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Full-Text Articles in Civil and Environmental Engineering

Comparing The Feasibility Of Cutting Thin-Walled Sections From Five Commonly Used Metals Utilizing Wire Electric Discharge Machining, Richard C. Stephenson Jul 2007

Comparing The Feasibility Of Cutting Thin-Walled Sections From Five Commonly Used Metals Utilizing Wire Electric Discharge Machining, Richard C. Stephenson

Theses and Dissertations

Wire Electric Discharge Machining (wire-EDM) is a non-traditional machining process. Controlled electric sparks are successively used to vaporize part of a workpiece along a programmed path in order to machine a desired part. Because there is no tool that comes in direct contact with the workpiece, it is possible to machine thin, delicate parts. This thesis was designed to observe and analyze the differences in cutting capabilities for a conventional wire-EDM machine when cutting thin-walled sections from five commonly used metals utilizing a variation of roughing and finishing passes. The five metals that were used in this study are: Aluminum …

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Friction Stir Welding Of High-Strength Automotive Steel, Eric Michael Olsen Jul 2007

Friction Stir Welding Of High-Strength Automotive Steel, Eric Michael Olsen

Theses and Dissertations

The following thesis is a study on the ability to create acceptable welds in thin-plate, ultra-high-strength steels (UHSS) by way of friction stir welding (FSW). Steels are welded together to create tailor-welded blanks (TWB) for use in the automotive industry. Dual Phase (DP) 590, 780, and 980 steel as well as Transformation-Induced Plasticity (TRIP) 590 steel with thicknesses ranging from 1.2 mm to 1.8 mm were welded using friction stir welding under a variety of processing conditions, including experiments with dissimilar thicknesses. Samples were tested under tensile loads for initial determination if an acceptable weld had been created. Acceptable welds …

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Mechanisms Causing Ferric Staining In The Secondary Water System Of Brigham City, Utah, Robert Derring Wallace May 2007

Mechanisms Causing Ferric Staining In The Secondary Water System Of Brigham City, Utah, Robert Derring Wallace

Theses and Dissertations

Water from Mantua reservoir has, during some years, exhibited reddish-brown staining when used by Brigham City for irrigation. I propose that seasonal fluctuations in the reservoir chemistry create an environment conducive to dissolving iron from the iron-rich sediments, which subsequently precipitate during irrigation, resulting in a staining event. These conditions are produced by chemical and biological decomposition of organic matter, coupled with isolation of the hypolimnetic waters, which results in seasonal low concentrations of dissolved oxygen in these waters. Under these specific circumstances, anaerobic conditions develop creating a geochemical environment that causes iron and manganese reduction from Fe(III) to Fe(II) …

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Dynamic Full-Scale Testing Of A Pile Cap With Loose Silty Sand Backfill, Immanuel Kaleoonalani Runnels May 2007

Dynamic Full-Scale Testing Of A Pile Cap With Loose Silty Sand Backfill, Immanuel Kaleoonalani Runnels

Theses and Dissertations

Pile caps are used in foundation design to aid multiple single piles to act as a pile group to resist lateral forces that may cause overturning moments. The pile cap and pile group resist these forces by pile-soil-pile interaction, base and side friction along the pile cap-backfill interface, and passive earth resistance. Passive earth resistance has been neglected in design due to a limited amount of full-scale testing. This research presents the results of a combination of hydraulic actuator and eccentric-mass shaker full-scale testing of a pile cap with loose silty sand backfill to quantify the contribution of the passive …

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Evaluation Of Laboratory Durability Tests For Stabilized Aggregate Base Materials, Matthew B. Roper May 2007

Evaluation Of Laboratory Durability Tests For Stabilized Aggregate Base Materials, Matthew B. Roper

Theses and Dissertations

The Portland Cement Association commissioned a research project at Brigham Young University to compare selected laboratory durability tests available for assessing stabilized aggregate base materials. The laboratory research associated with this project involved two granular base materials, three stabilizers at three concentration levels each, and three durability tests in a full-factorial experimental design. The granular base materials consisted of an aggregate-reclaimed asphalt pavement blend obtained from Interstate 84 (I-84) and a crushed limestone obtained from U.S. Highway 91 (US-91), while the three stabilizer types included Class C fly ash, lime-fly ash, and Type I/II Portland cement. Specimens were tested for …

