Engineering Commons^™

Water Vapor Movement In Freezing Aggregate Base Materials, Maile Anne Rogers

Theses and Dissertations

The objectives of this research were to 1) measure the extent to which water vapor movement results in water accumulation in freezing base materials; 2) evaluate the effect of soil stabilization on water vapor movement in freezing base materials; 3) determine if the corresponding changes in water content are sufficient to cause frost heave during winter; 4) determine if the corresponding changes in water content are sufficient to cause reductions in stiffness during spring; 5) evaluate relationships between selected material properties, freezing conditions, and the occurrence and impact of water vapor movement; and 6) numerically simulate heat and water movement …

Condition Assessment Of Decommissioned Bridge Decks Treated With Waterproofing Membranes And Asphalt Overlays, Eric Scott Sumsion

Theses and Dissertations

The objective of this research was to assess the condition of four decommissioned bridge decks treated with waterproofing membranes and asphalt overlays following the completion of their service lives. Large samples were cut from each of the bridge decks immediately prior to demolition and taken to the Brigham Young University Highway Materials Laboratory, where extensive sampling and testing was performed. Methods used to evaluate the condition of the bridge deck samples included visual inspection, hammer sounding, Schmidt rebound hammer testing, resistivity testing, half-cell potential testing, linear polarization testing, cover depth measurement, and chloride concentration measurement. The samples were removed from …

Developing Guidelines For Including Mobility-Based Performance Specifications In Highway Construction Contracts, Shawn J. Larson

Theses and Dissertations

Construction zones can greatly affect the traffic flow on roadways, especially when lane closures are required. Traditionally, the Utah Department of Transportation (UDOT) has used traffic management specifications that only allow lane closures and road work to be done during predetermined hours or specifications that require a certain number of lanes to be open at all times. Recently, mobility-based work-zone traffic flow maintenance has been considered. This method requires continuous monitoring of mobility-based performance data and a mechanism to send alerts to the contractors when the mobility data does not meet the standards set by the specifications. UDOT recently tested …

Frost Susceptibility Of Base Materials Treated With Asphalt Emulsion, Noelle Anderson

Theses and Dissertations

The objective of this research was to investigate emulsion-treated base (ETB) frost susceptibility in terms of both freeze-thaw cycling and frost heave. The research performed in this study involved laboratory testing of ETB materials sampled from both the Redwood Road and 7800 South reconstruction projects in northern Utah. The effects of freeze-thaw cycling were evaluated by comparing the stiffness and strength of tested specimens to the same properties of control specimens not subjected to freeze-thaw cycling. Frost heave testing enabled evaluation of the effects of emulsion content and degree of curing on the volumetric stability of ETB materials during sustained …

The Performance Of Risk Management And Innovation In Construction Manager/General Contractor Delivery In Civil Construction Applications, Rebecca M. Owens

Theses and Dissertations

Project teams that deliver high risk, complex projects in the civil construction industry need tools to enable successful delivery. Construction Manager/General Contractor (CM/GC) is an innovative alternate delivery method, providing one such a tool. CM/GC furnishes public agencies with an attractive option for delivering projects in a less adversarial and more constructive manner by involving the contractor during design. The sophisticated public owner does not have to relinquish control of the details of the design in order to accelerate the schedule or see the benefits of real-time cost estimating data. There are also significant cost and schedule benefits with not …

Numerical Modelling Of Downburst Interaction With Bluff Body, Aditi Jog

Electronic Thesis and Dissertation Repository

The objective of this study is to investigate the interaction of a bluff body with a downburst flow. Numerical investigation of the flow field using CFD analysis was carried out for three different downburst sizes (h/d=1, 2, 4) under suitable boundary conditions subjected to constant jet velocity. The downburst-structure interaction study was conducted for two jet diameters (h/d=1 and 4) and two radial locations from the downburst center.

