Civil Engineering Commons^™

Non-Contact Acoustic Emission Detection Of Rail Defects Using Air-Coupled Sensors, Lei Jia

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rail defects, whether internal or external, present significant safety risks. Acoustic Emission (AE) technology has emerged as a promising technique for monitoring damage progression and detecting these rail defects. This project addresses this critical concern by testing air-coupled optical microphones for non-contact AE detection. The goal of this research is to investigate AE signal characteristics using both rail-mounted and vehicle-mounted methods, establishing the understanding of AE signals in relation to defects and their effectiveness in identifying them.

This research focused on investigating air-conduct sensors in the lab-controlled pencil lead break (PLB) test. The objective was to evaluate the propagation characteristics …

Prediction Of Cost And Schedule Changes In Transportation Projects Through Historical Bid And Change Order Document Analysis – Using Oklahoma Dot Project Cases., Rabin Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Construction bid documents encompass project specifications, drawings, schedules, and other critical details and are the foundation for project bidding and execution. Accurate bid documents are essential to ensure project bids are competitive, realistic, and aligned with requirements. However, bid documents are susceptible to risks from various sources. Failure to identify and rectify these risks can result in inaccurate cost estimates and higher bids. Therefore, identifying and resolving risks within bidding or contract documents are of utmost importance. While prior research has shed light on potential risk factors within the bid documents, a noticeable gap remains in the literature regarding identifying …

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. …

Exploring Variably Saturated Flow Formulations For Modflow: Implementing A Fully 3d Richards' Equation In Modflow 6, Sebastian Vazquez-Gasty

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This thesis explores the implementation of a fully 3D Richards’ equation solution into MODFLOW 6 to solve for saturated/unsaturated flow. Currently, MODFLOW 6 has limited capability for solving unsaturated zone flow problems by using the Unsaturated Zone Flow (UZF) package, which neglects capillarity and assumes vertical 1-dimensional flow. Various formulations of the Richards’ equation were first evaluated for their strengths and weaknesses. Various numerical solution approaches to Richards’ equation were also studied to understand the robustness and efficiency of different approaches and to select one that would best fit into the MODFLOW 6 framework. The MODFLOW 6 framework was also …

Performance Of Geopolymer Concrete Incorporating Recycled Aggregates And Glass Fibers, Mohammed Abughali

Thesis/ Dissertation Defenses

This study aims to investigate the potential use of geopolymer concrete (GC) incorporating recycled concrete aggregates (RCA) and glass fibers (GF) as a sustainable alternative to traditional cement-based concrete. It comprehensively evaluated the impact of RCA and GF on the fresh, physical, mechanical, and durability properties. A blended precursor binder consisting of ground granulated blast furnace slag and fly ash was utilized. To mitigate the challenges associated with the brittle behavior and low crack resistance of GC, mainly when incorporating RCA, two types of GF were used. Type A had a length of 24 mm, while Type B exhibited a …

Integrated Sustainability Analysis Of A Shared Micro-Mobility System In University Campus: Life-Cycle Assessment And User Impact Study Of Electric Scooters, Md Afif Rahman Chowdhury

LSU Master's Theses

The objective of this study is to evaluate the environmental, economic, and social impacts of implementing e-scooter technology on the LSU campus. The study is structured into three main parts: (1) an environmental life-cycle assessment of e-scooters, (2) a comparative environmental and economic impact assessment of e-scooters, cars, and campus shuttle buses, and (3) a comprehensive survey of e-scooter users to assess their characteristics, satisfaction levels, and comfort while using e-scooters on the LSU campus.

To achieve the objectives of the study, a life-cycle assessment (LCA) was conducted to assess the environmental sustainability of e-scooters, encompassing all stages from raw …

Next Generation Permeable Pavement For Enhanced Durability And Functionality, S M Tanvir

LSU Master's Theses

Porous Asphalt Concrete (PAC), also known as Open-Graded Friction Course (OGFC), is known for its high permeability, which provides benefits such as enhanced rainwater drainage, improved skid resistance, and reduced hydroplaning risks. These characteristics are due to its high air void content, allowing water to flow through the pavement and reducing splash, spray, and noise compared to conventional asphalt mixes. However, this high air void content also contributes to durability concerns, such as raveling, stripping, and clogging, which can reduce service life and increase costs, making OGFC more expensive than conventional asphalt mixtures.

