Civil Engineering Commons^™

Degradation Performance Modeling And Optimal Maintenance Planning Of Deteriorating Critical Infrastructures, Hung Q. Nguyen

USF Tampa Graduate Theses and Dissertations

Serving as the backbone of the nation’s economy, a large and growing number of deteriorating critical infrastructures, such as transportation and water infrastructures, are underperforming, aging, becoming structurally deficient, and must be repaired or replaced. Due to the influence of a variety of factors (e.g., material structure, design, operation, and environmental conditions) at different phases of lifecycle and the costly data acquisition process, field degradation of deteriorating infrastructures is highly uncertain with limited degradation data. The co-location and spatial proximity between many infrastructures, such as road and water infrastructures, further makes them physically and operationally interdependent. The sheer deterioration of …

Simulating Flood Control In Progress Village, Florida Using Storm Water Management Model (Swmm), Azize Minaz

USF Tampa Graduate Theses and Dissertations

Flooding is a natural event caused by heavy rains, melting snow, high tides, and anthropogenic impacts such as channel clogging, improper land use, and deforestation. In this study, the strategies for controlling flooding seek to establish flood prevention systems by implementing grey infrastructure and green infrastructure practices. The main objective of this thesis is to analyze the study area, Progress Village Neighborhood in Delaney Creek Watershed, regarding flood risk and flood mitigation techniques. The analysis was performed using EPA SWMM 5.1 and Arcmap 10.7.1. The study used design storms,10-years 24 hours and 25-years 24 hours, to analyze flood risk in …

Impedance Analysis Of Anodized Aluminum And Structural Bridge Tendons, Justin Silnutzer

USF Tampa Graduate Theses and Dissertations

This is a two-part thesis with the overall investigation technique being electrochemical impedance spectroscopy (EIS). In the first part, EIS is used to estimate the layer thickness of anodized aluminum oxide. This required the development of an appropriate electrical circuit model; that with parameters that correspond to physical properties of the oxide. In this work, it was found that for thicker oxides of which the outer porous layer is greater than 12 microns, impedance may be used to estimate the outer layer thickness. However, further research is required to understand the role of outer porous layer structure on the impedance …

Effects Of Slurry Type On Drilled Shaft Strength, Cesar Quesada Garcia

USF Tampa Graduate Theses and Dissertations

The main objective of this research is to identify how the strength of drilled shafts is affected by the use of various types of drill slurry. When concrete is placed in drilled shafts it flows out radially and a laitance interface forms creating a crease on the backside of the reinforcement cage due to the laitance trapped in concrete flowing around the rebar. This can cause concrete to not fully encapsulate the steel making the shafts prone to corrosion and the strength of the cover concrete is locally reduced. Over the past 9 years 58, 42-inch diameter shafts have been …

High-Risk Traffic Crash Pattern Recognition And Identification Using Econometric Models And Machine Learning Models, Runan Yang

USF Tampa Graduate Theses and Dissertations

Roadway crashes have become a major cause of human deaths and injuries and caused much economic damage. According to World Health Organization (WHO), about 1.35 million people died in traffic crashes and over 50 million people injured from traffic crashes in the year of 2016 (World Health Organization, 2020). Nationally, in the U.S., the latest decade witnessed an increase of over 10% in traffic fatalities (National Highway Traffic Safety Administration (NHTSA), 2019). Similarly, in state of Florida, the fatal crashes increased by 4.62% from 2019 to 2020 (Florida Department of Highway Safety and Motor Vehicles, 2021). To prevent injuries and …

Assessment Of Scoured Bridges Subjected To Vessel Impact Using Nonlinear Dynamic Analysis, Amir S. Irhayyim

USF Tampa Graduate Theses and Dissertations

Scour has been the number one cause of bridge failure in the United States with an average of 22 bridges collapsing or being closed owing to severe deformation each year [1]. This work attempts to deal with two important issues: (1) Potential bridge failures during the co-occurrence of scour and ship impact; (2) Incorporating IDA analysis to predict bridge responses based on barge and collision parameters, and to generate fragility curves to predict the probability of exceedance damage states.