The results showed that the downburst size greatly dominates the intensity of the flow. The largest downburst resulted in the highest velocity magnitude near the ground and also covered a larger area …

Introducing The Vuepod: Development And Testing Of A Low-Cost Large-Scale Stereoscopic Immersive System Using 3d Lcd Televisions, Shane Makana Hayden

Theses and Dissertations

3D immersive visualization systems, or CAVEs™, have found wide adoption for use in geosciences, planetary science, medical research, and computer science. However, much of the potential for such systems in practical civil and environmental engineering settings has been severely limited due to 1) extreme costs in both hardware and software; 2) immobility due to calibration and darkroom requirements; and 3) extensive and expensive manpower requirements for both operation and maintenance. This thesis presents the development and testing of a new mobile low-cost immersive stereo visualization system -- the "VuePod" -- that attempts to address these challenges through the use of …

Specimen Size Effect On Shear Behavior Of Loose Sand In Triaxial Testing, Tarek Omar

Electronic Thesis and Dissertation Repository

Triaxial tests are widely used to determine the behavior and strength characteristics of soils without due attention to the differences in specimen size. Several drained and undrained monotonic triaxial compression shear tests are performed on three different specimen sizes of the same sand to investigate the influence of specimen size and scale effect on the shear behavior. The test results indicate that the behavior of loose sand is strongly influenced by the specimen size, with larger specimens exhibiting a stiffer behavior during isotropic compression, and mobilizing smaller shear strengths and effective friction angles. Triaxial testing also involves many sources of …

Experimental Modeling Of Wind Farm Topography And Canopy, Dan S. Parvu

Electronic Thesis and Dissertation Repository

As an important renewable energy source for electricity generation, wind energy must rely on efficient and accurate wind resource assessment for the siting and the design of wind farms. Traditionally relying on numerical modeling, current wind farms built in Canada, notably, experience an under-performance in terms of power generation. This work studies an alternative approach to wind farm modeling through experimental wind tunnel testing.

The objective of the work is to develop methodologies on how topographic and forest canopy models should be built as scale models of full scale wind farms. The models developed are validated by comparing the data …

Structural Analysis And Optimization Of Skyscrapers Connected With Skybridges And Atria, Amy Jean Taylor Mccall

Theses and Dissertations

Skybridges and atria between buildings are becoming more and more popular. Most current skybridge connections are either roller or rigid-connections. This dissertation presents an investigation of the structural analysis and optimization of skyscraper systems with hinge-connected skybridges, and compares the results to skyscraper systems with roller-connected skybridges and to skyscraper systems without skybridges altogether. Also presented is an investigation of the structural analysis and optimization of skyscrapers both with and without atria between the buildings. It was assumed that the atria envelope was constructed with cushions made from lightweight, transparent, and flexible Ethylene Tetrafluoroethylene (ETFE). A simplified skyscraper skybridge model …

Investigation Of Hollow Bar Micropiles In Cohesive Soil, Osama F. El Hadi Drbe

Electronic Thesis and Dissertation Repository

Micropiles are used in various applications, including low capacity micropile networks, underpinning and seismic retrofitting of existing foundations and high capacity foundations for new structures. They facilitate fast installation with a high degree of ground improvement. The current Federal Highway Administration (FHWA) design guidelines designate hollow bar micropiles as Type B micropiles, even though their construction technique is different than typical Type B, which results in overly conservative design. In addition, the current practice for construction of hollow bar micropiles is limited to drilling bit/hollow bar diameter ratio of 2.5 or less. In this thesis, full-scale load tests were conducted …

Treatment Of Combined Sewer Overflows Using Ferrate (Vi), Rohan Gandhi

Electronic Thesis and Dissertation Repository

Prevention of pollution from combined sewer overflows (CSOs) is currently a major concern due to their impact on aquatic and human environment. With the stringent regulations related to the CSOs treatment, it is necessary to develop an efficient, fast and low cost treatment technique that meets the applicable criteria. In this work, the comprehensive study was done to determine the efficiency of ferrate (VI) for the treatment of CSOs. At a Fe (VI) dose of 0.24 mg/l, TCOD, SCOD, TBOD₅, SBOD₅, TSS, VSS, TP, TN and soluble TN removal efficiencies of 71%, 75%, 69%, 68%, 72%, …

