Civil and Environmental Engineering Commons^™

Performance Of Geotechnical Systems Under Extreme Hydroclimatic Events Using Finite Element Modeling, Tharshikka Vickneswaran

All Dissertations

Failure of geotechnical systems during hydroclimatic events such as heavy rainfall, flood, and drought often leads to significant socio-economic loss. The time-dependent stability and deformation behaviors of geotechnical systems subjected to hydroclimatic events must be investigated using a coupled flow-deformation formulation because the strength and deformation parameters vary with the degree of saturation and/or matric suction of the soil. Although the impacts of the hydroclimatic events on the geotechnical systems are assessed and summarized in the previous studies, all the analyses were carried out in a loosely coupled manner and/or uncoupled manner without considering the effects of water flow in …

Computational Study Of Dense Gas Dispersion In Urban Areas, Rasna Sharmin

All Dissertations

A series of steady-state simulations have been conducted to investigate removal of dense gas from a simple square canyon formed between two square cross-section obstacles. Due to urbanization and industrialization, there always lies a high risk of exposure to harmful pollutants which can result from accidental release of toxic gasses. Those are often denser than the atmosphere. and can easily get trapped in between buildings in urban canopies. It is important to have full understanding of flushing mechanism of dense fluid inside urban canopies by steady turbulent flow because the exposure to these toxic dense gasses can be catastrophic. There …

Characterization Of Water Flow And Solute Transport Driven By Preferential Flow In Soil Vadose Zone, Abdullah Al Mamun

All Dissertations

The vadose zone acts as a buffer zone between the ground surface and the aquifers underneath and controls the transmission of infiltrating water and contaminants, for example, pesticides and chemical spills. Therefore, understanding the flow and transport processes that dominate the vadose zone is important. Macropores are ubiquitous and particularly found in abundance in the vadose zone. These macropores facilitate preferential flow, through which water travels rapidly deep into the soil, bypassing most of the porous matrix. Preferential flow and transport have environmental significance as their processes impact hydrology, ecology, agriculture, subsurface contamination, and waste management sectors. Thus, the overall …

Digitalization Of Construction Project Requirements Using Natural Language Processing (Nlp) Techniques, Fahad Ul Hassan

All Dissertations

Contract documents are a critical legal component of a construction project that specify all wishes and expectations of the owner toward the design, construction, and handover of a project. A single contract package, especially of a design-build (DB) project, comprises hundreds of documents including thousands of requirements. Precise comprehension and management of the requirements are critical to ensure that all important explicit and implicit requirements of the project scope are captured, managed, and completed. Since requirements are mainly written in a natural human language, the current manual methods impose a significant burden on practitioners to process and restructure them into …

Machine Learning Based Surrogate Model For Hurricane Storm Surge Forecasting In The Laguna Madre, Cesar E. Davila Hernandez

Theses and Dissertations

Texas coastal communities are at constant risk of hurricane impacts every storm season. It is especially important to model and predict storm surge variations during hurricane and storm events. Traditionally, hurricane storm surge predictions have been the result of numerical hydrodynamics based simulations. This type of simulations often requires high amounts of computational resources and complex ocean modelling efforts. Recently, machine learning techniques are being explored and are gaining popularity in hydrologic and ocean engineering modelling fields based on their performance to model nonlinear relationships and low computational requirements for prediction. Advances in machine learning and artificial intelligence (A.I.) demand …

Behavior Of Narrow Mechanically Stabilized Earth Walls With Secondary Reinforcement, Abraham Alejandro Alvarez Reyna

Theses and Dissertations

Mechanically Stabilized Earth (MSE) walls have been used in past decades as an alternative, cost-effective, and performance solution to replace conventional retaining walls. AASHTO guidelines recommend a reinforcement length-to-height ratio of 0.7. However, this ratio is not applicable where there exist constraint conditions. FHWA guidelines recommend the minimum reinforcement length-to-height ratio of 0.3 for Narrow Mechanically Stabilized Earth (NMSE) walls in these cases. However, published guidelines have not sufficiently accounted for several parameters influencing NMSE performance and efficiency. Using finite element analysis (PLAXIS 2D), this study focuses on finding a relation between the length-to-height ratio and other parameters/components of the …