For bridges, flooding is considered the most threatening hazard. According to the National Bridge Inventory (NBI) [2], 500,000 out of 615,000 …

Estimating The As-Placed Grout Volume Of Auger Cast Piles, Tristen Mee

USF Tampa Graduate Theses and Dissertations

Augered Cast-in-Place (ACIP) piles are a geotechnical foundation element increasingly used to support large publicly funded structures as an alternative to drilled shafts or driven piles. ACIP piles are constructed by drilling an excavation to the full length of the designed pile with a continuous flight auger. Grout (cement, sand, and water mixture) is then pumped through the hollow auger stem to begin grouting the excavation. After establishing an initial head pressure, the auger is slowly extracted while the remainder of the pile is grouted. Once the auger is completely removed, the steel reinforcement cage is lowered into the grouted …

Effects Of Downdrag On Pile Performance, Malaak Omelia Araujo

USF Tampa Graduate Theses and Dissertations

All soils settle under the weight of newly constructed embankments. In the case of MSE wall-type embankments, piles are driven prior to embankment construction. Under the weight of the newly constructed embankment, the soil surrounding the piles may settle more than the piles themselves. This downward movement potentially drags the piles down and induces a force within the pile known as downdrag. The research on the downdrag phenomenon involving cohesionless granular soils is sparse, thus the focus of this study is to investigate the effects of downdrag on pile performance driven in Florida sandy soils. A site consisting of soil …

The Impact Of Land Use Change On Hydrology Using Hydrologic Modelling And Geographical Information System (Gis), Nattachan Luesaksiriwattana

USF Tampa Graduate Theses and Dissertations

Surface and groundwater conditions in west-central Florida are highly interactive, with shallow water table and sandy soil. Land use types including forests, agricultural areas, and urbanization affect water resources differently. Change in land use, associated with expanding the urban environment to support human needs, significantly impacts surface water infiltration and runoff characteristics. Construction of infrastructures such as buildings and housing can result less water to infiltrate through the soil, with increased surface water runoff and decline in evapotranspiration. A computerized hydrologic model, Hydrological Simulation Program-FORTRAN (HSPF), couple to a spreadsheet groundwater model and a Geographical Information System (GIS) were applied …

Chlorine Taste Threshold And Acceptability As A Water Disinfectant Among Indigenous Ngäbe And Non-Indigenous In Rural Panama, Ashley Osler

USF Tampa Graduate Theses and Dissertations

More than two billion people globally still lack access to safely managed drinking water (WHO & UNICEF, 2021). Although gains in access to water service over the past two decades have been large, universal access to safe and affordable drinking water (SDG 6, target 6.1) is not on track to be achieved. In Panama, safely managed drinking water access has not been measured. However, the data on basic water access illustrates the large disparities between rural and urban areas of Panama. While 98% of urban Panamanian households have basic access to water, only 86% of rural Panamanian households, and 54% …

Trajectory Optimization For Connected And Autonomous Vehicle Platooning And Split Operations: Modeling And Experiments, Qianwen Li

USF Tampa Graduate Theses and Dissertations

Emerging connected and autonomous vehicle (CAV) platoon technology holds great potential in improving mobility, enhancing riding comfort, reducing fuel consumption, and mitigating congestion. It reduces car-following gaps via cyber connections. Further, it smooths vehicle trajectories via automated control. Smoothed trajectories and improved aerodynamic efficiency from reduced car-following gaps improve fuel and space efficiency, thus improving traffic performance.

Motivated by such promising advantages, this dissertation investigates trajectory optimization for two basic CAV platoon operations, i.e., platooning and split, which are the premise to implement this technology to benefit society. Two two-stage optimization problems are formulated to solve the platooning and split …

A System Architecture For Water Distribution Networks, Noha Abdel-Mottaleb

USF Tampa Graduate Theses and Dissertations

This dissertation examines structure-function relationships of water distribution networks (WDNs), with focus on improving the decision-making process for water utilities. WDNs are lifeline infrastructure systems, necessary for the functioning of cities. Yet water utilities around the world struggle with emerging challenges that include but are not limited to aging infrastructure components, limited budgets, increased interdependencies between infrastructure systems, increased rates of urbanization, and increasing extreme weather conditions. This is why enhancing the performance of WDNs is a priority for water utilities around the world. This research begins to delineate a system architecture for WDNs and evaluates the use of various …

