Civil Engineering Commons^™

The Stability Of Nanobubbles And Its Application In Contaminated Sediment Treatment, Shaini Dilsha Aluthgun Hewage

Dissertations

This dissertation consists of two sections. First, nanobubbles' stability and behavior are studied using experimental and theoretical approaches. Second, nanobubbles application combined with ultrasound to remediate contaminated sediments is discussed.

The stability study consists of four sections. (i). Laboratory investigation to determine bubble size distributions and zeta potentials for different gases, pH levels, temperatures, and salt conditions. (ii). A theoretical study based on the diffused double layer theory to explain nanobubbles' behavior in different NaCl concentrations. (iii). Nanobubbles' stability in electrolyte solutions under different ion valencies using deionized water, NaCl, Na₂SO₄, Na₃PO₄, …

An Experimental Investigation Of Alternative Wave Attenuation Mechanisms For A Modular Breakwater, Richard Perry

Electronic Theses and Dissertations

Global warming and sea level rise threaten to render traditional coastal protection structures as less effective. Floating breakwaters offer the advantages of adapting to rising sea level, allowing important material transport to occur, and being able to deploy and adapt to varying environmental conditions (seabed, depth, etc.). Traditional floating breakwaters typically consist of reflective concrete structures that are limited semi-sheltered locations. This research aimed to construct floating breakwaters out of lightweight materials with a smaller footprint while utilizing alternative attenuation mechanisms. Three breakwaters consisting of a box, beach, and pipe designs were constructed at 1:40 scale and tested in a …

Investigating The Role Of Iron In The Photogranulation Phenomenon, Abeera Ayaz Ansari

Doctoral Dissertations

Oxygenic photogranules (OPGs) are dense spherical microbial aggregates that are used for self-aerating wastewater treatment. Filamentous cyanobacteria are key granulating species, providing structural backbone and integrity in OPGs. Currently, the mechanisms for selecting filamentous cyanobacteria and their ability to form spherical OPGs are not well understood. Literature shows that iron (Fe) availability plays a significant role in the cyanobacterial growth and colony formation. Moreover, Fe availability is known to be dependent upon light, which is an essential growth substrate for the phototrophs. This research has investigated the role of Fe in the photogranulation phenomenon and the impact of light intensity …

Laboratory Testing And Mechanistic Analysis Of Treated Subgrade Soils, Hari Kumar Reddy Yarrapureddi

Civil Engineering Theses

Calcium-based stabilizing agents such as cement and lime have been extensively used to improve the engineering properties of base and subgrade layers of pavement systems. Recently, polymers and chemical stabilizers have become popular due to cost efficiency, ease of application, and fast curing times. In this study, California Bearing Ratio (CBR) values of polymer and chemical treated soils were compared with the CBR values of soils treated with conventional stabilizers. Parametric sensitivity analyses was carried out on key parameters including the type of subgrade soil, stabilizing agent, stabilizing agent treatment levels, and moisture conditioning. Additionally, numerical analyses was performed to …

Expanding The Concept Of Comprehensive Area Ratio Parameter To The South-Central States Towards Simplifying The Structural Evaluation Of Flexible Pavements At The Network Level, Nitish R. Bastola

Civil Engineering Theses

The surface deflection bowl data collected through Non-Destructive Testing (NDT) has been widely utilized by various Department of Transportation (DOTs) in the South-Central States and other places. The primary purpose of using deflection-based NDTs in network-level assessment is to identify a weak pavement section that requires further analysis at the project level. The falling weight deflectometer (FWD) test is one of the common NDT based tests utilized by highway agencies in assessing the performance of the flexible pavement. However, a robust method to evaluate pavement sections utilizing FWD data from all the sensors are seldom developed. There is always a …

Moisture Monitoring Of A Clt Structure In A Southern Climate, Elizabeth Poblete

Graduate Theses and Dissertations

Understanding of moisture behavior in cross laminated timber (CLT) is critical to the widespread use of CLT in construction in the United States. Currently, very little data exists on the long-term impact of moisture on CLT. The objective of this research is to collect data regarding the long-term moisture variation in the CLT panel at the University of Arkansas Adohi Hall residence hall. The climate of Northwest Arkansas is different from previously monitored buildings, as they were in the Pacific Northwest. Comparatively, Northwest Arkansas has a warmer climate with higher average annual precipitation. Waterproofing efforts are usually employed to prevent …

