Civil and Environmental Engineering Commons^™

Vibration-Based Algorithm For Diagnostic And Prognostic Condition Monitoring Of Railroad Bearings And Wheels, Jeffery Ray Pams

Theses and Dissertations

Bearing and wheel failure accounts for the majority of equipment-related train derailments on US railroads. Current wayside monitoring systems have been insufficient in the prevention of catastrophic derailments prompting the rail industry to explore the possible integration of onboard condition monitoring systems into their rail operations. The University Transportation Center for Railway Safety (UTCRS) in partnership with Hum Industrial Technology, Inc., has developed a wireless onboard system intended for the condition monitoring of railroad bearings and wheels. This thesis presents the development, evaluation, and implementation of an algorithm designed to be used in conjunction with these systems to provide railroad …

Selecting Green Wall Adoption Best Solutions Using Optimization: Addressing Barriers And Maximizing Benefits, Samar Nadeem

Theses and Dissertations

This research explores the potential of green walls as a sustainable solution to mitigate urban challenges and align with global climate change objectives. Despite their ecological and social benefits, green wall implementation faces significant barriers, hindering their adoption. Consequently, this study aims to develop a comprehensive framework to identify the obstacles, propose feasible solutions, and provide actionable strategies for promoting green walls. This framework incorporates an optimization model specifically designed for government-led solutions, evaluating their feasibility based on administrative feasibility, community acceptance, technical feasibility, industrial acceptance, and long-term adoption potential. By quantifying and prioritizing solutions based on their cost, feasibility, …

Use Of Pushed-In Pencel Pressuremeter Test For Shallow Foundation Design In Florida Fine Sands, Brhane Weldeanenya Ygzaw

Theses and Dissertations

A comprehensive evaluation was conducted on the performance, consistency, and practical application of various in-situ geotechnical testing methods for predicting the settlement and bearing capacity of shallow foundations in Florida’s fine sands. The methods assessed include the Standard Penetration Test (SPT), Cone Penetration Test (CPT), Dilatometer Test (DMT), pushed-in PENCEL Pressuremeter Test (PPMT), and the pre-bored TEXAM Pressuremeter Test. A dual approach controlled indoor testing at the FDOT State Materials Office (SMO) and field investigations at three representative sites (Kingsley, Trenton, and the UCF research site), formed the experimental foundation.

Over thirty settlement prediction techniques and thirteen bearing capacity estimation …

Understanding Water Washing Needs Of Hydrochar Generated From The Hydrothermal Carbonization Of Food Wastes To Establish Minimum Post-Processing Needs For Soil Amendment Application, Neve Renee Steger

Theses and Dissertations

Hydrothermal carbonization (HTC) is an advantageous and potentially environmentally beneficial approach for the conversion of wet biomass and waste streams into a value-added solid product referred to as hydrochar. Although hydrochar composition and properties generated from the carbonization of a variety of feedstocks have been well studied, there is a need for understanding whether hydrochar requires further refinement and/or treatment prior to being used in environmental applications, particularly when using the hydrochar as a soil amendment. Understanding the need for and extent of hydrochar post-treatment is critical in identifying environmentally beneficial and economically attractive strategies for hydrochar use. In this …

Investigation Of Shear Modulus And Material Damping Of A Lightly Cemented Silty Sand Representing Offshore Soil, Joshua Jeanjaquet

Theses and Dissertations

Offshore structures remain highly relevant, making the dynamic characterization of offshore soils critical. Since many offshore soils are cemented, understanding their response to dynamic loads is essential for developing accurate models that improve the reliability and cost-effectiveness of offshore structure designs. This study examines the impact of cement content on shear modulus, shear modulus reduction, shear wave velocity, and material damping of lightly cemented fine silty sand. A series of Resonant Column and Torsional Shear tests were conducted. The results were analyzed and compared to existing literature. The modified hyperbolic model was proposed to characterize the shear modulus and damping …

Investigating The Influence Of Volumetric Water Content In The Upper Layer Of Soil On Embankment Factor Of Safety, Kiera Rose Hughes

Theses and Dissertations

Geohazards, including landslides and embankment failures, pose significant risks to railway infrastructure, necessitating early recognition methods for effective risk mitigation. This research explores the relationship between the volumetric water content in the upper soil layer and the embankment's factor of safety (FOS) to improve early detection and stability assessment. A parametric analysis was conducted to evaluate how variations in the soil type (shear strength and hydraulic conductivity), slope geometry (angle and height) and recharge conditions (rainfall intensity and duration) affect the FOS. Using the GeoStudio software, seepage and slope stability analyses were performed for two baseline soils, as well as …