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Investigation Of The Iron Oxidation Kinetics In Mantua Reservoir, Scott H. Lathen May 2007

Investigation Of The Iron Oxidation Kinetics In Mantua Reservoir, Scott H. Lathen

Theses and Dissertations

Irrigation of the municipal cemetery in Brigham City, Utah resulted in stained headstones in 2001 and 2002. The water used in the irrigation came from Mantua reservoir, a medium sized impoundment situated near the mouth of Box Elder Canyon. In order for Brigham City to establish a city wide secondary pressurized irrigation system using water from Mantua reservoir, the cause and the source of staining problem must be determined. Previous research (Wallace 2006) determined that the source of the staining was the reduction of iron found in Mantua Reservoir sediments that occurred when seasonal variations in the reservoir caused anaerobic …

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A Prioritization Process For Access Management Implementation In Utah, Kordel T. Braley May 2007

A Prioritization Process For Access Management Implementation In Utah, Kordel T. Braley

Theses and Dissertations

Appropriate access management techniques can improve the safety and efficiency of arterial roads. In order to determine which roads can most benefit by the implementation of access management techniques, a prioritization process was developed to recommend various access management treatments such as limiting access points, installing raised medians, and ensuring adequate signal spacing along corridors. To serve as the basis for the performance index, a database was created including identifying features, characteristics, and crash history for 175 arterial road segments on Utah state routes. Stepwise linear regression was applied to the data collected to determine which characteristics of the roads …

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Evaluation And Installation Guidelines For Advance Warning Signal Systems In Utah, Aaron Paul Jensen May 2007

Evaluation And Installation Guidelines For Advance Warning Signal Systems In Utah, Aaron Paul Jensen

Theses and Dissertations

Advance warning signals (AWS) provide information warning drivers in advance of the end-of-green phase for an approaching signalized intersection. The purpose of this research was to develop guidelines for the placement of AWS in Utah, both conditions to evaluate the need for AWS installation and guidelines for the AWS system design. The conditions were based on literature of other transportation agencies that had similar AWS systems and were developed using the Policy Delphi method. The Policy Delphi method is the development of a specific policy area through the means of discussion by a committee of experts correlating views and information …

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Use Of The Clegg Impact Soil Tester To Access Rutting Susceptiblity Of Cement-Treated Base Material Under Early Trafficking, Garth B. Reese May 2007

Use Of The Clegg Impact Soil Tester To Access Rutting Susceptiblity Of Cement-Treated Base Material Under Early Trafficking, Garth B. Reese

Theses and Dissertations

In order to avoid the occurrence of early-age damage, cement-treated base (CTB) materials must be allowed to cure for a period of time before the pavement can be opened to traffic. Trafficking of a CTB before sufficient strength gain has occurred can lead to marring or rutting of the treated layer. The specific objectives of this research were to examine the correlation between Clegg impact values (CIVs) determined using a heavy Clegg impact soil tester and rut depths measured in newly constructed CTB and subsequently establish a threshold CIV at which rutting should not occur.The experimental work included field testing …

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Statnamic Lateral Loading Testing Of Full-Scale 15 And 9 Group Piles In Clay, Rick Davon Broderick Mar 2007

Statnamic Lateral Loading Testing Of Full-Scale 15 And 9 Group Piles In Clay, Rick Davon Broderick

Theses and Dissertations

Studies of seismic and impact loading on foundation piles is an important and a focused interest in the engineering world today. Because of seismic and other natural events are unpredictable, uncontrollable and potentially unsafe it is a vital study to understand the behavior and relationship structures in motion have on there foundation. Statnamic Loading has become a popular method of studying this relationship in a controlled environment. Two groups of 9 and 15 driven hollow pipe piles were tested in saturated clay at the Salt Lake City Airport in July of 2002. The 9-pile group (3x3 configuration) was separated at …

