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Articles 661 - 690 of 1335

Full-Text Articles in Civil and Environmental Engineering

Numerical And Experimental Investigations Of Dam And Levee Failure, Ezzat Youssef Elhassan Mohamed Elalfy Dec 2015

Numerical And Experimental Investigations Of Dam And Levee Failure, Ezzat Youssef Elhassan Mohamed Elalfy

Theses and Dissertations

Both numerical and experimental investigations are conducted to study the failure of earthen dams and levees. Boussinesq equations describing one-dimensional unsteady flow including non-hydrostatic pressure distribution are solved numerically along with Exner equation for the sediment mass conservation to include the effects of the streamline curvature on the failure of non-cohesive earthen embankments. In addition, the effects of the steep bottom slope on the flow variables during the failure are studied by solving the Saint- Venant equations modified for steep bed slope along with the Exner equation to simulate non-cohesive earthen embankment failure due to overtopping. The Boussinesq equations are …

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Experimental Study Of Longitudinal Sorting Of Particles Differing In Size And Density, Nabila Mahjabeen Dec 2015

Experimental Study Of Longitudinal Sorting Of Particles Differing In Size And Density, Nabila Mahjabeen

Theses and Dissertations

Transport, deposition and erosion of sediment particles differing in size, shape and density may result in particle segregation, which in geosciences applications is generally referred to as sediment sorting. A thorough understanding of sediment sorting processes is important to describe and model a wide variety of natural processes such as the decrease in particle size and/or density in a fluvial system (downstream fining and/or lightening), the formation of economic placers, concentration of heavy minerals, chemical and metal pollutants etc. Sorting of sediment grains associated with sediment transport in the streamwise direction results in the development of longitudinal sorting patterns. Vertical …

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Confluence Of Density Currents Over An Erodible Bed, Hassan Ismail Dec 2015

Confluence Of Density Currents Over An Erodible Bed, Hassan Ismail

Theses and Dissertations

Results from laboratory experiments on conservative density current confluence are reported. Hydraulic characteristics and morphodynamic consequences of the confluence of two continuous release density currents in a horizontal, 45 degree asymmetrical junction are examined and compared to those of terrestrial river junctions. It was observed that density current confluence is markedly different than those in river junctions primarily due to the ease of the dense fluid to convect into the ambient fluid in the junction zone. Upward convection in the junction resulted in low horizontal velocity and shear stresses on the bed of the junction zone, followed by re-plunging to …

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Use Of Personality Profile Assessments In The Construction Industry, Brian Richard Childs Dec 2015

Use Of Personality Profile Assessments In The Construction Industry, Brian Richard Childs

Theses and Dissertations

Various industries are using personality profile assessments as tools to help reduce employee turnover. Employee turnover is a continuing challenge in the construction industry that has negative effects on construction companies. Research found that it was difficult to know if companies in the construction industry are using personality profile assessments as a tool to help reduce employee turnover. After understanding that other industries were using personality profile assessments in their hiring, promoting, team building and leadership development to reduce turnover, it was desired to understand if the construction industry was doing the same. This research performed a survey among the …

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A Pilot Study To Determine The Performance Of Tension Lap Splices In Reinforced Masonry Made With Light-Weight Grout, Brandon Richard Corbett Dec 2015

A Pilot Study To Determine The Performance Of Tension Lap Splices In Reinforced Masonry Made With Light-Weight Grout, Brandon Richard Corbett

Theses and Dissertations

The use of light-weight building materials in modern construction has resulted in efficient designs and considerable cost savings by reducing structural weight and supporting sections. This has only been possible because of many years of research to better understand the properties of the light-weight material, and its structural behaviors. However, light-weight grout is a relatively new building material in reinforced masonry construction and little is known about its structural properties. The main objective of this study was to determine if the use of light-weight grout would impact the performance of reinforcing steel, specifically development length, in masonry construction.The research included …

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Laboratory Resilient Modulus Measurements Of Aggregate Base Materials In Utah, Kirk David Jackson Dec 2015