Cyclic And Post-Cyclic Response Of Silt And Sandy Silt Soils, Ali El Takch

Electronic Thesis and Dissertation Repository

A series of cyclic and monotonic constant-volume ring shear tests were carried out to determine the cyclic and post-cyclic response of silts and sandy silts with 25% and 50% sand. The elastic soil behavior at very small shear strain (γ < 10^-4%) was investigated through shear wave velocity (Vs) measurements using bender elements at vertical stresses ranging from 50 to 300 kPa, while strain-controlled constant volume cyclic ring shear tests were conducted to establish shear modulus (G) and damping ratio (D) at larger shear strain amplitudes (γ > 0.01%). Liquefaction and strain-softening occurred at excess pore water pressure ratios (r_{u …}

Rural To Urban Intercity Transit User Characteristics Analysis, Demand Estimation And Network Design, Hongtai Yang

Doctoral Dissertations

Rural transit always plays a critical role in transporting rural residents, especially the ones who do not have a car, cannot drive, or choose not to drive. Intercity bus (ICB), deviated fixed route transit (DFRT) and demand responsive transit (DRT) are three major modes of rural public transportation. Although there are more DFRT and DRT service providers and services in the US, due to institutional issues, there are much more studies about ICB than DFRT and DRT. Meanwhile, state governments are struggling on how to improve the rural transit system with limited budget. This dissertation is aimed to fill the …

Bond Performance Of High-Capacity Strands In High Strength Concrete, Xin Jiang

Doctoral Dissertations

18-mm-diameter (0.7-in.) strand has the ability to introduce almost twice the prestressing force of 13-mm-diameter (0.5-in.) strand and 135% of the prestressing force of 15-mm-diameter (0.6-in.) strand, which could result in a significant increase in the span capacity of the current AASHTO bulb tee girders without having to modify the sections or acquire new forms. To date, the information regarding the bond performance of 18-mm-diameter (0.7-in.) prestressing strand is very limited, preventing its application despite its attractive high-strength. Also, our understanding of the bond mechanism is incomplete and non-quantitative; a rational understanding of the bond mechanism would help predict the …

Bedload Transport Sampling, Characterization And Modeling On A Southern Appalachian Ridge And Valley Stream, Patrick Lasater Mcmahon

Doctoral Dissertations

Estimates of bedload transport rates developed from existing transport models are notoriously inaccurate(Wilcock 2001). The gravel bed models addressed in this study include the Meyer-Peter and Muller; Parker, Klingeman, and McLean; and Wilcock two-fraction models. The question of whether or not these models predict bedload transport rates in a Southern Appalachian Ridge and Valley stream is complicated by the fact that these models have only been previously assessed in terms of their agreement with bedload transport rates measured in the Western regions of the U.S. Further, due to the strongly non-linear form of bedload transport models discrete errors and cumulative …

Effects Of Data Resolution And Human Behavior On Large Scale Evacuation Simulations, Wei Lu

Doctoral Dissertations

Traffic Analysis Zones (TAZ) based macroscopic simulation studies are mostly applied in evacuation planning and operation areas. The large size in TAZ and aggregated information of macroscopic simulation underestimate the real evacuation performance. To take advantage of the high resolution demographic data LandScan USA (the zone size is much smaller than TAZ) and agent-based microscopic traffic simulation models, many new problems appeared and novel solutions are needed. A series of studies are conducted using LandScan USA Population Cells (LPC) data for evacuation assignments with different network configurations, travel demand models, and travelers’ compliance behavior.

First, a new Multiple-Source-Nearest-Destination Shortest Path …

Investigation Of Asphalt Pavement Mixture Blending Utilizing Analytical Chemistry Techniques, Benjamin Frank Bowers

Doctoral Dissertations

The use of Reclaimed Asphalt Pavement (RAP) in new pavement mixtures is a topic of interest throughout the transportation industry and academia due its economic and environmental implications. There is concern however about how well the binder from the RAP blends with new, virgin binder when the mixture is created. Insufficient blending of the aged and unaged binders may compromise the long-term pavement performance. In this study, an enhanced staged extraction method is coupled with two chemical testing techniques to develop a novel approach for evaluating blending efficiency from a qualitative and quantitative perspective: Gel Permeation Chromatography (GPC) and Fourier …