Key Characteristics Of Long-Lived Portland Cement Concrete Airfield Pavements In The United States Air Force Enterprise, Cameron J. Palmer

Theses and Dissertations

The United States Air Force maintains a $30 billion portfolio of airfield pavements essential for national security. Despite their importance, budget constraints have limited average annual repair funding to $260 million over the past decade, requiring pavements to last significantly longer than their typical life span. This project addresses the central question: What design features or characteristics contribute to the longevity of Portland Cement Concrete (PCC) airfield pavements? Utilizing data from AFCEC's Airfield Pavement Evaluation (APE) team and the PAVER sustainment management system, this study employed linear regression, logistic regression, and deep artificial neural network (ANN) modeling techniques to identify …

Efficiency Of Enzyme Induced Carbonate Precipitation (Eicp) By Crude Extract Urease For Geotechnical And Geoenvironmental Applications, Kaniz Roksana

Theses and Dissertations

Geotechnical engineering is currently facing challenges, including accommodating rapid urbanization, adapting to climate change impacts, and prioritizing sustainability, all while ensuring the safety and stability of critical infrastructure. Biocementation is a recently developed new branch in geotechnical engineering that offers innovative and eco-friendly solutions by leveraging natural processes to enhance soil properties. This dissertation examines the potential of soybean extract urease as a cost-effective substitute for analytical-grade enzymes in Enzyme Induced Carbonate Precipitation (EICP) applications for biocementation. This research examines its effectiveness in various aspects, such as coastal erosion control, desiccation crack remediation, and the removal of heavy metals. Essential …

Comparison Of A Terrestrial And Handheld 3d Laser Scanner In As-Built Building Information Model (Bim) Creation, Cedric Scott Jankowski

Theses and Dissertations

Advances in computer processing have allowed mobile 3D laser scanners to begin to rival terrestrial scanners in terms of accuracy and scanning speed. While terrestrial scanners are the established instrument used in BIM creation for existing buildings, their cost, immobility, and size warrants a comparison to mobile scanners. This evaluation used scans created with both scanner types, the resulting point clouds, and 3D models created by tracing these point clouds to compare the BIM models and resulting floorplans, which were checked against direct on-site measurements. Because terrestrial scanners are considered state-of-the-art, the evaluation focused primarily on comparing mobile scanner and …

Evaluating Educational Benefits Of A Custom Cyber Game: ‘Hvac Attack!’, Jillian S. Valente

Theses and Dissertations

Cyber competition and conflict remain an enduring concern for the Department of Defense (DoD). Positive control of cyberspace is crucial across the vast diversity of military operations and supporting activities. Military members play an important role in cyber prevention, detection, and remediation, but most receive relatively little training outside of the annual Cyber Awareness Challenge. Particular career fields within the DoD may benefit from specialized training in cybersecurity, in particular the civil engineering (CE) community supporting critical infrastructure protection. Prior research has suggested that game-based learning (GBL) can be beneficial for teaching cyber concepts.

Maintenance Strategy And Budgeting Optimization For United States Air Force Facilities, Sophia C. Hirtle

Theses and Dissertations

Mission readiness in the United States Air Force (USAF) is critically dependent on the sustainment and maintenance of aging facilities. However, budgetary and manpower constraints have led to a significant backlog of deferred maintenance, estimated at $137 billion. To address these challenges, this research develops an optimization model that aids in prioritizing facility maintenance strategies within a fixed budget. The methodology incorporates existing USAF data from BUILDER, NexGenIT, and financial records to create a simulation-based optimization framework at the base level. The model evaluates four different maintenance strategies—replacement only, preventative maintenance only, corrective maintenance only, and a combination of preventative …

Evaluating Atmospheric Water Generation For The Indo-Pacific: Predictive Modeling, Energy Considerations, And Regional Viability, Jose I. De La Serna

