Civil Engineering Commons^™

Coupled Simulation Of Loading And Response Of Columns Under Extreme Events, Navid H. Allahverdi

Dissertations

Forces imparted to structural columns during blast-induced loading depends on the shape and size of columns as well as on the intensity of the blast. Column's geometry - i.e., shape and size - influences the flow field around the column and consequently the flow field determines forces experienced by the column The main objective of this research is to estimate the forces imparted to columns in a blast event through studying the air flow field around columns

In this study, the physics of shock wave reflection and rarefaction waves are reviewed with application to describing the air flow around columns …

Ecotourism And Water Quality: Linking Management, Activities And Sustainability Indicators In The Caribbean, Ken Darrie Thomas

USF Tampa Graduate Theses and Dissertations

Ecotourism from its genesis and founding theories has been set out to conserve and preserve the environment through sustainable operation that includes surrounding communities in efforts to reduce their poverty levels. Over the years ecotourism has been hypothesized to have departed from this ideal with several researchers, through social, qualitative analyses, have said that these non-sustainable ecotourism operations are simply due to poor management. This work sought to test this central hypothesis as a first approach to quantitatively linking ecotourism activities to management with surface water quality as the key indicator of sustainable ecotourism as a complex system through systems …

Implications Of Climate-Driven Variability And Trends For The Hydrologic Assessment Of The Reynolds Creek Experimental Watershed, Idaho, V. Sridhar, Anurag Nayak

Civil Engineering Faculty Publications and Presentations

The Soil and Water Assessment Tool (SWAT) model was used to assess the implications of long-term climate trends for the hydroclimatology of the Reynolds Creek Experimental Watershed (RCEW) in the Owyhee Mountains, Idaho of the Intermountain West over a 40- year period (1967-2006). Calibration and validation of the macroscale hydrology model in this highly monitored watershed is key to address the watershed processes that are vulnerable to both natural climate variability and climate change and . The model was calibrated using the streamflow data collected between 1997 and 2006 from the three nested weirs, the Reynolds Mountain East (RME) , …

Laboratory Approach To Modeling The Initiating Mechanism In The Piping Failure Of Sandy Soils, Olalekan O. Olorunsola

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

This research intends to develop a testing apparatus to measure the critical gradient in sandy soils. The designed apparatus will be used in subsequent studies to develop a relationship between critical hydraulic gradient, soil properties and the inclination of the exit face.

This study evaluates several design modification to assess the effects of the modifications, and develop a design that most closely models the field mechanism of piping initiation. The design is initiated from a conceptual design and is executed into the first version. This design is called the Alpha Version. The next version, or more precisely, the Beta Version, …

Characterizing Ecologically Relevant Variations In Streamflow Regimes, Kiran J. Chinnayakanahalli

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Maintaining the ecological health of streams is vital for sustainable water resources management. Streamflow is a primary factor influencing the structure and function of ecological communities. A quantitative understanding of how stream biota respond to variation in streamflow is required for stream bioassessment. This dissertation focuses on quantifying relationships between streamflow regime and stream macroinvertebrate richness and composition. The contribution comprises statistical models that predict stream macroinvertebrate class from streamflow regime and predict streamflow regime from watershed attributes, and a tool that helps derive watershed attribute variables used in these models.

The dissertation is a collection of three papers. In …

Pullout And Tensile Behavior Of Crimped Steel Reinforcement For Mechanically Stabilized Earth (Mse) Walls, Oscar Ernesto Suncar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many research studies made on hundreds of MSE walls have shown that in order to get lower values of lateral earth pressure coefficients from an active condition on the backfill soil, thus lower exerted loads and stresses on the reinforcement, the wall needs to yield. This is typical of extensible polymer-based wall systems, such as geosynthetics. Steel systems, on the other hand, are very rigid and do not allow enough deformation on the wall to generate the active condition.

For this research, steel reinforcement for MSE walls that behaves similar to geosynthetics was developed. This was done by using crimps …

Water Allocation Challenges In Rural River Basins: A Case Study From The Walawe River Basin, Sri Lanka, D. K. Neelanga Weragala

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation evaluates the water allocation challenges in the rural river basins of the developing world, where demands are growing and the supply is limited. While many of these basins have yet to reach the state of closure, their water users are already experiencing water shortages. Agricultural crop production in rural river basins of the developing world plays a major role in ensuring food security. However, irrigation as the major water consumer in these basins has low water use efficiency. As water scarcity grows, the need to maximize economic gains by reallocating water to more efficient uses becomes important. …

Internal Design Of Mechanically Stabilized Earth (Mse) Retaining Walls Using Crimped Bars, Bernardo A. Castellanos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Current design codes of Mechanically Stabilized Earth (MSE) Walls allow the use lower lateral earth pressure coefficient (K value) for designing geosynthetics walls than those used to design steel walls. The reason of this is because geosynthetics walls are less rigid permitting the wall to deform enough to work under active pressures instead of at rest pressures as in steel walls.

