Engineering Commons^™

Climate-Driven Changes In Water Quality By Physiographic Region: A Case Study Of Taos County, New Mexico, Michaela Eamma

Civil and Environmental Engineering Theses and Dissertations

Socioeconomic growth and stability in rural regions of the United States where agriculture is the dominant industry are highly reliant on access to sufficient surface water supplies. The water quantity crisis experienced worldwide in recent years has introduced questions about how to best maintain the quality of our remaining resources. Ensuring adequate access to drinking and irrigation water mandates that we protect existing surface water sources and anticipate future threats to quality. The impact of climate change on surface water quality is not spatially uniform, introducing the need to study the water-atmosphere-land system comprehensively.

This research aims to study the …

Equity In Transportation: Data Driven Analysis Of Transportation Services And Infrastructures, Javad Jomehpour Chahar Aman

Civil and Environmental Engineering Theses and Dissertations

Achieving equity in transportation is an ongoing challenge, as transportation options still vary tremendously when it comes to marginalized populations. This dissertation addresses this challenge by conducting a comprehensive review of existing transportation equity literature and identifying two critical gaps: the lack of data-driven approaches to studying spatial mismatch between transportation supply and demand, and limited information on women's perceptions and expectations towards emerging transportation services.

Chapter two introduces the concept of transportation "deserts," specifically transit deserts and walking deserts, and develops data-driven frameworks to identify and investigate neighborhoods with limited transportation service supply but high demand. The frameworks compare …

A Mechanics-Based Analytical Solution For Restrained Beams With Application To Progressive Collapse Behavior, Leven Deputy

Civil and Environmental Engineering Theses and Dissertations

This dissertation presents an axially restrained beam (ARB) model that incorporates axial-flexural interaction throughout the entire static load-deflection curve: the elastic material range, the plastic, flexural dominant range, the range beyond plastic flexure with increasing catenary effect, and the full catenary range. Energy methods are applied to static load-deflection curves to determine dynamic load-deflection relationships. Specifically, this dissertation considers the two conditions; Pinned-Pinned-Pinned (PPP) which has no flexural resistance at the boundaries, and Fixed-Fixed-Fixed FFF (also Pinned-Fixed-Pinned, PFP) condition which provides the beam with flexural resistance at the boundaries equal to flexural capacity of the beam. Behavior is explained analytically …

Component Testing And Characterization Of An Innovative Pressurized Sand Damper For The Response Modification Of Structures, Konstantinos Kalfas

Civil and Environmental Engineering Theses and Dissertations

This study is partly motivated by the need to develop sustainable energy dissipation devices that do not suffer from oil leakage due to failure of their end seals and from displacement limitations; and partly from the need to develop a robust damper that consists only of traditional civil engineering materials (sand and steel) in association with the use of post-tensioned steel rods with which practitioner civil engineers are familiar. Past failures of fluid dampers are both disruptive and costly, therefore not in-line with the current design paradigm of sustainable engineering, where the design and construction of structural systems shall meet …

Indirect Bridge Monitoring Using Crowdsourced Smartphone Data From Passing Vehicles, Jase Sitton

Civil and Environmental Engineering Theses and Dissertations

Bridges become susceptible to deterioration and damage as they age and are subjected to continually increasing demands. Bridge inspections help insure the integrity and safety for service and are conducted on a regular, but usually infrequency, basis. Traditional evaluation methods include visual inspections and permanent sensor installations. Visual inspections are both time and labor intensive and often require bridge closure or service interruption, while cost and logistics complications often prevent practical, widespread deployment of permanent sensor installations. Sensors, including smartphones, in moving vehicles may be used to monitor bridge condition over time and provide valuable insight into the dynamic behavior …

Leveraging Crowdsourced Navigation Data In Roadway Pluvial Flash Flood Prediction, Arefeh Safaei-Moghadam

Civil and Environmental Engineering Theses and Dissertations

This dissertation develops and tests a new data-driven framework for short-term roadway pluvial flash flood (PFF) risk estimation at the scale of road segments using crowdsourced navigation data and a simplified physics-based PFF model. Pluvial flash flooding (PFF) is defined as localized floods caused by an overwhelmed natural or engineered drainage system. This study develops a data curation and computational framework for data collection, preprocessing, and modeling to estimate the risk of PFF at road-segment scales. A hybrid approach is also developed that couples a statistical model and a simplified physics-based simulation model in a machine learning (ML) model to …

