Structural Engineering Commons^™

Structural Analysis And Design Methodologies Of Roller Coasters, Benjamin Komar

Williams Honors College, Honors Research Projects

This project explores the structural analysis behind the design of roller coaster tracks and supports as practiced by modern engineers. It also examines various roller coaster design methods currently in use. This research will be used to craft a detailed explanation of the roller coaster design process. Additionally, a 3D model of a roller coaster was developed based on the researched design procedures, featuring three track sections with different loading conditions to create a supporting structure for 2D truss analysis. The results of the truss analysis were then compared to those obtained using RISA-3D, a finite element structural design software.

The Towering Inferno: Art, Policy, And Legacy, Charles R. Jennings

Publications and Research

The Christian Regenhard Center for Emergency Response Studies, leveraging the expertise of its faculty, staff, Advisory Board and colleagues, has consistently programmed activities focused on high-rise fire safety. The upcoming 50^th anniversary of the film The Towering Inferno was an inspiration.

We decided this would be more lighthearted and less purely technical than many of our events. We wanted to consider both the film, and use it to reflect on the state of fire safety in tall buildings in New York City.

Of course it does not escape us that the topic of fire safety is a serious one, …

Comparative Analysis Of Lidar And Close-Range Photogrammetry Techniques For Inspection Of Mse Walls In Two Georgia Bridges, Md. Mehrab Hossain

College of Graduate Studies: Theses & Dissertations

Mechanically Stabilized Earth (MSE) retaining walls are durable, settlement tolerant, easy to install, and present cost-effectiveness, in highway bridges. Nevertheless, the cost of repairing MSE walls is high, and it is crucial to have an accurate, quantitative, and scalable inspection method for early detection of potential problems. This study aims to analyze and evaluate undesired displacements that may affect these walls over time. For this, two remote-sensing technologies are considered: Light Detection and Ranging (LiDAR) and 3D Close Range Photogrammetry (CRP). Their performances are compared against an accurate Robotic Total Station (RTS) device, serving as the benchmarking instrument. This work …

Reuse Of Calcium Carbonate (Caco3) Recovered From Discarded Carpets As Filler In Fiber-Reinforced Polymer (Frp) Composites, Roshan Devkota

Graduate Theses, Dissertations, and Problem Reports (ETD)

Over four billion pounds of carpet are discarded annually in the United States, making carpet waste a significant environmental concern. Calcium carbonate (CaCo₃) constitutes up to 45% of the mass of most synthetic carpets. Reusing this CaCo₃ as a filler in the rapidly growing fiber-reinforced polymer (FRP) industry, which is projected to reach USD 10.38 billion, presents a low-cost, practical approach to developing a market-based solution to post-consumer carpet waste.

This study investigates the reuse of CaCo₃ recovered from discarded carpet backing as a filler in FRP composites, focusing on its mechanical viability in comparison to virgin CaCo₃. The methodology …

The Impact Of Skew On The Flexural Behavior Of Press-Brake-Formed Tub Girders, Matthew Allan Weatherholt

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Short Span Steel Bridge Alliance (SSSBA) is a group of bridge and buried soil steel structure industry leaders who have joined together to provide educational information on the design and construction of short span steel bridges in installations up to 140 feet in length. Press-brake-formed-tub-girders (PBFTGs) were developed by a technical working group within the SSSBA in response to a rising demand for rapid infrastructure replacements for short span bridge applications. PBFTGs are produced from structural steel plate and can be finished as weathering steel or galvanized. After being cold bent to the appropriate shape, shear studs are welded …

A Durability Evaluation Of Class B Concrete Bridge Substructures Under West Virginia Freeze–Thaw Conditions, Nathaniel Wayne Dunbar

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study evaluates whether the West Virginia Division of Highways (WVDOH) Class B concrete specification for bridge substructures remains adequate under modern durability and design-life expectations. The current specification, which permits a minimum compressive strength of 3,000 psi, reflects practices established when shorter service lives were generally assumed. Modern AASHTO LRFD provisions are based on a 75-year design life, raising concern that this lower-strength concrete may not provide sufficient durability under West Virginia’s climatic conditions.

To address this issue, bridge inspection data, regional climate mapping, and durability modeling were used to assess the condition and performance of concrete substructures across …

Developing Inexpensive Sensors That Can Detect Roof Collapse From Snow Loads, Edward Sandy

Dissertations, Master's Theses and Master's Reports

In cold regions in the United States, residential timber structures are susceptible to roof collapses due to heavy snow accumulation. The recent updates in ASCE 7-22 have introduced reliability-targeted ground snow loads, leading to significant increases in design snow loads for certain areas. Despite this development, existing buildings in these regions designed under historical code requirements may be under-designed for snow load. This fact provides motivation to owners of these structures to pursue effective monitoring and mitigation strategies to prevent structural failures. This research focuses on the development of an early warning system utilizing cost-effective slope monitoring sensors to estimate …

Experimental Insights Into Friction Losses Of Post-Tensioned Precast Full-Scale Girders, Mostafa Serry

Theses and Dissertations

The use of post-tensioning in construction has revolutionized the construction industry and made way for several construction and structural applications that were unattainable before. One of the most important topics that are synonymous with the use of post-tensioning is the matter of accurately calculating the short-term and long-term losses that arise in pre-stress. One of the prominent types of losses is the friction losses that occur during the jacking of the concrete elements due to its impact on structural integrity and longevity.

