Engineering Commons^™

Truss Bridge Damage Localization And Severity Estimation Using Influence Lines, Hamoud Alshallaqi

Civil and Environmental Engineering Theses and Dissertations

The safety of bridges is one of the primary concerns of researchers, engineers, and bridge owners and managers, especially when bridges are approaching the end of their intended service lives. The estimation of bridge condition and remaining service life is critical to prioritize the allocation of available funding for repairs and rehabilitation. Various methods, including both dynamic and static approaches, have been developed to detect and localize bridge damage and estimate its severity. This research presents a methodology for detecting a single damaged member in a truss bridge and estimating the severity of the damage using static vertical deflection influence …

Thermal And Mechanical Numerical Modeling Of Extrusion-Based 3d Printed Reinforced Polymers For Selecting Manufacturing Process Parameters, Sunil Bhandari

Electronic Theses and Dissertations

Extrusion-based 3D printing of thermoplastic polymer composites manufactures parts that have nonhomogenous, orthotropic, and process-dependent macro-scale material properties. As a part of the dissertation, research works were carried out to: • improve the interlayer mechanical properties and reduce the orthotropy, • use experimentally homogenized orthotropic material properties to numerically model the mechanical behavior of the non-homogenous orthotropic 3D printed parts, • create an efficient numerical thermal model to predict the process-dependent thermal history of the 3D printed part, and • aid the manufacturing process by selecting a suitable set of processing parameters based on a simplified sequentially coupled thermomechanical model. …

Behavior Of Wind Turbine Towers And Blades Under Tornado Wind Fields, Mohamed Abugazia

Electronic Thesis and Dissertation Repository

The installation rate of wind turbines around the world is increasing significantly. Therefore, wind turbine farms are constructed in plentiful wind resources areas that put a considerable number of wind turbine towers under severe wind conditions. As a result, failures due to unexpected wind loads on either the blades or the tower are increasing. In addition, wind turbines are designed to resist synoptic wind loads as per the current guidelines, which do not consider high-intensity wind (HIW) events such as tornadoes. The built-in-house numerical code “HIW-WT” has been developed in this study to model wind turbines under three-dimensional wind fields …

Field Durability Test Of Clt Wall Envelope Using Physical Barriers Against Termites And Structural Performance Of Nailed Hold-Down Brackets Connected To Fungus-Exposed Clt Walls, Kamal Neupane

Theses and Dissertations

The effectiveness of using commercial polyethylene flashing and stainless-steel mesh in CLT wall systems as the termite barriers were evaluated in a short-term field test. American Wood Protection Association (AWPA) E21's visual ratings ranged from 10 to 9 in the specimens showing little damage when no physical barriers were used. Termites were able to crawl beyond the physical barriers in few specimens showing the necessity of further research on height and installation method of physical barriers. On the second part, the effect of decay caused due to Postia placenta, a brown-rot fungus, on the structural performance of hold-down brackets connected …

Mixing Temperature, Binder Content, And Dust Content Effects On Stone Matrix Asphalt, Abhinash Subedi

Theses and Dissertations

This study focuses on the effects of mixing temperature, binder content, and dust content on the performance of Stone Matrix Asphalt (SMA). Mixes produced at different mixing temperatures and with or without added polymer modified binder (P_b) and/or bag house dust (BHD) were evaluated. Two different types of specimens: laboratory mixed laboratory compacted, and plant mixed laboratory compacted were evaluated by Cantabro Mass Loss (CML) testing in an unaged condition or after a laboratory conditioning protocol (CP) was applied. Additional P_b and BHD were added to plant produced mixes in the laboratory before mixing. Results showed that …

Additive Manufacturing Of Soil Using Bio-Cementation, Christina Childress

Graduate Theses and Dissertations

Microbially Induced Calcite Precipitation (MICP) is an emerging soil treatment technique that is proven to increase strength, decrease erosion, reduce liquefaction risk, enhance slope stability, decrease compressibility, decrease swelling potential, and overall create a more competent soil. The benefits and applications of MICP are broad, and this research seeks to broaden them further by developing a single-phase additive manufacturing application with no treatment time delay. This is done by analyzing layering behaviors of five USCS soil classifications (100 % Ottawa sand, sand clay mixtures, and 100% lean clay) which provides insight into process variables such as the solution volume and …

