Civil and Environmental Engineering Commons^™

Investigation Of Longitudinal Joints Between Precast Prestressed Deck Bulb Tee Girders Using Latex Modified Concrete, Clark Baer

Theses and Dissertations

This study investigates the behavior and performance of latex modified concrete (LMC) as a closure pour material with a U-bar connection detail in longitudinal joints between precast deck bulb tee bridge girders with integral concrete decks. The objective was to determine if the joint detail was capable of resisting service shear and moment stresses as well as eliminate the formation of cracks in the joint during fatigue loading. This study tested two large scale reinforced concrete slab specimens measuring 6 ft x 6 ft x 8 in joined together by the longitudinal joint detail in fatigue flexure shear loading. The …

A Model Experiment To Assess The Effects Of Inclusions On Wave Propagation In Soil Media, Thomas Houston

Theses and Dissertations

The research described involved analyzing and characterizing changes to propagating surface waves that are caused by items embedded in a half-space consisting of a soil medium. Numerical and experimentally obtained data of three-dimensional surface wave responses to dynamic impulse loading were examined. Results from this research are compared to changes to surface waves observed in previous investigations that were caused by the presence of voids and inclusions embedded in an elastic half space. The focus of this work was to identify whether the characteristic responses identified in previous studies, based substantially on analytical and finite element analyses results, can be …

Assessment Of Damage In Concrete Structures Using Acoustic Emission, Marwa Abdelrahman

Theses and Dissertations

Evaluating the integrity of concrete structures is an essential procedure to ensure structural safety and durability. Non-destructive testing (NDT) is needed for localizing and characterizing the growing damage in existing structures and also for quality control of new structures. Visual inspection is a commonly used method; however it is not suitable for early detection of damage and very dependent on the experience of the inspector. More research is needed to establish advanced methods for structural health diagnosis such as acoustic emission (AE). Acoustic emission is notably sensitive to active damage in concrete structures. This thesis includes three studies that mainly …

Structural Health Monitoring Of Concrete Systems, Matthew Kelly Jones

Theses and Dissertations

Concrete material is widely used around the world for the construction of many infrastructure including highway bridges, residential and commercial building, dams, electric power generation plants, and nuclear power plants. It is therefore practical to continue development of both improved structural systems as well as innovative condition assessment techniques for new and existing concrete structures. This thesis includes two studies which focus on structural health monitoring of concrete systems. The first project deals with performance assessment of an in-situ precast approach slab system and the second is an investigation of acoustic emission (AE) as a condition assessment technique for alkali-silica …

Impact Of Curing Time And Curing Stress On The Mechanical Behavior Of Cement-Improved And Cement-Fiber-Improved Soft Soil, Ryan Daniel Starcher

Theses and Dissertations

In order to improve the engineering properties of soft soils, materials, such as cement and fiber, can be introduced to the soil mass. Currently, design criterion for a cement-soil mixture requires only the measurement of unconfined compressive strength. This simple measurement may not be adequate to describe the behavior that results from differing field loading conditions. A series of consolidation tests and unconfined compression tests were conducted with special attention being paid to the effects of curing time and vertical curing stress. It is shown that the introduction of cement into soft soils results in decreased compressibility and increased unconfined …

Selection And Clustering For Disease Associated Genetic Variants, Yubo Zou

Theses and Dissertations

Epigenetics is the study of chemical reactions, which are orchestrated for the development and maintenance of an organism. Genetic or epigenetic variants (GEVs) encompass different types of genetic measures, such as Deoxyribonucleic acid (DNA) methylation at different CpG sites, expression level of genes, or single nucleotide polymorphisms (SNPs). With the development of technology, huge amount of genetic and epigenetic information is produced. However, the rich information potentially brings in challenges in data analyses. Thus it is necessary to reduce the dimension of data to improve efficiency. In my dissertation, I will focus on two directions of dimension reduction: variable selection …

Experimental Study On Piping Failure Of Earthen Levee And Dams, Yusuf Ahmed Sharif

Theses and Dissertations

Piping in an earthen levee, one of the main causes of failure, is a complex phenomenon. Most of the available research on piping failure has been on non-cohesive sandy soils. Jet Erosion Test and Hole Erosion Test have been conducted to study piping failure in an indirect manner. However, no general purpose formula is presently available to describe the erosion process due to complex erosion characteristics of cohesive soils in earthen levees.