Laboratory Resilient Modulus Measurements Of Aggregate Base Materials In Utah, Kirk David Jackson

Theses and Dissertations

The Utah Department of Transportation (UDOT) has fully implemented the Mechanistic-Empirical Pavement Design Guide for pavement design but has been using primarily level-three design inputs obtained from correlations to aggregate base materials developed at the national level. UDOT was interested in investigating correlations between laboratory measurements of resilient modulus, California bearing ratio (CBR), and other material properties specific to base materials commonly used in Utah; therefore, a statewide testing program was needed. The objectives of this research were to 1) determine the resilient modulus of several representative aggregate base materials in Utah and 2) investigate correlations between laboratory measurements of …

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An Automated Tool For High Resolution Visualization Applied To Transient Watershed Models, Noah Robert Taylor Dec 2015

An Automated Tool For High Resolution Visualization Applied To Transient Watershed Models, Noah Robert Taylor

Theses and Dissertations

Numeric hydrologic models can aid in water resource management by providing predictive simulations of water behavior. As computers become more advanced, the models developed also become more complex using more data to represent larger areas for forecasting hydrologic behavior. Unfortunately, as the simulations use more data, the output often becomes difficult to manage and share without investing time and effort into setting up server environments or decreasing the quality of the output to compensate for an efficient and effective user experience. A proposed solution to facilitate the accessibility of massive hydrologic model output is through the web-based visualization tool developed …

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Evaluating Long-Term Land Cover Changes For Malheur Lake, Oregon Using Envi And Arcgis, Ryan Joseph Woods Dec 2015

Evaluating Long-Term Land Cover Changes For Malheur Lake, Oregon Using Envi And Arcgis, Ryan Joseph Woods

Theses and Dissertations

Land cover change over time can be a useful indicator of variations in a watershed, such as the patterns of drought in an area. I present a case study using remotely sensed images from Landsat satellites for over a 30-year period to generate classifications representing land cover categories, which I use to quantify land cover change in the watershed areas that contribute to Malheur, Mud, and Harney Lakes. I selected images, about every 4 to 6 years from late June to late July, in an attempt to capture the peak vegetation growth and to avoid cloud cover. Complete coverage of …

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Shaking Table Testing To Evaluate Effectiveness Of Prefabricated Vertical Drains For Liquefaction Mitigation, Caleb Robert Oakes Dec 2015

Shaking Table Testing To Evaluate Effectiveness Of Prefabricated Vertical Drains For Liquefaction Mitigation, Caleb Robert Oakes

Theses and Dissertations

This study was designed to evaluate the ability of vertical drains to prevent liquefaction and limit associated settlement. Drain performance was investigated using full-scale tests with vertical drains in liquefiable sand using a laminar shear box with acceleration time histories applied at the base. Performance of the sand box with drains in these tests was compared with performance of the sane box without drains in previous tests. The test data was also used to create case histories which can be used for further research and calibration of computer models. Although some investigations regarding vertical drains have been performed with centrifuge …

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Numerical Analysis Of Passive Force On Skewed Bridge Abutments, Zifan Guo Dec 2015

Numerical Analysis Of Passive Force On Skewed Bridge Abutments, Zifan Guo

Theses and Dissertations

Accounting for seismic forces and thermal expansion in bridge design requires an accurate passive force-deflection relationship for the abutment wall. Current design codes make no allowance for skew effects on passive force; however, large scale field tests indicate that there is a substantial reduction in peak passive force as skew angle increases. A reduction in passive force also reduces the transverse shear resistance on the abutment. The purpose of this study is to validate three-dimensional model using PLAXIS 3D, against large scale test results performed at Brigham Young University and to develop a set of calibrated finite element models. The …

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Economic Feasibility And Increased Sustainability Of Short Span Arch Culvert, Rafsan Jani Rafi Nov 2015

Economic Feasibility And Increased Sustainability Of Short Span Arch Culvert, Rafsan Jani Rafi