Energy Dissipation In A Sand Damper Under Cyclic Loading, Ehab Sabi

Civil and Environmental Engineering Theses and Dissertations

Various seismic and wind engineering designs and retrofit strategies have been in development to meet structures' proper and safe operation during earthquake and wind excitation. One such method is the addition of fluid and particle dampers, such as sand dampers, in an effort to reduce excessive and dangerous displacements of structures. The present study implements the discrete element method (DEM) to assess the performance of a pressurized sand damper (PSD) and characterize the dissipated energy under cyclic loading. The idea of a PSD is to exploit the increase in shearing resistance of sand under external pressure and the associated ability …

Modeling Framework And Solution Methodologies For On-Demand Mobility Services With Ridesharing And Transfer Options, Sepide Lotfi

Civil and Environmental Engineering Theses and Dissertations

The growing complexity of the urban travel pattern and its related traffic congestion, along with the extensive usage of mobile phones, invigorated On-Demand Mobility Services (ODMS) and opened the door to the emergence of Transportation Network Companies (TNC). By adopting the shared economy paradigm, TNCs enable private car owners to provide transportation services to passengers by providing user-friendly mobile phone applications that efficiently match passengers to service providers. Considering the high level of flexibility, convenience, and reliability of ODMS, compared to those offered by traditional public transportation systems, many metropolitan areas in the United States and abroad have reported rapid …

Equity Of Urban Neighborhood Infrastructure: A Data-Driven Assessment, Zheng Li

Civil and Environmental Engineering Theses and Dissertations

Neighborhood infrastructure, such as sidewalks, medical facilities, public transit, community gathering places, and tree canopy, provides essential support for safe, healthy, and
resilient communities. This thesis proposes, develops, and implements an innovative approach to thoroughly examine the presence and condition of neighborhood infrastructure.
It demonstrates the necessity of considering multiple infrastructure types when studying
neighborhood infrastructure and its equity. This thesis provides an automated assessment
framework as well as case studies among four major metropolitan cities across the United
States, which expands the research opportunities for future infrastructure-related research.

A Coupled Smoothed Particle Hydrodynamics-Discrete Element Method Framework For The Dynamic Response Of Saturated Geotechnical Systems, Saman Farzi Sizkow

Civil and Environmental Engineering Theses and Dissertations

Investigating the past failures of various geotechnical systems during major seismic events, reveals the importance of developing a robust framework that can reliably analyze complex geotechnical systems. Up to now, fully continuum techniques have been the most popular choice for this type of problems. These methods use sophisticated constitutive models which need careful fine-tuning to successfully mimic the macro-scale dynamic behavior of coupled systems. The discrete element method (DEM) is, by nature, the best option for discontinuous systems such as soil. Furthermore, it has effective means to handle soil-structure interaction. Therefore, many attempts have been made to couple DEM with …

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 …

Infrastructure Deficiency Correlation With Pedestrian/Cyclist Crashes: A Data-Driven Approach, Farbod Tavakkoli Khomeini, Barbara Minsker, Michael Hahler, Janille Smith-Colin, Xinlei Wang

Civil and Environmental Engineering Theses and Dissertations

A model for identifying the impacts of infrastructure deficiency on road traffic safety is needed to help governments prioritize strategic investments to increase public safety. During the 2010-2019 period, U.S. pedestrian and cyclist fatalities rose by 44% and 36%, respectively, and previous studies have shown a positive correlation between pedestrian/cyclist crashes and low-income areas. To our knowledge, this study is the first to investigate further the reasons behind the higher probability of pedestrian and cyclist crashes in low-income areas. The proposed hypothesis is that the higher probability of pedestrian and cyclist crashes in low-income areas correlates with higher infrastructure deficiencies …

A Restrained Beam Sub-Model Assembly (Rbsa) For Progressive Collapse Analysis, Muath Alhumaidi

Civil and Environmental Engineering Theses and Dissertations

The progressive collapse failure mode occurs in buildings when a load-carrying element is lost due to extreme events such as explosions caused by terrorist attacks or vehicular impacts. Guidelines and many researches efforts have been established in order to limit and prevent total collapse of buildings after losing a load-carrying component (e.g., a column). Two famous examples of progressive collapse are the 1968 Ronan Point apartment building kitchen explosion on the 18^th floor and the 1995 Alfred P. Murrah Federal Building bombing in Oklahoma City. Both examples resulted in fatalities and injuries. A small number of these …

Response Modification And Seismic Protection Of Yielding Structures Equipped With Inerters And Hysteretic Dampers, Gholamreza Moghimi

Civil and Environmental Engineering Theses and Dissertations

This study investigates the seismic response of structures with sustainable, long-stroke response modification devices. The main thrust of the dissertation is the investigation of the seismic response of yielding structures equipped with supplemental rotational inertia, or inerters. The last chapter of this dissertation investigates the seismic response of multistory yielding steel structures equipped with pressurized sand dampers.

