Civil Engineering Commons^™

A Simplified Stress Analysis Of Functionally Graded Beams And Influence Of Material Function On Deflection, Elias Ali

Faculty Scholarship

This paper aims at providing a simplified analytical solution for functionally graded beam stress analysis and optimized material gradation on the beam deflection. The power-law (P-FGM) and exponential (E-FGM) material functions were considered for an exact solution of the normal and shear stress distributions across the beam thickness. Optimization of material function on the FGM beam deflection, which is new of its kind, was also investigated considering both simply supported and cantilever beams. It was observed that the non-dimensional normal stress and shear stress are independent of the elastic moduli values of the constituent materials but rather depends on both …

Multi-Type Assessment Of Global Droughts And Teleconnections, Zahir Nikraftar, Abdorrahman Mostafaie, Mojtaba Sadegh, Javad Hatami Afkueieh, Biswajeet Pradhan

Civil Engineering Faculty Publications and Presentations

Several drought indices have been developed based on various processes (e.g., precipitation, soil moisture, vegetation health) that respond differently to modes of climate variability, shadowing their relatability to teleconnections, which in turn, limits drought forecasting. In this study, we advanced the multivariate analysis of droughts by using long-term Terrestrial Water Storage estimates, soil moisture and precipitation data along with normalized difference vegetation index. To this end, we employed a Vine copula approach using Archimedean and Elliptical copula families to generate two novel multivariate drought indices called Combined Standardized Drought Index (CSDI), based on agricultural, meteorological, hydrological and ecological univariate indices …

Factors Influencing The Usage Of Shared E-Scooters In Chicago, Farzana Mehzabin Tuli, Suman Mitra, Mariah B. Crews

Civil Engineering Faculty Publications and Presentations

The rapid popularity growth of shared e-scooters creates the necessity of understanding the determinants of shared e-scooter usage. This paper estimates the impacts of temporal variables (weather data, weekday/weekend, and gasoline prices) and time-invariant variables (socio-demographic, built environment, and neighborhood characteristics) on the shared e-scooter demand by using four months (June 2019-October 2019) period of data from the shared e-scooter pilot program in Chicago. The study employs a random-effects negative binomial (RENB) model that effectively models shared e-scooter trip origin and destination count data with over-dispersion while capturing serial autocorrelation in the data. Results of temporal variables indicate that shared …

An Experimental And Computational Study Of 3-Dimensional Compact Windborne Debris Flight, Ta'jon Jordan

All Theses

In this thesis, the stochastic nature of 3-dimensional compact windborne debris flight is investigated experimentally and computationally. Previous literature (Holmes, 2004) analyzed the impact of strong winds on compact debris with applications to windborne debris flight. Baker (2007) derived the 2-dimensional equations of motion into a generalized dimensionless form that reveals the fundamental controlling parameters of compact debris flight. However, these models assume that compact debris is spherical, and the flight is, therefore, 2-dimensional. However most compact debris is not spherical, and its flight is 3-dimensional. Herein a previously developed model for free-falling compact windborne debris flight (Ahsanulllah et al., …

An Investigation Of The Flexural Strength And Toughness Of Hybrid Plain And Fiber Reinforced Concrete For Pavement Applications, Wesley Keys

Graduate Theses and Dissertations

For decades, many solutions have been evaluated to combat cracking in concrete pavements. The study presented in this paper evaluates and compares the flexural performance under a third point loading configuration of plain concrete (PC) beams, fully fiber reinforced concrete (FRC) beams, and hybrid PC and FRC beams, with a top PC and bottom FRC layer. The purpose of this hybrid approach was to provide FRC in only half the section, saving cost, while providing a PC surface layer that is easier to finish. All PC top layers were applied at an age of 7-days, considered a reasonable time for …

Retrospective Analysis Of Impacts Of Highway Bypass And Widening Projects, Sanjeev Bhurtyal

Graduate Theses and Dissertations

Community members often worry that highway projects may have negative impacts on their local economies. This is typical for highway bypass and widening projects in small cities (population less than 50,000). It is a challenge for planners to balance public concerns of economic decline with desired project outcomes of mobility and safety. Much of this challenge stems from a lack of information on post-project outcomes related to economic and safety impacts of new construction projects. Thus, there is a need for an evidence-based framework to help planners with the decision-making process and better inform the community on potential outcomes. This …