Sustainability In Construction: Using Lean Management Principles To Reduce Waste, Matthew Waite

Theses and Dissertations

The construction industry is facing many challenges. There are growing consumer demands for sustainable building. The construction industry generates a significant portion of the waste going into landfills. The construction industry has failed to keep pace with productivity in the manufacturing industry. Through adoption of Lean management principles, the construction industry can become more sustainable while increasing productivity. The literature was evaluated for three concepts: Lean management principles interaction with sustainability, the current state of sustainability in the construction industry, and the current state of Lean management principles in the construction industry. Lean management philosophies interactions with sustainability has been …

Modeling Distributed Source Control Infrastructure At Neighborhood Scale For Mitigating Flood Risk In Amite River Watershed, Ahmad Amin Shefai

LSU Master's Theses

Flooding has always been a major threat to mankind. This is particularly true in urban areas due to urbanization-induced increasing impervious areas and subsequent increasing urban surface runoff, causing an increasing flooding risk to urban areas in spite of the fact that extensive flood control infrastructure has been constructed. The overall goal of this thesis is to present a distributed source control infrastructure-based approach for mitigating the flood risk. The new flood mitigation approach is demonstrated through the model implementation of a series of distributed source control infrastructure systems in the city of Denham Springs at a neighborhood scale. The …

Effect Of The C-Source And Cod/N On Nitrite And Partial Nitrate Denitrification, Ahmed Fathy Elyas Badia

Electronic Thesis and Dissertation Repository

The main objectives of this study were: (i) to investigate dynamic specific denitrification rates (SDNR) from nitrite at various chemical oxygen demand (COD) / nitrogen (N) ratios using municipal wastewater (MWW) and acetate, and to study the kinetic parameters, (ii) to investigate the dynamic specific denitrification rates (SDNRs) from nitrite at various COD/N ratios in a system that uses methanol as a complementary carbon source, and studying the effect in case if nitrate replaced nitrite, and (iii) to investigate and compare between the nitrite shunt and N-PDN-anammox technologies through studying the dynamic specific denitrification rates (SDNRs) from nitrate and nitrite …

P-Cresol Biogenesis During Bioremediation Aimed At Stimulating Chlorinated Solvent Dehalogenation, Alexis Gathings

LSU Master's Theses

The broad goal of the research described in this thesis was to better understand the potential for biologically mediated production of p-cresol in groundwater at a Superfund site located in south Louisiana. Previous literature reports that microorganisms known to carry out the transformation from L-tyrosine to p-cresol occur in diverse environments.

In the research described in this thesis, studies were conducted utilizing groundwater from the Superfund site during the course of enhanced in situ bioremediation practices aimed at stimulating reductive dehalogenation of chlorinated solvent contamination. Microbial communities established with groundwater sampled from the Superfund site were observed to …

The Seasonal Effects Of Photovoltaic Cells On Sedum Eco Roof Substrate Moisture, Brook M. Thompson

University Honors Theses

This paper investigates a combined PV eco roof system and analyzes the soil moisture levels in front of the panels and directly underneath the PV Cells on an experimental ecoroof platform in Portland, Oregon. The purpose of the study was to examine how PV Cells create differences in the moisture level of the soil on the ecoroof. Four moisture sensors were set in different quadrants in four experimental testbeds, and the moisture level data was recorded from October 18^th, 2018 to September 10^th, 2019. The study found that in with heavy rainfall, the front of the …

Biomechanics Of Trees Under Extreme Wind Loading Events, Mojtaba Dargahi

Electronic Thesis and Dissertation Repository

For urban planners, arborists and foresters, understanding tree stability under self-weight and applied loads from wind and snow is important when developing management strategies to reduce the risk of damage from these abiotic agents. Current predictive approaches are generally empirical and based on a posteriori surveys of failures. A more rigorous engineering approach to understanding response phenomenon in trees subjected to extreme winds has been attempted herein. The size of trees and their architecture (shape and structure) greatly influence their mechanical stability under dynamic loading. Considering trees as porous media, wind loads on them are affected by their resistance to …

