Civil and Environmental Engineering Commons^™

Application Of Electrical Impedance Tomography To Cementitious Composites, Hugo Zazueta

Theses and Dissertations

This thesis explores the feasibility of using Electrical Impedance Tomography (EIT) for detecting damage in cementitious composites. Cementitious composites, such as concrete and cement mortar, are insulating; any conductive properties arise from the moisture within their pores and capillary structures. The proposed concept herein is that formed internal damages in cementitious composites consequently alter their pore and capillary structure, which can then be detected through EIT imaging. To construct tomographic images, the Gaussian Newton (GN) reconstruction algorithm, enhanced with priors, was employed. The results were then compared across different reconstruction processes. Cylindrical cement pastes and cement mortar samples were prepared, …

Quantifying Extreme Events: Applications Of Probabilistic Methods To Quantify Riverine And Coastal Flood Dynamics In South Carolina And Neighboring Coastal Communities, Ryne Phillips

Theses and Dissertations

Extreme flood events have been persistent throughout history and have challenged human populations around the globe. Over time, scientists and engineers have developed tools and technology to support flood risk management. Most, if not all, of these tools rely on some form of the field of stochastic hydrology. Stochastic hydrology is a broad discipline, but the overarching principle is to use statistical and data-driven techniques to develop an understanding of one or more hydrologic variables (e.g., flood flow or peak storm tide). However, the need for large sample sizes of data that offer insight into all possible combinations of outcomes …

Integration Of Machine Learning In Structural Health Monitoring For Damage Identification And Response Prediction In Bridges, Naga Lakshmi Chittitalli Ravuri

Theses and Dissertations

Machine learning-based structural health monitoring (ML-SHM) plays a pivotal role in enhancing structural resilience. By recognizing potential hazards, implementing resistance measures, facilitating swift recovery, and continuously monitoring structural health, ML-SHM ensures proactive maintenance and minimizes recovery delays post-events. Leveraging machine learning algorithms and sensor data, ML-SHM enables early detection of anomalies, prediction of failures, and adaptive responses, enhancing the structure's ability to withstand and recover from adverse conditions. This integrated approach not only improves the structure's performance and adaptability but also contributes to overall safety and longevity. This thesis presents a comprehensive exploration of structural health monitoring (SHM) techniques for …

Assessment For Sustainable Transportation Systems In Egypt, Hagar Mohamed Fares

Theses and Dissertations

The assessment of a sustainable transportation system poses a significant challenge for local governments, as it dramatically influences the promotion of environmentally friendly modes of transportation with the objective of safeguarding the public's welfare and health in their daily activities. The integration of such assessment should be implemented from the initial stages of system planning to its operational and maintenance phases, particularly in light of the increasing number of urban development activities nationwide. In order to facilitate decision-making processes, it is imperative to establish an efficient rating system that incorporates cultural and social constraints and comprehensively considers the three dimensions …

A Machine Learning Framework For Predicting Fabrication Hours For Industrial Steel Structure Projects, Dalia Ibrahim

Theses and Dissertations

Construction projects are considered high risk projects especially due to their required large capital making them require extreme attention in estimation as overestimating a project will lead to losing bids and underestimating them will lead to incurring more costs than budgeted resulting in losses. However, estimators are often faced with very tight timelines to finish their estimates leading them to primarily rely on their experience disregarding some crucial factors resulting in inaccurate estimates. In the steel structures industry, the steel fabrication phase accounts for 30 to 40% of the overall project cost; in addition, the steel industry is labor driven; …

Development Of A More Sustainable High And Ultra-High-Performance Concrete, Enrique Chirino Andalco

Theses and Dissertations

The urgent need to address climate change and environmental damage presents humanity with significant challenges that must be tackled quickly, not acting promptly will result in irreversible consequences, such as extreme weather events, public health risks, and water shortages, among other impacts.

Due to its enormous size and variety of uses, the construction industry is a key factor in addressing the climate challenge. Specifically, concrete as the most used construction material in the world is a good target for developing innovative and Sustainable improvements to reduce environmental impacts.