Additive Manufacturing Of Soil Using Bio-Cementation, Christina Childress

Graduate Theses and Dissertations

Microbially Induced Calcite Precipitation (MICP) is an emerging soil treatment technique that is proven to increase strength, decrease erosion, reduce liquefaction risk, enhance slope stability, decrease compressibility, decrease swelling potential, and overall create a more competent soil. The benefits and applications of MICP are broad, and this research seeks to broaden them further by developing a single-phase additive manufacturing application with no treatment time delay. This is done by analyzing layering behaviors of five USCS soil classifications (100 % Ottawa sand, sand clay mixtures, and 100% lean clay) which provides insight into process variables such as the solution volume and …

Shear Strength Of Concrete Beams Made With Belitic Calcium Sulfoaluminate Cement, Caleb W. Chesnut

Graduate Theses and Dissertations

The need for a cleaner alternative to portland cement (PC) concrete has led to increasing interest in alternatives to PC. Structural properties of most of these alternative cements are still an open research topic. One promising alternative cement is belitic calcium sulfoaluminate (BCSA) cement. The study presented in this paper investigated the shear strength, long term compressive strength, and carbonation in BCSA cement and PC concrete beams. A total of twelve eight-foot long beams were made; eight BCSA cement concrete beams and four PC concrete beams to be tested at various ages depending on cement type. Two beams of each …

Improve The Prediction Of Camber, Deflection, And Prestress Losses In Precast, Prestressed Concrete Bridge Girders, Ahmed Ali Hussein Al Mohammedi

Graduate Theses and Dissertations

Many precast, prestressed concrete girders have camber less or higher than the design values. This discrepancy between the design and the actual camber creates construction problems when installing the cast-in-place concrete deck. The objective of this research was to improve the accuracy of estimating long-term camber, deflection, and prestress losses of precast, prestressed concrete girders.

The experimental program consisted of measuring concrete properties and performing field measurements of camber, deflection, and prestress losses for girders in Arkansas. The investigation involved testing nine full-scale girders from two prestressed concrete plants that regularly supply concrete girders to bridge projects in Arkansas. The …

Formation Of Reactive Nitrogen Species During Dichloramine Decay And Their Impact On N Nitrosodimethylamine Formation Under Drinking Water Conditions, Huong Thu Pham

Graduate Theses and Dissertations

NDMA occurrence and formation pathways in drinking water systems are reviewed and NDMA yields are compared on the basis of disinfectant type, water chemistry, and precursor category. In chloramination, despite monochloramine being the predominant species between pH 7-9, evidence suggests that dichloramine is the primary species involved in NDMA formation. This is somewhat confounding as NDMA yields are maximal at pH 9, yet at pH 9 dichloramine decays faster than it forms and hence is present at trace levels; additionally, the proposed mechanism involves a spin-forbidden incorporation of dissolved oxygen as a triplet, which is presumably kinetically slow. This review …

Role Of Binder Compositions And Carbonate Polymorphs On The Performance Of Carbonation Activated Cementitious Composites, Mohammad Rakibul Islam Khan

Civil Engineering Dissertations - Archive

The most energy-intensive manufacturing industry in the US is the Ordinary Portland Cement (OPC) industry. This industry is responsible for 5-8% of global CO2 emissions caused by humans. The calcination of limestone to produce high lime calcium silicate and high manufacturing temperature (1450°C) are responsible for this significant amount of CO2 emissions. This CO2 footprint of the cement-based composites can be decreased by utilizing cementitious materials with low-lime calcium silicate. Low-lime calcium silicates are typically semi-hydraulic or non-hydraulic. As a result, it is necessary to activate those materials in order to increase their reactivity. Alkali activators, carbonation curing (CO2 curing), …

Rainfall-Induced Slope Failure – An Early Warning System, Md Aminul Islam

Civil Engineering Dissertations - Archive

Globally, slope failures cause substantial death tolls and economic loss. Embankments constructed on high plasticity clay are vulnerable to cyclic swelling and shrinkage when subjected to climate. Thus, over time, soil softens and reduces effective shear strength, and shrinkage cracks on slopes can act as pathways for rainfall infiltration, which increases pore water pressure and lowers the shear strength below critical levels, resulting in slope failure. This study aims to develop early warning criteria for rainfall-induced slope failure. Study areas were Tarrant, Dallas, Johnson, and Ellis, where soil types and a humid subtropical climate result in frequent slope failures. The …

