Engineering Commons^™

An Assessment Of The Accuracy Of The Euler-Bernoulli Beam Theory For Calculating Strain And Deflection In Composite Sandwich Beams, Qhinhon D. Ho

University of New Orleans Theses and Dissertations

This study focuses on assessing the accuracy of the Euler-Bernoulli beam theory as computational bases to calculate strain and deflection of composite sandwich beam subjected to three-point and four-point bending. Two groups of composite sandwich beams tests results will be used for comparison purposes. Mechanical properties for the laminated skin are provided by researchers from University of Mississippi (Ellen Lackey et al., 2000). Mechanical properties for the balsa wood core are provided by Alcan Baltek Corporation. Appropriate material properties and test geometries are then used in the Euler-Bernoulli-based algorithm in order to generate analytical data for comparison to experimental data …

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 …

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 …

Assessment Of Classifiers For Potential Voice-Enabled Transportation Apps, Md Majbah Uddin

Theses and Dissertations

Transportation apps are playing a positive role for today’s technology-driven users. They provide users with a convenient and flexible tool to access transportation data and services, as well as collect and manage data. In many of these apps, such as Google Maps, their operations rely on the effectiveness of the voice recognition system. For the existing and new apps to be truly effective, the built-in voice recognition system needs to be robust (i.e., being able to recognize words spoken in different pitch and tone). The goal of this study is to assess three post-processing classifiers (i.e., bag-of-sentences, support vector machine, …

Slope Stability Enhancement Of An Upstream Tailings Dam: Laboratory Testing And Numerical Modelling, Yazeed A. Alsharedah

Electronic Thesis and Dissertation Repository

Mine tailings are the byproduct of mining activities, which need to be disposed of once the ore is extracted. They can be disposed of in either dry or wet forms. The latter is most common with the tailings being disposed of in the form of slurry inside retention structures. The retention structure may be a natural, manmade, or built dam, which is the case in most of nowadays mining locations. In this thesis, improving the stability of an upstream tailings dam using soil additives is investigated. The experimental phase of this study involved laboratory tests conducted to characterize mine tailings …

Site Development At The Corner Of Drake And Stadium, Ahmad Sear Rahimi

Honors Theses

This report presents the site layout alternatives for the development located at the corner of Drake and Stadium in Kalamazoo, Michigan. In the report four different layouts are suggested and followed by best management practices for grading and earthwork plans, porous asphalt pavement design, storm water retention design for the proposed site, and storm sewer pipe design. The redesign of the Costco Development Site aims to maximize efficiency of the development area through the warehouse and gas station location, parking lot layout, and trucking routes. Grading design is developed based on the existing site conditions before construction took place. The …

The Aerodynamic And Dynamic Loading Of A Slender Structure By An Impacting Tornado-Like Vortex: The Influence Of Relative Vortex-To-Structure Size On Structural Loading, Matthew Nicholas Strasser

Graduate Theses and Dissertations

Structural loading produced by an impacting vortex is a hazardous phenomenon that is encountered in numerous applications ranging from the destruction of residences by tornados to the chopping of tip vortices by rotors. Adequate design of structures to resist vortex-induced structural loading necessitates study of the phenomenon that control the structural loading produced by an impacting vortex. This body of work extends the current knowledge base of vortex-structure interaction by evaluating the influence of the relative vortex-to-structure size on the structural loading that the vortex produces. A computer model is utilized to directly simulate the two-dimensional impact of an impinging …

Application Of Polyacrylamide-Based Floc Logs For Turbidity Control At Highway Construction Sites, Kien Ngo

Graduate Theses and Dissertations

Runoff waters generated on highway construction sites can have turbidities in excess of the proposed EPA regulatory standard of 280 NTU due to large areas of exposed soil. The objective of this research was to develop best management practices (BMPs) for the use of anionic polyacrylamide (PAM) based Floc Logs, for turbidity control. Five commercially available types of PAM-based Floc Logs were evaluated in jar tests, using soil excavated from Cato Springs Research Center (CSRC, Fayetteville AR) and six types of clay from the Clay Minerals Society (Chantilly, VA). These results show that no single Floc Log type was suitable …

Assessing The Water Quality Benefits Of Green Infrastructure Stormwater Control Measures., Sam Abdollahian

Electronic Theses and Dissertations

Permeable pavements systems and tree boxes are a common type of Green Infrastructure (GI) Stormwater Control Measures (SCMs) that are often used for mitigating the stormwater runoff. In this study two permeable pavement systems and a tree box installed along parking lanes of an urban street in Louisville, KY, were investigated to evaluate their performance on improving stormwater runoff quality. The water quality monitoring was accomplished by analysis of samples collected from stormwater runoff and the captured stormwater volume at the bottom of the permeable pavements’ sub-base reservoir and by a drain gauge (lysimeter) installed in the tree box. Pollutants …

Bankfull Geomorphic Relationships And Hec-Ras Assessment In Small Catchments Of The Cumberland Plateau Ecoregion, Ryan Lee Hodges