Adaptation Strategies To Mitigate Impacts Of Sea Level Rise On A Freshwater Aquifer Supply On A Barrier Island, Kaylyn Bellais

Graduate Theses and Dissertations (2019 - present)

Adaptation strategies are used to reduce vulnerability in response to storms and sea-level rise (SLR). An adaptation tipping point for a barrier island is said to exist when an adaptation strategy fails. Previous studies have applied statistics to identify adaptation tipping points and construct adaptation pathways as a function of quantity of SLR. This study is focused on Alligator Lake and Oleander Pond on the barrier island Dauphin Island, AL; a site residents and community leaders identified as vulnerable to saltwater intrusion under future SLR conditions. Therefore, the purposes of this study are to numerically simulate impacts of a storm …

Design Of A Freight Transportation Outreach Curriculum, Breanna Stoesz

Civil Engineering Undergraduate Honors Theses

This project is centered around finding a solution to the shortage of truck drivers within the freight industry. Specifically, this project aims to lessen this shortage by ensuring potential future drivers are aware of the benefits of the industry and are encouraged to consider this career path for themselves. By producing an engaging and educational freight transportation curriculum for middle and high school students to go through in outreach programs, these students would have an increased likelihood of joining the trucking profession and encourage others to become informed about the profession as well. In addition to the direct driving role, …

The Effect Of Changing Land Use On Streamflow Statistics And Flood Flows Across Select Gages In Northwest Arkansas, Timothy Mcmullen

Civil Engineering Undergraduate Honors Theses

Since 1901, heavy rainfall events have increased in the United States in both intensity and frequency, and population in the United States has increased, resulting in significant land use changes. Both of these trends could explain an increase in observed flood magnitude and frequency. In order to determine if a relationship exists between land use/land cover and changing stream flows in northwest Arkansas, this study analyzed temporal changes in various flow statistics for fourteen stream gages and compared the rates of change in flow statistics from gages on streams with watersheds that have varying land uses, i.e. urban, agricultural, and …

Determining Earthquake Impacts On Arkansas' Roadway Network: An Application Of Hazus., Simon Rothwell

Civil Engineering Undergraduate Honors Theses

Natural hazards are a dangerous and unpredictable aspect of life on earth. They can cause devastating damage to our surroundings that makes movement of people, goods, and emergency services difficult. There is a need to plan for these disasters to ensure that damages to our infrastructure and people are minimized. It can be difficult for planners to determine which parts of a roadway network are most vulnerable to a specific disaster and what their impact on the rest of the network may be. This thesis uses a nationally available natural disaster estimation tool developed by FEMA called “Hazus” (FEMA, 2020). …

Comparing The Stiffness Of Cold In-Place Recycled Asphalt Pavement To Hot Mix Asphalt: Determining The Reproducibility Of The Stiffness Rebound Test, Tanner Turben

Civil Engineering Undergraduate Honors Theses

The Stiffness Raveling Mechanism Test (SRMT) was originally developed as an indirect measure of pavement stiffness to determine a pavement’s tendency to ravel, a type of damage. Regarding rehabilitation of existing roadways by Full Depth Reclamation (FDR) Cold In-Place Recycling (CIR), concern of field repeatability was expressed (Hill & Braham, 2016).

An analysis of lab-compacted samples of CIR and Hot Mix Asphalt (HMA) was performed to determine if the results could be reproduced between CIR and HMA. Additionally, the experiment observed the effects of percent air voids, temperature, and moisture conditioning on CIR and HMA. Three samples were prepared for …

Community Transportation Needs And Willingness To Use Shared Micromobility: A Case Study Of Fort Smith, Arkansas, Anthony Michael Kammerer

Civil Engineering Undergraduate Honors Theses

Shared micromobility is utilized in “targeted service areas with the usage generally intended for short trips such as "first- and last-mile" connections to complete trips made via other modes, including transit” (Price et al., 2021). In the United States, this practice has especially taken off with the implementation of sharing-based systems. This is evidenced by ridership numbers in the United States growing from 84 million riders nationwide in 2018 to 136 million riders in 2019 (NACTO, 2020). Users often use their smart phone or another similar device to unlock the vehicle after paying a fee on the device through their …

Evaluating The Effects Of Curing Methods On Bcsa Cement Concrete, Hannah Allen

Civil Engineering Undergraduate Honors Theses

BCSA cement is a type of cement that makes concrete set up much quicker than typical portland cement concrete. BCSA cement concrete also has a much higher compressive strength than that of portland cement concrete. This study was conducted to determine the effect of different curing conditions on the compressive strength of BCSA cement concrete.