Challenges And Opportunities To Deep Retrofitting Of Traditional Fabric Buildings To Achieve Nearly Zero Energy Building (Nzeb), Maria Lopez Zambrano, Paul Kenny, Jamie Goggins

Civil Engineering Research in Ireland 2020

Many of our traditional buildings are disappearing or in danger of being under utilised because they are not comfortable for modern day living and do not meet our present day needs. If a building does not have a use, inevitably it deteriorates and eventually becomes a ruin or gets demolished. It is important to retrofit these buildings, which are part of our identity and can be powerful tourist attractions even though most of them are not listed. Some owners want to apply for retrofitting schemes and grants, but they are rejected because there are no standard solutions to achieve low …

Can Deap Help Us To Predict The Energy Demand And Indoor Temperature Of Homes Before And After Renovation? A Case Study From Dublin, Paul Moran, Jamie Goggins

Civil Engineering Research in Ireland 2020

Improving the energy efficiency of buildings via retrofitting is seen as one of the key mitigation measures to reducing the energy demand and carbon emissions of the built environment in Ireland. However, while energy efficiency retrofits for buildings are effective in theory, the energy savings estimated by statistical or engineering models can often be inaccurate. The Domestic Energy Assessment Procedure (DEAP) is the standard assessment procedure used for assessing the energy performance standard of residential buildings in Ireland. This paper examines the gas energy demand for space and water heating and the internal temperature profiles in contrast to DEAP estimates …

St. Mary And St. Anne Cathedral, Cork: An Optimum Heating Solution For Heritage Buildings?, Christopher Shiell, Roger P. West

Civil Engineering Research in Ireland 2020

Cathedrals and most churches are characterised by having large internal, undivided spaces and permeable building envelopes. They are often used little, intermittently, but predictably and, in spite of the fact that they are unique in still being largely used for the purpose for which they were built many centuries ago, they are now often used for additional purposes, for which they were never designed. These uses include concerts, graduation ceremonies, filming and a host of other uses all of which require a level of thermal comfort not envisaged by the original builders. Research was undertaken by the authors into the …

Art In Engineering: Evoking A Creative Response From Engineering Students And More, Jamie Goggins, Marta Fuente, Eamonn Madden

Civil Engineering Research in Ireland 2020

The concept of creativity being only associated with writers, painters, and artistic professions is outdated. The future engineer must embrace maths, art and creativity to unlock innovative solutions. Traditional engineering courses with an emphasis predominately on maths and science can produce graduates who are constrained in developing design solutions without creativity to unlock innovative solutions. This paper describes a short course introduced in the School of Engineering at NUIGalway in 2018 to expose students to creative thinking research and principles and engage in various forms of creative expression (photography, painting and essay writing) to articulate their response to a set …

Teaching Of Structural Analysis Into The Future, Dermot O'Dwyer

Civil Engineering Research in Ireland 2020

The engineering curriculum has always been full. In the past civil and structural engineers studied a wide variety of technical subjects within the broad field of engineering science and spent many hours working on design projects. Modern engineering curricula try to cover these areas while also dedicating more time to structured group-work, report writing and communication skills. Although students spend longer in college the number and range of technical fields that students must master is considerably larger than in the past. As a result the time available to any one topic area has reduced. At the same time the work …

The Broader Development Of The Student Engineer Through Industry Based Experiential Learning, Donogh Coleman, Ted Mckenna, Mary Moloney

Civil Engineering Research in Ireland 2020

The global drive for industry-aware and industry-ready engineering graduates, has led to the development and integration of experiential learning through work placements. Industry is looking to recruit graduates with not just the requisite technical engineering skills, but also graduates with inter alia high levels of teamwork and communications skills. This has been recognised by CIT with the integration of work placement in most of its undergraduate programmes. This paper provides an overview of the student placement process in the Department of Civil, Structural and Environmental Engineering at CIT, includes the work placement alternative which was implemented due to the COVID-19 …

