Civil and Environmental Engineering Commons^™

Proposed Astm Standard For The Stokoe-Type Resonant Column Torsional Shear Device, Anh Tuan Tran

Graduate Theses and Dissertations

Resonant Column Torsional Shear (RCTS) testing has become one of the most commonly used methods for determining laboratory soil stiffness and soil damping. The RCTS test has been accepted and is commonly utilized during the permitting of new nuclear facilities. However, there is still no available public standard for performing RCTS tests using the Stokoe-type device. Therefore, an ASTM standard for calibration and performance of RCTS tests using the Stokoe-type RCTS device is presented herein. Data collected using the Stokoe-type RCTS devices at the University of Arkansas (UofA) and at the Norwegian Geotechnical Institute (NGI) also aided in the development …

Testing And Development Of Pre-Stressed Cfrp Retrofit Strategies For Controlling Fatigue Cracking In Steel Waterway Lock Gate Structures, Maggie Langston

Graduate Theses and Dissertations

Steel waterway lock gates across the national inland waterway transportation network are reaching and exceeding their intended service life, often experiencing component failures that lead to service interruptions. Unscheduled maintenance and repair of lock gates can be expensive and cause economic ripples throughout the entire inland waterway network. These lock gate component failures are often caused by fatigue cracking from repeated loading during operation. This thesis develops and tests a prestressed carbon fiber reinforced polymer (CFRP) fatigue retrofit for controlling fatigue demands within lock gate components. The study expands upon a recent analytical work by Lozano (2017) by experimentally investigating …

Barge Prioritization, Assignment, And Scheduling During Inland Waterway Disruption Responses, Liliana Delgado-Hidalgo

Graduate Theses and Dissertations

Inland waterways face natural and man-made disruptions that may affect navigation and infrastructure operations leading to barge traffic disruptions and economic losses. This dissertation investigates inland waterway disruption responses to intelligently redirect disrupted barges to inland terminals and prioritize offloading while minimizing total cargo value loss. This problem is known in the literature as the cargo prioritization and terminal allocation problem (CPTAP). A previous study formulated the CPTAP as a non-linear integer programming (NLIP) model solved with a genetic algorithm (GA) approach. This dissertation contributes three new and improved approaches to solve the CPTAP.

The first approach is a decomposition …

Liquefaction-Induced Dragload And/Or Downdrag On Deep Foundations Within The New Madrid Seismic Zone, Ishimwe Elvis

Graduate Theses and Dissertations

Deep foundation elements are typically used to transfer structural loads for multi-story buildings and large-span bridges to a competent soil layer when 1) the soil close to the ground surface has no sufficient bearing capacity, and when 2) liquefiable soils are encountered. The majority of the bridges constructed within seismic zones rely upon the stability of earthen embankments and deep foundation that are installed above or within liquefiable soil deposits. Despite large factor of safety values or different load and resistance factors being used to adequately design deep foundations within seismic areas, soil liquefaction may cause extensive damage to the …

The Intrinsic Properties Of Reconstituted Soils, Nabeel Shaker Mahmood

Graduate Theses and Dissertations

Reconstituted specimens are often utilized to characterize engineering properties of cohesive soils. A series of undrained triaxial tests were conducted on reconstituted soil specimens to evaluate 1) the influence of stress path, 2) the intrinsic shear strength behavior, and 3) the small-strain characteristics. The stress path tests were conducted on kaolinite specimens reconstituted from slurries with water content values of one and one-half times the liquid limit of the soil (1.5LL). To evaluate the intrinsic undrained shear strength and the intrinsic small-strain properties, the triaxial tests were performed on kaolinite and illite specimens that were reconstituted at two levels of …

Direct Potable Reuse Of Wastewater, Molly Churchwell

Chemical Engineering Undergraduate Honors Theses

Water is essential to our societies and mankind. Currently, 844 million people across the globe lack access to potable water. By 2025, it is projected that half of the world population will be in a region of water stress.5 The water crisis is often thought of as a problem limited to places that have always struggled to have clean water, but it is now affecting new areas such as the southwest United States. With increasing population demands and drought, the feasibility of direct potable reuse (DPR) of wastewater is being considered. According to an EPA report in 2017, there are …

