward And Inversion Schemes For Cross-Borehole Ground Penetrating Radar, Donald Jones

UNF Graduate Theses and Dissertations

Tomography is an imaging technique to develop a representation of the internal features of material using a penetrating wave, such as an electromagnetic wave. The calculation method used is an example of an inverse problem, which is a system where the input and the output are known but the internal parameters are not. These parameters can be estimated by understanding the responses of a penetrating wave as it passes through the unknown media. A forward problem is just the opposite; the internal structure and input penetrating wave is known and the output is determined. For both forward and inverse problems, …


Development Of A One-Way Coupled Diffraction/Trapped Air Model For Predicting Wave Loading On Bridge Superstructure Under Water Wave Attack, Christian Hillary Matemu Jan 2018

Development Of A One-Way Coupled Diffraction/Trapped Air Model For Predicting Wave Loading On Bridge Superstructure Under Water Wave Attack, Christian Hillary Matemu

UNF Graduate Theses and Dissertations

In recent years, a number of researchers have applied various computational methods to study wind wave and tsunami forcing on bridge superstructure problems. Usually, these computational analyses rely upon application of computational fluid dynamic (CFD) codes. While CFD models may provide reasonable results, their disadvantage is that they tend to be computationally expensive. During this study, an alternative computational method was explored in which a previously-developed diffraction model was combined with a previously-developed trapped air model under worst-case wave loading conditions (i.e. when the water surface was at the same elevation as the bottom bridge chord elevation). The governing equations …


A Novel Design To Harness Water-Wave Energy, Abdallah El Safty, Abdallah Walid El Safty Jan 2018

A Novel Design To Harness Water-Wave Energy, Abdallah El Safty, Abdallah Walid El Safty

UNF Graduate Theses and Dissertations

Renewable energy sources are essential to our future, not only because they generally minimize harm to our environment but are also a relatively free source of energy that are available for generations to come. Wind and solar energy are proven sources of renewable energy, but both are highly variable. On the other hand, water wave energy is relatively persistent in locations around the world. Many researchers have tried to capture the energy of ocean waves, some were successful, but most were not. Harnessing wave energy is not a simple matter. One must design systems that can withstand the extreme forces …


The Role Of Wave Self-Similarity In Nearshore Wave Spectra, Morgan M. Smith Mr. Jan 2018

The Role Of Wave Self-Similarity In Nearshore Wave Spectra, Morgan M. Smith Mr.

UNF Graduate Theses and Dissertations

Nonlinear wave-wave interactions and wave breaking contribute to nearshore wave energy dissipation. These factors can be analyzed by the principles of wave self-similarity. The equilibrium range can be shown in wind-driven wave spectra that exist in the form ( ) and However, the appropriate methods used to determine this loss of energy are controversial. This study examines an approach that reinvestigates the self-similarity principles. Wave spectra with lower peak periods are dominated by nonlinear wave-wave interactions which produce a scaling in shallow water. This thesis investigates the relative role of spectral similarity in different conditions in the nearshore region of …


Evaluation Of Traffic Incident Timeline To Quantify The Performance Of Incident Management Strategies, Henrick Joseph Haule Jan 2018

Evaluation Of Traffic Incident Timeline To Quantify The Performance Of Incident Management Strategies, Henrick Joseph Haule

UNF Graduate Theses and Dissertations

Transportation agencies are introducing new strategies and techniques that will improve traffic incident management. Apart from other indicators, agencies measure the performance of the strategies by evaluating the incidents timeline. An effective strategy has to reduce the length of the incident timeline. An incident timeline comprises various stages in the incident management procedure, starting when the incident was detected, and ending when there is the recovery of normal traffic conditions. This thesis addresses three issues that are related to the traffic incident timeline and the incident management strategies.

First, co-location of responding agencies has not been investigated as other incident …


Soil Improvement Using Microbial Induced Calcite Precipitation And Surfactant Induced Soil Strengthening, Matthew P. Davies Jan 2018

Soil Improvement Using Microbial Induced Calcite Precipitation And Surfactant Induced Soil Strengthening, Matthew P. Davies

UNF Graduate Theses and Dissertations

Microbially induced calcite precipitation (MICP) has been used for a number of years as a technique for the improvement of various geological materials. MICP has been used in a limited capacity in organic rich soils with varying degrees of success. Investigators hypothesized that microbially-induced cementation could be improved in organic soils by using a surfactant. Varying amounts of Sodium Dodecyl Sulfate (SDS) were added to soils of varying organic content and a mixing procedure was used to treat these soils via MICP. Treated specimens were tested for unconfined compressive strength (UCS). Results appeared to show direct relationships between SDS content …


Potential Replacement Of The Us Navy's Rapid Penetration Test With The Method Of Multichannel Analysis Of Surface Waves, William Fletcher Jan 2018

Potential Replacement Of The Us Navy's Rapid Penetration Test With The Method Of Multichannel Analysis Of Surface Waves, William Fletcher

UNF Graduate Theses and Dissertations

The United States Navy (USN) currently utilizes a Rapid Penetration Test (RPT) on both land and in water as the means to determine whether sufficient soil bearing capacity exists for piles in axial compression, prior to construction of the Elevated Causeway System (Modular) [ELCAS(M)] pile-supported pier system. The USN desires a replacement for the RPT because of issues with the method incorrectly classifying soils as well as the need to have a less labor-and-equipment-intensive method for geotechnical investigation.

The Multichannel Analysis of Surface Waves (MASW) method is selected herein as the potential replacement for the RPT. The MASW method is …


Enhancing The Existing Microscopic Simulation Modeling Practice For Express Lane Facilities, Kelvin S. Machumu Jan 2017

Enhancing The Existing Microscopic Simulation Modeling Practice For Express Lane Facilities, Kelvin S. Machumu

UNF Graduate Theses and Dissertations

The implementation of managed lanes (MLs), also known as dynamically priced express lanes, to improve freeway traffic flow and personal throughput is on the rise. Congestion pricing is increasingly becoming a common strategy for congestion management, often requiring microscopic simulation during both planning and operational stages. VISSIM is a recognized microscopic simulation software used for analyzing the performance of managed lanes (MLs). This thesis addressed two important microscopic simulation issues that affect the evaluation results of MLs.

One of the microscopic simulation issues that has not yet been addressed by previous studies is the required minimum managed lane routing decision …


Strength Property Variability In Microbial Induced Calcite Precipitation Soils, Jacob Fuller Jan 2017

Strength Property Variability In Microbial Induced Calcite Precipitation Soils, Jacob Fuller

UNF Graduate Theses and Dissertations

Microbial Induced Calcite Precipitation (MICP) is an attractive alternative for a variety geotechnical ground improvement practices commonly used today and has a variety of potential applications. This research focuses primarily on its use as a soil stabilization technique using the bacteria Sporosarcina Pasteurii and a single injection point percolation method adapted from previous research in granular soils. This method, and most published data, show an inherent variability in both physical and engineering properties due to the distribution of precipitated calcite within the specimen. The focus of this research is on the quantification of the variability in shear strength parameters induced …


Safety Implications Of Transit Operator Schedule Policies, Hung Hoang Jan 2016

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 …