Experimental investigations in a flume to understand the piping erosion process in an earthen levee are conducted in this research. One of the sidewalls and the bottom of …

Removal Of Synthetic Organic Compounds And Nom By Single-Walled Carbon Nanotubes-Ultrafiltration And Forward Osmosis Membrane System, Jiyong Heo

Theses and Dissertations

This overall theme of this dissertation is to investigate the potential engineered application of low pressure membranes incorporated with single-walled carbon nanotubes (SWNTs) and forward osmosis (FO) membrane systems for the removal of synthetic organic compounds (SOCs) and natural organic matter (NOM) from drinking water sources. The focus is on the use of SWNTs-ultrafiltration (UF) and FO membrane systems to facilitate the removal of these compounds and potential applications of these membrane system designs for reducing the energy demands and membrane fouling in environmental water filtration process and seawater desalination. The SWNTs-UF results indicate that SOCs transport is influenced by …

Application Of Agent-Based Approaches To Enhance Container Terminal Operations, Omor Sharif Abul Bashar Mohammad

Theses and Dissertations

Queuing at marine terminal gates has long been identified as a source of emissions and high drayage costs due to the large number of trucks idling. The first study in this dissertation addresses queuing of trucks at marine terminal gates and presents a novel agent-based framework where the drayage companies can minimize congestion by using the provided real-time gate queuing information. The problem was tackled based on the approach of El Farol Bar problem from game theory. Our proposed model can be used as a means of managing demand for the marine terminals, assuming that drayage firms will adjust their …

Experimental Investigation Of Steady Flows At A Breached Levee, Cyrus K. Riahi-Nezhad

Theses and Dissertations

Steady flow at a breached levee is studied in this dissertation through a generalized model and a case study. The generalized experimental set-up consists of a main channel with an opening in its side wall and an adjustable sluice gate at its downstream end. Water surface elevation and the three-dimensional velocity field are measured by a point gauge and an Acoustic Doppler Velocimeter (ADV), respectively. Time-averaged measured values of velocity field and free surface elevation are presented. In addition, Froude Number, turbulent kinetic energy (TKE) and bed shear stress are computed from the measured results. Results show that the flow …

Syntactic And Semantic Interoperability Among Hydrologic Models, Mostafa Mohamed Elag

Theses and Dissertations

Development of integrated hydrologic models requires coupling of multidisciplinary, independent models and collaboration between different scientific communities. Component-based modeling provides an approach for the integration of models from different disciplines. A key advantage of component-based modeling is that it allows components to be created, tested, reused, extended, and maintained by a large group of model developers and end users. One significant challenge that must be addressed in creating an integrated hydrologic model using a component-based approach is enhancing the interoperability of components between different modeling communities and frameworks. The major goal of this work is to advance the integration of …

Quantifying Regional-Scale Water Storage Using Models And Observations: Application For Drought Assessment In South Carolina, Mirza Md Mozaddid Billah

Theses and Dissertations

Hydrologic models are widely used to determine the occurrence and severity of droughts, and to aid in the decision making process for reducing drought impacts. These models apply approaches including water and energy balance equations to determine water availability at field to continental scales. One challenge in implementing hydrologic models at larger scales (regional to continental) is the lack of data with sufficient spatial and temporal resolution to represent actual conditions within the modeling domain. If such data is available, the challenge remains how best to find, access, and process the data so that it can be used within hydrologic …

Acoustic Emission Source Characterization Of Fatigue Crack Extension In Steel Bridge Material, Md Mozahid Hossain