A new concept of crimped steel bars was recently introduced. This new type of bar was tested for tension and pullout behavior. Results on tests made on crimped bars show that putting those crimps in the steel bar will …

Increased Functionality Of Floodplain Mapping Automation: Utah Inundation Mapping System (Utims), Brian K. Stevens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Floodplain mapping has become an increasingly important part of floodplain management. Floodplain mapping employs mapping software and hydraulic calculation packages to efficiently map floodplains. Modelers often utilize automation software to develop the complex geometries required to reduce the time to develop hydraulic models.

The Utah Inundation Mapping System (UTIMS) was designed to reduce the time required to develop complex geometries for use in floodplain mapping studies. UTIMS reduces the time required to develop geometries used in floodplain management studies. The automated geometries developed include: flood specific river centerlines, bank lines, flow path lines, cross sections, and areal averaged n-value polygons. …

Reliability-Based Underseepage Analysis In Levees Using Monte Carlo Simulation, Lourdes Polanco

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A new method for assessing the potential for unsatisfactory levee performance due to underseepage is presented. Specifically, the method assesses the potential for the initiation of piping (the internal backward erosion of the foundation or embankment caused by seepage). Current assessment methods consist of deterministic seepage analyses and simplified reliability methods. Deterministic methods produce either a maximum hydraulic exit gradient or a Factor of Safety against piping but they do not account for high levels of uncertainty in soil properties and subsurface geometry that are inherent to many levee analyses. The most common simplified reliability approaches that are currently being …

Ultimate Shear Capacity And Residual Prestress Force Of Full-Scale, Forty-One-Year-Old Prestressed-Concrete Girders, Parry Osborn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The ultimate shear capacity of prestressed concrete beams is difficult to predict accurately, especially after being in service for an extended period of time. The Utah Department of Transportation asked researchers at Utah State University to experimentally determine the existing shear capacity of 41-year-old prestressed, decommissioned concrete bridge girders and then provide recommendations on how to increase that ultimate shear capacity. This thesis presents the research findings that relate to the existing shear capacity of the prestressed concrete girders.

Eight AASHTO Type II bridge girders were tested up to failure by applying external loads near the supports to determine their …

Data Analysis Of Utah's I-80 And I-215 Bridges - For The Use In The Development Of Accelerated Bridge Construction Standards, Erik S. Rosvall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study discusses five bridges on Utah's I-80 that were replaced in the summer of 2008 using Accelerated Bridge Construction methods. Each superstructure was built offsite and moved into place with the use of Self-Propelled Modular Transporters. The bridges were instrumented and monitored during the moving process to investigate the effects of moving an entire superstructure into place. Collected data was analyzed to find the level of stress each superstructure experienced during lifting, moving, and placement of each bridge.

The change in supporting conditions from when the superstructure was built to being transferred onto Self-Propelled Modular Transporters caused significant stress …

A Study Of Cause And Effect Relationships Of Snowmelt-Induced Movement For The Skunk Hollow Landslide, Brent P. Randall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Skunk Hollow Landslide (located 1 mile north of Mantua, UT along US-89) was instrumented with an automated monitoring system to aid in the determination of the triggering mechanism of slow moving landslides. Data was transmitted wirelessly through telecommunications to allow year-round, real-time monitoring of the site. Measurements were recorded and analyzed for the first season of landslide movement (fall 2009 to spring 2010) to better understand the correlations between snowmelt and movement initiation. Based on the first year of data, it appears that the Skunk Hollow Landslide is controlled by water infiltrating into the slide mass through cracks and …

Full-Scale Testing Of 40 Year Old Prestressed Aashto Girders That Have Been Retrofitted In Shear By Externally Applied Carbon Fiber Reinforced Polymer Wraps, David A. Petty

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Utah Department of Transportation (UDOT) is interested in the application of rehabilitation techniques to strengthen their AASTHO prestressed bridge girders for shear. Utah's bridges are exposed to deterioration from rain, snow, and the introduction of salt for ice removable. This requires innovative rehabilitation techniques to address the deteriorations of their highway bridges, especially the ends of bridge girders where water and salt are more common due to construction joints. Carbon Fiber Reinforced Polymers (CFRP) are becoming more prevalent as a tool in highway bridge rehabilitation.