Masters Theses

There is a great need for state governments to have effective watershed restoration and mitigation efforts to return degraded ecosystems to a stable, healthy condition. Given the growing investment in stream restoration efforts, there is an urgent need for tools to assess and improve the effectiveness of restoration efforts at local, state, and nationwide scales. In 2000 there was less than ten stream restoration permits provided by the state of Tennessee and has increased each year with almost forty permits issued in 2013. To better achieve successful stream restoration, appropriate channel designs must be used that reflect the hydraulic conditions …

Experimental Evaluation Of Beneficial Use Of Lake Michigan Dredged Materials In Flyash Based Geopolymer Concrete, Sara Dashti

Theses and Dissertations

Dredging harbors and rivers are necessary to maintain the appropriate water depth for navigation. However the disposal facilities for storing dredged materials around the U.S. Great Lakes are at or near their capacities and finding beneficial uses for these materials is a major concern. On the other hand, carbon emission and global warming have become the greatest environmental issues during the last decade. Cement manufacturing is a major contributor to CO2 release into the atmosphere. The objective of this study was to develop a low-cost, environment-friendly geopolymer concrete paste with dredged materials as a substantial mix ingredient. Geopolymer concrete does …

Robust Model Development For Evaluation Of Existing Structures, Saurabh Prabhu

All Dissertations

In the context of scientific computing, validation aims to determine the worthiness of a model in supporting critical decision making. This determination must occur given the imperfections in the mathematical representation resulting from the unavoidable idealizations of physics phenomena. Uncertainty in parameter values furthers the validation problems due to the inevitable lack of information about material properties, boundary conditions, loads, etc. which must be taken into account in making predictions about structural response. The determination of worthiness then becomes assessing whether an unavoidably imperfect mathematical model, subjected to poorly known input parameters, can predict sufficiently well in its intended purpose. …

Investigation Into Mechanisms And Mitigation Of Alkali-Silica Reaction In Sustainable Portland Cement Concrete Containing Recycled Glass Materials, Kaveh Afshinnia

All Dissertations

A significant portion of recycled glass from municipal waste streams is not found to be suitable for reuse as cullet in the production of new glass containers, and as a result it is disposed in landfills. One of the appropriate ways to reduce the disposal of waste glass in landfills is by using it in portland cement concrete as an aggregate material and/or supplementary cementitious material to replace portion of portland cement. The high silica content of the soda glass (approximately 70%) can potentially behave as a pozzolanic material when finely ground, which may enhance the mechanical and durability properties …

Improving The Implementation Of Pavement Preservation Strategies In South Carolina, Franklin Reed

All Theses

With compounding budget constraints on infrastructure, cost effective solutions to maintain roadways are becoming increasingly important. Pavement preservation provides a cost effective option to keep the roadway network at an acceptable level. However, pavement preservation is a relatively new concept that many states have not fully implemented successfully. This research supports efforts to improve the pavement preservation practices in the state of South Carolina. It analyzes the current pavement preservation practices in South Carolina as well as other states to identify where improvements could be made. The research also outlines a treatment tracking program for the state of South Carolina …

Behavior Of Buried Composite Arch Bridges, Harold J. Walton

Electronic Theses and Dissertations

This dissertation presents experimental results and numerical analysis for short-span buried composite arch bridges whose main structural members are concrete-filled fiber reinforced polymer (FRP) tube arches (CFFTs). This investigation focuses on soil- structure interaction of the bridge system to expand understanding beyond isolated arch performance. Soil plays several roles: weight on the structure, restraining arch movement, and dissipating surficial truck loads.

Investigation focused on experimental and numerical analysis of subscale bridge systems. Four bridge systems were constructed with two different span-to-rise ratios (5:1 and 2.67:1) and two different materials (linear-elastic steel and CFFT). Tested systems were half-scaled from commercial bridge …

A Robust Data Exchange Framework For Connected Vehicle Technology Supported Dynamic Transit Operations, Yucheng An

All Theses

Transit systems are an integral part of surface transportation systems. A connected vehicle technology (CVT) supported transit system will assist the users to manage trips both dynamically and efficiently. The primary focus of this research is to develop and evaluate the performance of a secure, scalable, and resilient data exchange framework. In the developed data exchange framework, a new data analytics layer, named Transit Cloud, is used to receive data from different sources, and send it to different users for a Dynamic Transit Operations (DTO) application. The DTO application allows the transit users to request trip information and obtain itineraries, …

Condition Assessment Of Clemson University's Parking Network And Development Of A Framework To Support Pavement Management, Yazurved Sai Vishwaksen Aravalli

All Theses

The concept of pavement management system for Clemson University parking network provides a rehabilitation programming strategy for parking and transportation services department at Clemson University. The department invests funds to keep parking lots in good condition which pays large rewards in terms of savings for both Clemson University and parking lot users. Clemson University Pavement Management System (CU-PMS) will provide quality information for better decisions to ensure the funds invested gets the best value. This project consists of developing a useful and efficient network-level PMS for Clemson University parking lot network. The study area includes all the parking lots in …