An Investigation Of The Flexural Strength And Toughness Of Hybrid Plain And Fiber Reinforced Concrete For Pavement Applications, Wesley Keys

Graduate Theses and Dissertations

For decades, many solutions have been evaluated to combat cracking in concrete pavements. The study presented in this paper evaluates and compares the flexural performance under a third point loading configuration of plain concrete (PC) beams, fully fiber reinforced concrete (FRC) beams, and hybrid PC and FRC beams, with a top PC and bottom FRC layer. The purpose of this hybrid approach was to provide FRC in only half the section, saving cost, while providing a PC surface layer that is easier to finish. All PC top layers were applied at an age of 7-days, considered a reasonable time for …

Retrospective Analysis Of Impacts Of Highway Bypass And Widening Projects, Sanjeev Bhurtyal

Graduate Theses and Dissertations

Community members often worry that highway projects may have negative impacts on their local economies. This is typical for highway bypass and widening projects in small cities (population less than 50,000). It is a challenge for planners to balance public concerns of economic decline with desired project outcomes of mobility and safety. Much of this challenge stems from a lack of information on post-project outcomes related to economic and safety impacts of new construction projects. Thus, there is a need for an evidence-based framework to help planners with the decision-making process and better inform the community on potential outcomes. This …

Shear Strength Of Concrete Beams Made With Belitic Calcium Sulfoaluminate Cement, Caleb W. Chesnut

Graduate Theses and Dissertations

The need for a cleaner alternative to portland cement (PC) concrete has led to increasing interest in alternatives to PC. Structural properties of most of these alternative cements are still an open research topic. One promising alternative cement is belitic calcium sulfoaluminate (BCSA) cement. The study presented in this paper investigated the shear strength, long term compressive strength, and carbonation in BCSA cement and PC concrete beams. A total of twelve eight-foot long beams were made; eight BCSA cement concrete beams and four PC concrete beams to be tested at various ages depending on cement type. Two beams of each …

Effect Of Various Speed Management Strategies On Bicycle Crashes For Urban Roads In Central Florida, Jorge Ugan

Electronic Theses and Dissertations, 2020-

In recent years, cycling has become an increasingly popular transportation mode around the world. In contrast to other popular modes of transportation, cycling is more economic and energy efficient. While many studies have been conducted for the bicycle safety analysis, most of them were limited in terms of bicycle exposure data and on-street data. This study tries to improve the current safety performance functions for bicycle crashes at urban corridors by utilizing crowdsource data from STRAVA and on-street speed management strategies data. Speed management strategies are any roadway alterations that causes a change in motorists' driving behavior. In Florida, these …

Improving Pedestrian Safety With The Implementation Of The Demand-Responsive Transverse Rumble Strip As A New Traffic Safety Countermeasure, Md Shakhawat Hossen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The traditional TRS has been extensively used as a traffic calming device to provide cognitive alerts in the form of sound and vibration to drivers. However, TRS always remains fixed on the road and thus exerts cognitive alerts, irrespective of any potential downstream hazards. Moreover, the continuous exposure to rumble strips has been identified as a source of discomfort and annoyance for drivers, which limits its application to potentially useful scenarios. This study explores a rumble strip design with dynamic behavior named as Demand-Responsive Transverse Rumble Strip (DRTRS) in order to address the limitations of static TRS. The study incorporates …

Quaternary Ammonium Compounds As Precursors To Disinfection Byproducts, Padmanabhan Krishnaswamy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disinfection of drinking water is crucial for providing a safe potable water supply. Some of the most common disinfectants employed are chlorine, chloramines and ozone. While these disinfectants successfully inactivate pathogenic microorganisms, they simultaneously react with inorganic or organic precursors to form toxic byproducts, most commonly referred to as disinfection byproducts (DBPs). While there is a wide variety of organic matter and disinfection byproducts known, in this study we have looked into the potential of certain quaternary ammonium compounds (QACs) to act as precursors to form DBPs, namely trihalomethanes (THMs), haloacetonitriles (HANs) and nitrosamines.