Theses and Dissertations

Short span box culverts are widely used for stream flow passing throughout the State of Arkansas. Arkansas State Highway and Transportation Department (AHTD) has standard box culverts ranging from 4 ft to 12 ft in span to use for individual box culvert combination. This study is strictly for culverts with a total span range from 10 ft to 30 ft. To achieve more than 12 ft culvert span, AHTD uses different combinations of standard box culverts. As a result, the clear span becomes smaller and may cause higher debris accumulation near the culvert openings. The goal of this study is …

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Bending Behavior Of Carbon/Epoxy Composite Isobeam Structures, Brandon A. Asay Sep 2015

Bending Behavior Of Carbon/Epoxy Composite Isobeam Structures, Brandon A. Asay

Theses and Dissertations

This research demonstrated the fabrication, flexural testing, and analysis of nominally 5 ft (1.5 m) 6-bay and 10 ft (3 m) 12-bay carbon/epoxy IsoBeam™ structures. The rectangular cross-section was 5 in (12.7 cm) wide by 10 in (25.4 cm) high. The IsoBeam structure is a composite lattice structure that is a geometric derivative of the IsoTruss® structure. Modifying the geometry to yield a rectangular cross-section provides additional applications for these beams as structural elements in buildings, aircraft, vehicles, and other structures. The diameters of the constituent members of the IsoBeam, namely the longitudinal and diagonal members, were sized such that …

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Developing Pavement Performance Prediction Models For The State Of Arkansas, Lena Baker Abu-Ennab Aug 2015

Developing Pavement Performance Prediction Models For The State Of Arkansas, Lena Baker Abu-Ennab

Theses and Dissertations

Pavement management systems (PMS) provide a methodology for synthesizing all the activities related to the pavement network. These include all the activities involved in the planning and programming, design, construction, maintenance, and rehabilitation (1). The effective implementation and utilization of PMS requires a systematic approach involving condition assessment and performance modelling. A very important part of such approach is the use of pavement performance prediction models to predict the future condition of pavements based on present condition. This study presents a methodology used to develop network level pavement performance prediction models for the pavement network in the state of Arkansas. …

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Evaluating The Security Of Smart Home Hubs, Steven A. Christiaens Aug 2015

Evaluating The Security Of Smart Home Hubs, Steven A. Christiaens

Theses and Dissertations

The goal of this research is to improve the security of smart home hubs by developing a standard against which hubs can be evaluated. This was done by first reviewing existing standards, guides, and collections of best practices. I determined that adapting or extending an existing standard was the best way to proceed. Potential candidates were selected, and after thorough comparison, I chose to extend the OWASP Application Security Verification Standard (ASVS). Extensions were composed of additional security requirements to address smart home hub functionality not covered by the existing requirements of the ASVS. These additional requirements were developed based …

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A Method For Using Pre-Computed Scenarios Of Physically-Based Spatially-Distributed Hydrologic Models In Flood Forecasting Systems, Herman Guillermo Dolder Aug 2015

A Method For Using Pre-Computed Scenarios Of Physically-Based Spatially-Distributed Hydrologic Models In Flood Forecasting Systems, Herman Guillermo Dolder

Theses and Dissertations

Every year floods are responsible of a significant number of human losses, many of which could be avoided with a broader implementation of flood forecasting systems. Nevertheless, there are still some technological and economic limitations that impede the creation of these systems in many parts of the world. At the core of many flood forecasting systems is a hydrologic model that transforms the weather forecast into a flow forecast. Using real-time modeling for potential floods poses a series of problems: if the model is complex, the computational power required can be significant, and consequently expensive, and if the model is …

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Evaluation Of The Accuracy Of Traffic Volume Counts Collected By Microwave Sensors, David Keali'i Chang Jul 2015

Evaluation Of The Accuracy Of Traffic Volume Counts Collected By Microwave Sensors, David Keali'i Chang