Development Of A Next-Generation Non-Proprietary Portable Concrete Barrier, Riley Ruskamp

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

Portable concrete barriers (PCBs) are segmented barriers made of precast concrete units that are connected by various load-bearing hardware. PCBs are typically used to shield work zones by redirecting errant vehicles upon impact with the barrier system. Most commonly-available PCBs have demonstrated performance issues arising from the sloped face of the barrier, which encourages vehicles to pitch and roll during impact, potentially resulting in vehicle rollover. Concerns also exist regarding the large dynamic deflections exhibited by these systems that can encroach upon the protected work zone or require anchoring to prevent large displacements. In addition to these concerns, the American …

Risk Assessment Of Hazardous Material Transportation For Small And Tribal Communities, Harrison Redepenning

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

By and large transportation of hazardous materials (HazMat) across the US is increasing, with truck transportation as the most common method of transport. Smaller communities (population <5,000) and Native American communities often lack the economic and political influence to quantify the dangers that HazMat incidents present to the immediate and surrounding areas. Lack of such information is an impediment to adequate preparedness in cases of HazMat incidents. This research focuses on assessing the vulnerability of small and tribal communities in Nebraska to the impacts of highway HazMat incidents. This was done by estimating the expected number and type of HazMat incidents per population in each community. Additionally, statistical analysis was conducted on actual HazMat incidents to determine if small and Native American communities experience a higher rate of incidents per population and per HazMat VMT than large and other small communities respectively. For per population, it was found small versus large is statistically significant while Native American versus other small communities was not significant. For per HazMat VMT, neither comparison was found to be statistically significant. In estimated HazMat incidents, actual HazMat incidents per population, and actual HazMat incidents per HazMat VMT, small communities had higher mean values than their large counterparts. Communities on Native American reservation land experienced a higher estimated and lower actual HazMat incident rate per population than other small communities. For actual HazMat incidents per VMT, Native American communities had a higher rate than other small communities.

Advisor: Aemal Khattak

Experimental And Numerical Analysis Of Soil-Geosynthetic Composite For A Geosynthetic-Reinforced Roadway System, Daniel Robertson

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

The present research conducted tests to evaluate the reinforcing performance of geosynthetics including three geogrids (GG1, GG2, and GG3) and one geotextile (GT) for three different soil types – sand, clay, and red shale. All geosynthetics showed great improvement under the lowest confining pressure. The report concluded that between the Large-Scale Direct Shear test, the Large-Scale Pullout Box, and the FLAC simulation, the three geogrids showed the greatest improvement when conducted with sand. The sand could withstand a much greater normal pressure than either clay or red shale. The biaxial geogrids, GG1 and GG3, had ideal results for lower stress …

Discrete Element Modeling Of The Shape- And History-Dependent Behavior Of Granular Materials, Feiyang Chen

All Dissertations

Granular materials, such as biomass feedstocks, agricultural grains, pharmaceutical pills, and geomaterials, are widespread in nature, industrial systems, and everyday life. Fundamentally, the bulk mechanical behavior of granular materials is governed by particle-level attributes such as particle morphology, surface roughness, and contact behavior. Among various numerical methods developed for modeling granular materials, the particle-based discrete element method (DEM) is particularly suited and effective in modeling the mechanical, flow, and failure behavior of granular materials.

Focusing on one specific type of granular material (i.e., biomass feedstocks), the main objective of this dissertation is to develop and validate novel DEM models that …

Using Safety Performance Models, Autonomous Vehicle Data, And Machine Learning To Develop Contextual Complexity Criteria To Establish A Standardized Process For On-Road Evaluation Of Medically At-Risk Drivers Considering Static And Dynamic Factors Of The Roadway Environment, Vijay Bendigeri