Using by-products from other industries in concrete manufacturing is a common and …

Machine Learning Predictive Models For Load Identification Of Railroad Bridges Subjected To Train-Induced Vibration, Md Masnun Rahman

Theses and Dissertations

The U.S. rail network is among the world's largest, safest, and most efficient. However, many its railway bridges, which play an essential role in its connectivity, are over 100 years old, showing signs of structural deterioration exceeding their practical service life. The increased weight and speed of modern trains also pose a risk to these bridges. Traditional load identification and monitoring technologies like Weigh-in-Motion (WIM) systems are rarely used on railway bridges due to their cost and practical limits. This thesis explores a cost-effective approach to utilize vibration sensors on railway bridges to identify and predict train load features (speed …

Numerical Study Of New Tuned Mass Friction Damper For Seismic Protection Of Civil Structures, Syed Muhammad Bilal Haider

Theses and Dissertations

Tuned Mass Friction Dampers (TMFDs) are passive control systems designed to mitigate vibrations in civil structures subjected to extreme lateral forces such as windstorms and earthquakes. The objective of this thesis is to propose a new TMFDs with enhanced energy dissipation capability for seismic protection of multi-story frame buildings. This new TMFD is termed as “Tuned Mass Multi-Sliding Friction Damper” (TMMSFD) consisting of multiple masses connected to the primary structure through linear springs and while sliding relative to each other at multiple sliding surfaces. TMMSFD offers an improved damping mechanism with reduced stick-slip motion effects compared to standard TMFDs which …

A Dedicated Lane Analysis For Supply Chain Resilience In The U.S.-Mexico Border: Cost-Comparison And Simulation Models, Carlo A. Zorola Gonzalez

Theses and Dissertations

Supply chains have been actively developing and implementing strategies to enhance resilience in response to various disruptive events like the COVID-19 pandemic, hurricanes, geopolitical tensions, and climate change. These strategies aim to address demand and supply imbalances, logistical challenges, and policy restrictions encountered in transborder commerce. One area significantly impacted by such disruptions is cross-border trade between the US and Mexico. Understanding these strategies is crucial for achieving supply chain resilience, defined as the ability of a supply chain to quickly adapt to sudden disruptions without affecting the flow of goods. In both the US-Mexico and US-Canada borders …

Development Of A Model To Predict Maximum Crack Width And Spacing In Reinforced Concrete Beams Under Flexural Stress, Saeed Alghamdi

Theses and Dissertations

Cracking in reinforced concrete structures is unavoidable due to the low tensile strength of concrete. Even though minimizing cracks on exposed concrete surfaces is significantly important from the aesthetics point of view, it is also very important for the durability and overall performance of the structure.

Flexural members must be designed to minimize cracking that may occur during the structure's service life. Even though there has been a lot of experimental work on crack width over the last several decades, a literature review reveals that researchers still can't agree on which variables are most important. Part of the reason for …

Amazon Fba Vs Fbm; A Strategic Approach To Determine Which Method Can Effectively Utilize Project Management Principles To Enhance Your Success As A New Amazon Seller., Tiffany Renee White

Theses and Dissertations

Navigating the complexities of a platform such as Amazon demands a strategic approach guided by project management principles. A comparative analysis of Fulfillment by Amazon (FBA) and Fulfillment by Merchant (FBM) methods were completed by focusing on how project management principles optimize product acquisition, supply chain management, and shipping methods for Amazon sellers. The objectives of this study included the identification of top product acquisition tools, the evaluation of inventory management software, assessing shipping methods, and determining the most effective fulfillment process for Amazon seller success. A mixed-methods approach was applied, involving an Amazon seller survey, literature review, data analysis, …

Utilization Of Confined Concrete In The Bottom Slab Of Double Composite Box Girder Bridges, Harry Craik

Theses and Dissertations

A mathematical model is proposed for the confinement of rectangular confined reinforced concrete elements under compression. The model was modified from existing models applied to rectangular confined concrete specimens. The present model applies to rectangular reinforced concrete cross-sections with a core aspect ratio of at least 2.0 and a high effective confinement index. The model applies to normal and high-strength concrete and incorporates the spacing of the transverse reinforcing hoops, the strength of the reinforcing bars, the reinforcing quantity, and the core aspect ratio of the section. The proposed model was verified against extensive experimental data, and there was a …