Theses and Dissertations

Over the past few years, the Utah Department of Transportation (UDOT) has developed a system called the Signal Performance Metrics System (SPMS) to evaluate the performance of signalized intersections. This system currently provides data summaries for several performance measures including: 1) Purdue Coordination Diagram, 2) Speed, 3) Approach Volume, 4) Purdue Phase Termination Charts, 5) Split Monitor, 6) Turning Movement Volume Counts, 7) Arrivals on Red, and 8) Approach Delay. There is a need to know the accuracy of the data that are being collected by the Wavetronix SmartSensor Matrix and displayed in the SPMS. The TAC members determined that …

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Correlation Of Fluorescence Spectroscopy And Biochemical Oxygen Demand (Bod5) Using Regression Analysis, Alexander Tetteh Narteh Jul 2015

Correlation Of Fluorescence Spectroscopy And Biochemical Oxygen Demand (Bod5) Using Regression Analysis, Alexander Tetteh Narteh

Theses and Dissertations

This research uses Regression analysis of fluorescence spectroscopy results to correlate with Biochemical Oxygen Demand (BOD5). Fluorescence spectroscopy was applied to samples taken from seven sample sites in the Provo and Orem waste water treatment plants found in Utah County. A total of 161 samples were collected for this research. 23 samples each were taken from four sites in the Provo waste water treatment plant namely Provo head works, aeration basin, primary filter settlement basin and the Provo effluent basin. The Orem head works, the clarifier and the Orem effluent basin were the three sample sites in the Orem waste …

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Development Of A Simplified Performance-Based Procedure For Assessment Of Liquefaction Triggering Using Liquefaction Loading Maps, Kristin Jane Ulmer Jul 2015

Development Of A Simplified Performance-Based Procedure For Assessment Of Liquefaction Triggering Using Liquefaction Loading Maps, Kristin Jane Ulmer

Theses and Dissertations

Seismically-induced liquefaction has been the cause of significant damage to infrastructure and is a serious concern in current civil engineering practice. Several methods are available for assessing the risk of liquefaction at a given site, each with its own strengths and limitations. One probabilistic method has been shown to provide more consistent estimates of liquefaction risk and can be tailored to the specific needs of a given project through hazard-targeted (i.e. based on return periods or likelihoods) results. This type of liquefaction assessment is typically called “performance-based,” after the Pacific Earthquake Engineering Research (PEER) Center's performance-based earthquake engineering framework. Unfortunately, …

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Large-Scale Testing Of Passive Force Behavior For Skewed Bridge Abutments With Gravel And Geosynthetic Reinforced Soil (Grs) Backfills, Amy Fredrickson Jul 2015

Large-Scale Testing Of Passive Force Behavior For Skewed Bridge Abutments With Gravel And Geosynthetic Reinforced Soil (Grs) Backfills, Amy Fredrickson

Theses and Dissertations

Correct understanding of passive force behavior is particularly key to lateral evaluations of bridges because plastic deformation of soil backfill is vital to dissipation of earthquake energy and thermally-induced stresses in abutments. Only recently have studies investigated the effects of skew on passive force. Numerical modeling and a handful of skewed abutment tests performed in sand backfill have found reduced passive force with increasing skew, but previous to this study no skewed tests had been performed in gravel or Geosynthetic Reinforced Soil (GRS) backfills. The goal of this study was to better understand passive force behavior in non-skewed and skewed …

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A Cloud-Based Gssha Index Map Editor Utility For Watershed Decision Support, Jocelynn Marie Anderson Jul 2015

A Cloud-Based Gssha Index Map Editor Utility For Watershed Decision Support, Jocelynn Marie Anderson

Theses and Dissertations

Preventing damages from flooding is critically important for city managers and planners.Efforts in protecting infrastructure from flooding are often coupled with building hydrologicmodels to provide predictions of what is likely to happen during storm events. As land usechanges, these models must be updated, which is more challenging with sophisticated models. Ateam of researchers from universities in Utah and Wyoming have been developing tools forwater management in the Intermountain West as part of a collaborative NSF research grantcalled CI-WATER. In particular, a free and open source web platform called Tethys has beendeveloped to support the development and hosting of hydrologic web …