The thesis examines this critical aspect of friction losses in post-tensioned concrete structures. The study focuses on full-scale, …

A Comparative Study Between Soft Structures And Hard Structures For The Protection Of Egypt’S Coastlines Against Climate Change, Donia Eldwib

Theses and Dissertations

Coastal communities worldwide face unprecedented threats from climate change, with rising sea levels, increased storm intensities, and accelerated coastal erosion posing significant risks. Egypt, with over 3,000 kilometers of coastlines along the Mediterranean and Red Seas, it is particularly vulnerable due to its densely populated and economically critical low-elevated coastal zones. With the Mediterranean Sea, and the Nile Delta specifically under huge threats, this study examines the different coastal protection strategies used to address these climate change impacts. Different coastal protection structures have been used throughout the years starting with the well-known hard structures moving on to greener alternatives such …

The State Of The City's Bridges, Leo G. Miranda

Capstones

An analysis by NYCity News Service of 2024 federal bridge inspection found that 118 segments of city bridges are in poor condition, around 8% of all bridges citywide. Among these are segments of major highways and bridges like the Brooklyn Queens Expressway, FDR Drive, Harlem River Drive, Grand Central Parkway and even a part of the iconic Brooklyn Bridge. On a single stretch of highway, where the Grand Central Parkway and the Whitestone Expressway meet in Queens, there are seven parts of highway or ramps in poor condition.

Bridge segments can be any raised roadway that passes over another parkway, …

Enhancing Civil Infrastructure Performance Through Lidar-Based Dynamic Monitoring And Phased-Construction Bridges, Khalid Hossam Alkady

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation aims to enhance the performance and structural integrity of civil infrastructure systems through two primary goals. The first goal is to develop and rigorously validate end-to-end frameworks for full-field monitoring of the dynamic response of civil structures via Ground-based Lidar (GBL) scanners. GBL can be employed to sample point clouds at a high sampling rate for dynamic data collection, which addresses the limitations of using contact-based sensors in structural health monitoring (SHM) applications used for early-detection of structural damage.

The second goal of this dissertation concerns the challenges associated with constructing bridges in phases, so they can remain …

Increasing Drift Capacity Of Non-Ductile Concrete Shear Walls Through Confinement With Fiber-Reinforced Polymer Application, Andrew Duong, Sophia Maglabe, Sheyna Rongong

Architectural Engineering: Graduate Reports

The seismic response and laboratory testing of pre-1980s reinforced concrete (RC) shear walls commonly exhibit undesirable concrete crushing and rebar buckling in the wall end-zones leading to a flexural compressive failure. The lack of ductility of these walls is attributed to low reinforcement ratios and absence of special boundary elements (SBE) as required by modern design code. Thus, the authors are proposing a fiber reinforced polymer (FRP) retrofit method to provide confinement to the end-zones of pre-1980s walls equivalent to that of an SBE. Current industry applications of FRP have largely been for shear strengthening of RC beams, columns, and …

Fitting Quality Of Nmr Relaxation Data To Differentiate Asphalt Binders, Rebecca M. Herndon, Kevin Lai, Magdy Abdelrahman, Klaus Woelk

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Asphalt binder performance grades (PGs) are important metrics in designing pavements for effective transportation infrastructure. the PG system relies on the binder's stiffness and is determined through energy- and time-intensive physical testing. Physical properties, like stiffness, can also be determined by spin–lattice NMR relaxometry, a non-destructive chemical method. NMR relaxometry can quantify the molecular mobility of materials by determining relaxation times from exponential decays of excited nuclear magnetization. While relaxation times have been used to determine physical properties of materials, a quantitative relation to the PG grades of asphalt binder is yet to be established. in this study, T1 NMR …

Analyzing Tms 402 -22 : Design Of Special Reinforced Masonry Shear Walls, Tristan D. Aranda

Architectural Engineering

This experiment examines possible inconsistencies in the TMS 402-22 masonry code between Section 7.3.2.5 and Section 9.3.5.6.2, regarding the requirements for special boundary elements in Special Reinforced Masonry Shear Walls. By investigating the two sections, it can be determined whether the two sections are in accordance with each other regarding aspect ratio. Tensile forces and strains are calculated respectively for each wall and block type and are compared to the respective tensile yield forces and ductile strains. This determines which respective boundary elements go past yield and become ductile. Based on this determination, recommendations can be made to the …