Seasonal Change In Bacteria Levels And Eluent Comparison For The Enumeration Of E. Coli And Enterococci From Recreational Beach Sand, Kyle Hines

Theses and Dissertations

Research into the causes of bacterial contamination of recreational beaches has been increasing. Many researchers are now looking to enumerate bacteria from beach sands in order to find the connections between the water and sand quality. As the number of these studies increase, there is a need to determine a standard procedure for enumerating bacteria from sand. The eluent that a researcher chooses could impact the results that they obtain due to ionic strength. The first part of this paper compares the E. coli and Enterococci counts of identical sand samples using phosphate buffered saline and distilled water as eluents. …

Assessing Trichloromethane Formation And Control In Algal-Stimulated Waters Amended With Nitrogen And Phosphorus, Clinton Mash

Graduate Theses and Dissertations

Nitrogen (N) and phosphorus (P) enrichments can stimulate algal growth in drinking water sources, which can cause increased production of disinfection byproduct (DBP) precursors. However, the effect of systematic N and P enrichments on DBP formation and control has not been adequately studied. In this work, we enriched samples from a drinking water source - sampled on April 5, May 30, and August 19, 2013 - with N and P to stimulate algal growth at N:P ratios covering almost five orders of magnitude (0.2-4,429). To simulate DBP-precursor removal processes at drinking water treatment plants (DWTPs), the samples were treated with …

Assessing The Impact Of Chlorine Residual On Trihalomethane And Haloacetonitrile Formation Under Chlorination And Chloramination Disinfection Regimes, Thien Duc Do

Graduate Theses and Dissertations

A disinfection byproduct (DBP) formation potential (FP) test can be used to indirectly measure the concentration of DBP precursors in natural waters, permitting assessment of various DBP-related treatment processes and control strategies. While these tests require a 7-day chlorine residual (CR) between 3-5 mg L^-1 as Cl², it is not well known if this recommended residual corresponds to the true DBPFP (i.e., the maximum concentrations) for trihalomethanes (THMs) and haloacetonitriles (HANs). In this study, THMs and HANs were quantified as a function of CR under three common disinfection regimes: (1) free chlorine at pH 7.0 (FC7), (2) …

Development Of Novel Bioelectrochemical Systems For In Situ Nitrate Removal From Groundwater, Yiran Tong

Theses and Dissertations

This study aims to develop new approaches for in situ nitrate removal from groundwater by using bioelectrochemical systems (BES). BESs employ bioelectricity generated from organic compounds to drive nitrate moving from groundwater into the electrode chamber and reduce nitrate to nitrogen gas by heterotrophic denitrification. In first phase experiments, nitrate ions were driven into the anode chamber of a de-coupled reactor, whose electrode chambers were separated, where heterotrophic denitrification took place with organic reduction. It was proved that by applying additional electrical potential at 0.8V, the reactor could achieve highest removal rate of 208.2±13.3 g NO3--N/m3/d, when initial nitrate concentration …

Mechanical Properties And High-Temperature Performance Of A Polyester Resin Modified Using Fgd Gypsum, Morteza Janbaz

Theses and Dissertations

High-temperature performance of polyester- based construction materials is an important consideration when fire safety is a concern. These materials are typically used as non-structural components of buildings and other structures. Structural retrofits using fiber-reinforced polymer (FRP) composites are also gaining popularity. However, a major disadvantage of polymer- based materials (including FRP composites) is their flammability and toxic gas generation at high temperatures. The main objective of this research effort was to determine the mechanical properties and high-temperature performance of a polyester resin modified with various amounts of an industrial by-product additive. The additive used was Flu-Gas Desulfurization (FGD) gypsum, which …

Predictive Maturity Of Inexact And Uncertain Strongly Coupled Numerical Models, Ismail Farajpour

All Dissertations

The Computer simulations are commonly used to predict the response of complex systems in many branches of engineering and science. These computer simulations involve the theoretical foundation, numerical modeling and supporting experimental data, all of which contain their associated errors. Furthermore, real-world problems are generally complex in nature, in which each phenomenon is described by the respective constituent models representing different physics and/or scales. The interactions between such constituents are typically complex in nature, such that the outputs of a particular constituent may be the inputs for one or more constituents. Thus, the natural question then arises concerning the validity …