Theses and Dissertations

The probability of Acoustic Emission (AE) detection associated with fatigue crack extension in steel bridge components is a difficult problem due to the complexity of the AE sources. AE is a very promising technique for structural health monitoring and automated micro-crack detection as it is generated by the material itself, unlike other nondestructive testing techniques (for example impact echo and ultrasonics), which require external input sources. Characterizing the source of AE is an ongoing challenge because AE sensors are not only sensitive to the AE signals but also to mechanical noise and reflections. It is therefore difficult to interpret the …

Liquefaction Potential Of South Carolina Coastal Plain Soils Using Dilatometer Data, Joseph Ronald Williamson

Theses and Dissertations

In recent years much research has been focused on developing the flat plate dilatometer (DMT) as a tool to estimate the liquefaction potential of soils. Currently the DMT is over shadowed by the more accepted methods of estimating liquefaction potential which utilize test data from either the standard penetration test (SPT), cone penetration test (CPT), or shear wave velocity test (Vs). The SPT, CPT, and V_s tests are all well-developed methods of estimating liquefaction potential and are supported by extensive databases; however, the DMT is believed by many researchers to be the superior alternative. Due to the DMT's minimal …

Assessing Corrosion Damage In Post -Tensioned Concrete Structures Using Acoustic Emission & A Preliminary Investigation Of Biopolymer Doped Cement Mortar For Use In Structural Restoration, Aditya Appalla

Theses and Dissertations

A sizeable portion of the civil infrastructure is made from concrete. An estimate shows that about 7 billion cubic meters of concrete is made annually worldwide. With the deterioration of the infrastructure due to aging or external factors, significant monetary and technological investment is needed for condition evaluation, maintenance and repair. Two areas that account for a considerable portion of this investment are condition evaluation for maintenance of corroded concrete structures and mortar patching for repair and rehabilitation.

The primary method of evaluation of a structure is by visual inspection. But this method is limited as some crucial areas in …

Structural Design Of Flexible Etfe Atrium Enclosures Using A Cable-Spring Support System, Ryan Paul Bessey

Theses and Dissertations

This research designed and analyzed an innovative structural support system for ETFE (ethylene tetrafluoroethylene) atrium roofs between buildings. A cable-spring system was conceived, which is much lighter and more flexible than arches, frames, trusses, and beams which usually support ETFE roofs. Flexibility was a desirable property because the displacements may vary significantly among the buildings supporting the ETFE atrium roof during wind and seismic loading. The springs in the cable-spring system allow large differential displacements without exerting large support reactions on the buildings. The flexibility of the cable-spring system was compared to the cable-strut system which is used to support …

Complexity Of Bed-Load Transport In Gravel Bed Streams: Data Collection, Prediction, And Analysis, Darren D. Hinton

Theses and Dissertations

Bedload transport has long been known for its complexity. Despite decades of research, significant gaps of understanding exist in the ability to assess and predict bedload movement. This work introduces a comprehensive bedload database that is a compilation of field samples collected over the past 40 years; compares prediction formulae using a subset of the database; evaluates the influence of the armor layer on stream response to sediment input based on a hypothesis linked to one of the tested formulae, presents a mathematically manipulation of the empirical Pagosa Good/Fair formula for bedload transport into a format similar to the semi-empirical …

Best Practices Using Building Information Modeling In Commercial Construction, Simon Beveridge

Theses and Dissertations

There has been an increase in adoption of building information modeling (BIM) by commercial contractors over the past few years but there is not a clear indication of current application or the frequency of each use. This research was undertaken to determine the frequency and best practices of using BIM in commercial construction. Leading commercial contracting firms were contacted and employees were selected to complete a telephone survey that was designed to determine how they are using BIM. It was found that BIM is being used with more frequency on projects, with plans to continue to implement it even further …

Two-Refinement By Pillowing For Structured Hexahedral Meshes, J. Bruce Malone

Theses and Dissertations

A number of methods for adaptation of existing all-hexahedral grids by localized refinement have been developed; however, none ideally fit all refinement needs. This thesis presents the structure to a method of two-refinement developed for conformal, structured, all-hexahedral grids that offers flexibility beyond what has been offered to date. The method is fundamentally based on pillowing pairs of sheets of hexes. This thesis also suggests an implementation of the method, shows the results of examples refined using it and compares these results to results from implementing three-refinement on the same examples.