The ubiquitous nature of QACs in …

Drying Of Digested Biosolids For Weight Reduction Prior To Disposal, Juan Manuel Canales

Open Access Theses & Dissertations

Disposal of belt filter pressed digested sludge (known as biosolids) to landfills cost El Paso Water about $1.1 million in the past year. With an increasing population, the amount of influent wastewater to El Paso treatment plants will also increase, resulting in increased biosolids generation and biosolids disposal costs. A method for reducing biosolids transportation cost is biosolids drying.The cost that El Paso Water pays for transporting biosolids to a dedicated landfill facility is based on the weight of the biosolids that are carried. Biosolids collected from the belt filter presses is about fifteen percent solids by weight, with water …

Structural Impacts Of Super Heavy Load (Shl) Vehicles On Transportation Infrastructure, Ali Morovatdar

Open Access Theses & Dissertations

Operation of non-conventional Super Heavy Load (SHL) vehicles is an ongoing challenge for transportation stakeholders and the traveling public across the nation. Despite facilitating the movement of heavy, large, and non-divisible loads, passages of such vehicles with complex loading configurations that typically weigh several folds of the permissible weight limits set forth by regulatory agencies have been adversely affecting the structural integrity of pavement facilities. This translates into accelerated damage of pavement structures, which in turn poses safety concerns for users of the transportation facilities. Accurate quantification of such detrimental impacts is the precursor to preserve the existing transportation facilities. …

Building Energy Model Simulation Of A Single Building In Comparison To A Broader Building Stock, Paola Michelle Santillano

Open Access Theses & Dissertations

Residential facilities and buildings are the largest consumers of energy in the United States. More than 76% of electricity and more than 40% of all energy consumption comes from providing a comfortable and healthy environment in buildings. Prioritizing building energy technology goals for performance and cost can significantly reduce energy use within the next ten years despite a substantial forecasted population increase. Retrofitting existing buildings and improving future construction has the potential to realize cost savings and environmental benefits over time. A key component to realizing these benefits is regional building energy modeling. One of the challenges to widespread building …

Magnetorheological Cementitious Inks For 4d Printing Of Origami Inspired Auxetic Concrete Elements, Aparna Shashikant Deshmukh

Theses and Dissertations

Existing concrete technology relies on the use of considerable volumes of raw materials, large energy consumption and so associated with severe corresponding environmental impacts. This impact is the driving force for the development of sustainable concrete including a wide range of concrete with supplementary cementitious materials and advanced manufacturing. Recent developments in the field are further inspired by the digital concrete based on 3D printing (3DP) technology which require tailor-made concrete mixtures. The main challenge for 3D printing of concrete is to develop printable ink material, thus this research focuses on characterisation of cementitious materials based on smart materials-materials that …

Seismic Performance Assessment Of Building Contents: Monetary Losses And Injuries, Sereen Majdalaweyh

All Dissertations

Building contents include all the components that are not attached to the building which the owners place after the construction phase, such as furniture, electrical equipment, glassware, and other personal items. Loss and damage assessment of building contents proved to be challenging in performance-based earthquake engineering frameworks because of the data sparsity. Damages to building contents during an earthquake not only cause monetary losses; tumbling and over-toppling of heavy building contents could result in injuries and even deaths of occupants. While major advancements have been made in performance-based earthquake engineering; however, the focus is mainly on damages and collapse risk …

An Experimental And Computational Study Of 3-Dimensional Compact Windborne Debris Flight, Ta'jon Jordan

All Theses

In this thesis, the stochastic nature of 3-dimensional compact windborne debris flight is investigated experimentally and computationally. Previous literature (Holmes, 2004) analyzed the impact of strong winds on compact debris with applications to windborne debris flight. Baker (2007) derived the 2-dimensional equations of motion into a generalized dimensionless form that reveals the fundamental controlling parameters of compact debris flight. However, these models assume that compact debris is spherical, and the flight is, therefore, 2-dimensional. However most compact debris is not spherical, and its flight is 3-dimensional. Herein a previously developed model for free-falling compact windborne debris flight (Ahsanulllah et al., …