An Assessment And Exploration Of Recent Methodological Advances In Safety Data Analysis, Suryaprasanna Kumar Balusu

USF Tampa Graduate Theses and Dissertations

The injury severity and frequency of traffic crashes can be further reduced by implementing appropriate traffic safety measures. Several advanced methodologies have been developed in the recent decades to more accurately identify the factors affecting road safety. Such methodologies have helped policy makers formulate appropriate safety measures directed toward increasing seatbelt and helmet use, reducing speed limits in school zones, implementing adolescent driver programs, and so on. However, each methodological approach has its own strengths and weakness and could lead to different inferences. This dissertation assesses and explores a number of recently developed methodologies and their application to traffic safety …

Minimum Cut-Sets For The Identification Of Critical Water Distribution Network Segments, Xiliang Mao

USF Tampa Graduate Theses and Dissertations

To ensure adequate performance of water distribution networks, utilities must identify critical segments within the network that will adversely affect users when failures occur. Currently, time consuming hydraulic simulations are used for such criticality analyses. A method can be of great benefit for utilities if it can easily evaluate the criticality of water distribution network segments. This research applies topology-based methods for the preliminary screening of critical segments. This study evaluated the connectivity between sources and each demand segment in water distribution networks using minimum cut-sets. Through topological analysis, the minimum cut -set between the source node and each demand …

Influence Of Coating Defects Within The Lock Seams On The Corrosion Performance Of Aluminized Steel Drainage Pipes, Mohammed Al Yaarubi

USF Tampa Graduate Theses and Dissertations

The electrochemical behavior of aluminized steel is investigated to determine the corrosion performance of coating deficiencies generated within the lock seams during the fabrication of aluminized steel corrugated pipe. Electrochemical techniques and visual and profilometric analysis are used to assess the ability of the aluminum and zinc coating to provide sufficient galvanic protection to the underlying steel in the presence of a crevice. Also, Crevice coupons and lock-seam samples were used in this investigation in different environmental conditions simulating natural water conditions to relate the corrosion rate with the level of protection that the coating will provide. In addition, a …

Corrosion Propagation Of Stainless Steel Reinforced Concrete, Nelly Sofía Orozco Martínez

USF Tampa Graduate Theses and Dissertations

Structural durability is a growing concern in global infrastructure. The infrastructure report card released by the American Society of Civil Engineers (ASCE) indicates that approximately 9.1% of the total bridges in the United States were structurally deficient in 2016. In addition, it suggests that about 40% of the total bridges in the country are now 50 years or older. This issue becomes even more critical in structures exposed to aggressive environments such as marine structures. Thus, federal and regional efforts are now being directed towards infrastructural durability improvement to improve the long-term cost-efficiency of civil infrastructure.

Corrosion prevention strategies may …

Corrosion Durability Service Life Of Calcium Silicate-Based Reinforced Concrete, Carolina Páez Jiménez

USF Tampa Graduate Theses and Dissertations

Corrosion of reinforcing steel is a major area of study for assessing durability of reinforced concrete infrastructure. Conventional concrete infrastructure designs use ordinary Portland cement (OPC) as the primary cementitious material. However, the world's current challenge to achieve sustainable development requires the cement industry to reduce its environmental impact, as it is responsible for 8% of the anthropogenic CO2 emissions. Hence, a new type of cement has been developed. This novel calcium silicate cement (CSC) reduces the carbon dioxide emissions during its manufacturing process as compared to OPC, providing an environmentally-sound alternative for reinforced concrete fabrication.

Corrosion of steel reinforcement …

Corrosion Rate Prediction In Frp-Concrete Repair, Mohammad A. Khawaja

USF Tampa Graduate Theses and Dissertations

Research has proven that wrapping structural elements with fiber-reinforced polymers (FRPs) slows down chloride-induced corrosion rate but does not stop it. Although FRP has been used for corrosion repair for over 40 years, predictive corrosion rate models for FRP-concrete systems are limited in literature. This dissertation presents an oxygen diffusion-based predictive framework to estimate corrosion rate in FRP-concrete systems.

