Civil and Environmental Engineering Commons^™

The Rise In Height And Curb Weight Of The Top-Selling Vehicles In The United States From 1991 - 2025: Implications For Engineering Design And Vulnerable Road Users, Samuel L. Steinman-Friedman

Civil Engineering Theses

Road fatalities are higher in the United States than in other high-income regions. In 2024, 39,254 people died on roads in the United States compared to 19,940 in the European Union. These two regions have comparable exposure metrics, such as population size, roadway network length, and fatalities per mile traveled. Light trucks dominate the U.S. market, whereas hatchbacks are prevalent in Europe. The trendline of the average height and curb weight of the top-selling vehicles in the United States has increased by 0.24 inches and 23.52 pounds per year since 1991. The average 2025 top-selling U.S. passenger vehicle is 7.5 …

Integrated Thermal, Energy, And Structural Performance Assessment Of A Novel In-Service Shallow Geothermal Bridge Deicing System, Alireza Fakhrabadi

Civil Engineering Dissertations

Understanding the performance of bridge deck deicing systems under winter weather conditions is important for improving transportation safety and reducing long-term deterioration of bridge infrastructure. Bridge decks are more vulnerable to icing than ground-supported pavements because they are exposed to ambient air, wind, and radiation from multiple directions, while they do not receive thermal support from the underlying soil. Conventional deicing methods, especially chloride-based salts, can reduce ice formation in the short term, but repeated application may accelerate reinforcement corrosion, concrete damage, and environmental concerns. Therefore, shallow geothermal energy has been considered as a sustainable alternative for bridge deck deicing …

Design And Fabrication Of A Scaled Automated Dairy Farm Model: A Report, Md Towfiqur Rahman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Summary

This study investigates how ventilation systems work in dairy barns and builds a scaled model to support education and research. The project is designed to help students from the University of Nebraska–Lincoln (UNL), K-12 learners, and researchers in animal science, veterinary medicine, and engineering gain visual experience with dairy facility components and processes. Different ventilation methods were studied, leading to the design of a 1/64-scale tunnel-ventilated dairy barn meant for 60 Holstein Friesian cows. Barn dimensions were set based on real Holstein cow measurements to ensure proper cow comfort, while airflow requirements were calculated and scaled down. Miniature fans …

Triangulating Primary Sources, Professional Judgement, And Llm-Generated Summaries: Educating Nurses In An Ai-First World, Sarah Oerther, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Multi-User Collaboration In Augmented Reality For Beyond-Visual-Line-Of-Sight Bridge Inspection, Joel Murithi Runji, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Bridge inspection traditionally relies on scaffolds, snooper trucks, and aerial robots for hard-to-reach areas beyond the visual line of sight of inspectors. This study automates the collaborative inspection workflow for multiple users when inspecting hard-to-reach bridge sections by interfacing low-cost multimodal sensors mounted on a magnetically wheeled climbing robot with augmented reality devices in a cyber-physical system. Non-destructive and visual sensors provide near real-time information of automated steel thickness measurements and visual observations of corrosive regions, respectively. The visual sensors also support robot teleoperation. The cyber-physical system is evaluated for its user-friendliness and performance. The system performance is quantified by …

Heat-Related Injuries And Fatalities In Roofing: Osha Investigations From 2003-2024, Kenneth S. Sands Ii, Benjamin Marshall

The Professional Constructor

This study examines 52 heat-related roofing incidents recorded by the Occupational Safety and Health Administration (OSHA) between 2003-2024 to describe patterns in outcomes and identify trade-specific prevention opportunities. Researchers built a structured dataset from OSHA investigation summaries and analysed frequencies of the incidents and their associations with month, time of day, project type, end use, and age to complement a thematic review of narrative abstracts. Fifty-eight percent of cases were fatalities, with the remainder split between hospitalized and non-hospitalized injuries; these statistics underscore the consequences of heat events that trigger OSHA reporting. There was a clear relationship between number of …

Managing Green And Sustainable Construction Projects: A Computational Analysis Of Associated Risks And Challenges For Improved Performance, Bahaa Chammout, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Green and sustainable building practices have emerged as effective strategies to address the environmental challenges posed by the construction industry. This includes unsustainable resource utilization, excessive waste production, greenhouse gas emissions, and high energy consumption. However, the integration of green and sustainable initiatives in construction introduces distinct risks and challenges that affect project management and may lead to claims and disputes. To this end, and while previous research examined dispute causation across various aspects of the construction industry, there is limited investigation of the unique and complex nature of risks and challenges - and consequently conflicts, claims, and disputes - …

Reliability-Based Performance Evaluation Of Slurry Wall For Leakage Control At Chakaria Landfill, Bangladesh, Shishir Bhandari

Civil Engineering Theses

Landfill leachate threatens groundwater quality in low-lying coastal Bangladesh, where a shallow water table and a discontinuous natural clay barrier heighten contamination risk beneath municipal solid waste sites. At the Chakaria Landfill in Cox's Bazar District, a cement-bentonite slurry wall was proposed as a vertical cutoff to control seepage, but its reliability under the site's high-groundwater condition had not previously been evaluated in probabilistic terms.