Seismic Response Of Stiffening Elastic Systems, Andrew Scott Morgan

Theses and Dissertations

Traditional seismic load resisting systems in buildings are designed to undergo inelastic deformations in order to dissipate energy, resulting in residual displacements. This work explores an approach to eliminate these residual displacements. The systems investigated have low initial stiffness which increases at a predefined displacement, and are therefore called stiffening elastic systems. This thesis begins with an examination of single-degree-of-freedom stiffening elastic systems. A case study is presented which suggests that the benefits from stiffening elastic behavior may be limited to systems which would have long periods if designed traditionally. A thorough parameter study is also presented which indicates the …

Evaluation Of The Degree Of Blending Of Reclaimed Asphalt Pavement (Rap) Binder For Warm Mix Asphalt, Luis Gaitan

Theses and Dissertations

The paving industry in recent years has seen the emergence of a plethora of warm mix asphalt (WMA) technologies and application. With most states incorporating a recycled asphalt pavement (RAP) limit, it is necessary for WMA to not only serve as a greener technology but to work in conjunction with current RAP practices. Presently, most agencies assume a full blending condition in their mixtures which may lead to under asphalted mixtures. The purpose of this study is to develop a methodology for quantifying the degree of blending that occurs in WMA RAP mixtures at higher percentages of RAP. In addition …

Lateral Resistance Of Piles Near Vertical Mse Abutment Walls, Jacob S. Price

Theses and Dissertations

Full scale lateral load tests were performed on five piles located at various distances behind MSE walls. Three of the five test piles were production piles used to support bridges, and the other two piles were located behind a MSE wing walls adjacent to the bridge abutment. The objective of the testing was to determine the effect of spacing from the wall on the lateral resistance of the piles and on the force resisted by the MSE reinforcement. Tentative curves have been developed showing p-multiplier vs. normalized spacing behind wall for a length to height ratio of 1.1 and 1.6. …

Buckling And Crippling Of Square Steel Thin-Walled Tubes Fabricated With Symmetrically-Overlapping U-Channels And Foam, David Camenish Gelder

Theses and Dissertations

Testing and analysis has been performed on square steel thin-walled tubes fabricated using symmetrically-overlapping U-channels and foam. This research analyzes flange-to-flange attachment, effect of foam in the columns, effect of adhesive stiffness, and influence of steel thickness, as related to the local buckling loads, global buckling loads, and crippling loads. Four 14-foot (4.27 m) foam-filled, thin-walled, galvanized steel columns were manufactured by Novatek, Inc. and tested in axial compression with pinned boundary conditions. For three of the four configurations, the two-piece 4-in. (10.2-cm) square shell surrounded prefabricated polystyrene foam inserts; the fourth column had no foam insert. The column outer …

A Comparative Study Of Strength And Stiffness Of Thin-Walled Specimens Fabricated By Fdm And 3d Printing Technologies, Miranda Rodrigo

Theses and Dissertations

Rapid Prototyped part failure constitutes a major issue for both RP providers and customers. When parts fail the reputation of the vendor is heavily deteriorated, customer dissatisfaction increase and replacement of the broken parts is often necessary to avoid the loss of future business. Product design teams often run into situations where Rapid Prototyped parts are not able to withstand shipping and handling and delivered broken or while demonstrating and examining the parts. When done in the face of customers this builds a perception of poor quality and lack of aptitude on the design group as well as the RP …

A Server-Based Tool For Automating Modflow Simulations For Well Permitting Decision Support, David J. Jones