The dissertation has three main components. First, a core framework that is referred to as Khawaja-Sen-Bhethanabotla (KSB) model. In the KSB model, statistical methods were used to extend experimental data on oxygen permeation coefficients. These data were for one and two …

Longitudinal Trajectory Tracking Analysis For Autonomous Electric Vehicles Based On Pid Control, Hossein Amiri

USF Tampa Graduate Theses and Dissertations

The implementation of autonomous vehicles has huge potential for revolutionizing transportation as we currently know it. All use cases of autonomous vehicles require the vehicle to travel on a pre-specified path. Accurate tracking of this defined trajectory is a crucial aspect of the implementation of autonomous vehicles; a controller system is required to translate this pre- defined trajectory in the form of the throttle, brake, and steering inputs. This project covers the application of a Proportional-Integral-Derivative (PID) controller to achieve longitudinal trajectory tracking of autonomous electric vehicles with stability and accuracy in the CARLA autonomous driving simulation platform. The implemented …

Prediction Of The Effects Of Turbulence On Vehicle Hydroplaning Using A Numerical Model, Thathsarani Dilini Herath Herath Mudiyanselage

USF Tampa Graduate Theses and Dissertations

Pneumatic hydroplaning has been identified as one of the major causes of wet weathertraffic accidents. Therefore, knowledge of potential hydroplaning speeds is crucial in designing roadways to reduce crash risks. It has been shown that the tire inflation pressure is the predominant factor affecting the hydroplaning speed while factors such as the water film thickness also contribute heavily to this phenomenon. Extensive research has been directed at the development of accurate models to predict the effects of vehicle characteristics, pavement conditions and water film thickness on hydroplaning. Current literature does not indicate any studies directed at understanding the effects of …

Feasibility Of Epoxy Bond Enhancement On High-Strength Concrete, Amanda A. Lewis

USF Tampa Graduate Theses and Dissertations

While fiber-reinforced polymer materials have many applications in various industries,when used structurally, many cases, such as flexural and shear strengthening, are considered bond critical. Interfacial bond quality between a fiber-reinforced polymer system and the substrate is dependent on two mechanisms: chemical bonding and mechanical interlock, with mechanical interlock having the greater effect on bond quality. Mechanical interlock describes the type of bond that occurs as a result of surface roughness and substrate porosity and can be significantly affected by surface preparation methods and surface moisture. This study aims to explore the possibility of enhancing bond quality between carbon-fiberreinforced polymers and …

The Effect Of Cement And Blast Furnace Slag Characteristics On Expansion Of Heat-Cured Mortar Specimens, Jair G. Burgos

USF Tampa Graduate Theses and Dissertations

Delayed ettringite formation (DEF) is a durability issue that typically occurs in concrete exposed to high temperatures at an early age such as precast elements and massive concrete structural elements. There are many advantages to precast concrete such as its quality control, better safety control, and reusable forms, which make them cheaper than casting on site [1]. Heat curing of precast concrete is conducted to obtain high early-strength. However, in doing so, durability issues can arise in the form of internal sulfate attack also known as DEF, if the internal temperature of concrete exceeds 70°C. Past this threshold, ettringite decomposes …

Designing Next-Generation Transportation Systems With Emerging Vehicle Technologies, Zhiwei Chen

USF Tampa Graduate Theses and Dissertations

Recent advances in computing and artificial intelligence have enabled the development of various emerging vehicle technologies, e.g., autonomous vehicles (AV) and modular autonomous vehicles (MAV). These technologies bring new scientific and engineering problems challenging transportation researchers and practitioners. This dissertation aims to develop a suite of scalable computational and analytical tools for designing and analyzing next-generation transportation systems with the MAV technologies. Also, we intend to empirically study the system impacts in terms of the quality of service, energy implications, and inequality impacts.

For MAV system design, we develop a methodological framework centering at theoretical properties of the optimal system …

Strength Restoration Of Corrosion Damaged Piles Repaired With Carbon Fiber Reinforced Polymer Systems, Jethro Clarke

USF Tampa Graduate Theses and Dissertations

Of the 12,741 bridges accounted for by the Florida Department of Transportation (FDOT), approximately 50% were built between the 1950s and 1960s. During this period, bridges were typically constructed in coastal environments using pile bents. Now, the main threat to bridges in these environments is corrosion, which occurs in the splash zones of most bridge piles. These zones contain high concentrations of chlorides, oxygen and moisture, the corner stones of a highly corrosive environment. Corrosion compromises steel reinforcement in these areas leading to cracking, spalling and an inevitable loss of capacity.