Evaluation Of Beach-Fx — Beach Nourishment Planning Model – Miami Beach Case Study, Brennan Chase Banks

Theses and Dissertations

Miami Beach, located on the Southeast coast of Florida, is a concerning location for coastal erosion because of the increasing intensity and frequency of tropical storms, nuisance flooding, and accelerated sea-level rise due to climate change. Miami Beach is famous for its beautiful beaches, making it a location of high interest for tourists, citizens, and investors. It is vital for coastal practitioners to accurately model coastal processes, beach evolution, and storm damage during the planning stage of coastal protection projects. The U.S. Army Corps of Engineers developed the Beach-fx model as a tool for engineers, planners, and economists to …

Mechanistic Empirical Design Of Flexible Pavements For Biopolymer Treated Soils, Vishweshwaran M

Theses and Dissertations

Cognizing the contamination effects of chemical soil modifiers on soil and groundwater, the assessment of the ability of biopolymers to improve the engineering properties of soils has gained attention in the last decade. As a soil additive, biopolymers have the potential to solve the trilemma of sustainability, price and soil suitability. Two polysaccharides and two protein biopolymers have been adopted in this study to enhance the geotechnical properties of fine-grained soils.

Design thickness catalogues were developed for a three-layered flexible pavement using 3D finite element analysis (FEA) and layered elastic analysis. The catalogue aims to provide structurally reliable thickness values …

Characterization Of Per- And Polyflouroalkyl Substances In Aqueous Filmforming Foam Wash Waters, John M. Diskin

Theses and Dissertations

The fiscal year 2020 National Defense Authorization Act mandated the publication of a military specification for a fluorine-free firefighting foam available for use no later than October 1, 2023. Replacing AFFF with a fluorine-free alternative creates the issue of decontaminating current firefighting infrastructure of residual PFAS without replacing these systems. To eliminate outstanding PFAS, the proposed solution is to drain the AFFF from current fire suppression systems and flush the plumbing three times with uncontaminated water. This study tested the efficacy of the triple rinse method by conducting scaled down experiments on a variety of plumbing components from a retired …

Machine Learning Predictions Of Electricity Transfers Between Balancing Authorities In The Carolinas, Victoria Groleau

Theses and Dissertations

Climate change through reduced streamflow, increased temperatures, and other factors impacts the efficiency of energy generation systems. The United States electric grid is comprised of a large network of balancing authorities engaged in trading electricity to maintain balance between supply and demand. The generation of electricity, a pivotal component of this balance, is impacted by climate change and weather variability as well as the growing demand for energy. Several hydro climatological factors such as streamflow, air temperature, and wind speed significantly influence the efficiency of power plant electricity generation. Due to the exchange of electricity between balancing authorities, impacts to …

Long-Term Deterioration And Investment Modeling Of Water Distribution Infrastructure, Bethany M. Dorian

Theses and Dissertations

The United States Air Force (USAF) and municipal utilities rely on asset management processes to maximize utility of infrastructure assets while decreasing maintenance and repair costs. One of the core tenants of asset management is assessing the condition of the asset, which for water distribution pipes is challenging and costly to obtain. As a result, asset managers often rely upon pipe deterioration modeling using existing data, filling in the gaps when assessments are not available. This thesis uses USAF water distribution network data to develop a series of time-homogenous Markov chain probability models based on two sampling methods and four …

Integrating Eod And Readiness Competencies Into The Ce Cgo Competency Framework, Kristina L. Johnson

Theses and Dissertations

In the last few years, the strategic focus of the United States defense posturing has shifted from legacy conflict in the Middle East to focusing on the Pacific with increased emphasis that Airmen must be educated and trained to deter or prevail in any conflict. To achieve this goal, the Department of Air Force (DAF) has evolved to utilizing a competency-based education framework with the Civil Engineer career field adopting this strategy and releasing the first version of their occupational competencies in 2020. However, DAF force posturing has evolved since 2020. With the new deployment system, Agile Combat Employment scheme …