Assessment Of Stormwater Infrastructure For Mitigating Flooding And Non-Point Source Pollution, Helia Farzaneh

Civil Engineering Theses - Archive

Flooding is the top natural hazard impacting coastal and inland communities in Texas. Beyond its destructive impact on rising waters in communities, flooding-induced stormwater negatively affects the quality of large bodies of water. Stormwater runs over land, washes off pollutants, and deposits them into rivers which causes water quality issues in bays and estuaries. In addition, the stormwater increases nutrients, sediments, oxygen-demanding substances, pathogens, and toxins which results in hypoxia in the aquatic system. During the last 5-6 years, severe storm events such as Tropical Storm Beta (September 2020), Tropical Storm Imelda (September 2019), Hurricane Harvey (August 2017) have caused …

Fire Performance Of Hybrid Fiber Reinforced Self-Consolidating Concrete (Hfrscc) With Glass Pozzolan, Rishabh Kumar

Civil Engineering Theses - Archive

This research focuses on the effects of hybridizing self-consolidating concrete (SCC) using steel (SF) and polypropylene (PP) fibers to study their benefits post-fire exposure. In an attempt to reduce cement’s environmental impacts and to make concrete more sustainable, this research also studies the substitution of cement using glass pozzolan. Limited research has been done in this regard previously, hence this research makes an effort to bridge the enormous knowledge gap. No research has reported tensile, compressive, and flexural strength of SCC with hybrid fibers and glass pozzolan, making this research unique. Based on previous research, the replacement rate of cement …

Performance Evaluation And Retrofitting Options For An Impact Damaged Non-Composite Steel Girder Bridge, Mohd Mezanur Rahman

Civil Engineering Dissertations - Archive

The Federal Highway Administration (FHWA) has rated about 32% of total bridges in US as structurally deficient or functionally obsolete. One of the most frequently encountered issues for this deficiency is the impact created by cars that exceed the posted clearance for a bridge. Impact damage leads to concrete spalling or cracking, exposed or broken reinforcement/prestressing strands, global and local buckling of the structural member or piercing through the steel girder. For Example, St. Francis Bridge (North Bound) carrying St. Francis Avenue over I-30 east of downtown Dallas was impact damaged by an eighteen-wheeler carrying a heavy-duty wrecker on 29th …

Evaluation Of Geotechnical Parameters Of Soil Using Electrical Resistivity Imaging, Md Asif Akhtar

Civil Engineering Dissertations - Archive

Electric resistivity imaging (ERI) is an effective non-destructive and rapid measuring way of obtaining continuous soil subsurface resistivity profiles. An ERI technique can be used to identify moisture variations and soil heterogeneities in an area. Thus, ERI is becoming a popular tool in geotechnical (FHWA, 2015)engineering; however, it only provides qualitative information at the current time. Using qualitative images, it is challenging to extract quantitative geotechnical information, such as the type of soil, moisture content, degree of saturation, and atterberg limit, of the subsurface. Several studies have described the electrical resistance of soil as a function of pore fluid conductivity …

Change In Sedimentation Regime Due To Bridge Construction Activities: A Field Study At Fm 2478 Bridge Over Wilson Creek, Mckinney, Texas, Subhas Kandel

Civil Engineering Theses - Archive

Bridge construction activities can cause soil disturbances that introduce sediments into a receiving stream and potentially impact its quality and the ecosystem. The impacts of bridge construction activities are studied in two ways: overland erosion and in-stream sediment concentration. For this research, the overland erosion of Wilson Creek in McKinney, Texas was monitored from four erosion plots constructed on its banks, near the bridge construction activities zone. The instream water quality was examined during the construction period by measuring the Total Suspended Solids (TSS) and the turbidity of water samples, and the sediment and water samples were collected and analyzed …

Carbon Footprint Assessment And Emissions Reduction Strategies For The University Of Texas At Arlington, Dravid Sabarish Villavan Kothai