Operational And Embodied Energy Analysis Of 8 Single-Occupant Dwellings Retrofit To Nzeb Standard, Richard O'Hegarty, Shane Colclough, Oliver Kinnane, Donal Lennon, Etienne Rieux

Civil Engineering Research in Ireland 2020

In line with the Energy Performance of Buildings Directive, Irish dwellings are being retrofit to near Zero Energy Building (nZEB) standards - with a number of the deep energy retrofits classified as A-rated. As a result of the low operational energy, the embodied energy share of an nZEB's life cycle energy is significantly increased. Therefore, to obtain a holistic picture of the change in energy profile of buildings, the embodied energy of the material added to achieve that low performance should also be taken into account. This paper presents results from a case study of 8 single-occupant terrace bungalows retrofit …

Loading On Long Span Bridges In Heavily Trafficked Areas, Michael Quilligan, Eugene O'Brien

Civil Engineering Research in Ireland 2020

The critical traffic loading condition for long-span bridges is congestion when vehicles may be closely spaced together. Data on very high traffic flows is limited however, as induction loops which are typically used to collect traffic data, are ineffective when traffic flow breaks down. A number of long span bridges are located in areas of high traffic with periods of recurring congestion occurring daily. While the inter-vehicle gap distances are greater than those occurring during non-recurring full stop accident type events, the high frequency of the recurring congestion events can increase the probability of a critical load case occurring.

A Numerical Study Of The Effect Of Wind Barriers On Traffic And The Bridge Deck, Yuxiang Zhang, Philip Cardiff, Jennifer Keenahan

Civil Engineering Research in Ireland 2020

Wind actions can have a great impact on both bridges and traffic on bridges. However, structures designed to shelter the traffic from wind can influence the aerodynamic performance of the bridge deck, especially for long-span bridges. This study compares the effect of non-perforated walls and perforated walls used as wind barriers for traffic by conducting Computational Fluid Dynamics (CFD) simulations on three-dimensional geometries of a four-lane bridge deck. Steady-state simulations employ the Reynolds-Averaged Navier Stokes (RANS) method with the k-epsilon turbulence model and all simulations use parallel computing. An open-sourced software OpenFOAM is used.

Repair & Rehabilitation Of Daly's (Shakey) Bridge, Cork City, Michael Minehane, John Gamble

Civil Engineering Research in Ireland 2020

This paper describes the rehabilitation of (Shakey) Bridge, an existing single-span suspension bridge crossing the northern channel of the River Lee in Cork City. The bridge was opened in 1927 to replace an earlier ferry crossing at the same location. Daly’s bridge is included on the Record of Protected Structures and the National Inventory of Architectural Heritage. It remains the only suspension bridge in Cork City and is the only surviving bridge of its kind in Ireland. It is considered to be a significant contributor to the architectural heritage of the city. This case study describes the project development including …

Long-Run Traffic Simulations For Multi-Lane Road Bridges, Róisín Donnelly, Lorcan Connolly, Ilaria Bernardini

Civil Engineering Research in Ireland 2020

The maintenance and repair of ageing bridges is a concern for road infrastructure managers. This issue is amplified by the increasing weights and frequency of travel of freight vehicles in recent times. In order to accurately assess the risk of damage for road bridges, it is essential to have knowledge of both historical and current bridge loading. When available, site-specific Weigh-in-Motion (WIM) data can be effective in creating representative load models for a structure. However, for cases where WIM data is not available and in cases where future damage must be predicted, it is necessary to simulate appropriate data using …

Simulation Of Traffic Loading On Long Span Bridges, Hang Zhang, Michael Quilligan

Civil Engineering Research in Ireland 2020

Existing long span load models have typically been developed using a number of conservative assumptions, and as such are more applicable to the design of new bridges rather than the assessment of existing structures. Excessive conservatism in such assumptions can lead to expensive and unnecessary interventions in existing bridges. Furthermore, existing load models do not always allow for correlations in traffic weights and vehicle positions on the bridge.