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Objective Test Methods For Waveguide Audio Synthesis, Steven Gregory Wood Mar 2007

Objective Test Methods For Waveguide Audio Synthesis, Steven Gregory Wood

Theses and Dissertations

Acoustic Physical Modeling has emerged as a newer musical synthesis technique. The most common form of physical modeling synthesis in both industry and academia is digital waveguide synthesis. Commercially available for the past thirteen years, the top synthesizer manufacturers have chosen to include physical modeling synthesis in their top of the line models. In the area of audio quality testing, the most common tests have traditionally been group listening tests. While these tests are subjective and can be expensive and time-consuming, the results are validated by the groups' proper quality standards. Research has been conducted to evaluate objective testing procedures …

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Rectification Of 2-D To 3-D Finite Element Analysis In Buried Concrete Arches Under Discrete Loading, Adam D. Aagard Mar 2007

Rectification Of 2-D To 3-D Finite Element Analysis In Buried Concrete Arches Under Discrete Loading, Adam D. Aagard

Theses and Dissertations

Construction of tunnels and small- to medium-span bridges is a $12 billion per year industry in the United States, with a significant portion going into buried arch structures. Notwithstanding such expenditure, modern arch design and construction, in many cases, is highly conservative. This is because the closed-form solutions used by most designers today do not correctly account for soil-structure interaction. In fact, soil-structure interaction makes a closed form solution impossible. With the advent of high power computers in recent years, some designers have turned to finite element (FE)modeling as the main vehicle of analysis. Such numerical procedures provide an accurate …

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Lifetime Testing Of Wire-Grid Polarizers With Selected Over-Coatings, Steven J. Malone Mar 2007

Lifetime Testing Of Wire-Grid Polarizers With Selected Over-Coatings, Steven J. Malone

Theses and Dissertations

Wire-grid polarizers (WGPs) offer superior extinction, durability, angle of incidence, and heat resistance when compared to traditional organic polarizers. WGPs are found in applications such as high lumen lighting, laser devices, high lumen digital cinema projectors, LED packaging, and other integrated optical applications and are driving the need for over-coatings. Over-coating a WGP has been found to increase lifetime and durability. This research provides lifetime data on coated and uncoated WGPs. WGPs over-coated with 100nm of SiO2, 300nm of MgF2, and with no over-coating were heated to temperatures of 450 ºC, 500 ºC, and 550 ºC and timed until they …

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Early Age Assessment Of Cement Treated Materials, Tyler B. Young Mar 2007

Early Age Assessment Of Cement Treated Materials, Tyler B. Young

Theses and Dissertations

In order to avoid the occurrence of early-age damage, cement-treated base (CTB) materials must be allowed to cure for a period of time before the pavement can be opened to traffic. The purpose of this research was to evaluate the utility of the soil stiffness gauge (SSG), heavy Clegg impact soil tester (CIST), portable falling-weight deflectometer (PFWD), dynamic cone penetrometer, and falling-weight deflectometer for assessing early-age strength gain of cement-stabilized materials. Experimentation was performed at four sites on a pavement reconstruction project along Interstate 84 near Morgan, Utah, and three sites along Highway 91 near Richmond, Utah; cement stabilization was …

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Significant Trade Contractor Performance Characteristics As Evaluated By Big-D Construction, Conrad C. Johnson Mar 2007

Significant Trade Contractor Performance Characteristics As Evaluated By Big-D Construction, Conrad C. Johnson

Theses and Dissertations

The purpose of this research is to determine which aspects, other than price, of trade contractor performance are the most important to the general contractor, Big-D Construction. The impression a trade contractor leaves on the project manager and superintendent provides an indication of their performance. To determine what tasks trade contractors perform that most greatly impact overall perception of the general contractor's project manager and superintendent, hundreds of trade contractors were evaluated in ten separate categories and were then given an overall rating. The correlation between each category and the overall rating was found. The categories were then sorted from …