Civil Engineering Theses - Archive

In the past decade, many universities have started to ascertain their emissions and benchmark their progress towards sustainability and climate control. The University of Texas at Arlington (UTA) is no exception in working toward the goal of carbon neutrality. While UTA continues to grow and transform, its goal is to simultaneously reduce energy intensity and greenhouse gas (GHG) emissions. To this end, the Office of Sustainability is maintaining a carbon inventory for each year to track GHG emissions and provide information to guide reduction strategies. The primary objectives of this research were: 1. To update UTA’s greenhouse gas emissions inventory …

Effect Of Various Speed Management Strategies On Bicycle Crashes For Urban Roads In Central Florida, Jorge Ugan

Electronic Theses and Dissertations, 2020-2023

In recent years, cycling has become an increasingly popular transportation mode around the world. In contrast to other popular modes of transportation, cycling is more economic and energy efficient. While many studies have been conducted for the bicycle safety analysis, most of them were limited in terms of bicycle exposure data and on-street data. This study tries to improve the current safety performance functions for bicycle crashes at urban corridors by utilizing crowdsource data from STRAVA and on-street speed management strategies data. Speed management strategies are any roadway alterations that causes a change in motorists' driving behavior. In Florida, these …

Decision Tool For Prioritizing Bridge Repair Or Replacement, Nyoka Amy Florius

Civil Engineering Dissertations - Archive

Bridges are typically damaged/deteriorated due to various factors that require close evaluation to make informed decisions about repair/replacement. There are several aspects of study to evaluate bridges for repair/replacement, such as age, structural adequacy, and frequent usage. Further, bridges which are in poor condition must be identified to mitigate their damage/deterioration and as a result, maintain a safe environment for users. Therefore, to assess the need for funding, state Departments of Transportation are required to evaluate bridges by considering several factors, while prioritizing safety. In Texas, the Highway Bridge Program is responsible for funding bridges which are listed for repair/replacement. …

Improving Probabilistic Quantitative Precipitation Forecasting Using Machine Learning And Statistical Postprocessing Methods, Mohammadvaghef Ghazvinian

Civil Engineering Dissertations - Archive

The objective of this research is to address the limitations inherent in conventional statistical postprocessing schemes to generate probabilistic quantitative precipitation forecasts (PQPFs) and improve postprocessed PQPFs quality through introducing new robust statistical models and machine learning frameworks. This dissertation comprises three main elements. First, a new, two-part scheme for creating PQPFs from single-valued quantitative precipitation forecasts is introduced. This scheme, herein referred to as the Mixed-type Non-Homogenous Regression (MNHR), combines the use of logistic regression for estimating rainfall intermittency, and non-homogeneous regression for estimation of additional parameters of the conditional distribution. The performance of MNHR is evaluated relative to …

The Potential Of Location Data For Contact Tracing And Understanding Individual Mobility During The Covid-19 Pandemic, Marcus Figaro

Electronic Theses and Dissertations, 2020-2023

In this study, we first review contact tracing methods used during the COVID-19 pandemic and provide an analysis of the benefits and drawbacks of different data collection and privacy protection methods. Our findings provide the benefits and drawbacks of using GPS versus Bluetooth for contact tracing, as well as the different data collection and storage methods and their effectiveness in protecting user privacy. We then analyze Twitter data to understand individual mobility behavior and sentiment by using a Natural Language Processing tool on text content of user tweets and Tweet coordinate data. Social media's ability to provide data on location …

Detecting And Evaluating Cracks On Aging Concrete Members With Deep Convolutional Neural Networks, Brendan Barnes

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Cracks in concrete structures are evaluated through a timely and subjective manual inspection. The location of cracks is often recorded in an inspection report where some cracks are measured. Although measurements or locations may not be necessary for all cracks observed in concrete members, if quantitative data can be gathered in an autonomous way, allowing measurement data to be used in tracking changes in spatial and temporal scales, this quantitative data can provide useful information not yet captured in the manual inspection process. This thesis aims to construct an image-based crack detection and evaluation pipeline that can assist health monitoring …

Structural Impacts Of Super Heavy Load (Shl) Vehicles On Transportation Infrastructure, Ali Morovatdar

Open Access Theses & Dissertations

Operation of non-conventional Super Heavy Load (SHL) vehicles is an ongoing challenge for transportation stakeholders and the traveling public across the nation. Despite facilitating the movement of heavy, large, and non-divisible loads, passages of such vehicles with complex loading configurations that typically weigh several folds of the permissible weight limits set forth by regulatory agencies have been adversely affecting the structural integrity of pavement facilities. This translates into accelerated damage of pavement structures, which in turn poses safety concerns for users of the transportation facilities. Accurate quantification of such detrimental impacts is the precursor to preserve the existing transportation facilities. …