Dynamics Of Flexible Freestanding Structures Under Ground Motion Excitation, Seyed Mohammadreza Farooghi Mehr

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Freestanding structures are characterized by being unattached at the base, exhibiting rigid or flexible motion under ground motion excitation with various potential responses including rocking (rotation at the base about corner points), pure sliding, slide-rocking, and overturning. While rigid freestanding structures have been extensively studied, the behavior of flexible freestanding structures—particularly the interaction between modes involving sliding—remains underexplored. Existing literature has focused on the deformation and rocking motions of flexible freestanding structures through both analytical and experimental approaches, which have shown indications of sliding at the base. These findings highlight the necessity of incorporating sliding motion into analytical models to …

Deep Learning Vision-Based Bridge Inspection With Resource-Constrained Unmanned Aircraft Systems, Ji Young Lee

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Bridge inspection is critical for ensuring structural integrity, extending the service life of infrastructure, and minimizing maintenance costs. As bridges age and endure increasing loads, regular inspections help detect early signs of wear, such as cracks or corrosion, that could impact safety and performance. However, traditional inspection methods are labor-intensive, requiring significant time, specialized equipment, and manual access to challenging areas, which can lead to costly disruptions. Additionally, reliance on human inspectors introduces subjectivity, with assessments varying by individual expertise. These factors highlight the inefficiencies and safety risks in current inspection practices, underscoring the need for more objective, efficient solutions. …

Field Evaluation Of Transverse Post-Tensioning And Latex Modified Concrete On Bridge Load Distribution, Paige Waters

All Theses

The Airport Road Bridge (ARB) over Rocky Creek in Greenwood, SC is one of 377 channel bridges in South Carolina currently load-posted, limiting vehicle weight and potentially restricting access to vital services. The South Carolina Department of Transportation (SCDOT) seeks a cost-effective method to strengthen these bridges and enhance their load-sharing capacity.

Through live load field testing, this research seeks to use two retrofitting techniques – transverse post-tensioning (PT) and latex modified concrete (LMC) overlay – to determine whether or not channel bridges can be improved. Direct tension testing was also performed to evaluate the substrate-overlay bond of the LMC …

Final Report - Qa/Qc Guidelines On Drone-Based Remote Sensing For Bridge Element Inspection, Genda Chen, Woubishet Z. Taffese, Ritesh Sharma, Zhenhua Shi

Project IM-4

Remote sensing of elevated infrastructure via robotic platforms has recently gained increasing interest in bridge inspection. Such automated bridge inspection can not only overcome accessibility and safety challenges but also improve objectivity and consistency of the measured data compared to current visual inspection practices. With the advent of advanced technologies, quality assurance (QA) and quality control (QC) for robot-based bridge inspection become imperative. This study aims (1) to understand actionable inspection activities and procedures in route planning, sensor preparation and measurement, ground truth selection, and statistical analysis; (2) to outline assessment matrices and best practices for drone-based images to achieve …

Enhancing Frp-Concrete Interface Bearing Capacity Prediction With Explainable Machine Learning: A Feature Engineering Approach And Shap Analysis, Yanping Zhu, Woubishet Zewdu Taffese, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study introduces a novel approach to predict the shear bearing capacity of FRP-concrete interfaces using explainable machine learning. Eight algorithms are employed: three standalone models (Artificial Neural Network, Support Vector Regression, and Decision Tree) and five ensemble learning models (Bagging, Random Forest, Adaptive Boosting, Gradient Boosting, and Extreme Gradient Boosting). Four scenarios with varying input features, including engineered features inspired by mechanics-based bearing capacity equations, are examined. Notably, the inclusion of engineered features such as the stiffness of the FRP strip (Kf) significantly enhanced prediction accuracy and efficiency, although the width correction coefficient (bf/bc) did not yield significant benefits, …

Anti-Corrosion Performance Of Magnesium Potassium Phosphate Cement Coating On Steel Reinforcement: The Effect Of Boric Acid, Fan Zhang, Jihui Qin, Kangyi Cai, John J. Myers, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

It has recently been found that magnesium potassium phosphate cement (MKPC) paste coating applied on the surface of steel reinforcement can effectively retard the onset of corrosion and suppress corrosion reactions. However, the fast-setting nature of MKPC—which is a merit in repair—can be problematic in a practical engineering process of coating the steel reinforcement with MKPC paste. To address this problem, boric acid (H₃BO₃) was added as a retarder in an MKPC formulation to prolong the setting time. This work investigated the impact of boric acid (at 5% by weight of MgO) on the anti-corrosion performance …