In recent years, significant strides have been made in …

An Inferential Study Of The Potential Consumer Value Of Free Charging For Users Of Public Electric Vehicle Charging Infrastructure, Divyamitra Mishra

USF Tampa Graduate Theses and Dissertations

Although there is economic and marketing evidence of consumers assigning additional benefits to free products and bundles, there is limited research into the behavioral consequences of offering public electric vehicle charging for free. Previous exploratory research by Maness and Lin analyzed possible economic and environmental benefits from offering free public charging infrastructure and policy. Their work found that providing free public charging infrastructure could increase plug-in electric vehicle sales and cause decreased reliance on fossil fuels in the personal transportation sector. However, their study assumed the increased value which consumers would place on free charge events. This project proposes to …

Effects Of Physical And Chemical Characteristics Of Slags And Cements On Durability Of Portland Cement-Slag Blended Systems, Farzaneh Nosouhian

USF Tampa Graduate Theses and Dissertations

Ground granulated blast furnace slag (GGBFS) which is a commonly used supplementary cementitious material (SCM) needs to be more investigated for improving durability of concrete elements and service life of concrete structures. This research focuses on the effect of the physical and chemical characteristics of GGBFS and portland cement on durability of portland cement-slag blended systems. The effect of cement replacement level is also investigated using control mixes (no slag) and four different levels of slag content. To this end, eight GGBFS and eight portland cements were selected based on their physical characteristics and chemical composition. Four series of experimental …

The Effects Of Surface-Water Flow On The Quality Of Groundwater And Surface-Water Systems, Quanghee Yi

USF Tampa Graduate Theses and Dissertations

My research has focused on the effects of surface-water flow on the quality of groundwater and surfacewater systems. For the first part of my research (Chapter 2 ), I s tudied the effects of s urface flow system changes in the water-conservation areas and canals in southeast Florida on the quality of groundwater in the surficial aquifer system.

For the second part of my research, by developing analytical models using the superposition method, I investigated the effects of bidirectional surface-water flow on the conservative contaminant concentrations (Chapter 4) and mean residence time (Chapter 5) in streams and rivers as well …

Structural And Agricultural Value At Risk In Florida From Flooding During Hurricane Irma, Alexander J. Miller

USF Tampa Graduate Theses and Dissertations

Flooding is the most costly type of natural disaster, as well as the most frequent. To provide risk-based flood insurance, providers such as FEMA must be able to accurately determine an asset’s risk of flooding. Additionally, after a flooding event, providers need to quickly determine the direct damages that occurred to verify insurance claims and provide assistance to the affected communities. Many current approaches to flood risk and flood damage estimation involve the use of data or statistical extrapolation that can add various sources of uncertainty into the final damage estimate. In order to reduce uncertainties in flood risk analyses, …

Post-Overlay Flexible Pavement Performance Modeling And Its Application In Sustainable Asphalt Overlay Policy Making, Chunfu Xin

USF Tampa Graduate Theses and Dissertations

Highway pavement is a critical component of the highway transportation infrastructure. After the construction of a pavement system, pavement condition will deteriorate over time due to a combination effect of material aging, traffic loading, and environmental impact. To restore the pavement performance and to reduce its adverse effects on public users and environment, asphalt overlay activities are conducted frequently during the service life of a pavement. As a key component that bridges the overlay policies with future pavement performance, economic cost and environmental impact, the forecast accuracy of post-overlay pavement performance model is extremely important. However, most of previous studies …

Rapid Cross-Section Imaging With Magnetic And Impedance Sensors For Grout Anomaly Detection In External Post-Tensioned Tendons, Hani Freij

USF Tampa Graduate Theses and Dissertations

Post-tensioned (PT) bridges have had severe corrosion issues with tendons that fail suddenly without prior notice. The corrosion of external post-tensioned tendons has been associated with grout deficiencies/anomalies from inadequate grouting. Deficiencies include voids, regions of chalky low strength grout, and regions where excessive water content or even free water is present. In those zones mechanical bonding of strand to the grout is degraded and, of more concern, the strand steel risks corrosion failure reducing the expected lifespan of the structure. As tendons are critical structural components, it is important to detect those deficiencies during inspection preferably by a cross …