Civil and Environmental Engineering Commons^™

Simulation-Based Assessment Of Operational Strategies For Visibility-Responsive Variable Speed Limits, Jiyeon Ban

Theses

Managing speed limits in adverse weather is crucial for highway safety. Variable Speed Limit systems aim to adjust speed limits according to weather conditions, yet many traffic management centers depend on manual operator judgment. Rapid visibility fluctuations, along with operators handling multiple responsibilities, can cause delays in responding to deteriorating conditions, increasing the risk of rear-end collisions. A VSL control strategy is developed using real-time Road Weather Information System data to enable more proactive and effective adjustments. Microsimulation analysis indicates that visibility-responsive VSL operations can reduce conflicts by 59% in fog. Applying VSL only to fog-affected sections yields clear safety …

Evaluating Stormwater & Carbon Benefits Of Urban Street Trees, Anthony J. Rodriguez Diaz

Theses

Urban areas experience a multitude of environmental challenges, including flooding and air pollution. In response to these pressures, urban forests have emerged as an essential nature-based strategy to enhance resilience and reduce climate-related risks. The implementation and expansion of urban street trees further contribute to this effort by mitigating stormwater runoff and reducing atmospheric carbon emissions.

Fortunately, advances in environmental modeling have made it increasingly possible to quantify these ecosystem services using specialized software. The United States Department of Agriculture (USDA) Forest Service's i-Tree suite exemplifies this progress. The software provides a comprehensive set of tools designed to quantify environmental …

Groundwater Quality And Health Risk Assessment In The Fujairah Region Using Hydrogeochemical, Statistical, And Spatial Approaches, Mohammed Khaled Alawlaqi

Theses

Groundwater is a valuable resource in the arid climate of the United Arab Emirates, where growing population, agricultural, and industrial activities are putting increasing pressure on the limited groundwater reserves. This work investigates the hydrogeochemical characteristics of groundwater in the Fujairah region to assess water quality and potential health risks. A total of 64 groundwater samples were collected from the Eastern Shallow Aquifer (ESA) and the Ophiolite aquifer in the study area and were analyzed for physicochemical parameters, major ions, and trace metals. Hydrogeochemical methods such as Piper, Gibbs, Chadha, and Schoeller diagrams were used to identify water types and …

Groundwater Storage Dynamics In Abu Dhabi Emirate Using In-Situ And Grace Data, Tala Jalal Maksoud

Theses

Water scarcity presents a significant challenge to the sustainable development; especially in arid regions like Abu Dhabi Emirate. Addressing concerns over nonrenewable aquifer depletion, caused by agricultural expansion and lifestyle advancements, has, therefore, become crucial in such regions. This thesis investigates Groundwater Storage (GWS) dynamics in Abu Dhabi Emirate by integrating satellite data from the Gravity Recovery and Climate Experiment (GRACE) with in-situ data from 257 wells over two decades (2002-2022), employing GIS and RS technologies. The main aim of this study is to provide a comprehensive approach to evaluate GWS dynamics considering multiple perspectives including: dealing with missing datasets, …

Hybrid Treatment Method Of Biofiltration Preceded With Advanced Oxidation Process For The Removal Of Emerging Contaminants From The Wastewater Treatment Plant Effluent, Anjali Mohan Payathuparambil

Theses

The global demand for potable quality water has been on a continuous rise. Consequently, water reuse is now considered as an alternative to significantly expand supplies of freshwater in communities facing water shortages. Most of the conventional wastewater treatment plants (WWTP) are not efficient in the removal of emerging contaminants from the water, which will cause serious issues to the environment, human and animal life. This research investigated the possibilities of treating wastewater for reuse. First, the feasibility of utilizing a biofiltration system without pre-treatment for removing emerging contaminants from the WWTP effluent was investigated. Two types of biofilter media- …

Design And Evaluation Of Geopolymer Composite As A Potential Sorbent Of Heavy Metals From Water, Ebtesam Mohammed Alghafri

Theses

Reducing the levels of heavy metals in water is crucial, given their severe environmental and health impacts. Various methods exist for heavy metals removal. Yet, they mostly come with multiple drawbacks, such as costly treatments and limited efficiency. Previous studies have found geopolymer to be a promising sorbent because it is synthesized using by-product materials, making it an eco-friendly and economically sustainable alternative. Limited studies explored the sorption potential of fly ash-slag blended geopolymers; none examined the effect of mix design factors synergically on sorption, mechanical properties, and durability, and few considered solution characteristics and operating conditions simultaneously. Therefore, this …