Recovering Bioresources From Integrated Photo-Bioelectrochemical System, Li Xiao

Theses and Dissertations

Compared to traditional wastewater treatment technologies, the electricity generation is one of the most important advantages of bioelectrochemical systems (BES). However, due to its high cost and low energy production, BES technologies are still far away from feasible application. The main purpose of this work was to investigate ways to improve the electricity generation and reduce the cost of BES technologies. We focused on microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) as two representative BES technologies. In order to improve the energy performance of MFCs, an accurate evaluation of the energy is necessary. However, the common evaluation methods …

Investigation Of Application Niche For Sustainable Wastewater Treatment Using Microbial Fuel Cells, Patrick Thomas Kelly

Theses and Dissertations

Microbial fuel cells represent a sustainable wastewater treatment technology due to its simultaneous treatment of contaminants and electricity production. Selection of suitable substrates is important to identifying proper application of microbial fuel cell (MFC) technology. In this work, four identical MFCs were used to treat the wastes sampled from different stages of a cheese wastewater treatment process, and both treatment performance and energy balance were examined. The two MFCs treating liquid wastes achieved more than 80% removal of total chemical oxygen demand (TCOD), while the other two MFCs fed with sludge or cheese whey removed about 60% of TCOD. The …

Biogeochemical Modeling Of The Response Of Forest Watersheds In The Northeastern U.S. To Future Climate Change, Afshin Pourmokhtarian

Dissertations - ALL

In this dissertation I assessed the potential hydrochemical responses of future climate change conditions on forested watersheds in the northeastern U.S. using climate projections from several atmosphere ocean general circulation models (AOGCMs) under different carbon dioxide (CO2) emissions scenarios. The impacts of changing climate on terrestrial ecosystems have been assessed by observational, gradient, laboratory and field studies; however, state-of-the-art biogeochemical models provide an excellent tool to investigate climatic perturbations to these complex ecosystems. The overarching goal of this dissertation was to apply a fully integrated coupled hydrological and biogeochemical model (PnET-BGC) to evaluate the effects of climate change and increasing …

Standardized Longitudinal Connection Detail For Decked Precast Prestressed Concrete Girders, Ramzi Muftah Ali Abduallah

Masters Theses

The use of decked precast prestressed concrete girders (DPPCG) is becoming popular in accelerated bridge construction. DPPCGs are assembled and connected on site using grout or concrete longitudinal connections. The durability performance of these connections is a concern. The objective of this research is to document the longitudinal connection behavior with respect to its design parameters, and establish a process for developing a standardized connection detail considering the demands due to live load and temperature gradient (TG) load. In order to demonstrate this process, decked bulb-tee and decked box-beam girders were considered. Finite element models, under various types and levels …

An Analysis On Soil Properties On Predicting Critical Hydraulic Gradients For Piping Progression In Sandy Soils, Tammy Jacobson

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Piping is a form of internal erosion in which soil particles are eroded at a seepage exit location due to the forces imposed on the particles by seeping water. Laboratory testing was performed on a variety of soils in order to assess a correlation between unit weight, angle of internal friction, grain size, gradation, and void ratio and the critical hydraulic gradient at which piping initiates and progresses. A multi-variable regression analysis was used to form equations to predict critical hydraulic gradient based upon each of these soil parameters. Variations in the accuracy of these equations are thought to be …

Sediment Microbial Fuel Cell As Sustainable Power Resource, Ananta Kothapalli

Theses and Dissertations

This research demonstrates that Ceratophyllum demersum a root less non vascular aquatic plant has negatively affected the power generation from a Sediment Microbial Fuel cell (SMFC). In SMFC the reduced organic matter in the sediment in water produces electrons, which reduces oxygen. Whereas in Plant SMFC continuous supply of organic matter to the anode is done by rhizodeposition (root exudates). Six SMFCs were run for more than 3 months to see the effect of plants, pH and temperature on power generation. Out of six only two SMFC showed stable data. The maximum power density 18 ± 1mW/m3 was generated from …