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Evaluation Of Empirical Prediction Methods For Liquefaction-Induced Lateral Spread From The 2010 Maule, Chile, MW 8.8 Earthquake In Port Coronel, Nicole D. Williams Jul 2015

Evaluation Of Empirical Prediction Methods For Liquefaction-Induced Lateral Spread From The 2010 Maule, Chile, MW 8.8 Earthquake In Port Coronel, Nicole D. Williams

Theses and Dissertations

Over the past several decades, empirical formulas have been developed and improved to predict liquefaction and lateral spread based on a database of case histories from observed earthquakes, such as Youd et al. (2002) and Rauch and Martin (2000). The 2010 Maule Chile earthquake is unique first of all because it is recent and was not used to develop recent liquefaction and lateral spread evaluation methods, and therefore can be reasonably used to evaluate the effectiveness of such equations. Additionally, the 8.8 magnitude megathrust event fills a significant gap in the databases used to develop these empirical formulas, which tends …

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Use Of Roadway Attributes In Hot Spot Identification And Analysis, David R. Bassett Jul 2015

Use Of Roadway Attributes In Hot Spot Identification And Analysis, David R. Bassett

Theses and Dissertations

The Utah Department of Transportation (UDOT) Traffic and Safety Division continues to advance the safety of roadway sections throughout the state. In an effort to aid UDOT in meeting their goal, the Department of Civil and Environmental Engineering at Brigham Young University (BYU) has worked with the Statistics Department in developing analysis tools for safety. The most recent of these tools has been the development of a hierarchical Bayesian Poisson Mixture Model (PMM) of traffic crashes known as the Utah Crash Prediction Model (UCPM), a hierarchical Bayesian Binomial statistical model known as the Utah Crash Severity Model (UCSM), and a …

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Lateral Resistance Of Pipe Piles Near 20-Ft Tall Mse Abutment Wall With Strip Reinforcements, Jason James Besendorfer Jul 2015

Lateral Resistance Of Pipe Piles Near 20-Ft Tall Mse Abutment Wall With Strip Reinforcements, Jason James Besendorfer

Theses and Dissertations

Full scale lateral load testing was performed on four 12.75x0.375 pipe piles spaced at 3.9, 2.9, 2.8, and 1.7 pile diameters behind an MSE wall which was constructed for this research to determine appropriate reduction factors for lateral pile resistance based on pile spacing behind the back face of the wall. The load induced on eight soil reinforcements located at various transverse distances from the pile and at different depths was monitored to determine the relationship between lateral load on the pile and load induced in the reinforcement. Each pile was loaded towards the wall in 0.25 in. increments to …

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A System Dynamics Approach To The Efficacy Of Oxime Therapy In Sub Lethal Exposure To Sarin Gas, Daniel J. Droste Jun 2015

A System Dynamics Approach To The Efficacy Of Oxime Therapy In Sub Lethal Exposure To Sarin Gas, Daniel J. Droste

Theses and Dissertations

The 2010 National Security Strategy states, The effective dissemination of a lethal agent would endanger the lives of thousands of people and have unprecedented economic, societal, and political consequences. We must continue to work at home with first responders and health officials to reduce the risk associated with high-consequence threats . Nerve agents, such as Sarin gas, are considered high consequence threats. The threat of use of agents such as Sarin is as much a threat today as any other time in our history. However, the suggested treatment protocol is not as precise as it could be. Debate exists over …

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A Simplified Performance-Based Procedure For The Prediction Of Lateral Spread Displacements, Levi Thomas Ekstrom Jun 2015

A Simplified Performance-Based Procedure For The Prediction Of Lateral Spread Displacements, Levi Thomas Ekstrom

Theses and Dissertations

Characterization of the seismic hazard and ground-failure hazard of a site using traditional empirical lateral spread displacement models requires consideration of uncertainties in seismic loading, site conditions, and model prediction. Researchers have developed performance-based design methods to simultaneously account for these sources of uncertainty through the incorporation of a probabilistic analytical framework. While these methods can effectively handle the various sources of uncertainty associated with empirical lateral spread displacement prediction, they can be difficult for engineers to perform in a practical manner without the use of specialized numerical tools. To make the benefits of a performance-based approach accessible to a …