All Dissertations

The field of transportation engineering has an opportunity to positively impact the medical community, specifically the clinicians who evaluate, train, and rehabilitate at-risk drivers. Driving Rehabilitation Specialists (DRSs) have an essential role in making roads safer for medically-at-risk drivers, their passengers, and other road users. DRSs conduct on-road driving evaluations, which are considered the gold standard to make fitness-to-drive decisions due to their high face validity. Most DRSs use a fixed route, meaning the exact same route is used to evaluate each client. When a DRS develops a fixed route, that clinician identifies characteristics of the roadway they think are …

Pedestrian Evacuation: Vulnerable Group Member Influence On The Group Leaders’ Decision-Making And The Impact On Evacuation Time, Terra Lynne Elzie

Computational Modeling & Simulation Engineering Theses & Dissertations

As pedestrian evacuations of buildings, outdoor venues, and special events occur, dynamic interactions between pedestrians and vehicles during egress are possible. To model pedestrian and vehicle evacuations, simulation models have evolved to incorporate more realistic crowd characteristics and behaviors to provide improved results. Past studies using modeling and simulation, specifically agent-based modeling, have explored pedestrian behaviors such as decision-making, navigation within a virtual environment, group formations, intra-group interactions, inter-group dynamics, crowd behaviors such as queuing and herding, and pedestrianvehicle interactions. These studies have led to relevant insights helpful to improving the accuracy of evacuation times for normal and emergency egress …

Data-Driven Framework For Understanding & Modeling Ride-Sourcing Transportation Systems, Bishoy Kelleny

Civil & Environmental Engineering Theses & Dissertations

Ride-sourcing transportation services offered by transportation network companies (TNCs) like Uber and Lyft are disrupting the transportation landscape. The growing demand on these services, along with their potential short and long-term impacts on the environment, society, and infrastructure emphasize the need to further understand the ride-sourcing system. There were no sufficient data to fully understand the system and integrate it within regional multimodal transportation frameworks. This can be attributed to commercial and competition reasons, given the technology-enabled and innovative nature of the system. Recently, in 2019, the City of Chicago the released an extensive and complete ride-sourcing trip-level data for …

Application Of Lanthanides In Wastewater Treatment And Water Reuse, George William Kajjumba

UNLV Theses, Dissertations, Professional Papers, and Capstones

Much of the world’s population feed on grains (wheat, rice, and corn). Corn is as sensitive as it is productive. This thirsty, fast-growing plant goes into thermal shock in drought. In 2014, California lost over $2.2 billion in crop production due to drought. The Horn of Africa (in 2011) and Sahel (in 2012) faced humanitarian disasters due to food and water scarcity. The higher frequency of climate change and the erratic nature of rain, combined with underlying economic and social vulnerabilities, has meant that food and water scarcity is here to stay. To improve food and water scarcity, water reclamation …

Contaminants Of Emerging Concern Behavior Within Water Renewal Facilities, Joshua C. Baker

Boise State University Theses and Dissertations

Emerging constituents (ECs), also called contaminants of emerging concern (CECs) are defined by the United States Environmental Protection Agency (U.S.EPA) as: “…pharmaceuticals and personal care products.” This also includes per- and polyfluoroalkyl substances (PFAS), which are used in waterproofing and non-stick cooking products. It is highly likely that regulatory limits will be placed on many ECs because they tend to accumulate in the environment and biological tissues with little to no transformation. ECs pose a threat to the ecological systems of our nation and the fundamental need for clean water by all life on earth. Clean water is essential for …

Evaluating Plant Uptake Of 4,4'-Methylenedianiline, Jeff Wight

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

4,4’-Methylenedianiline (MDA) is an important industrial chemical used primarily in the production of polyurethane. It is toxic and a suspected human carcinogen. Polyurethane is used in a wide variety of applications such as furniture cushioning, coatings, adhesives, sealants, and elastomers. Polyurethane in soil may degrade and release MDA. This is concerning due to some models predicting a high potential for MDA to be taken up by plants and stored in edible tissue, creating a possible route of exposure for humans and animals. In this project, the potential for MDA to be take up by plants was investigated in order to …