A Bayesian Belief Networks Approach To Prioritize Road Safety Mitigation Measures For Eco-Mobility Modes, Fatmah Mohamed Alyammahi

Theses

This study presents an innovative decision-making approach that enables the prioritization of road safety measures for eco-mobility users—pedestrians, cyclists and light-electric micromobility riders—in Abu Dhabi. The analysis uses 2032 eco-mobility crash records (1016 pedestrian, 567 bicycle, 449 e-scooter) from 2020-2023 supplied by Abu Dhabi Police and the Department of Municipalities and Transport. A supervised Bayesian Belief Network (BBN) was constructed around six empirically estimated variables: visibility, predictability, road curvature, obstructions, lighting and speed limit. Maximum-likelihood conditional-probability tables were derived from the cleaned dataset; Beta priors were applied only where cell counts were sparse. Ten conventional machine-learning models—including Random Forest, Gradient …

Utility Of New Remote Sensing Data In Evaluating The Hydrological Response To Land Use And Land Cover Changes, Chithrika Jayamini Alawathugoda

Theses

Land use and land-cover (LULC) changes have profound impacts on hydrological responses, influencing runoff dynamics and flood risks. This study focused on two contrasting watersheds undergoing rapid LULC transformations: the arid Wadi Ham watershed in the UAE and the tropical Imphal watershed in India. The research emphasized the critical role of accurate LULC data for hydrological modeling in climate-sensitive regions, where land-use changes are accelerating. Using high-resolution PlanetScope and Sentinel-2 satellite imagery, LULC maps were developed and classified using Maximum Likelihood (ML) and Random Forest (RF) algorithms. PlanetScope imagery paired with the RF classifier achieved the highest overall accuracy, with …

Numerical Simulation Of Concrete Beams With Discontinuity Regions Reinforced With Nonmetallic Reinforcing Bars, Amena Mohammad Ousama

Theses

Nonmetallic Glass Fiber-Reinforced Polymer (GFRP) reinforcing bars are considered a viable alternative to the conventional steel reinforcement because of their high strength-to-weight ratio and noncorrosive nature. This research aimed to investigate the nonlinear structural behavior of GFRP-reinforced concrete beams with discontinuity regions (D-regions) through numerical analysis. Three-dimensional (3D) numerical models were developed to simulate the nonlinear structural behavior of GFRP-reinforced deep beams with and without web openings. The models adopted realistic constitutive laws that accounted for the nonlinear behavior of the materials used. Predictions of the numerical models were validated against published experimental data. A parametric study was conducted to …

Establishing A Scootability Index To Prioritise Road And Footway Infrastructure Improvements For Smooth And Safe E-Scooter Usage, Nadia Jalal Maksoud

Theses

The intensifying use of electric scooters as a form of transportation calls for new infrastructure assessment methods to improve the smoothness and safety of facilities in which these devices are ridden. Despite the extensive research on the infrastructure requirements of bicycles, there is a dearth of studies on electric scooters. This study aims to define the main infrastructure requirements for electric scooters in an urban context. A mixed-methods approach is employed combining quantitative and qualitative data collection and regression analysis. To provide a basis for a so-called multi-dimensional “scootability” index that covers all aspects pertaining to the safety and smoothness …

Using Metal-Organic Frameworks (Mofs) In Producing Self-Curing Concrete, Lama Fathi Allan

Theses

Curing of concrete is the presence of adequate moisture content in concrete throughout its early stages to produce the desired properties, as it is significant in improving the concrete microstructure and pore structure and hence in developing its performance and durability. However, good curing is not always practical in several cases, such as in hot weather regions and areas of water inadequacy. For that reason, the need to develop self-curing concrete attracted several researchers. The use of self-curing agents minimizes the water evaporation from concrete and consequently increases its water retention capacity compared to conventional concrete. This thesis is concerned …

Potential Of Flow Energy Reduction By Coral Reef: Hydrodynamic Analysis On Acropora Species, Faisal Karim