Investigating Initial Interactions Between Silver Nanoparticles And Wastewater, Casey Gibson

Biological and Agricultural Engineering Undergraduate Honors Theses

The use of nanoparticles (NPs) has increased exponentially in the last 15-20 years, especially in the consumer market. NPs are currently found in over 1800 commercial products, including cosmetics, clothing, packaging, and toys. As a result, NPs can enter the environment via wastewater (WW) streams, leading to new challenges in WW treatment. This study focuses on the initial fate of silver nanoparticles (AgNPs) in WW. The AgNP interaction including aggregation and dissolution in both synthetic and real WW were studied. Real WW was collected from the primary-clarifier, secondary-clarifier, and effluent WW streams at two local WW treatment plants (Westside and …

Chloride Salt Inhibition On Lipid Production In Wastewater-Grown Algae For Biofuel Production, Will Richardson

Biological and Agricultural Engineering Undergraduate Honors Theses

Algae are increasingly being recognized as useful organisms for many applications in today’s world. Their ability to remove nitrogen, phosphorus, and trace metals from water while adding oxygen to water makes them an attractive tertiary treatment technology in municipal wastewater treatment facilities. At the same time, algae produce lipids and carbohydrates that are useful for biofuel production, and they are not a human food crop unlike many biofuel feedstocks. In this study the effect of increased chloride concentrations in wastewater was assessed on the ability of two species of algae, Chlorella vulgaris and Scenedesmus dimorphus, to function as a …

Assessing Auto-Flocculation Of Microalgae In Wastewater Treatment, Alexander Parr

Biological and Agricultural Engineering Undergraduate Honors Theses

Biofuels produced from algae have the prospect to provide a cheap, carbon neutral alternative to fossil fuels. However, the high cost for harvesting algae limits its wide application, as the preferred algae strains for biofuel production are typically unicellular microalgae that do not settle in water very well. Recently, researchers have been focusing on developing a biological method to achieve the sedimentation of algae through flocculation. A recent study has concluded that introducing microalgae that self-flocculates increases the recovery of the desired microalgae, similar to the effect of using coagulant to flocculate the algae. This option can potentially be more …

Removal Of Carbamazepine From Drinking Water, Jordan Alex Gadberry, Adam Johnson, Juan Rodriguez, Paola Marrero-Rivera, Tom Krumpolc, Zach Wiese

Chemical Engineering Undergraduate Honors Theses

Due to the increasing prevalence of prescription medication over the past few decades, pharmaceuticals have accumulated in various water sources. This has become a public health concern because many pharmaceuticals have limited research on the effects of chronic low-level exposure. According to the World’s Health Organization (WHO), traces of pharmaceuticals products have been reported in different water sources such as surface waters, wastewater, groundwater, and drinking water.^[1] One pharmaceutical of interest that has been detected in water sources is carbamazepine. Carbamazepine (CBZ) is a common pharmaceutical prescribed for the treatment of seizure disorders, neuropathic pain, and various psychological disorders. …

Direct Potable Reuse Of Wastewater, Boyce Bethel

Chemical Engineering Undergraduate Honors Theses

Water is essential to our societies and mankind. Currently, 844 million people across the globe lack access to potable water. By 2025, it is projected that half of the world population will be in a region of water stress.⁵ The water crisis is often thought of as a problem limited to places that have always struggled to have clean water, but it is now affecting new areas such as the southwest United States. With increasing population demands and drought, the feasibility of direct potable reuse (DPR) of wastewater is being considered. According to an EPA report in 2017, there …

Direct Potable Reuse Of Wastewater, Aaron Henry, Molly Churchwell, Lauren Clark, Boyce Bethel, Dakota Rusk, Sabrina Castle

Chemical Engineering Undergraduate Honors Theses

Water is essential to our societies and mankind. Currently, 844 million people across the globe lack access to potable water. By 2025, it is projected that half of the world population will be in a region of water stress.5 The water crisis is often thought of as a problem limited to places that have always struggled to have clean water, but it is now affecting new areas such as the southwest United States. With increasing population demands and drought, the feasibility of direct potable reuse (DPR) of wastewater is being considered. According to an EPA report in 2017, there are …