A Statistical Analysis Of Phased Construction Projects, Timothy M. Dejong

Theses and Dissertations

The construction industry is known for exceeding target budgets and schedules, and Department of Defense projects are no exception. The Air Force Installation & Mission Support Center (AFIMSC) manages a budget of $3.14 billion to repair, alter, demolish, and maintain Air Force facilities. However, an ever-increasing backlog of maintenance and repair work and a consistently underfunded repair program pose an increased financial risk to the sustainability of the construction and repair program. Phasing large construction efforts is a potential strategy that has recently been used to yield efficiencies by AFIMSC program managers. This study presents a statistical analysis of phased …

Modeling Recovery Of The Florida Electric Transmission Grid After Severe Weather Event, Wei B. Guan

Theses and Dissertations

Predicted changes to the climate are expected to increase the frequency and severity of extreme weather events. The Florida electric grid is a critical infrastructure system susceptible to severe weather events, especially hurricanes, causing widespread damage and outages. A foundational concept of the electric grid’s resilience is its ability to recover after extreme weather events, such as hurricanes and flooding. The recovery of the electrical grid after an extreme event is predicated upon the electrical asset's remoteness and the component's level of damage. Using fragility analysis, previous models have assessed the mean time to recover for transmission towers and substations …

Predictive Analytics For Military Construction Overruns: A Machine Learning Approach, William D. Hunter

Theses and Dissertations

This research focused on analyzing cost and schedule overruns in a specific set of Air Force MILCON projects. Using data from the Built Infrastructure Common Operating Picture (BICOP), several advanced machine learning techniques, including LASSO regression and Random Forest, were applied to uncover patterns and build predictive models. The work sought to enhance the decision-making capabilities and efficiency of project managers within the Air Force through data-driven insights. A key finding from the models indicated that location was the most important factor in influencing a project’s tendency toward cost and schedule overrun. The best model for predicting schedule overrun achieved …

Advanced Oxidation Of Tert-Butanol With Ultraviolet Light Emitting Diodes And Hydrogen Peroxide, Lauren R. Mainolfi

Theses and Dissertations

Tert-butanol (TBA), a versatile chemical widely used in industrial processes, poses exposure risks through inhalation, ingestion, and skin contact. Environmental contamination, often from industrial activities, emphasizes the importance of robust waste management and monitoring to protect water supplies from potential TBA migration and ensure drinking water safety. This study employed hydrogen peroxide (H2O2): TBA molar ratios of 100, 200, 400, and 500:1 in a Continuous Flow Stirred-Tank Reactor (CSTR) with UV-LED as the TBA degradation mechanism in an Advanced Oxidation Process (AOP). The UV-LEDs and H2O2 were synergistically employed to generate hydroxyl radicals in an advanced oxidation process. Gas chromatography–mass …

Quantifying Resilience And Redundancy For Air Force Linear Infrastructure, Ryan C. Jakovich

Theses and Dissertations

The historical underfunding of USAF infrastructure necessitates a strategic approach to reduce excess infrastructure while preserving resilience in the face of potential first-strike scenarios. This thesis formulates an infrastructure resilience metric that assesses network performance under varying degrees of damage. Furthermore, the study calculates the impact of redundant infrastructure by introducing added structural elements and measuring the resultant reduction in performance loss during damage scenarios. Utilizing USAF geospatial infrastructure data, adjacency matrices representing graph theory networks were constructed in Arc GIS Pro and evaluated using coding languages from the IGraph library and algorithms developed in RStudio. The newly proposed performance …

Optimizing Hub And Spoke Selections For Adaptive Basing In Agile Combat Employment, Alan Heng

Theses and Dissertations

Advancing technologies and emerging competitors within the Indo-Pacific region have rendered the use of fixed installations for United States Air Force (USAF) operations less than optimal for generating airpower. The adoption of Agile Combat Employment (ACE) is imperative and emphasizes a hub-and-spoke model. However, the methodology for selection of contingency locations remains undecided. Current selection of optimal sites hinges on an optimization framework, employing either rank-based or mathematical approaches that consider various criteria to assess and quantify each location. These criteria are then addressed through objectives and constraints, forming the basis for an effective decision-making process. This paper introduces two …