Theses

One of the most crucial components of the ocean ecology is coral reefs. Being environmentally sustainable, natural structures like coral reefs have recently drawn a lot of attention as a means of reducing the flow energy. The absence of scientific validations on the potential of coral reefs in reducing high-energy flow limits engineering applications of coral reefs to the benefit of civilization. In this research, extensive experimental studies were carried out to investigate the capabilities of coral reefs, to reduce high-energy flows. To determine the high-energy wave reduction by coral reefs, the coral roughness coefficient along with the coral structure …

Closing The Modern Irish Municipal Wastewater Phosphorus Cycle, Ciaran O’Donnell

Theses

Phosphorus (P) is an essential life-supporting nutrient for which there is no substitute. P naturally cycles within nature. Modern farming practice and food production have altered the natural P cycle. Successive crop harvests remove P from the soil as crops and transport them to urban areas to feed the population. To replace P removed from the soil through these crop harvests, mineral P fertilisers are applied to the soil to sustain crop production. Mineral P fertilisers are derived from finite phosphate rock. The European Union does not have an indigenous supply of phosphorus rock, which poses a significant issue for …

Sludge-Based Activated Carbon: Characterization And Performance For Removal Of Methylene Blue From Aqueous Solution, Ahmad Anwar Al Madhoon

Theses

Domestic wastewater treatment plants in the United Arab Emirates (UAE) produce 122 thousand tons of dried sludge annually. About 70% of this sludge is dumped in landfills, creating water and soil contamination. Sludge is an energy-rich organic material that could be converted into activated carbon by thermal or chemical processes. Potassium hydroxide has shown great potential as an activating agent for producing high-quality sludge based activated carbon (SBAC). However, its use adds to the cost of the production process. Thus, there is a need for an alternative activating agent that is not costly. One possible chemical is carbide lime which …

Mitigating Progressive Collapse Resistance Of Reinforced Concrete Framed Structures With Innovative Reinforcing Scheme, Ahmad Zaki Abdelkarim

Theses

The objective of this thesis is to numerically investigate the performance and efficiency of a novel proposed mitigating method to improve the resistance of reinforced concrete (RC) floor systems to progressive collapse as a result of a potential column failure. The proposed mitigating method applies to RC floor systems in framed structures, and it is based on a concept of developing self-generated “post-tensioning” axial compressive forces within segments of the floor beams that bridge over the potential failed column. To achieve this goal, the proposed method is comprised of adding diagonal top and bottom steel bars within the floor slab …

Performance Evaluation Of Glass-Fiber Reinforced Cement-Free Geopolymer Concrete, Mohammad Zuaiter

Theses

The alkali-activation of aluminosilicate materials produces a geopolymer binder that promises to be a sustainable replacement to cement in concrete. Yet, such concrete has experienced brittle behavior and poor resistance to cracking. As a means of improving its performance, this research assesses the feasibility of utilizing glass fibers in slag-fly ash blended geopolymer concrete for structural applications. A blend of slag and fly ash served as the binding material. Two types of glass fibers were used individually or as a hybrid combination. Type A and B glass fibers had similar properties but different lengths of 24 and 43 mm, respectively. …

Using Metal-Organic Frameworks (Mof) To Reduce The Carbon Footprint Of Concrete, Mona Ibrahim El-Hallak

Theses

The production of concrete by the construction industry has a massive impact on the environment. The process of manufacturing its main component, cement, releases a considerable amount of anthropogenic carbon dioxide. This thesis is concerned with the production of sustainable and eco-friendly concrete that integrates metal-organic frameworks (MOF) to capture and offset the CO₂ emissions emitted during the production of cement. The main objective is to synthesize a MOF capable of capturing CO₂ in concrete through accelerated carbonation curing and to assess its impact on concrete performance. Different parameters were examined, including the MOF content, initial curing duration, …

Numerical Modelling Of Externally-Bonded Fiber Reinforced Polymer Shear-Strengthened Reinforced Concrete Beams Subjected To Fatigue Loading, Nagwa Ibrahim Fares

Theses

An extensive number of existing structures persistently exposed to fatigue loading such as bridges, offshore structures, pavements, and highways, are in urgent need of repairing and strengthening. This may be attributed to the continuous increase in the load requirements, change of the structure’s function, and meeting current load standards. Among the potential methods of rehabilitation and strengthening of existing reinforced concrete structures, the externally bonding fiber reinforced polymers (FRP) composites are gaining massive popularity and becoming a viable and cost-effective method. Shear failure of reinforced concrete (RC) beams is known to be brittle, which occurs without prior sufficient warnings; therefore, …