Development And Testing Of A Deployable Double Layer Tensegrity Grid, Michael Quilligan, Valentin Gomez-Jauregui, Cristina Manchado, Cesar Otero

Civil Engineering Research in Ireland 2020

Tensegrity is a structural principle based on the use of isolated or contiguous pin jointed components in compression inside a net of continuous tension. Although the concept has been studied for many decades, relatively few examples of tensegrity structures have been used for civil engineering purposes.

Reinforcement Of Timber Elements In Compression Perpendicular To The Grain Using Compressed Wood Dowels, Michael Conway, Conan O'Ceallaigh, Sameer Mehra, Annette M. Harte

Civil Engineering Research in Ireland 2020

In the past decade, there has been an increased focus on the environmental impacts of construction and a movement towards more sustainable construction products. Timber is one such sustainable product that can achieve these environmental targets but, while timber has a high strength-to-weight ratio parallel to the grain, it demonstrates poor strength perpendicular to the grain. As a result, stress perpendicular to the grain is an important factor in the design of timber structures, especially in areas of concentrated loading, such as supports. This paper describes a study, which examines the use of compressed wood dowels as a sustainable alternative …

An Evaluation Of Design Issues Identified During Reviews Of Structural Designs Of Buildings From 2015 To 2020, Patrick Crean, Richard Osborne

Civil Engineering Research in Ireland 2020

A recent study on failures of structures in Ireland indicated that approximately 40% could be apportioned to designer error. A 2019 report into recent structural cracking of a high-rise building in Sydney Australia recommended that Independent third party checking by a Chartered Engineer should be a requirement on all major projects prior to construction. The report also stated that the critical elements of the design on these projects should be identified. It is obvious that a certain percentage of buildings constructed each year contain design flaws and only a small proportion of these ever result in a failure. However there …

A Review Of The Engineering Constraints And Project Management Challenges Involved In Utilising Scot’S Church As A Heritage Asset Through Responsible Adaptive Reuse And Conservation Strategies, Óisín Smith

Civil Engineering Research in Ireland 2020

In the field of structural building, there has been a rising popularity in adaptive reuse of older structures, which stems from a variety of stimuli. Apart from preserving built heritage, providing old buildings with new functions promotes sustainability while preventing and containing urban sprawl. Target 11.4 of the United Nation’s Sustainable Development Goals Agenda 2030 explicitly outlines that “more efforts to protect and safeguard the world’s cultural and natural heritage” are required. In order to valorise and regenerate obsolescent structures, intervention is often required. The dissertation provides a comprehensive overview of conservation engineering and demonstrates the importance of an engineer’s …

Potential Of A Low-Calcium Fly Ash (Fa) For The Production Of Alkali-Activated Materials., Omar Alelweet, Sara Pavia

Civil Engineering Research in Ireland 2020

Coal-FA from power stations is an industrial waste abundantly produced in the world. FA can be used as a silicate precursor, and activated with an alkali-metal source to produce alkali-activated materials (AAMs). AAMs are more sustainable than other traditional products, as the use of waste for their production, reduces carbon emissions, and raw materials and energy consumption. This paper studies the properties, composition and reactivity of an Irish FA to establish its potential for the production of AAMs. The results clearly evidenced that the FA is reactive. It is ultrafine, it has a high specific surface area and is partially …

Durability And Sustainability Of Pavement Quality Concrete In Airfields, Aidan Fogarty, Mark Richardson

Civil Engineering Research in Ireland 2020

Direct emissions from the aviation industry accounts for 2% of global emissions. If global aviation was a country it would be in the top 10 emitters. The International Civil Aviation Organization (ICAO) forecasts that emissions could grow by a further 300-700% by 2050. In 2010 global cement manufacture released 3270 million metric tonnes of CO2 into our atmosphere. In 2020 that amount is estimated to be 4370 million metric tonnes of CO2. This will account for around 8% of global CO2. Replacing Portland cement with 70% GGBS in concrete reduces the carbon footprint associated with the cement content in concrete. …