This research focuses on identifying the failure …

Geotechnical Characterization Of Saline Sabkha Soil Of Abu Dhabi, Uae, And Its Stabilization Using Steel Slag And Sodium Silicate, Ahmed Maher Abdulla

Thesis/ Dissertation Defenses

Saline sabkha soil is widely distributed across the Abu Dhabi coastal regions of the UAE. These soils are associated with geotechnical problems that principally emerge from the heterogeneous nature of the soil and its high soluble salt content. Upon exposure to fresh water, the soluble salt dissolves, resulting in loss of the bond that once cemented the soil particles. In addition, the volume occupied by the salt minerals becomes part of the voids between the particles. This process results in a weak and loose soil structure of lower bearing capacity that is ready to collapse upon being subjected to loads. …

Understanding Contributing Factors To Injury Severity And Improper Driver Actions In Work Zone Crashes And Evaluating Smart Work Zone Applications For Safety Improvement, Rakesh Rangaswamy

USF Tampa Graduate Theses and Dissertations

A work zone can be described as a roadway designated for construction, maintenance, or other activities that temporarily disrupt the normal traffic flow. Due to this disrupts in traffic conditions, work zones may bring sudden shifts in driving experience, depending on the sort of work zone present, creating unpredictable maneuvers, and putting both motorists and workers at risk. To understand these issues, this study uses work zone accident data obtained from Florida and uses several methodological techniques, including the mixed logit model with variance and mean heterogeneity, temporal instability test, log-likelihood test, out-of-sample analysis, and ANOVA test.

Firstly, this study …

Float: A Multi-Scale Flood Loss Assessment Tool Developed From Experimentally Derived Material Damage, Anna Katya Opel

Doctoral Dissertations

Current practice of flood loss prediction presents limitations in accurately predicting building flood losses at multiple scales. While whole-building estimates can more accurately predict high-level losses (i.e., large groups of buildings), a significant analysis error is revealed with small-scale (i.e., individual, or small groups of buildings) investigation. The novel approach of collecting experimental flood data to support damage estimation has provided sufficient evidence that current damage models can and do under or overestimate loss. This research has developed a multi-scale approach to assessing flood losses based on experimentally derived material damage. The methodology is stored and accessible in a multi-scale …

Quality Assurance Of Cast-In-Place Foundation Elements, Tristen Mee

USF Tampa Graduate Theses and Dissertations

Construction of cast-in-place concrete deep foundation elements is a common practice, yet performed almost entirely blind, leaving uncertainty in the quality of the as-built, below-ground element. This dissertation focuses on three quality assurance aspects of cast-in-place foundations: an automated concrete tracking system for drilled shafts, an alternate approach to identifying if mass concrete conditions exist in cast-in-place foundations, and as-built auger cast pile grout volume determination.

The volume of concrete in a drilled shaft is relatively easy to track on a truck-by-truck basis, as well as the height of the rising concrete per truck. However, a more detailed volume distribution …

Partnering With Communities To Understand Social Determinants Of Health (Sdoh) Impacts On Access To Shared Micromobility, Elizabeth K. Mcclain, Kaitlynn Walker, Ganesh Kumar, Ashley Bright, Clare Aziz, Ann W. Banchoff, Zacharia N. Doueiri, Abby C. King, Suman Mitra

Civil Engineering Faculty Publications and Presentations

This study explored the facilitators and barriers of community bike share use in a mid-sized city with high incidence of poverty and racial diversity using a community-based participatory action research (CBPAR) photovoice framework with the Stanford Our Voice (OV) Discovery Tool digital application. Community members participated in one of three community citizen science walks with follow up focus groups facilitated by osteopathic medical student researcher to address “What makes it easy or hard to ride a bike using the bike share?” Twenty-seven diverse community members partnered with four osteopathic medical students exploring vulnerable individuals’ lived experiences, beliefs/understanding of the Social …

Integrating Gis And Ca-Markov Model To Study Urban Dynamics Of Salem, India In Terms Of Pattern, Intensity And Direction, Linda Theres B