This study evaluated the wall's performance using a two-dimensional SEEP/W finite-element seepage model, a validated response surface (RSM) equation relating seepage rate to wall permeability, thickness, depth, and a Hasofer-Lind first-order reliability (FORM) analysis built …

Concord Public Transportation Improvement Project, Jacob Holt

Honors Theses and Capstones

The capital city of Concord, New Hampshire, has been served by Concord Area Transit (CAT) since 1989. Despite continued population growth and economic development within the city, CAT’s fixed route bus system has remained unaltered since 2011. The purpose of this project is to rework the CAT system to provide service that better aligns with Concord resident’s current needs. A public survey was conducted to gather data regarding Concord resident’s needs, habits, and perception of the existing system, which was used in the development of the revised system. The project includes suggestions for both system-wide and route-specific modifications. Key changes …

Restoring Tidal Function: Hydrologic And Erosion Controls, On Rare Plant Distribution In New Hampshire Salt Marshes, Nikhila B. Lampman

Honors Theses and Capstones

No abstract provided.

Probability Of Detection For Corrosion-Induced Mass Loss And Yield Strain In Metal Structures Using Fe-C Coated Long Period Fiber Gratings Sensors And Electroresistive Strain Gauges, Ying Zhuo

Doctoral Dissertations

"Graphene-based, Fe-C coated long-period fiber grating (LPFG) sensors individually reveal a causal relation between LPFG wavelength change and Fe-C mass loss. Their correlation parameters vary significantly between the sensors mainly because hydrophobic multilayer graphene and graphene oxide make sensor fabrication inconsistent. This study explores MXene-based, Fe-C coated LPFG sensors due to MXene’s inherent hydrophilic property in the presence of surface functional groups such as hydroxyl and oxygen and the probability of detection (POD) for mass loss from Fe-C coated LPFG sensors when deployed at a fixed location. A novel fabrication process incorporating Piranha solution pretreatment is proposed to ensure uniform …

Accelerating Circular Economy Transition For A Sustainable Built Environment: A Systems-Based Framework, Radwa Walid Yassin Eissa

Doctoral Dissertations

"The Circular Economy (CE) has gained momentum as a transformative framework for steering the construction value chain towards greater sustainability. However, this transition requires shifts in production and consumption patterns, adoption of circular business models, and the replacement of linear practices. Despite growing interest, CE adoption in construction faces persistent challenges, including sectoral fragmentation, lack of integrated governance frameworks, and limited coordination among stakeholders. This dissertation aims to accelerate the CE transition in the built environment through a multi-scale, interdisciplinary approach spanning five modules: (1) Module 1 develops a construction value chain-structured portfolio of CE strategies and assesses their implementation; …

Analytical And Empirical Data-Driven Risk-Governance Design Across The Different Phases: Creating Informed Policy Adjustments For The Transportation Project Lifecycle, Mariam A. Elazhary

Doctoral Dissertations

"Transportation infrastructure is a critical foundation for economic productivity, yet agencies still face challenges in translating the expanding transportation datasets into defensible, phase-specific risk-governance tools. This dissertation addresses this gap by developing analytical and empirical, data-driven approaches to support risk governance across the transportation project lifecycle. Module 1 uses a panel model with bid-letting data to examine how out-of-state contractor participation affects pre-award competition and to derive entry-governance rules. Module 2 analyzes nonfatal injury data through iterative multiple linear regression and fatality data through association-rule change mining to identify multi-factor safety-risk configurations and develop adaptive safety-governance provisions. Module 3 develops …

Quantifying, Forecasting, And Mitigating Construction Labor And Material Challenges In A Dynamic Global Economy Using Econometrics And Deep Learning, Ahmed Gamal Elsayed Mohamed Shiha