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Modeling Dissolved Oxygen In Lake Powell Using Ce-Qual-W2, Nicholas Trevor Williams Mar 2007

Modeling Dissolved Oxygen In Lake Powell Using Ce-Qual-W2, Nicholas Trevor Williams

Theses and Dissertations

Water quality models in the Colorado River Basin have been developed for the basin, river, and individual reservoirs. They are used to support water quality programs within the basin. The models are periodically reviewed and updated to improve the accuracy of simulations. Improving the usefulness of the Lake Powell model, one of the key reservoirs in the basin, is the subject of this study. Lake Powell is simulated using a hydrodynamic and water quality model, CE-QUAL-W2. Previously the model has been used at Lake Powell to simulate hydrodynamics, temperature, and total dissolved solids with a reasonable degree of accuracy. An …

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A Qualitative Study Of Selected Quality Knowledge And Practices In Guangdong Province, China, Tyler R. Thomas Mar 2007

A Qualitative Study Of Selected Quality Knowledge And Practices In Guangdong Province, China, Tyler R. Thomas

Theses and Dissertations

The manufacturing industry has become very competitive in today's global market environment. Many US companies are faced with the choice of keeping their manufacturing domestic or looking to low cost off-shore countries to take advantage of the labor costs differences. To gain an understanding of the state of manufacturing in China, a major focus in the manufacturing world today, this thesis was undertaken. This thesis presents the findings of research conducted in Guangdong Province, China in June - July, 2005. This research addressed customer focus, leadership and general manufacturing and quality knowledge and practices of small, medium and large sized …

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Calibration Procedure For A Microscopic Traffic Simulation Model, Carole Turley Mar 2007

Calibration Procedure For A Microscopic Traffic Simulation Model, Carole Turley

Theses and Dissertations

The inputs to a microscopic traffic simulation model generally include quantitative, but immeasurable data describing driver behavior and vehicle performance characteristics. Engineers often use default values for parameters such as car-following sensitivity and gap acceptance because it can be difficult to obtain accurate estimates for these parameters. While recent research has indicated that the accuracy of a simulation model can significantly improve if driver behavior parameters are calibrated to local data, this is not a typical practice. Manual calibration of these parameters is often too time-consuming to be cost-effective. Researchers have applied automated calibration procedures using genetic algorithms to these …

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Parameter Importance Of An Analytical Model For Transport In The Vadose Zone, Tanner Hans Bushnell Mar 2007

Parameter Importance Of An Analytical Model For Transport In The Vadose Zone, Tanner Hans Bushnell

Theses and Dissertations

The American Society of Testing and Materials (ASTM) has established a three tier risk-based corrective action (RBCA) program for cleaning up petroleum release sites, which is supported by the Environmental Protection Agency. RBCA programs make the cleanup of spill sites more efficient by requiring additional site information only when a more accurate risk assessment is needed. For spill sites that do not pass the first tier general assessment, a Tier 2 evaluation involving site specific information and screening level models to assess the potential risk must be conducted. Screening level models generally require site specific input parameters. To increase efficiency …

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Culvert Hydraulics: Comparison Of Current Computer Models, Elizabeth Anne Thiele Mar 2007

Culvert Hydraulics: Comparison Of Current Computer Models, Elizabeth Anne Thiele

Theses and Dissertations

The hydraulic analysis of culverts is complicated when using hand calculations. Fortunately, several computer programs are available to assist in analyzing culvert hydraulics, some of which include HY-8, Fish X-ing, Broken-back Culvert Analysis Program (BCAP), Hydraflow Express, Culvert Master, Culvert, and Hydrologic Engineering Center River Analysis System (HEC-RAS). While all of these programs can simulate the behavior of flow through a culvert, slightly different methodologies are utilized among the programs to complete a full hydraulic analysis, resulting in different predictions for headwater depth, flow control, and outlet velocities. The purpose of this paper is to compare (1) the available hydraulic …

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Spot Friction Welding Of Ultra High-Strength Automotive Sheet Steel, Jack H. Sederstrom Mar 2007