Data Driven Methods For Large Scale Network Level Traffic Modeling, Rezaur Rahman

Electronic Theses and Dissertations, 2020-

Rapid growth in population along with urban-centric activities impose a massive demand on existing transportation systems, thus increasing traffic congestion and other mobility related challenges. To overcome such challenges, we need network-scale models to accurately predict real-time traffic demand and associated congestion. However, traditional network modeling approaches have shortcomings due to the complexity in traffic flow modeling, limited scope to incorporate real-time data available from emerging data sources and requiring excessive computation time to generate accurate estimation of traffic flows. Advancement in traffic sensing technologies with big data has created a new opportunity to overcome these challenges and implement deployable …

Hybrid Structural Health Monitoring Using Data-Driven Modal Analysis And Model-Based Bayesian Inference., Jice Zeng

Electronic Theses and Dissertations

Civil infrastructures that are valuable assets for the public and owners must be adequately and periodically maintained to guarantee safety, continuous service, and avoid economic losses. Vibration-based structural health monitoring (VBSHM) has been a significant tool to assess the structural performance of civil infrastructures over the last decades. Challenges in VBSHM exist in two aspects: operational modal analysis (OMA) and Finite element model updating (FEMU). The former aims to extract natural frequency, damping ratio, and mode shapes using vibrational data under normal operation; the latter focuses on minimizing the discrepancies between measurements and model prediction. The main impediments to real-world …

Development And Promotion Of Mass Timber Noise Barrier For Highways, Harsh Bothra

All Theses

Highways are some of the biggest causes of noise pollution in the United States of America. To deal with the traffic noise coming from these highways, noise barriers have been erected across major highways. The goal is to reduce as much noise as possible through a sustainable solution. Unfortunately, the use of steel and concrete, commonly used materials, have undesired environmental impacts. A suggested sustainable alternative material would be mass timber. Mass timber products such as cross-laminated timber (CLT) and mass plywood panels (MPP) has attracted the attention of the construction industry in the U.S, as they are sustainable, light, …

Deriving Generalized Temperature-Dependent Material Models For Masonry Through Fire Tests And Machine Learning, Aditya Avinash Daware

All Theses

Masonry is one of the oldest and commonly used building materials in the construction industry. Among a variety of benefits, masonry provides low-cost construction, fire, and weather protection as well as thermal and sound insulation. In addition, masonry has superior material properties at elevated temperatures which is reflected by its slow degradation of its mechanical and thermal properties. Literature shows that we do not have a uniform material model that describes the mechanical degradation of masonry under fire conditions. As such, this limits the use of masonry in fire-based performance design of masonry structures. To bridge this knowledge gap, this …

A Linear Dynamical Perspective On Epidemiology: Interplay Between Early Covid-19 Outbreak And Human Mobility, Shakib Mustavee

Electronic Theses and Dissertations, 2020-

This research investigates the impact of human activity and mobility (HAM) in the spreading dynamics of an epidemic. Specifically, it explores the interconnections between HAM and its effect on the early spread of the COVID-19 virus. During the early stages of the pandemic, effective reproduction numbers exhibited a high correlation with human mobility patterns, leading to a hypothesis that the HAM system can be studied as a coupled system with disease spread dynamics. This study applies the generalized Koopman framework with control inputs to determine the nonlinear disease spread dynamics and the input-output characteristics as a locally linear controlled dynamical …

Development Of Lambda Factors For Masonry Design With Lightweight Grout, Rumi Shrestha

All Theses

Reduction in structural mass, improvement in thermal performance, and reduction in shrinkage cracking through internal curing are some of the reasons that lightweight (LW) aggregates have been used in structures and pavements for decades. However, lightweight grout is still not permitted for use in reinforced masonry construction by the TMS 402/602-16 code. In order to realize the benefits of lightweight grout in U.S. reinforced masonry construction, a codified procedure for its use is required which must be informed by experimental testing.