Theses and Dissertations

Numeric groundwater modeling techniques can assist water resources regulators pursuing prudent and foresightful aquifer management decisions. Unfortunately, the amount of time and professional expertise required to wield modern groundwater models often exceeds the resources of regulating agencies – even for simple modeling tasks that are repetitive in nature. In an effort to increase the accessibility of groundwater modeling resources, a server-based automated well permitting decision support system was designed. The prototype system allows a user to 1) input properties for any number of candidate wells, 2) execute an associated MOFLOW model, and 3) view relevant results of the simulation on …

Culvert Roughness Elements For Native Utah Fish Passage: Phase Ii, Suzanne Kim Monk

Theses and Dissertations

Native fishes have become an increasingly important concern when designing fish passable culverts. Many operational culverts constrict waterways which increase velocities and prevent upstream passage of small fish species. The current method to ensure fish passage is to match the average cross sectional velocity to the sustained swim speed of the fish. This study investigates the passage rates of leatherside chub (Lepidomeda aliciae) and speckled dace (Rhinichthys osculus) at three sites (an arch culvert with substrate bottom, box culvert with bare bottom, and a stream section with no culvert) located on Salina Creek near Salina, UT. It was found that …

Principal Components Analysis, Factor Analysis And Trend Correlations Of Twenty-Eight Years Of Water Quality Data Of Deer Creek Reservoir, Utah, Nicolas Alejandro Gonzalez

Theses and Dissertations

I evaluated twenty-eight years (1980-2007) of spatial-temporal water quality data from Deer Creek Reservoir in Utah. The data came from three sampling points representing the lotic, transitional and lentic zones. The data included measurements of climatological, hydrological and water quality conditions at four depths; Surface, Above Thermocline, Below Thermocline and Bottom. The time frame spanned dates before and after the completion of the Jordanelle Reservoir (1987-1992), approximately fourteen miles upstream of Deer Creek. I compared temporal groupings and found that a traditional month distribution following standard seasons was not effective in characterizing the measured conditions; I developed a more representative …

Structural Properties Of Iclt Wall Panels Composed Of Beetle Killed Wood, David Edward Wilson

Theses and Dissertations

Interlocking Cross Laminated Timber (ICLT) wall panels are a new wood construction product similar to Cross Laminated Timber panels. Besides being an innovative structural system, they also utilize beetle killed timber from many of the forests that have been devastated by the Mountain Pine Beetle. Three tests were performed on three ply ICLT panels measuring 8 feet (2.44m) wide, 8 feet (2.44m) tall and 8.5 inches (21.6cm) thick to determine the racking, flexural and axial strengths of the wall panels. After each test was performed the walls were disassembled and investigated for cause of failure. Using the data from the …

High Reclaimed Asphalt Pavement In Hot Mix Asphalt, Alan Norton Jr

Theses and Dissertations

When old roads have to be replaced, the existing pavement, known as Reclaimed Asphalt Pavement (RAP) is ripped up, milled, and stockpiled and can be used in the creation of new mixes in order to save money and resources. New Jersey state specifications limit the percentage of RAP that can be used to 15% for surface courses and 25% for the intermediate and base courses; however, other states have implemented much higher RAP percentages. The limitations are placed because the interaction between the virgin and residual RAP binder is unknown, with respect to the amount of residual binder that is …

Reducing Residual Drift In Buckling-Restrained Braced Frames By Using Gravity Columns As Part Of A Dual System, Megan Boston

Theses and Dissertations

Severe earthquakes cause damage to buildings. One measure of damage is the residual drift. Large residual drifts suggest expensive repairs and could lead to complete loss of the building. As such, research has been conducted on how to reduce the residual drift. Recent research has focused on self-centering frames and dual systems, both of which increase the post-yield stiffness of the building during and after an earthquake. Self-centering systems have yet to be adopted into standard practice but dual systems are used regularly. Dual systems in steel buildings typically combine two types of traditional lateral force resisting systems such as …