Inerters are mechanical devices with resisting force proportional to the relative acceleration of their end nodes. This class of response modification devices complements the traditional fluid viscous damping devices with resisting force proportional to the relative velocity at their end-nodes. Mass-amplification is the …

Characterization Of An Urban Watershed: The Case For Rowlett Creek Watershed Impaired By Bacteria And Nutrient Concerns, Heather Firn

Civil and Environmental Engineering Theses and Dissertations

Firn, Heather B.S., Southern Connecticut State University, 2009 M.S., Southern Connecticut State University, 2013

Characterization of an Urban Watershed: The Case

for Rowlett Creek Watershed Impaired by Bacteria

and Nutrient Concerns

Advisor: Professor Wenjie Sun

Master of Science conferred May, 15, 2021

Thesis completed April, 27, 2021

Water quality and its relationship with urbanization is one of many nationwide environmental concerns. Rowlett Creek is located in an urban watershed in the Dallas-Fort Worth Metroplex. Since 2014, it has been listed by the Texas Commission on Environmental Quality as impaired for bacteria and as a screening limit concern for nitrate. Water …

Characterization Of Uranium, Lead, And Rare Earth Element Pollution In Natural Soils And Sediments, Hope Rasmussen

Civil and Environmental Engineering Theses and Dissertations

Heavy metals in the environment add to the global burden of pollution, negatively impacting public health and ecosystem resilience. This study included projects regarding uranium (U), lead (Pb), and rare earth elements (REE) in natural samples, due to their known toxicity, ubiquity, and relevance in context to recent pollution trends. The first project focused on testing the potential of using a hydroxyapatite product as a remediation solution for U-contaminated groundwater and soil at an EPA Superfund site. The results showed that the U was sequestered in a highly crystalline mineral form within the solids, guiding the EPA to specify the …

A Modeling Framework For Urban Growth Prediction Using Remote Sensing And Video Prediction Technologies: A Time-Dependent Convolutional Encoder-Decoder Architecture, Ahmed Hassan Jaad

Civil and Environmental Engineering Theses and Dissertations

Studying the growth pattern of cities/urban areas has received considerable attention during the past few decades. The goal is to identify directions and locations of potential growth, assess infrastructure and public service requirements, and ensure the integration of the new developments with the existing city structure. This dissertation presents a novel model for urban growth prediction using a novel machine learning model. The model treats successive historical satellite images of the urban area under consideration as a video for which future frames are predicted. A time-dependent convolutional encoder-decoder architecture is adopted. The model considers as an input a satellite image …

Optimizing The Methanotrophic Production Of Polyhydroxyalkanoates Using Mixed Microbial Bacteria Cultures, Kai Cheng

Civil and Environmental Engineering Theses and Dissertations

The use of petroleum-based plastics has caused serious economic and environmental problems. It is imperative to develop sustainable ways to produce valuable and environmentally-friendly materials. Methanotrophic bacteria are known for assimilating methane while generating polyhydroxybutyrate (PHB) biopolymers, which are potential substitutes for conventional plastics. Additionally, biologically generated methane and volatile fatty acids (VFAs) are abundant and readily accessible through anaerobic digestion of organic wastes. Thus, optimizing the methanotrophic production will bring significant economic and environmental benefits.

In section one, a feast-famine based cultivation system was adopted to produce PHAs using Hyphomicrobium, and Methylocysits dominated bacterial culture. The mixed bacterial culture …

Space And Depth-Resolved Naturally Occurring Toxic Groundwater Species In Bangladesh And Rwanda: Origination And Risk Analysis, Kenneth Hamilton

Civil and Environmental Engineering Theses and Dissertations

Access to safe potable water is a necessity for all. Groundwater is a commonly relied upon drinking water source for many areas around the world. This is especially true for communities in high density, rural settings. Such is the case for populations near Cox’s Bazaar, Bangladesh, and in the Bugesera region of Rwanda. Sediment and groundwater contamination, through toxic dissolved species, represents a significant public health risk to exposed populations. Tropical soils, such as the soil profiles in Bangladesh and Rwanda, often contain higher concentrations of heavy metals (Rieuwerts, 2007). Additionally, nitrate from fertilizers, are widely used on the soils …

Hybrid Vehicle-Drone Routing Problem For Pick-Up And Delivery Services Mathematical Formulation And Solution Methodology, Aline Karak

Civil and Environmental Engineering Theses and Dissertations

The fast growth of online retail and associated increasing demand for same-day delivery have pushed online retail and delivery companies to develop new paradigms to provide faster, cheaper, and greener delivery services. Considering drones’ recent technological advancements over the past decade, they are increasingly ready to replace conventional truck-based delivery services, especially for the last mile of the trip. Drones have significantly improved in terms of their travel ranges, load-carrying capacity, positioning accuracy, durability, and battery charging rates. Substituting delivery vehicles with drones could result in $50M of annual cost savings for major U.S. service providers.