This research is a pilot project directed to characterize the performance of LW grout in comparison to normal weight …

Improve The Prediction Of Camber, Deflection, And Prestress Losses In Precast, Prestressed Concrete Bridge Girders, Ahmed Ali Hussein Al Mohammedi

Graduate Theses and Dissertations

Many precast, prestressed concrete girders have camber less or higher than the design values. This discrepancy between the design and the actual camber creates construction problems when installing the cast-in-place concrete deck. The objective of this research was to improve the accuracy of estimating long-term camber, deflection, and prestress losses of precast, prestressed concrete girders.

The experimental program consisted of measuring concrete properties and performing field measurements of camber, deflection, and prestress losses for girders in Arkansas. The investigation involved testing nine full-scale girders from two prestressed concrete plants that regularly supply concrete girders to bridge projects in Arkansas. The …

Formation Of Reactive Nitrogen Species During Dichloramine Decay And Their Impact On N Nitrosodimethylamine Formation Under Drinking Water Conditions, Huong Thu Pham

Graduate Theses and Dissertations

NDMA occurrence and formation pathways in drinking water systems are reviewed and NDMA yields are compared on the basis of disinfectant type, water chemistry, and precursor category. In chloramination, despite monochloramine being the predominant species between pH 7-9, evidence suggests that dichloramine is the primary species involved in NDMA formation. This is somewhat confounding as NDMA yields are maximal at pH 9, yet at pH 9 dichloramine decays faster than it forms and hence is present at trace levels; additionally, the proposed mechanism involves a spin-forbidden incorporation of dissolved oxygen as a triplet, which is presumably kinetically slow. This review …

The Potential Of Location Data For Contact Tracing And Understanding Individual Mobility During The Covid-19 Pandemic, Marcus Figaro

Electronic Theses and Dissertations, 2020-

In this study, we first review contact tracing methods used during the COVID-19 pandemic and provide an analysis of the benefits and drawbacks of different data collection and privacy protection methods. Our findings provide the benefits and drawbacks of using GPS versus Bluetooth for contact tracing, as well as the different data collection and storage methods and their effectiveness in protecting user privacy. We then analyze Twitter data to understand individual mobility behavior and sentiment by using a Natural Language Processing tool on text content of user tweets and Tweet coordinate data. Social media's ability to provide data on location …

Mechanical Behavior Of Additively Manufactured Metallic Cellular Scaffold Structures For Bone Tissue Engineering, Mohammad Al-Barqawi

Theses and Dissertations

Critical-sized bone defects represent a significant challenge in the orthopedic field. Limitations on autograft and allograft as treatment techniques led researchers to explore the implantation of artificial bone tissue scaffolds. BTE scaffolds are three-dimensional cellular structures that provide mechanical support and behave like a template for bone tissue formation. Stress shielding in bones is defined as the bone weakening and reduction in bone density due to stiffness mismatch between the bone and the scaffold. This mismatch causes shielding of the bone by transferring stresses to the implant. The main motive of the research study is to address the stress shielding …

A Simulation-As-A-Service (Simaas) Cloud Computing Platform For Traffic Management, Zihao Jin

Theses and Dissertations

Traffic simulation is defined as a tool to replicate the real-world condition, produce the possible scenario, and facilitate scientific decision making, which can be divided as two categories: planning and operational management. However, the unavailability of vendor-supplied software, difficulty of finding sufficient staff, a lack of community awareness are the major factors impede the adoption of advanced techniques in simulation. This dissertation developed a Simulation-as-aService platform (SimaaS), based on cloud computing technology, which can seamlessly integrate transportation simulation engines with flexible cloud-based functional modules like network editor, modeling compiler, cloud middleware, and metrics dashboard to reduce the technical burden of …

Developing Implementable Policies Targeting Sustainable Building Construction Through International Policy Diffusion, Melisa Ciara Hancock

Boise State University Theses and Dissertations

The buildings and construction sector is one of the biggest sources of greenhouse gas emissions and contributes to vast list of negative impacts humans have on the environment through material production, natural resource usage, and waste. While many organizations like the United Nations (UN), OECD (Organization for Economic Co-operation and Development), and Architecture 2030 have been advocating for a shift to sustainability within the sector for decades, there is still a major disconnect between countries that have and haven’t implemented sustainability into all practices. This research focuses on analyzing the content of national building codes for their level of sustainability …