Theses and Dissertations

Atmospheric Water Generator (AWG) technology presents a promising solution for extracting and harvesting water from ambient air through condensation methods. This innovative approach offers a viable alternative for water production in regions with limited or unreliable water sources. AWGs operate most effectively in hot and humid environments, typically at temperatures of 80°F and relative humidity levels of 80%. As of 2020, the Department of Defense (DoD) has identified the Indo-Pacific region as a strategic focus for addressing future greatpower competition. Within the framework of Agile Combat Employment, this study evaluates the feasibility and performance of AWG technology at pre-determined locations …

Assessing The Feasibility Of Managed Aquifer Recharge For The United States Air Force, Daniel Hendrix

Theses and Dissertations

Water stress is becoming an increasing global issue, with 4 billion people (50% of the world’s population) experiencing water stress at least one month per year. By 2050, 60% of the world’s population and $70 trillion USD in global gross domestic product will be affected. This research analyzes 78 CONUS USAF installations to determine location-specific water stress and feasible Managed Aquifer Recharge (MAR) solutions. Although thousands of MAR projects have been implemented globally, active-duty USAF installations have yet to contribute to solving this growing issue. Important factors such as required subsurface conditions, physical limitations, design, cost, and regulatory constraints are …

Calibrating Airfield Pavement Asset Management For A Changing Global Climate: A Case Study At Fairchild Air Force Base, Emily L. Worthy

Theses and Dissertations

Military airfields and civilian airports serve as foundational nodes in the global transportation network, enabling travel, economic growth, and the projection of national security. This study investigates the relationship between climate variables projected through climate change and pavement degradation, with a focus on Fairchild Air Force Base (AFB). Using principal component regression (PCR), the research integrates historical pavement condition index (PCI) data with climate variables, including snowfall, precipitation, freeze-thaw cycles, solar irradiance, and wind speed to develop a predictive model of pavement performance under future climate scenarios, Representative Concentration Pathway (RCP) 4.5 and RCP 8.5. These models, for both Portland …

Developing Core Competencies For The Air Force Civil Engineer Asset Management Career Field, David A. Rochester

Theses and Dissertations

The United States Air Force (USAF) relies on a highly trained and capable workforce to maintain and manage its infrastructure, ensuring mission readiness and operational effectiveness. However, the increasing complexity of asset management, aging infrastructure, and evolving global threats necessitate a structured approach to developing the competencies required for Air Force Civil Engineer Asset Managers. This research aims to identify, develop, and validate core competencies specific to this career field, utilizing a structured methodology that combines an Education Working Group (EWG) with a Delphi study. The study begins with an expert-led EWG to generate an initial list of competencies based …

The Application Of Decision Analysis Theory For Space Allocation At The Air Force Institute Of Technology, Damian N. Soriano

Theses and Dissertations

This thesis investigates the application of Decision Analysis Theory to optimize space allocation at the Air Force Institute of Technology (AFIT). Through a Multi-Objective Decision Analysis (MODA) framework, this study addresses existing methodologies for space allocation in military, academic, and office settings; the rules, limitations, and factors influencing space utilization at AFIT; and approaches to improve office and lab allocations for institutional efficiency and fairness. This research incorporates qualitative and quantitative metrics, including faculty and student data, research outputs, and historical space usage. These findings highlight significant complexities in space allocation, particularly in reconciling administrative and research requirements with structural …

Atmospheric Water Generation: Experimental Observations And Assembly Of An Artificial Neural Network, Houston Hoss Anderson

Theses and Dissertations

This research investigated the performance of a Tsunami T50 Vapor Compression Cycle styled Atmospheric Water Generation (AWG) machine operated under ambient conditions in Dayton, Ohio. Water yield from the device was measured volumetrically and these values are paired with respective weather data, collected from a local monitoring station, to build an Artificial Neural Network in MATLAB and JMP software. Water yield varied over the course of this study but averaged 1.2L and maxed at 5L for 4-hour operating periods. This work is part of a 3-year project; future data is needed to enhance both training and validation of the model …

Molecular Scale Investigations Of Interactions Between Pfas And Concrete, Eric E. Keeler

Theses and Dissertations

Per- and polyfluoroalkyl substances (PFAS), widely referred to as “forever chemicals,” exhibit high environmental persistence and potential health risks due to their robust carbon-fluorine bonds. These substances are prevalent in aqueous film-forming foams (AFFF), used in industrial and military applications, and are known to contaminate environmental surfaces, including concrete. This study aims to characterize the molecular-level interaction energies of six PFAS species—PFOA, PFOS, PFHxS, PFHxA, 6:2 FTS, and PFBS—with calcium silicate, a key component of concrete, using density functional theory (DFT) calculations. Change in Gibbs free energy (ΔG) was determined for each of the interactions, revealing negative ΔG values for …