Improving Flood Inundation And Streamflow Forecasts In Snowmelt Dominated Regions, Irene Garousi-Nejad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Much effort has been dedicated to expanding hydrological forecasting capabilities and improving understanding of the continental-scale hydrological modeling used to predict future hydrologic conditions and quantify consequences of climate change. In 2016, the National Oceanic and Atmospheric Administration’s (NOAA) Office of Water Prediction implemented the National Water Model (NWM) to provide nationally consistent, operational hydrologic forecasting capability across the continental U.S. The primary goal of this research was to develop hydrological tools that include modeling of flood inundation mapping and snowmelt contributions to river flow in snowmelt-dominated regions across the Western U.S. This dissertation first presents terrain analysis enhancements developed …

Advancing Data Collection, Management, And Analysis For Quantifying Residential Water Use Via Low Cost, Open Source, Smart Metering Infrastructure, Camilo J. Bastidas Pacheco

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Urbanization, climate change, aging infrastructure, and the cost of delivering water to residential customers make it vital that we achieve a higher efficiency in the management of urban water resources. Understanding how water is used at the household level is vital for this objective.Water meters measure water use for billing purposes, commonly at a monthly, or coarser temporal resolutions. This is insufficient to understand where water is used (i.e., the distribution of water use across different fixtures like toilets, showers, outdoor irrigation), when water is used (i.e., identifying peaks of consumption, instantaneous or at hourly, daily, weekly intervals), the efficiency …

Evaluation Of Human And Ecological Water Management Tradeoffs In A Seasonal Watershed With Spatially-Distributed Demands, Jesse Lee Rowles

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

River managers must balance the needs of the ecosystems that rely on the river by leaving water instream, often while also considering human demands. It is especially difficult to balance these water needs in systems that are highly seasonal and have no instream storage (e.g., reservoirs) since water cannot be stored for use throughout the year. An example of a watershed that has both of these characteristics is the South Fork Eel River in coastal northern California. In order to evaluate tradeoffs between human and ecological demands in this system, a water allocation model with water management scenarios and environmental …

Assessing The Role Of Magnetite In Municipal Wastewater Treatment, Patricia Ayaa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Some municipal wastewater treatment (MWWT) facilities have adopted magnetite in their treatment processes through a technology called BioMag® to meet effluent regulatory requirements for total nitrogen and total phosphorus. However, there is limited information on the mechanisms and efficiency of magnetite in the removal of nitrogen (N) and phosphorus (P) from wastewater. This research, therefore, estimated its effectiveness in the removal of these nutrients, with a case study of the Marlay-Taylor Water Reclamation Facility in Maryland. The intervention analysis model was used, but a new forecasting approach to the model was proposed to fit the data in this study and …

Advances In Process Understanding And Methods To Support River Temperature Modeling In Large Regulated Systems, Bryce A. Mihalevich

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

River temperatures play a key role in determining the suitability of habitat for aquatic ecosystems. While thermal regimes are influenced by many factors, flow and temperature patterns in large rivers are often shaped by water development. As such, water management associated with large reservoirs and diversions have also altered aquatic ecosystems. As climate change introduces new climate and hydrologic patterns, the decisions water managers make to address changes in runoff may further impact aquatic ecosystems. This calls for robust modeling tools that can predict river and reservoir temperature responses to water management decisions over large regions. However, highly variable topography …

Evaluation Of Hydrograph Separation Techniques With Uncertain End-Member Composition, Eileen Page Lukens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Changes to precipitation and temperature occurring as a result of climate change can influence water sources (such as groundwater or snowmelt) that contribute to stream flow in a watershed. This is significant, as shifts in the amount of water coming from different water sources can shape watershed management decisions. One technique often used to investigate changes in water sources is hydrograph separation, a mathematical tool that allows for the quantification of the amount of water that came from different water sources. However, it can be difficult to perform hydrograph separations in remote watersheds as there may be insufficient infrastructure, i.e. …

Using Experiments, 3d Scanning, And Computational Fluid Dynamics To Analyze Variance In Minor Loss Coefficients, Adam B. Pack

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As water moves through pipes, it loses energy. The energy losses are due to friction and the minor losses associated with various pipe fittings, which change the direction of flow. Pipe bends, or elbows, are a common pipe fitting and a significant source of energy loss in piping systems. This research was performed to better understand the variability of energy loss due to different pipe elbow designs and to investigate methods to replicate these losses using numerical simulations.

Eight pipe elbows, all 3-inch, 90-degree, schedule 40 PVC elbows that vary by radius of curvature and/or end connection type, were tested …