Direct Potable Reuse Of Wastewater, Dakota Rusk, Molly Churchwell, Lauren Clark, Sabrina Castle, Boyce Bethel, Aaron Henry

Chemical Engineering Undergraduate Honors Theses

Water is essential to our societies and mankind. Currently, 844 million people across the globe lack access to potable water. By 2025, it is projected that half of the world population will be in a region of water stress. The water crisis is often thought of as a problem limited to places that have always struggled to have clean water, but it is now affecting new areas such as the southwest United States. With increasing population demands and drought, the feasibility of direct potable reuse (DPR) of wastewater is being considered. According to an EPA report in 2017, there are …

Direct Potable Reuse Of Wastewater, Lauren Clark

Chemical Engineering Undergraduate Honors Theses

Water is essential to our societies and mankind. Currently, 844 million people across the globe lack access to potable water. By 2025, it is projected that half of the world population will be in a region of water stress.⁵ The water crisis is often thought of as a problem limited to places that have always struggled to have clean water, but it is now affecting new areas such as the southwest United States. With increasing population demands and drought, the feasibility of direct potable reuse (DPR) of wastewater is being considered. According to an EPA report in 2017, there …

Direct Potable Reuse Of Wastewater, Sabrina Castle

Chemical Engineering Undergraduate Honors Theses

Water is essential to our societies and mankind. Currently, 844 million people across the globe lack access to potable water. By 2025, it is projected that half of the world population will be in a region of water stress.5 The water crisis is often thought of as a problem limited to places that have always struggled to have clean water, but it is now affecting new areas such as the southwest United States. With increasing population demands and drought, the feasibility of direct potable reuse (DPR) of wastewater is being considered. According to an EPA report in 2017, there are …

Development Of A Hydraulic Conductivity Placement Window Using Centrifuge Techniques, Greg Thomas

Civil Engineering Undergraduate Honors Theses

A centrifuge soil testing device, currently operated by researchers at the University of Arkansas, was used to develop a technique to determine a hydraulic conductivity placement window. The purpose of this research was to develop a placement window by means of a centrifuge instead of by means of a panel board. Soil specimens were created at standard PRcotor energy and at 50 percent of Standard Proctor energy at -3 percent of optimum, -1.5 percent of optimum, two specimens at optimum, +1.5 percent of optimum, and +3 percent of optimum water content. Values of hydraulic conductivity for the respective specimens were …

Development Of A Digital Rain-Sensing Irrigation Pump Controller And An Android Enabled Bluetooth Paddlewheel Flowmeter, Jayendra Mishra

Graduate Theses and Dissertations

For better irrigation efficiency, it is recommended that farmers track their water consumption to avoid over-irrigating. However, it is difficult to implement this as it is labor intensive to supervise pumps manually and available technologies require high investment. Therefore, a rain sensing pump controller for 3-phase electric irrigation pumps and a stand-alone portable Android enabled paddlewheel flowmeter has been developed to test their feasibility.

The pump timer is a retrofit device for irrigation pump panels. The controller allows an irrigator to start and stop the pump with less supervision. An infrared rain sensor is integrated with the controller to measure …

Essays On Applications Of Transportation Network Design And Optimization, Amirali Ghaharikermani

Graduate Theses and Dissertations

In this dissertation, we address different transportation problems. The three main outcomes are: designing a battery swap station network, studying gaps in Empty Container Management literature, designing a model with similar characteristics to the vehicle routing problem as well as implementation scenario for it to be applied for a real-world case.

For the designed battery swap station, a model is developed for customer demand satisfaction that permits construction of different types of BSS in the planning network. Our solution methodology is a Tabu Search algorithm combined with a dynamic programming initialization. Numerous tests showed that the proposed TS approach provides …

On The Fatigue Of Headed Shear Studs In Steel-Concrete Composite Bridge Girders, Brianna Laurene Ovuoba

Graduate Theses and Dissertations

Shear connectors are commonly used in steel bridges to join the concrete deck and steel superstructure, providing a mechanism for shear transfer across the steel-concrete interface. The most common shear connector is the headed shear stud. In the current AASHTO LRFD Bridge Specifications on composite design, shear stud fatigue often governs over static strength, and a large number of shear connectors often result. This dissertation investigates headed shear stud fatigue capacities and demands, and provides insight into conservancies in existing design specifications through examination of existing high-traffic bridge performance.