Theses and Dissertations

Urban populations have grown substantially in the modern era and the information age as people seek better living prospects. Currently, more than half of the world's population resides in the cities. Such growth must be monitored to ensure that people enjoy the boons of urban spaces, not the banes. Recognising the significance of urban studies, several researchers have attempted to analyse and predict urban dynamics using remote sensing, Geographic Information Systems, and machine learning methods. However, certain limitations exist, especially in improving the CAMarkov model's prediction performance. In addition, studies have suggested that growth characteristics, such as pattern, intensity, and …

Unlocking Telecommuting Patterns Before, During, And After The Covid-19 Pandemic: An Explainable Ai-Driven Study, Adedolapo Ogungbire, Suman Kumar Mitra

Civil Engineering Faculty Publications and Presentations

The COVID-19 pandemic has instigated a global paradigm shift in employment practices, precipitating a widespread transition to telework. While past events had no long-lasting effect on the continued working conditions of the population, it is unclear what a prolonged need for telecommuting on such a nationwide scale would continue to have on the working population. This study uses an explainable artificial intelligence approach to investigate the changes in those telecommuting across three periods: i) pre-pandemic, ii) pandemic, and iii) post-pandemic periods. Machine learning methods, including decision trees, random forest, extreme gradient boost, naïve Bayes, and artificial neural networks, were developed …

Building Services Engineering November/December 2024

Building Services Engineering

No abstract provided.

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 …

The Effects Of Wildfires On The Mental And Physical Health Of School-Age Children In North America: A Scoping Review, Sarah Oerther, Sarah Manspeaker, Alison Wix, Daniel Oerther, Carmen Marsit

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Background: Wildfires are occurring more often and with greater intensity, leading to longer and harsher fire seasons. As a result, children are more frequently exposed to wildfire smoke, which increases their risk of mental and physical health effects. Purpose: The purpose of our scoping review is to explore the current literature on what is known about the direct and indirect impacts of wildfires on the mental and physical health of school-age children in North America (5 to 18-year-olds). Methods: A health sciences librarian-assisted literature search, with input from the research team, was performed. Results: A total of 16 studies were …

The Influence Of Planning And Architectural Styles On The Sustainability Of The City Of Kumasi, Ghana, Elom Ayeke

Tanzania Journal of Engineering and Technology (TJET)

The city of Kumasi that was once dubbed the ‘Garden City of West Africa’ was founded in the late 17th century and served as the seat of government for the medieval Greater Asante Union. It later served as a commercial hub for the British Colony after undergoing massive transformation in the first two decades of the 19th century. Post-independence, the city went through various urban planning projects that mostly targeted social development. The architecture of Kumasi has also been changing through different periods of its history. This article examines the relationship between the evolution of the city of Kumasi through …

Relationship Between Historic Evolution, Urbanization And Mobility In Ibadan, Nigeria, Aisha Adams

Tanzania Journal of Engineering and Technology (TJET)

Ibadan is said to be the biggest indigenous city in Nigeria with a population of about 4.04 million, making it the third largest city in the country after Lagos and Kano. Since its founding in 1829, Ibadan has experienced urban evolution that is mostly unguided. With its high fertility rate, population growth and rural-to-urban migration, Ibadan has experienced significant urban sprawl that has resulted in challenges in urban mobility especially to the lower-income earners. This study looks at the relationship between urban planning, urbanization and mobility in the city of Ibadan. The study found that lack of integrated land use …

Urbanization And Urban Sprawl In The Post-Colonial Era Douala City, Cameroon, Sylvia Munisi

Tanzania Journal of Engineering and Technology (TJET)

The history of the port city of Douala spans pre-colonial period, colonial period of the Germans and French occupation, the post-colonial era and the contemporary situation with continuous occupancy of the coastal environment. This article looks at the relationship between the history of the city of Douala to the resulting urban situation focusing on governance structure as well as rapid urbanization. The findings show that governance structure allowing for a duality of modern political system and traditional cultural system of kingships and chiefdoms has an effect to the resulting urban sprawl. Moreover, rapid urbanization under this condition has an overall …