Doctoral Dissertations

"The construction industry contributes to the global economy, yet its cost management practices remain constrained by labor shortages and material price volatility. These challenges are intensified by economic disruptions, geopolitical tensions, and trade policy shifts. Despite a growing body of literature, five knowledge gaps remain unaddressed: (1) the absence of dynamic, and localized measures of construction labor shortages; (2) limited empirical investigation of macroeconomic leading indicators of labor shortages; (3) underutilization of deep learning (DL) algorithms in forecasting local construction labor earnings; (4) the limited treatment of structural breaks in existing construction material price forecasting models; and (5) the lack …

Perception Of Transportation Challenges And Their Influence On Mode Choice In A Small Us City: A Generalized Structural Equation Modeling Approach, Anindya Kishore Debnath, Suman Kumar Mitra

Civil Engineering Faculty Publications and Presentations

This study profiles individuals encountering transportation challenges by analyzing factors influencing their perceptions and how they affect mode choice decisions in Fort Smith, Arkansas. Using primary travel survey data, we estimated a multinomial logit (MNL) within a Generalized Structural Equation Model (GSEM) that controls for residential self-selection and car ownership endogeneity. We find that individuals from low-income households are more likely to perceive transportation challenges, particularly due to a lack of a car and inadequate public transport. Higher household car ownership generally diminishes perceived challenges, except regarding limited bike lanes. Weekend or late-shift workers are more likely to own cars …

Performance Evaluation Of Modified Moisture Barrier For Subgrade Stabilization Of Pavements On Expansive Soils, Md Tamim Shahriar

Civil Engineering Theses

Expansive soils inflict an estimated nine to fifteen billion dollars in annual damage to infrastructure across the United States, surpassing the combined losses from earthquakes, floods, hurricanes, and tornadoes (Nelson and Miller, 1997; Jones and Jefferson, 2012). In Texas, eighteen of twenty-five TxDOT districts contend with pavement failure rooted in moisture-driven volume change of subgrade clay, consuming roughly twenty-five percent of the agency's annual budget for maintenance and repair (Sebesta, 2002; Wanyan et al., 2010). Conventional remediation approaches, including soil replacement, chemical stabilization with lime or cement, and prewetting, are either prohibitively expensive, unsuitable for high-sulfate soils, or confined to …

A Four-Step Thermocatalytic Route For Converting Co2 Into High-Purity Oxalic Acid, Hao Feng, Muhammad Kashif Khan, Lei Li, Hongyan Ma, Xinhua Liang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This research outlines a four-step methodology for transforming CO₂ into high-purity oxalic acid. CO2 was first sequestered as KHCO₃ through its reaction with aqueous KOH, followed by hydrogenation using a supported AgPd/CNT catalyst in a batch reactor at an initial H₂ pressure of 60 bar and a temperature of 150°C. The formate yield reached 91.8% at optimum conditions. Potassium formate in the solid state was thermally coupled in the presence of KOH at 400°C under N2 flow, yielding potassium oxalate of up to 76% yield. The final step was the selective precipitation of potassium oxalate with ferrous …

Evaluating Training Effectiveness And Learning Transfer In The Kentucky Transportation Cabinet Safety Academy, Amanda L. Casolare

Theses and Dissertations--Civil Engineering

Effective evaluation of safety training is crucial to ensure that learning translates into safe work practices, particularly in high-risk public sector environments. The Kentucky Transportation Cabinet (KYTC) is developing a Safety Academy to enhance hazard recognition, risk management, and safety leadership within the organization. However, the Safety Academy has not yet been implemented, and formal evaluation methods for training have not been established. This study aimed to examine evidence-based training evaluation techniques and develop recommendations for evaluating the KYTC Safety Academy prior to program implementation.

This study employed an applied pre-implementation research design grounded in a comprehensive review of safety …

From Floodplain To Floodplain: Analyzing Stream And Riparian Restoration Methodologies And Impacts, Noah P. Lane

Theses and Dissertations--Biosystems and Agricultural Engineering

Stream restoration is a relatively new scientific field. Currently, there is not a definitive methodology for performing restorations that all professionals in industry and academia can agree upon. This has allowed for multiple ideologies to be developed and altered that vary by geographic location and the professional using them. In addition to the methodologies used, the publicly available design guidance published by state government organizations also varies by regulatory authority, method of analysis, ecoregion, and restoration objectives. In some cases, design guidance is replicated from a different geographical area and may not satisfy local needs or existing site conditions. Since …

Exploring Aggregate Morphological Characteristics Under Laboratory Polishing For Enhanced Pavement Skid Resistance, Ahmed S. El-Ashwah, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