To investigate stud capacity, a total of six high-cycle fatigue tests …

Development Of An Internal Camera-Based Volume Determination System For Triaxial Testing, Sean Elliott Salazar

Graduate Theses and Dissertations

Accurate measurement of axial, radial, and volumetric strain parameters are critical to the understanding of phase relationships and the constitutive behavior for saturated and unsaturated soils. The use of photographic monitoring techniques for laboratory-based measurement of these parameters have become common. A novel technique that utilized camera instrumentation located within the triaxial testing cell was developed and validated. By placing the instrumentation inside of the cell, instead of the instrumentation being located outside of the cell, the technique eliminated cumbersome corrections required to account for optical distortions due to 1) the refraction of light at the confining fluid-cell wall-atmosphere interfaces, …

Cost-Savings Of Implementing Site-Specific Ground Motion Response Analysis In Design Of Mississippi Embayment Bridges, Ethan Ryan Benton Baker

Graduate Theses and Dissertations

Deep dynamic site characterization and a site-specific ground motion response analysis (SSGMRA) were conducted for a bridge site in Monette, Arkansas. The SSGMRA indicated the design acceleration response spectrum determined using the American Association of State Highway and Transportation Officials (AASHTO) general seismic procedure could be reduced by 1/3 for the short period range due to attenuation of the short-period ground motions. The steel girder pile-bent bridge, originally designed using the AASHTO general seismic design procedure, was redesigned using the updated seismic demands estimated from SSGMRA. A cost-savings analysis was then conducted to determine the potential savings associated with conducting …

An Evaluation Of Borehole Hydraulic Conductivity Equations And Field Determined Soil Water Characteristic Curves, Johnathan Dale Blanchard

Graduate Theses and Dissertations

The methods utilized to determine the hydraulic conductivity of compacted clay liners (CCLs) are of importance for safe guarding the environment from landfill leachate. Therefore, the methods utilized in the analysis of the Two Stage Borehole (TSB) test, as described in the ASTM D6391-11 (Method A, B, and C) standard, were evaluated. Data from hydraulic conductivity tests, as performed on three test pads, were utilized to review the ASTM D6391-11 equations. Additionally, two test pads were instrumented with volumetric water content and soil water matric potential sensors to facilitate the determination of field-obtained soil water characteristic curves (SWCCs) and hydraulic …

Automated Pin-Dot Marking Effects On A709-Gr50 Steel Plate Fatigue Capacity, Michael Andrew Noernberg

Graduate Theses and Dissertations

During fabrication of multi-piece steel bridge assemblies, markings are often made on the steel surface to identify/track individual pieces or to provide reference for fabrication layout or later erection. Automated marking methods such as computer numerically controlled (CNC) pin-dot marking offer fabrication efficiencies; however, for marked steel sections subjected to frequent or repeated loading (i.e. bridge girders) many code specifications require experimental testing to verify any marking effects on fatigue capacity. In this study, the effects of automated pin-dot markings on the fatigue capacity of A709-Gr50 bridge steel are experimentally investigated from 13 specimens considering 2 marking frequencies (corresponding to …

Evaluation Of Water Resources And Hydraulic Influences In The Restoration Of The Western Part Of The Mesopotamian Marshlands, Ali Kareem Al-Quraishi

Graduate Theses and Dissertations

The purpose of this study is to assess the water resources and water conveyance system of the western part of the Mesopotamian marshes (Al-Hammar marsh) as well as develop a water conveyance system to distribute water throughout the western Al-Hammar marsh. These processes are significant to identify the current restoration problems and help to create restoration strategies for the marsh. Also, proper management strategy to the Al-Hammar marsh is necessary to preserve the marsh ecosystem, irrigate lands, and provide domestic necessities in the villages.