Quantifying The Impact Of Highly Corrosive Environments On Fsrm Budgets And Infrastructure Condition At Air Force Bases, Justin M. Weber

Theses and Dissertations

The Department of Defense (DoD) faces significant challenges in maintaining mission-critical infrastructure within highly corrosive environments, with annual costs exceeding $22.5 billion to combat corrosion. This thesis investigated the interplay between environmental severity, sustainment funding, and infrastructure performance. This research utilized Facility Sustainment, Restoration, and Modernization (FSRM) funding data, statistical analyses, and regression modeling, to evaluate how Environmental Severity Index (ESI) categories influence Base Condition Index (BCI) trends and the efficacy of the Facility Sustainment Model (FSM). The analysis revealed that installations in higher ESI categories required significantly greater investment per square foot to achieve comparable improvements in BCI. The …

Discovering Design Requirements For Next Generation Arctic Tension Fabric Shelters, Mark W. Mcveigh

Theses and Dissertations

Military operations to remote Arctic regions require large-span temporary shelters to house tactical aircraft and provide heated maintained spaces. However, the current System-50 Large Area Maintenance Shelters used by the United States Air Force and Department of Defense are inadequate for Arctic deployments. These shelters lack durability against extreme subzero temperatures, heavy snow accumulation, and high wind speeds. They also fail to address critical Arctic-specific design challenges including permafrost protection, foundation disruption caused by frost heaves, and efficient heating as a result of their inadequate thermal resistance properties. This research analyzed 20 years of climatological data from 8,399 weather observation …

Early-Phase Cost Estimation For Department Of Defense Construction Projects Via Artificial Neural Networks: Implications And Policy Recommendations For Artificial Intelligence Integration, Kobe T. Thompson

Theses and Dissertations

The Department of Defense lost over 500 million dollars between 2016 and 2024, partially due to poor early cost estimates resulting in cost overruns. practice for cost estimation relied on parametric techniques that incorporate historical data, subject matter experts in cost estimating, and predictive software applications. The main motivation for this study was to assess the viability of artificial neural networks as a means of providing a more accurate cost estimate in the early design phases of a construction project. The dataset initially contained approximately 48,000 data points from a database of various Air Force projects, including maintenance, repair, minor …

Proof Of Concept: Using Uas Technology To Accomplish Aerial Roof Inspections, Madison R. Fanning

Theses and Dissertations

With the growing use of simulation across industries, the digital twin remains an underexplored research area, particularly in emergency management and response. Its real-time updating capability is often overlooked due to the misconception that "digital twin" is merely a complex term for simulation. This paper highlights its distinctiveness through an evasion exercise involving two independent entities in a collocated environment. Using a highly integrated virtual environment (HIVE) and internet of things (IoT) devices, we link the physical system with an analytical simulation, demonstrating the impact of lag times in high-pressure scenarios. The computational model leverages agent-based modeling (ABM) and discrete-event …

Numerical Analyses Of Construction Materials At Different Scales For Improved Resilience And Sustainability Of Civil Infrastructures, Chenchen Huang

Theses and Dissertations

The resilience and sustainability of civil infrastructure are fundamental to supporting modern society in the face of growing environmental challenges and resource limitations. This study aims to use multi-scale numerical tools to evaluate mechanical performance of different construction materials under various environmental and loading conditions. Firstly, we adopt the discrete element method (DEM) to evaluate the influence of freeze-thaw cycles (FTCs) action on the mechanical properties of rock from the micro perspective. A simplified plastic model is proposed to capture the residual deformation produced during FTCs. To further explore the deterioration of FTCs on rock, the water-contained grain-based model (GBM) …

Flexural Strengthening Of Reinforced Concrete Beams Using Nsm Gfrp: Assessing Key Parameters, Berlant Arab

Theses and Dissertations

The structural integrity and longevity of Reinforced Concrete (RC) beams are critical to modern construction, influencing safety, usability, and maintenance costs over time. As civil engineering endeavors to meet the challenges posed by aging infrastructure and evolving usage demands, rehabilitating and strengthening RC structures have become essential practices globally. This research focuses on a prevalent yet innovative method of enhancing RC beams: the application of Near Surface Mounted (NSM) Glass Fiber Reinforced Polymer (GFRP) bars.