The first objective of …

Removel Of Polluntants From Aqueous Solution Via Graphene Oxide/Magnesium Oxide Nanocomposites, Mahdi Heidarizad

Civil and Environmental Engineering Theses and Dissertations

In this study, a series of graphene oxide/magnesium oxide nanocomposites (GO/MgO NCs) were synthesized and applied for the removal of Methylene Blue (MB) from aqueous solutions. The prepared NCs were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The results showed that MgO particles were successfully layered on GO. The impacts of different experimental variables on the removal of MB including GO/MgO NCs dosage, pH, contact time, and initial MB concentration were investigated.

Thereafter, we investigate the mechanism and kinetics of ozonation processes in the presence of GO/MgO NCs as a catalyst …

Evaluation Of The Mechanisms And Effectiveness Of Nano-Hydroxides, Wood And Dairy Manure-Derived Biochars To Remove Fluoride And Heavy Metals From Water, Anna Rose Wallace, Wenjie Sun Dr, Chunming Su Dr

Civil and Environmental Engineering Theses and Dissertations

The development of effective treatment processes for the removal contaminants, such as fluoride and heavy metals, from polluted water have been urgently needed due to serious environmental health and safety concerns. In this dissertation, a variety of materials including various (hydro)oxide nanomaterials, biochars and surface modified biochar were studied to evaluate their effectiveness and mechanism on removing fluoride or mixed heavy metals from water.

In the Chapter 2, this study investigated the adsorptive removal of fluoride from water using various (hydro)oxide nanomaterials, focusing on ferrihydrite, hydroxyapatite (HAP) and brucite, which have the potential to be used as sorbents for surface …

Equilibrium-Based Workload Balancing For Robust Emergency Response Operations In Metropolitan Areas, Parya Roustaee

Civil and Environmental Engineering Theses and Dissertations

This thesis presents an equilibrium-based modeling framework for emergency response (ER) workload balancing to achieve robust operation in large-scale metropolitan areas. The problem is formulated as a non-linear mathematical program (NLP), which determines the optimal workload cutoff for each ER station such that the weighted sum of the area-wide expected response time and its variation are minimized. The concept of Marginal Cost of Uncertainty (MCU) is introduced to measure the impact of a station’s workload increase on the area-wide service performance. The solution of the NLP is proved to be equivalent to a state of equilibrium in which all stations …

Behavior Of Geothermal Energy Piles Embedded In Rock, Ehab Sabi

Civil and Environmental Engineering Theses and Dissertations

Geothermal energy piles are categorized as closed systems. Energy piles are a relatively new technology which couples the structural role of traditional pile foundations to that of heat exchangers to fulfill the required energy demand of buildings and infrastructures. These foundations are equipped with pipes embedded in the concrete forming the pile. While connected to a heat pump, the fluid circulating inside these pipes provides the exchange of heat with the ground for heating and cooling purposes. As the undisturbed temperature at the shallower depths of the ground stays comparatively constant the whole year, being warmer than the surrounding temperature …

Spatial Exploration Of Trace Metals In Near-Surface Water And Soil In The Bolivian Altiplano, Lizzie Wilson

Civil and Environmental Engineering Theses and Dissertations

We analyzed soil and groundwater samples from the Bolivian Altiplano for trace metal concentrations, correlations and partitioning trends. Total digestion, sequential extraction and loss on ignition experiments were performed on soil samples. We ran aqueous samples on an ICP-MS. Results were analyzed to identify trace metal concentrations and find any significant correlations. We generated interpolated maps in ArcGIS to spatially analyze results. Results for elevated concentrations of interest were divided into sub-groups of organophilic metals, oxoanions and divalent metals and include vanadium, arsenic, selenium, zinc, nickel, lead, cobalt, uranium, copper and manganese. These elements are likely naturally sourced. We found …

Flexural Rigidity Estimation Using Noisy Static Influence Lines, Yasha Hajizeinalibiouki

Civil and Environmental Engineering Theses and Dissertations

Society depends on critical infrastructure to support everyday activities. Even as critical components of civil infrastructure approach and exceed their design lives, demand on these structures continues to increase. In light of the need for managing aging infrastructure, several opportunities exist for research that can aid infrastructure managers in significant the challenge of detecting, classifying, and mitigating structural impairments. This dissertation presents a novel framework for impairment detection through the capture and utilization of deformation influence lines for flexural rigidity estimation on Euler-Bernoulli beams. In this research study, mechanical theory, a computer-vision algorithm, and multiple numerical methods are integrated to …