This research investigates the application of various CFRP systems that can be used as …

Effects Of Submergence In Montana Flumes, Ryan P. Willeitner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As part of a continued research project for the Utah Water Research Laboratory and the State of Utah, a study of flow measurement devices is being conducted throughout the state. Initially the project included only measurement devices associated with high-risk dams, but has since been broadened to any measurement structure of interest for water users in the state. The physical dimensions, relative elevations, and flow accuracy were documented for each included device.

After visiting sixteen sites, it was found that fourteen of the measuring devices had incorrect geometries. Of these fourteen, thirteen of them were originally Parshall flumes. A large …

Time-Dependent Scour Depth Under Bridge-Submerged Flow, Yuan Zhai

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Failure of bridges due to local scour has motivated many investigators to explore the reasons of scouring and to give the prediction of the scour depth. But most scour prediction equations only address non-pressure-flow situations. Little research has been dedicated to another destructive scour, submerged-flow bridge scour (pressure flow scour) which can cause significant damages to bridges when partially or totally submerged during a large flood.

This thesis is specifically focused on the experimental study for time-dependent scour depth under bridge-submerged flow. The experiments were conducted in a self contained re-circulating tilting flume where two uniform sediment sizes and one …

Fringe Visibility Enhanced Extrinsic Fabry-Perot Interferometer Using A Graded Index Fiber Collimator, Yinan Zhang, Yanjun Li, Tao Wei, Xinwei Lan, Ying Huang, Genda Chen, Hai Xiao

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

We report a fringe visibility-enhanced extrinsic Fabry-Perot interferometer (EFPI) by fusion splicing a quarter-pitch length of a graded-index fiber (GIF) to the lead-in single mode fiber (SMF). The performance of the GIF collimator is theoretically analyzed using a ray matrix model and experimentally verified through beam divergence angle measurements. The fringe visibility of the GIF-collimated EFPI is measured as a function of the cavity length and compared with that of a regular SMF-EFPI. At the cavity length of 500 μm, the fringe visibility of the GIF-EFPI is 0.8, while that of the SMF-EFPI is only 0.2. The visibility-enhanced GIF-EFPI may …

Impact Of Ground-Level Aviation Emissions On Air Quality In The Western United States, Eric Edward Clark

Boise State University Theses and Dissertations

The aviation industry has experienced sustained growth since its inception result- ing in an increase in air pollutant emissions. Exposure to particulate matter less than 2.5 µm in diameter (PM_2.5) has been linked to respiratory health problems because it penetrates deepest into human lungs.

This thesis focused on the concentrations of three secondary aerosol species (i.e., sulfate, nitrate + ammonium and organic carbon) as they relate to the formation of total PM_2.5. There were three goals of this research: evaluate differences in total PM_2.5 concentration as (1) ground-level aviation emissions (i.e., up to 3,000 …

The Utah Pilot Bridge, Live Load And Dynamic Testing, Modeling And Monitoring For The Long-Term Bridge Performance Program, Steven M. Petroff

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As part of the Federal Highway Administration's Long-Term Bridge Performance Program, Live Load and Dynamic tests were conducted. A long-term monitoring plan was developed and presented for the Utah Pilot Bridge based on Live Load and Dynamic tests. As one of seven pilot bridges, the Utah Pilot Bridge is one of the first bridges used to initiate the LTBP Program. A formal permit approval process, with the Utah Department of Transportation, was followed to gain permission to conduct the tests and install long-term instrumentation. Analysis provided good results for each test completed, with a summary of test results presented. A …

Statistical Modeling And Analysis Of Injury Severity Sustained By Occupants Of Passenger Vehicles Involved In Crashes With Large Trucks, Ahmad Koupaenejad

UNLV Theses, Dissertations, Professional Papers, and Capstones

Crashes are the result of complex interactions between several factors representing driver, roadway, vehicle, and environmental characteristics. Understanding to what degree each factor contributes to the severity of a crash is not a simple task. The outcomes of crashes in the US have been an average of 42,000 deaths and 3 million injuries per year. To better understand the role of significant contributors to crashes, three sets of models using multinomial logit and one using ordered probit were calibrated. To calibrate these models, forty two independent predictor variables including driver/occupants characteristics, crash environment at the crash location, crash characteristics, and …