GFRP is increasingly favored in structural engineering due to its superior properties to traditional materials. These include high tensile strength, resistance to corrosion, lightweight nature, …

Predicting The Indirect Cost Of Construction Projects In Egypt: An Artificial Neural Network Approach, Aya Effat

Theses and Dissertations

Cost estimation is one of the vital processes in construction management that needs to be done early in any project in order to determine the project's budget. The accuracy of the cost estimate is a key factor in the success of construction projects since it enables project managers to successfully control the project’s expenses. Construction costs mainly consist of direct cost and indirect cost. Generally, indirect costs can be categorized into two types: site overheads and general overheads. In a construction project, overheads, particularly site overhead costs, make up a considerable portion of a contractor's budget. Accordingly, accurately estimating the …

Performance Assessment Of Fiber-Reinforced Asphalt Mixtures: A Comprehensive Laboratory And Full-Scale Investigation, Ali Raza Raza Khan

Theses and Dissertations

Asphalt concrete is a composite material widely used in the construction of roads; however, fatigue cracking (load associated), thermal cracking (non-load associated), and permanent deformation (or rutting) are the most challenging issues in flexible (or asphalt) pavement structures. These distresses affect ride quality and are considered the most well-known pavement deterioration types. Several modifiers have been used as potential solutions to cracking and rutting of asphalt mixtures (i.e., polymers, geogrids etc.). Among these modifiers, fibers were introduced to improve the resistance of asphalt mixtures to rutting and cracking. Addition of fibers into the asphalt mixture is always challenging because of …

Construction Change Order Data As Inputs For A Programmatic Risk Model, Eric C. Klein

Theses and Dissertations

Hurricane Michael struck Tyndall Air Force Base as a Category 5 storm with 160 mph winds, damaging or destroying 90% of its infrastructure (484 buildings). This devastation prompted the Department of Defense to rebuild Tyndall as the “Installation of the Future,” encompassing 44 Military Construction (MILCON) projects and 260 Facility Restoration, Sustainment, and Modernization (FRSM) projects. Since reconstruction began, over 630 Change Request Forms (CRFs) have been closed, adding $67.8 million in costs and 4,880 construction days. The Air Force Civil Engineer Center's Natural Disaster Recovery (NDR) Division developed a programmatic risk model to predict future costs and delays. However, …

Operation And Maintenance Costs In Reverse Osmosis Desalination Projects Adopting Public-Private Partnerships: A Comprehensive Investigation And Analysis, Mayar Mohamed Khairy

Theses and Dissertations

Water Desalination projects, specifically ones adopting reverse osmosis (RO) technology, play a pivotal role in addressing the scarcity of water globally. Since these projects require huge investments, there is an imperative need to focus on the role of public-private partnerships (PPPs) in their developments. This research tries to provide a comprehensive investigation into the factors affecting O&M costs in PPP desalination projects due to their importance.

A comprehensive research approach, including a literature review, expert interviews, survey analysis, and statistical tools, is adopted in this research aiming to identify key factors and recommendations based on best practices in O&M costs …

Sustainability Transformation For Healthcare Facilities Following Net Zero Model, Esraa Elmitainy

Theses and Dissertations

The healthcare industry is a field undergoing huge development. Focused on SDG 3 “Good Health and Well-being”, the healthcare industry, as the main health service provider, was marked by experts as a sector that should lead sustainable development by example. The current work aims to formulate a sustainability rating system for new and existing healthcare facilities to encourage the Egyptian healthcare industry to move towards sustainability according to net zero concepts. Additionally, the transition to net zero waste is investigated though experimental work to test the possibility of utilizing sterilized medical waste in cement-based bricks.

The rating system starts with …

Advanced Construction Scheduling: Capturing Conditional And Stochastic Relationships, Amr Elsabagh

Theses and Dissertations

Proper planning is a key factor in all business endeavors. This is especially important in the construction industry as a project is sensitive to countless factors that affect the project's time and cost. This created the need for agile and flexible schedules for close monitoring and dynamic planning for construction projects. The currently prevailing scheduling techniques are CPM and PERT, which professionals in the field widely use. These methods create static schedules that are vulnerable to any changes in the schedule logic, which often happens during construction projects. In addition, these Scheduling techniques do not capture the uncertainties and complex …