Spot Friction Welding Of Ultra High-Strength Automotive Sheet Steel, Jack H. Sederstrom

Theses and Dissertations

Spot friction welding (SFW) was performed on ultra high strength steel (UHSS) steel sheet commonly used in automobile manufacturing. Alloys studied included DP780, DP780EG, DP980, and DF140T sheet steel of varying thickness from 1.2 mm to 1.4 mm. Welding was accomplished using a PCBN standard tool. Weld strengths were then compared to a proposed AWS standard. Initial hardness readings were taken in cross sectioned samples. Grain structure in a SFW is presented. Resistance spot welds were created in three steels. This study focuses on the strength of SFW joints as compared to traditional resistance spot welding (RSW) in welding like …

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Effect Of Initial Surface Treatment Timing On Chloride Concentrations In Concrete Bridge Decks, Aimee Worthen Birdsall Jan 2007

Effect Of Initial Surface Treatment Timing On Chloride Concentrations In Concrete Bridge Decks, Aimee Worthen Birdsall

Theses and Dissertations

Bridge engineers and managers in coastal areas and cold regions frequently specify the application of surface treatments on concrete bridge decks as barriers against chloride ingress. In consideration of concrete cover thickness and the presence of stay-in-place metal forms (SIPMFs), the objective of this research was to determine the latest timing of initial surface treatment applications on concrete bridge decks subjected to external chloride loading before chlorides accumulate in sufficient quantities to initiate corrosion during the service life of the deck. Chloride concentration data for this research were collected from 12 concrete bridge decks located within the I-215 corridor in …

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Design And Construction Of Pavements In Cold Regions: State Of The Practice, Brad Steven Smith Dec 2006

Design And Construction Of Pavements In Cold Regions: State Of The Practice, Brad Steven Smith

Theses and Dissertations

The effects of frost action introduce many challenges in the design and construction of roadways in cold regions throughout the United States. The penetration of frost into pavement structures can lead to differential frost heave during winter and thaw weakening during spring. Both of these damage mechanisms lead to premature pavement distress, structural deterioration, and poor ride quality. Because the availability of naturally occurring non-frost-susceptible pavement base materials is rapidly diminishing in many areas while project budgets remain largely inadequate, pavement engineers are utilizing alternative materials and techniques to minimize such damage. The purpose of this research was to investigate …

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An Analysis Of The Accounting Methods Used By Builders Producing Twenty-Five Or Fewer Homes Per Year, David Andrus Dec 2006

An Analysis Of The Accounting Methods Used By Builders Producing Twenty-Five Or Fewer Homes Per Year, David Andrus

Theses and Dissertations

Accounting plays a crucial role in the success of any business, but it is particularly vital in the construction industry, a complex field that typically requires the coordination of multiple subcontractors and multiple jobs in any given year. Although small-volume home builders make up 70 percent of the membership of the National Association of Home Builders (NAHB), a trade association of the home building industry, little is known about the accounting practices of these builders. This thesis undertook to study the accounting practices of small-volume home builders. Small-volume home builders were defined as those producing 25 homes or fewer in …

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Information Infrastructure For Integrated Ecohydraulic And Water Resources Modeling And Assessment, R. Wallace, K. Pathak, M. Fife, Norman L. Jones, J. P. Holland, D. Stuart, J. Harris, C. Butler, D. R. Richards Dec 2006

Information Infrastructure For Integrated Ecohydraulic And Water Resources Modeling And Assessment, R. Wallace, K. Pathak, M. Fife, Norman L. Jones, J. P. Holland, D. Stuart, J. Harris, C. Butler, D. R. Richards

Faculty Publications

Watershed management increasingly requires ecohydraulic modeling and assessment within a regional context, rather than on a project-by-project basis. Such holistic modeling and assessment require evaluation capabilities across multiple temporal and spatial scales. Thus, modeling and assessment tools must be integrated in a scientifically and computationally effective infrastructure. The US Army Engineer Research and Development Center, in concert with the Hydrologic Engineering Center and its academic partners, including Brigham Young University, is establishing a comprehensive set of hydroinformatics modeling and assessment tools for ecohydraulic and water resources management applications, all linked based on a common data and information infrastructure. This paper …