Performance Assessment Of Existing Rc Bridges Equipped With Seismic Risk Mitigation Systems, Homam Mohamad Ghazal

Theses

Many bridges built before adopting current design standards may be at risk as they do not meet the latest seismic performance objectives. Bridges are vital infrastructure components required to be serviceable after earthquakes to avoid negative consequences on daily traffic. Previous seismic hazard studies considered the United Arab Emirates an earthquake-prone region subjected to two scenarios: (i) near-field events, and (ii) far-field earthquakes. Therefore, the vulnerability of pre-seismic code bridges in the UAE should be carefully assessed, and retrofit techniques should be proposed to mitigate possible earthquake losses. This study is thus devoted to assessing the seismic vulnerability of a …

Sediment Transport On The River Bandon, Co. Cork, Ireland, Laurence Lomasney

Theses

This thesis analyses sediment transport on the River Bandon, Co. Cork, Ireland. Bedload transport and suspended sediment transport were monitored on the River Bandon over an extended period to determine rates of transport over varying flow conditions. A literature review of sediment properties (individual and bulk sediment), sediment transport, and numerical modelling was undertaken. A manual field sampling programme was undertaken at different locations on the River Bandon to collect bed sediment and suspended sediment for laboratory testing. This data, and data collected using an automatic water sampler and bed sediment traps also, was used to determine baseline conditions for …

The Impact Of Wastewater Chemistry And Flow Characteristics On Hydrogen Sulfide Concentration, Mohsina Muhammed Sherief

Theses

Hydrogen sulfide (H₂S) is a naturally occurring, highly toxic gas that is formed from the decomposition of sulfur compounds. At low concentrations, H₂S is an irritant for the eyes, respiratory and gastrointestinal tract. At higher H₂S concentrations, it produces neurological impairment with dizziness, headache, and loss of consciousness. Mortality was reported to reach 6 percent following exposure to elevated concentrations. H₂S is generated in different industrial processes. In wastewater collection and treatment plants, H₂S is a common source of concrete and metal corrosion that has resulted in huge economic loss. …

Strengthening Of Concrete Deep Beams Using Carbon Fabric Reinforced Cementitious/Geopolymeric Matrix, Nour Mohamed Muhsen Khir Allah

Theses

This research aimed to examine the effectiveness of using carbon fabric-reinforced matrix (C-FRM) composites to improve the shear response of reinforced concrete (RC) deep beams. Ten RC deep beams with a/h of 1.6 were tested, where a is the shear span and his is the beam depth. Test parameters included the presence of internal shear reinforcement (no shear reinforcement and minimum shear reinforcement), number of C-FRM composite layers (one and two layers), angle of inclination of the second layer of CFRM (90o and 0o with respect to the longitudinal direction of the beam), and type of matrix (cementitious and geopolymer). …

Environmental Assessment Of The Impact Of Land-Based Discharges On Marine Water And Sediment Quality In Dubai, Uae, Ayman Fathy Halawa

Theses

The current seawater and Creek – Canal waterway in the Emirate of Dubai, UAE, is under tremendous pressure because of continuous urban water discharges from land-based sources. Therefore, the impact of urban water discharges on marine water and sediment quality in the Emirate requires a thorough assessment. The main objective of this study is to assess the impacts of effluent discharges on the quality of water and sediment in the open sea and Dubai Creek. The land-based sources include the power and desalination plants, industrial sector, sewage treatment plant, and stormwater runoff. To achieve the stated objective, relevant data on …

Comprehensive Characterization Of The Aerosol And Cloud Condensation Nuclei In The Uae, Farah Hassan Abdi

Theses

Cloud seeding has emerged as a significant alternative freshwater source in the United Arab Emirates (UAE). It is employed to manipulate weather conditions and increase precipitation in specific target regions. These efforts aim to densify clouds and enhance the likelihood of rainfall by inducing nucleation. This technique involves an operational crew aboard an aircraft that disperses substantial quantities of seeding particles, such as salts or silver iodide, into suitable clouds. These particles can serve as cloud condensation nuclei (CCN) and indirectly affect the rate of rainfall. In 2018, cloud seeding operations were responsible for approximately 10-15% of the UAE's total …