The overall project is divided into three main chapters which address the current ecological and hydrological …

Dem Study Of A Single Stone Column In A Clayey Stratum, Anibal Enrique Santos

Graduate Theses and Dissertations

Aggregate piers are an alternative ground improvement technique used for improving the bearing capacity and reducing the total and differential settlement of foundations supported on compressible soils. The piers are composed of a series of vibrationally compacted aggregate lifts from a desired depth up to the finished foundation level. The shear strength of the coarse-grained material comprising an aggregate pier is defined by its internal friction angle. There are several factors affecting the friction angle of the granular material that include: confining stress, particle shape, relative density and particle distribution (gradation). These factors are not directly considered in the design …

Using Historic Pavement Performance Data To Identify And Select Sites For Asphalt Mixture Design Studies, Allyson Richey

Civil Engineering Undergraduate Honors Theses

Since 1997 Arkansas asphalt mixtures have been designed using a procedure commonly known as ‘Superpave’. In a traditional Superpave mix design, the design considers only traditional volumetric parameters; however, recent advances in mix design technology emphasize mixture’s ability to perform in its environment. There are numerous factors which affect the performance characteristics of an asphalt mix. Certainly, the asphalt binder’s performance is a critical variable in this system. Asphalt binders are sensitive to temperature, so much so that their primary parameter on which they are recommended is a function of both temperature and the geographic latitude in which the pavement …

Investigating Fate Of Silver Nanoparticles In Wastewater Biofilms, Connie Marie Walden

Graduate Theses and Dissertations

As industrial advances make everyday life easier for human kind, the processes by which we need to maintain sanitary conditions for both water and wastewater treatment will become increasingly complex. Innovations in food packaging and textile design incorporate engineered nanoparticles (ENPs) to increase antimicrobial properties of clothing, maintain product color, and keep food in packaging from spoilage. For most products, ENPs released will enter the sanitary sewer system, and ultimately wastewater treatment plants. Biofilms grow universally on surfaces where a protective layer of extracellular polymeric substances (EPS) shields attached cells from stressors. In wastewater treatment, complex biofilms are utilized as …

Development Of Pre-Stressed Retrofit Strategies For Mitigating Fatigue Cracking In Steel Waterway Lock Gate Components, Christine Michelle Lozano

Graduate Theses and Dissertations

Lock gates are an important part of the transportation infrastructure within the United States (US), having many economic, safety, and environmental benefits over rail and highway transportation systems. Unfortunately, many existing lock gates throughout the US have reached or exceeded their initial design life and require frequent repairs to remain in service. Unscheduled repairs often increase as gates age, having a local economic impact on freight transport which can create economic ripples throughout the nation. Fatigue and corrosion are key causes of unscheduled service interruptions, degrading lock gate components over time. Additionally, because lock gates are submerged during operation, crack …

Methodologies For Solving Integrated Transportation And Scheduling Problems, Fereydoun Adbesh

Graduate Theses and Dissertations

This research proposes novel solution techniques to optimize two real-world problems in the area of scheduling and transportation. We first consider a model for optimizing the operations of dredges. In this problem, scheduling and assignment decisions are integrated across a finite planning horizon. Additional constraints and problem elements explicitly considered include, but are not limited, to environmental work window restrictions, budget limitations, dredge operation rates and schedule-dependent dredge availability. Our approach makes use of Constraint Programming (CP) to obtain quality and robust solutions within an amount of time small enough to be useful to practitioners. The expanded feature set of …

Coupling K-12 Music Education With Science, Technology, Engineering And Math (Stem) Curricula: Implementation Of A Stemusic Outreach Program, Mallory Maestri

Civil Engineering Undergraduate Honors Theses

Many studies have investigated the effects of music on evoking human emotions and diverse types of brain responses. One study by Juslin and Vastfjall indicates that hearing music can stimulate brain stem reflexes, create emotional contagion, recall episodic memories and provoke visual imagery. Due to the influence music has on human brain waves, researchers have been studying the effect of music on enhancing the spatial abilities of young students. Science, Technology, Engineering and Math (STEM) professions rely heavily on spatial skills. Research on the connection of music with spatial skills proposes that when the brain processes rhythm a “mental rotation” …