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Utah Commercial Motor Vehicle Weigh-In-Motion Data Analysis And Calibration Methodology, Luke W. Seegmiller Nov 2006

Utah Commercial Motor Vehicle Weigh-In-Motion Data Analysis And Calibration Methodology, Luke W. Seegmiller

Theses and Dissertations

In preparation for changes in pavement design methodologies and to begin to assess the effectiveness of the weigh-in-motion (WIM) system in Utah, the Utah Department of Transportation (UDOT) contracted with a Brigham Young University (BYU) research team to conduct an evaluation of their commercial motor vehicle (CMV) data collection system statewide. The objective of this research was to evaluate the CMV data collection program in the state of Utah and to make limited recommendations for potential improvements and changes that will aid in more detailed and accurate CMV data collection across the state. To accomplish the research objectives, several tasks …

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Consolidation And Interweaving Of Composite Members By A Continuous Manufacturing Process, Sarita L. Kesler Nov 2006

Consolidation And Interweaving Of Composite Members By A Continuous Manufacturing Process, Sarita L. Kesler

Theses and Dissertations

Recent research and development has resulted in a working prototype of an automated process for manufacturing IsoTruss® and other innovative open lattice composite structures which yields faster, and more predictable and consistent parts, while automatically consolidating individual members. This machine is sufficiently versatile to manufacture any type of open lattice structure fabricated from filamentary composite materials. The objectives of the research in this thesis were two-fold: (1) to validate this new process for making IsoTruss structures; and (2) to measure the compression strength and stiffness of specimens produced on the machine. In order to accomplish the first purpose, various parts …

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A New Spectroscopic Method For The Non-Destructive Characterization Of Weathering Damage In Plastics, Andrew Robert George Nov 2006

A New Spectroscopic Method For The Non-Destructive Characterization Of Weathering Damage In Plastics, Andrew Robert George

Theses and Dissertations

The weathering of plastics and composites is a problem because of the loss of both physical and mechanical properties that it causes in these materials. But this weathering effect has been difficult, and in some cases, impossible to characterize without the destruction of the plastic or composite part. Clearly a rapid, reliable, and non-destructive test for the extent of the weathering damage is critically needed. A recent problem that arose at Superyacht Solutions, a boat repair company in Australia, required a solution to just this problem. Such a test was developed for Superyacht Solutions, and is being applied across a …

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Assessment Of The Tube Suction Test For Identifying Non-Frost-Susceptible Soils Stabilized With Cement, Amy Lyn Crook Oct 2006

Assessment Of The Tube Suction Test For Identifying Non-Frost-Susceptible Soils Stabilized With Cement, Amy Lyn Crook

Theses and Dissertations

Frost heave is a primary mechanism of pavement distress in cold regions. The distress exhibited is dependent on the frost susceptibility of the soil within the depth of frost penetration, the availability of subsurface water, and the duration of freezing surface temperatures. Cement stabilization is one technique used to mitigate the effects of frost heave. The tube suction test (TST) is one possible method for determining the frost susceptibility of soils in the laboratory. The purpose of this research was to assess the utility of the TST for identifying non-frost-susceptible (NFS) materials stabilized with cement. This research investigated two aggregate …

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Automatic, Unstructured Mesh Generation For 2d Shelf Based Tidal Models, Cameron L. Mcdonald Sep 2006

Automatic, Unstructured Mesh Generation For 2d Shelf Based Tidal Models, Cameron L. Mcdonald

Theses and Dissertations

Numeric models use a collection of triangular facets called elements connected over a domain in what is referred to as a mesh or unstructured grid as the computational basis for calculations. The density of elements in a mesh affects the numeric stability of a model when performing computations. Furthermore, these meshes can be difficult and time consuming to create. This thesis describes an automated process of creating meshes which utilizes local truncation analysis to generate a spatially varied size function. An advancing frontal mesh generation algorithm uses this function to optimize node placement and density. Further analysis to better understand …

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