Performance Of Ultrasound-Assisted Forward Osmosis Membrane Process In Desalination Of Seawater, Bara Awwad Al-Sakaji

Theses

The objective of this study was to investigate the effect of using ultrasound on water flux through forward osmosis membrane when applied for seawater desalination. A synthetically prepared solution simulating seawater characteristics was used. Parameters considered in the investigation included membrane cross-flow velocity (0.25 and 1.0 cm/s), flow configuration (co-current versus counter-current), direction of ultrasound waves relative to the membrane side (active layer versus support layer), and type of draw solution (NaCl versus MgCl₂). Furthermore, a two-level factorial design was considered in the analysis of the results obtained from the experimental work. This study revealed that applying a …

Behavior Of Steel Fiber-Reinforced Geopolymer Concrete Made With Recycled Concrete Aggregates, Abdalla Ahmed Moallim Hussein

Theses

Industrial by-products and recycled concrete aggregates (RCA) have the potential to fully replace cement and natural aggregates, respectively, in the production of concrete rather than being discarded wastefully into landfills or stockpiles. Yet, their combined use in the development of a novel RCA geopolymer concrete has been limited to nonstructural purposes, owing to the inferior mechanical and durability properties of said concrete. To improve the properties of geopolymer concrete made with RCA, steel fibers may be added to the mix. This research aims to study the feasibility of reutilizing locally available industrial solid wastes and RCA in geopolymer concrete for …

Performance Of Cement-Free Geopolymer Concrete Made With Ceramic Waste Powder Using Taguchi Method, Ponalagappan Chokkalingam

Theses

The ceramic industry produces a substantial amount of waste during its production processes. Recycling and reutilizing such ceramic waste is a challenge due to its extended biodegradation period. Consequently, the ceramic industry is dedicated to attaining a sustainable solution to dispose of this waste rather than discarding it wastefully into landfills or stockpiles. In turn, the demand for ordinary Portland cement has been on a steady increase, leading to concerns about the sustainability of the construction industry. As a sustainable alternative to cement, alkali-activated binders have been proposed owing to their ability to reduce carbon emissions, preserve nonrenewable natural resources, …

Performance Evaluation Of Cement-Free Geopolymer Concrete Made With Recycled Concrete Aggregates And Steel Fibers, Jamal Ahmad Husam Samer Medljy

Theses

Sustainable and innovative alternatives have been investigated to replace concrete’s main components, natural aggregates, and cement. Previous studies have been carried out to replace NA and cement with recycled concrete aggregates (RCA) and inorganic alkali-activated geopolymer binders, respectively. Yet, such sustainable concrete has only been proposed for non-structural purposes, owing to the inferior properties of RCA. This research work aims to assess the feasibility of reutilizing RCA from construction and demolition waste and locally available industrial solid by-products in the production of sustainable geopolymer concrete for structural applications. The binding materials were either in the form of a single precursor, …

Incident Duration Time Prediction Using A Supervised Topic Modeling Method, Jihyun Park

Theses

Precisely predicting the duration time of an incident is one of the most prominent components to implement proactive management strategies for traffic congestions caused by an incident. This thesis presents a novel method to predict incident duration time in a timely manner by using an emerging supervised topic modeling method. Based on Natural Language Processing (NLP) techniques, this thesis performs semantic text analyses with text-based incident dataset to train the model. The model is trained with actual 1,466 incident records collected by Korea Expressway Corporation from 2016-2019 by applying a Labeled Latent Dirichlet Allocation(L-LDA) approach. For the training, this thesis …

Enhanced Removal Of Perfluorooctanoic Acid (Pfoa) Via Microwave-Fenton-Reactive Membrane Filtration, Fangzhou Liu

Theses

Perfluorooctanoic Acid (PFOA), one of the common per- and poly fluorinated alkylated substances (PFASs), is increasingly detected in the environment due to the diverse industrial applications and high resistance to degradation processes. This study evaluated degradation of PFOA in microwave-assistant catalytic membrane filtration, a process that integrates microwave catalytic reactions into a ceramic membrane filtration. First, water permeation of the pristine and catalyst-coated membranes were examined under the influence of microwave irradiation to analyse the impacts of the coating layer and water temperature increase on permeate flux, which were well interpreted by three models. Then, the PFOA removal was first …