An Analysis Of Military Construction Cost Escalation And How It Is Accounted For In Cost Estimating Practices, Benjamin D. Rieben

Theses and Dissertations

Construction escalation is a significant economic phenomenon that plays an important role in the construction industry. It refers to the steady increase in the costs associated with facility and infrastructure projects over time. Accurately capturing escalation is a key component in the development of construction cost estimates, and failure to adequately account for escalation can have far-reaching consequences. This is especially true for Military Construction (MILCON) projects, which account for billions of dollars of defense spending annually. The Department of Defense (DoD) utilizes a unit cost approach to develop rough order of magnitude (ROM) estimates for MILCON projects. The DoD …

Development Of A Metric To Quantify Facility Hardening, Jesse C. Solorzano

Theses and Dissertations

This research investigates the intricate aspect of infrastructure resilience, focusing on the distinction between hardening and resilience. Hardening, often used interchangeably, with enhancing resilience, involves strategies to strengthen facilities, networks, or systems against various threats. Despite its recognized importance in mitigating physical disruptions and enhancing facility functionality amid different threats, a significant vagueness persists in quantitatively defining hardening. This thesis addresses this gap by developing a quantifiable metric for facility hardening, separate from general resilience measures. The study begins by exploring the historical context of facility hardening, linked to catastrophic events and the need for resilient infrastructure. It explores various …

Evaluating United States Air Force Installation Water Security, Michael L. Berg

Theses and Dissertations

Water shortage at Mountain Home Air Force Base in the last decade ignited the need for an assessment of relative water security risk across United States Air Force installations. Current evaluation methods often differ from actual conditions suggesting a need to categorize security across the enterprise for multiple discrete locations. Indicator-based approaches for characterizing water security are common in academic literature but have little methodological consensus and have rarely been applied to discrete areas spread across geographically separated locations with diverse climates. Using a two-stage analytical hierarchy process and normalized utility functions, water security at 30 installations across the continental …

Comparing The Return Of Investment Of Maintenance And Repair Treatments On Airfield Pavements, Aljhon C. Barrogo

Theses and Dissertations

Two decades of taking risks with infrastructure has led to a $33B backlog in deferred maintenance and recapitalization for the USAF, with expectations that this amount will triple in the next three decades. As this reality materializes, it becomes evident that the condition of infrastructure under the care of the USAF will undergo accelerated degradation. To address and rectify this situation, the Infrastructure Investment Strategy (I2S) was introduced. While the policy commits to bolstering the infrastructure budget to two percent of replacement value, it also acknowledges the necessity of implementing complementary strategies to effectively course correct. One strategy implied in …

Assessing Military Parking: A Deep Learning Approach To Evaluating Standards And Impacts, Ryan D. Lalonde

Theses and Dissertations

Current United States Department of Defense (DoD) standards require a minimum amount of parking for each building. This requirement defines how much off-street parking to construct. However, the impact of these requirements remains unclear. This study builds upon the emerging field of overhead imagery analytics by directly tying it to parking on military installations. Specifically, this study leverages a pretrained deep learning car detection model, Car Detection – USA, developed by Esri for use within ArcGIS, and couples it with open-access temporal imagery sourced from Google Earth Pro to assess selected parking lots across Area B, Wright-Patterson Air Force Base, …

Selection Of Soil Stabilization Methods For Low-Volume Road Applications, Peter J. Spinks

Theses and Dissertations

This study examines a potential method of selecting an ideal soil additive to assist road planners in selecting an ideal soil stabilizer for low-volume road construction with in-situ soils. Essential for the socioeconomic success of rural communities, low-volume soil or gravel roads account for approximately 54% of US road expenditures to maintain and remediate. Soil stabilization can provide significant savings in regards to the cost, effectiveness, and environmental impacts of these roads. With hundreds of commercially available soil treatment products available with significant variations to their effects, it can be difficult for road planners to select the most appropriate product. …