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Assessing The Repercussions Of A Mass Departure Of Building Inspectors From The Code Professional Industry In Utah, George Reese Williams Jun 2015

Assessing The Repercussions Of A Mass Departure Of Building Inspectors From The Code Professional Industry In Utah, George Reese Williams

Theses and Dissertations

National studies suggest that eighty percent of existing code professionals are expected to retire within the next fifteen years. As part of this research, it was determined that approximately half of all licensed building inspectors in the State of Utah will reach retirement age within the next ten years. As building inspectors make up a large part of the Code Professional Industry this demographic was selected as the focus of this research. The purpose of this research project was to assess the urgent need for new entrants into the Code Professional Industry in Utah. As part of this research, trends …

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Tethys Platform: A Development And Hosting Platform For Water Resources Web Apps, Nathan R. Swain Jun 2015

Tethys Platform: A Development And Hosting Platform For Water Resources Web Apps, Nathan R. Swain

Theses and Dissertations

The interactive nature of web applications or “web apps” makes it an excellent medium for conveying complex scientific concepts to lay audiences and creating decision support tools that harness cutting edge modeling techniques. However, the technical expertise required to develop them represents a barrier for would-be developers. The barrier can be characterized by the following hurdles that developers must overcome: (1) identify, select, and install software that meet the spatial and computational capabilities commonly required for water resources modeling; (2) orchestrate the use of multiple FOSS and FOSS4G projects and navigate their differing application programming interfaces (APIs); (3) learn the …

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Laser Scanning Aggregates For Real-Time Property Identification, Andrew Branin May 2015

Laser Scanning Aggregates For Real-Time Property Identification, Andrew Branin

Theses and Dissertations

The strength of concrete and asphalt is provided by the aggregate stone within it, and as such maintaining a high standard for these materials is crucial in ensuring that these materials meet their projected design lives. One key factor to consider for an aggregate's long-term strength is its mineralogy, which can affect the strength and long-term performance of these materials. Conventional chemical testing techniques and petrographic examination methods presently exist which can be used to identify and/or quantify problematic minerals, however these tests are typically costly, time consuming, and/or require significant sample preparation and a controlled lab environment. The purpose …

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Modeling Force Main Systems For Surge Analysis And Studying Dynamic Response Due To Water Hammer, Wissam Al-Taliby May 2015

Modeling Force Main Systems For Surge Analysis And Studying Dynamic Response Due To Water Hammer, Wissam Al-Taliby

Theses and Dissertations

The major impact of water hammer on force mains integrity include excessive pressure oscillation that is usually accompanied by pipe vibrations. Models for simulating force main water hammer response have been developed. All of these models were based on the method of characteristics (MOC) and most of them were not calibrated for the lack of efficient field data. Although predicting maximum pressure during the first wave cycle is sufficient in most applications, some applications require precise prediction of pressure damping. One-dimensional models usually over predict pressure oscillation beyond the first cycle since they are based on steady friction expressions. It …

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Engineering Properties Of Pile Rebound Soils Based On Cone Penetration Testing, Hadeel Dekhn May 2015

Engineering Properties Of Pile Rebound Soils Based On Cone Penetration Testing, Hadeel Dekhn

Theses and Dissertations

High pile rebound (HPR) has been identified by Florida Department of Transportation (FDOT) to occur during the installation of square prestressed concrete piles at many sites in Florida. Significant pile rebound values of up to 1.5 inch/blow were measured resulting in increased blow counts. Pile refusal is a common occurrence when blow count exceeds 240 blow/ft; leading to pile redesign and economic consequences. The overall objective of this research is to identify the engineering properties of soil deposits which may cause HPR and develop improved correlations that may be used to predict HPR during the design process. Seven sites were …

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