As the use of recycled asphalt pavement (RAP) in pavement construction grows for sustainable development, it becomes essential to investigate potential frictional deterioration over time. This study evaluated the friction properties of recovered RAP material aggregates compared with raw aggregates across various polishing cycles. The micro-Deval test was employed to simulate aggregate loss of texture, while morphological and friction properties were measured using an aggregate imaging measurement system (AIMS-II), along with a British pendulum tester (BPT) and dynamic friction tester (DFT). Additionally, Fourier transform infrared spectroscopy (FTIR) was employed to assess its potential in determining the origin and composition of …

Evaluation And Design Of A Footing Hybrid Connection For Innovative Hollow-Core Fiber-Reinforced Polymer–Concrete–Steel Composite Columns, Mohanad M. Abdulazeez, Mohamed A. Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

To support the advancement of accelerated bridge construction in high-seismic regions, this study investigates a novel prefabricated column-to-footing connection designed for improved resiliency, constructability, and cost efficiency. The socket connection utilizes hollow-core fiber-reinforced polymer–concrete–steel (HC-FCS) columns with embedded corrugated steel pipes (CSPs). The composite HC-FCS column consists of a concrete shell sandwiched between an outer fiber-reinforced polymer tube and an inner steel tube. The inner steel tube is embedded into the footing connection of the HC-FCS column. The same authors tested the innovative socket connection on a large HC-FCS column under seismic loads, showing high ductility, strong moment and drift …

Evaluation Of Critical Shear Strength Of Soils In Nebraska Based On Revised Cpt, Chung R. Song, Bashar Al-Nimri, Basil Abu Al Sha'r, Dhurba R. Pandey, Jongwan Eun, Seunghee Kim

Nebraska Department of Transportation: Research Reports

This study evaluated the “Fully Softened Shear Strength (FSSS)” of soils in Nebraska based on a revised Cone Penetration Test(CPT) method. FSSS is a unique strength condition that soils show substantially reduced strength during rainy seasons, eventually causing failure of slopes and other structures.

The revised CPT was adapted to inject water at targeted depths, inducing controlled moisture infiltration and capturing real-time soil softening over designated intervals of 30, 60, or 90 minutes. Through tip resistance (qc) and sleeve friction (fs) measurements under “in-situ” and “wet” conditions, the test effectively identified fully disturbed/low strength zones around the sleeve. Simultaneous sampling …

The Use Of Recycled Plastic In Asphalt Pavements: Feasibility Study, Isabella Bueno, Robert Rea, Jamilla Teixeira

Nebraska Department of Transportation: Research Reports

The plastics industry has been actively exploring new end-market opportunities for the more than 35 million tons of waste plastics generated annually. The use of recycled WP in asphalt presents an opportunity to improve pavement performance while reducing the growing amount of WP being landfilled or released into the environment. However, the use of WP in asphalt mixtures poses challenges due to variations in plastic composition and the presence of non-plastic contaminants. The absence of standardized procedures has resulted in inconsistent integration methods and unclear roles of WP within asphalt concrete (AC) mixtures. Therefore, the goal of this multiphase study …

Development And Evaluation Of Crashworthy Approach Guardrail Transition With Increased Span Length Between Concrete Bridge Rail And First Transition Post – Phase I, Tewodros Yosef, Qusai Alomari, Ronald K. Faller, Robert W. Bielenberg, Scott Rosenbaugh

Nebraska Department of Transportation: Research Reports

This study developed and evaluated a 34-in.-tall Nebraska Department of Transportation (NDOT) thrie-beam approach guardrail transition (AGT) with an increased span between the concrete buttress end and the first transition post. The objective was to accommodate a wide range of common obstructions near bridge ends, including abutments, wing walls, drainage features, and utilities. A survey of NDOT districts identified critical obstruction geometries and informed design criteria. Most NDOT districts indicated that a maximum span of about 4 ft would be sufficient, and some preferred spans up to 6 ft. To accommodate a wider range of obstructions, the first transition post …

Assessment Of Truck Parking Demand And Safety During Normal And Severe Weather Conditions In Nebraska, Nathan Huynh, Li Zhao, Zhenghong Tang, Aida Riahifar, Jahangeer Jahangeer

Nebraska Department of Transportation: Research Reports

This project examined truck parking capacity, demand, and utilization patterns along I-80 in Nebraska. The objectives were to (1) document the capacity of public and private truck parking facilities along I-80, (2) analyze spatial and temporal trends in parking demand, (3) develop models to predict occupancy at parking facilities, (4) identify clusters of undesignated parking during inclement weather, and (5) assess whether truck parking shortages contribute to truck-involved crashes. Within a one-mile buffer of I-80, 21 public facilities and 49 private facilities were identified. The spatiotemporal analysis of these public and private truck parking facilities using the National Agriculture Imagery …