Data Driven Methods For Large Scale Network Level Traffic Modeling, Rezaur Rahman

Electronic Theses and Dissertations, 2020-2023

Rapid growth in population along with urban-centric activities impose a massive demand on existing transportation systems, thus increasing traffic congestion and other mobility related challenges. To overcome such challenges, we need network-scale models to accurately predict real-time traffic demand and associated congestion. However, traditional network modeling approaches have shortcomings due to the complexity in traffic flow modeling, limited scope to incorporate real-time data available from emerging data sources and requiring excessive computation time to generate accurate estimation of traffic flows. Advancement in traffic sensing technologies with big data has created a new opportunity to overcome these challenges and implement deployable …

Identification Of Resilience Dimensions And Development Of A Decision-Making System To Measure The Resilience Level Of Highway Networks, Thahomina Jahan Nipa

Civil Engineering Dissertations - Archive

Local as well as national economy and safety depend on the network characteristics of the transportation infrastructures. Destruction of transportation infrastructures causes the direct cost of the reconstruction as well as indirect cost due to loss of mobility. In addition, emergency response and recovery cannot be rendered if access to the affected community is hampered due to a damaged transportation network. Hence, researchers as well national and international organizations are focusing more on a resilience-based approach instead of a traditional recovery-based approach for the transportation infrastructures recently. As a result, there exist a high number of research articles that developed …

Optimization Of Concrete Pavement Design To Truck Platoon Loading, Mohsen Talebsafa

Civil Engineering Dissertations - Archive

Transportation is the major contributor toward economic growth and development. In the United States, more than 90% of commodities are transported through the roadway system. Due to the high demand for transportation of goods, there is a high demand in the road freight industry for innovative solutions, and new technologies to improve the sustainability and efficiency of transportation. Truck platooning is one of the most recent technologies with great potential to make road freight safer, cleaner, and more efficient. This technology uses connectivity technologies and automated driving systems to interconnect two or more trucks in a convoy. These automation technologies …

Evaluation Of Surface Asphalt Mixes Containing Recycled Asphalt Materials In North-East Texas Using Accelerated Pavement Testing, Ana Maria Coca

Civil Engineering Dissertations - Archive

Reclaimed asphalt pavement (RAP) and Reclaimed Asphalt Shingles (RAS) has proved to be an effective alternative to virgin materials in HMA production. Despite that recycling asphalt creates a cycle that optimizes the use of natural resources and sustains the pavement industry, State transportation departments have limited the maximum amount of RAP used in surface layers because of the variability concerns and lack of guidance provided. Even though at the moment, the United Stated recycles more RAP than Europe does in terms of percentage of the total RAP extracted from old pavements, it still lags Japan and other countries. A special …

Reuse Of Recycled Plastic For Plastic Road Design, Tahsina Islam

Civil Engineering Dissertations - Archive

The ever-increasing volume of traffic and the volatility of daily and seasonal temperatures that are being experienced globally make it essential that the quality and durability of roads are improved. Modifiers can improve the engineering properties of the asphalt mix in these situations. Perhaps plastics are the most promising of all types of modifiers. Since the disposal of plastic waste is a major concern for the environment, recycling of these waste materials is highly desired. The recycling and reuse of plastic waste is a prime example of sustainable waste management. It reduces the buildup of waste in landfills, thereby reducing …

A Linear Dynamical Perspective On Epidemiology: Interplay Between Early Covid-19 Outbreak And Human Mobility, Shakib Mustavee

Electronic Theses and Dissertations, 2020-2023

This research investigates the impact of human activity and mobility (HAM) in the spreading dynamics of an epidemic. Specifically, it explores the interconnections between HAM and its effect on the early spread of the COVID-19 virus. During the early stages of the pandemic, effective reproduction numbers exhibited a high correlation with human mobility patterns, leading to a hypothesis that the HAM system can be studied as a coupled system with disease spread dynamics. This study applies the generalized Koopman framework with control inputs to determine the nonlinear disease spread dynamics and the input-output characteristics as a locally linear controlled dynamical …