A Productivity Rate-Based Comparative Carbon Footprint Cost Analysis Of Small To Large-Sized Open-Cut Pipeline Installation Activities For Sanitary Sewerage Construction: A System Boundary Concept, Amir Reza Zakeri

Civil Engineering Theses

Underground sanitary sewer pipelines are essential components of urban infrastructure; however, open-cut pipeline installation requires excavation, bedding preparation, pipe placement, backfilling, embedment, and compaction activities that rely heavily on construction equipment and fuel consumption. As a result, open-cut installation can generate measurable greenhouse gas emissions during the construction phase. With increasing attention to sustainable infrastructure delivery, there is a need for a consistent approach to quantify construction-phase carbon footprint and convert those emissions into a comparable economic indicator. Accordingly, this thesis aims to create and apply a productivity rate-based calculation framework for estimating and comparing construction-phase CO₂e emissions and carbon …

Co-Sputtered Cuni Heteroatomic Electrocatalyst For Enhanced 5-Hydroxymethylfurfural Selective Electrochemical Conversion, Moumita Dikshit, Baleeswaraiah Muchharla, Luz Vazquez Rivera, Kapil Kumar, Sunita Sanwaria, Kishor Kumar Sadasivuni, Abdennaceur Karoui, Sandeep Kumar, Adetayo Adedeji, Bijandra Kumar

Civil & Environmental Engineering Faculty Publications

The electrochemical conversion of biomass-derived 5-hydroxymethylfurfural (HMF) represents a promising, economically viable, and environmentally sustainable approach for producing value-added chemicals using renewable energy and in situ hydrogen generated through water electrolysis. However, the electrochemical hydrogenation (ECH) of HMF remains challenging due to the inherently low catalytic activity and selectivity of the electrodes, compounded by competition with the kinetically favored hydrogen evolution reaction (HER) in aqueous electrolytes. In this work, we demonstrate that Cu_xNi_100-x heteroatomic thin films, fabricated via direct current (DC) magnetron co-sputtering, achieve a more than one order of magnitude increase in the HMF to 2,5-Bis-hydroxymethylfuran …

Nature-Based Solutions For Urban Resilience And Environmental Justice In Underserved Coastal Communities: A Case Study On Oakleaf Forest In Norfolk, Va, Farzaneh Soflaei, Mujde Erten-Unal, Carol L. Considine, Faeghe Borhani

Civil & Environmental Engineering Faculty Publications

Climate change and sea-level change (SLC) are intensifying flooding in U.S. coastal communities, with disproportionate impacts on Black and minority neighborhoods that face displacement, economic hardship, and heightened health risks. In Norfolk, Virginia, sea levels are projected to rise by at least 0.91 m (3 ft) by 2100, placing underserved neighborhoods such as Oakleaf Forest at particular risk. This study investigates the compounded impacts of flooding at both the building and urban scales, situating the work within the framework of the UN Sustainable Development Goals (UN SDGs). A mixed-method, community-based approach was employed, integrating literature review, field observations, and community …

Social Safety And Social Security: Validating Context-Specific Instruments For Slums, Liss D. Romero, Katherine Palacio, Zacheous Ako Abang, Valeria Silgado, Humberto Llinas, Leidy González, Erika Frydenlund, Daniel Bolivar, Jose J. Padilla

VMASC Publications

Social safety and social security are concepts that help explain a community's well-being by assessing how it manages and mitigate existing, or perceived, risks. However, these terms are often conflated, which can limit understanding, particularly in areas with unstable living conditions. This study explores both concepts in the context of residents living in slums. As the number of displaced people grows, slums and informal settlements are becoming increasingly common worldwide, making it essential to clarify these concepts. Residents of slums face numerous hazards, including crime, violence, inadequate housing, overcrowding, and limited access to essential services. To measure social safety and …

Sustainable Safety Planning On Two-Lane Highways: A Random Forest Approach For Crash Prediction And Resource Allocation, Fahmida Rahman, Cidambi Srinivasan, Xu Zhang, Mei Chen

Civil Engineering Faculty Publications

During the safety planning stage, accurate crash prediction tools are critical for prioritizing countermeasures and allocating resources effectively. Traditional statistical approaches, while long applied in this field, often depend on distributional assumptions that may introduce bias and limit model accuracy. To address these issues, studies have started exploring Machine Learning (ML)-based techniques for crash prediction, particularly for higher functional class roads. However, the application of ML models on two-lane highways remains relatively limited. This study aims to develop an approach to integrate traffic, geometric, and critically, speed-based factors in crash prediction using Random Forest (RF) and SHapley Additive exPlanations (SHAP) …