Comparative Analysis Of Buckling-Restrained Braced Frames In Eccentric Configuration (Brbf-Es) And Eccentrically Braced Frames (Ebfs), Peter T. Vayda

Civil Engineering Undergraduate Honors Theses

Continuing on the findings of “Using Buckling-Restrained Braced Frames in Eccentric Configuration,” by Dr. Gary S. Prinz, P.E., which determined that, from a performance standpoint, BRBF-Es could be a viable alternative for EBFs. A comparative analysis was conducted on the design procedures and initial cost estimates of BRBF-Es and EBFs. Upon designing four 12-Story buildings (two BRBF-Es and two EBFs), it was determined that BRBF-Es were easier to design due to the statically determinant system. The initial costs estimates of BRBF-Es; however, ranged upwards of 30% more cost than EBFs. Therefore, the initial investment of more intensive structural engineering design …

Proportioning And Properties Of Ultra-High Performance Concrete Mixtures For Application In Shear Keys Of Precast Concrete Bridges, Zhengqi Li

All Dissertations

Ultra-high performance concrete (UHPC) is defined as a cementitious based composite material with compressive strengths above 150 MPa, pre-and post-cracking tensile strengths above 5 MPa, and enhanced durability. To achieve desired properties, UHPC is typically produced with low water-cementitious materials (w/cm) ratio (i.e. w/cm < 0.25), high cementitious materials content (i.e. >1000 kg/m3), high quality aggregate, high dosage of high-range water reducing admixture (HRWRA) and reinforcing fibers. UHPC has distinct advantages in applications where narrow formwork and dense reinforcement are inevitable, high compressive strength concrete material is required and the surrounding environment is aggressive. The construction of shear keys in precast bridges is one of the important …

Operational Analysis Of Traditional Access Management Strategies & Demand-Responsive Access Control On Arterials, Joshua Mitchell

All Theses

Arterials are typically characterized by closely-spaced signalized intersections, high driveway density, and high traffic volumes. These characteristics contribute to congestion, as well as crashes. Access management strategies can address both operational and safety issues on urban arterials. This research focuses on the operational impacts of access management with two objectives: (1) quantify the impacts of ‘traditional’ access management strategies and (2) quantify the impacts of demand-responsive access control. To satisfy Objective 1, four traditional access management strategies were tested – (i) access spacing, (ii) corner clearance, (iii) access restriction, and (iv) raised median implementation. These were analyzed in four respective …

Design And Analysis Of Foundation For Onshore Tall Wind Turbines, Shweta Shrestha

All Theses

Wind turbines play a vital role in producing sustainable and clean energy to fulfill the growing energy needs. Energy generated from wind turbines being more sustainable and cost effective, many countries have taken a major step to develop wind turbines with large capacity. There has been a significant reduction in the levelized cost of energy (LCOE) since the 1980’s from the development of larger wind farms and from consistent performance improvements of wind turbine components. The power generation capacity of wind turbines has increased significantly over the years with the use of taller towers. When the tower height increases, the …

Shear Behavior Of Steel-Fiber Reinforced Ultra-High-Strength Self-Compacted Concrete Beams, Omar Jum’Ah Za’Al Al Rawashdeh

Theses

Ultra-high-strength concrete is a new class of concrete that has been the result of the progress in concrete material science and development. This new type of concrete is characterized with very high compressive strength; about 100 MPa. Ultra-high strength concrete shows very brittle failure behavior compared to normal-strength concrete. Steel fibers will significantly reduce the workability of ultra-high strength concrete. The development and use of self-compacting concrete has provided a solution to the workability issue. The combination of technology and knowledge to produce Ultra-High strength fiber reinforced self-compacting concrete was proved to be feasible. Few studies investigated the effect of …

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …

Safety Analysis Of Freeway Segments With Unobserved Heterogeneity And Second Order Spatial Effects, Eneliko Mujuni Mulokozi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Safety analysis of freeway networks entails the quantification of crash frequency influencing factors which include roadway and traffic characteristics, environmental factors as well as human factors. This quantification can be used to detect locations with large impacts on the occurrence of crashes which in turn assist engineers and planners to improve safety levels of the network. Roadway characteristics are comprised of the physical elements of the road geometry such as section length, median and right shoulders, speed-exchange lanes, the number of main facility as well as geometry of the entrance from and exit to the main freeway facility. Traffic characteristics …

A Multi-~Procedural Approach To Evaluating Walkability And Pedestrian Safety, Peris Nyagah

UNLV Theses, Dissertations, Professional Papers, and Capstones

Walking has sound health benefits and tends to be a pleasurable experience requiring no fuel, fare, license, nor registration. Whilst walking is recommended as part of physical activity, it is necessary to provide a conducive and safe walking environment. In an effort to determine an optimum combination of infrastructure that would create walkable, transit-oriented neighborhoods eliminating unnecessary motorized trips; various approaches evaluating an assortment of features in the walking environment have been implemented. However, some factors such as crash risk which have an essential contribution to the suitability of the walking environment have yet to be considered. Therefore the objective …

Alkali-~Activated Fly Ash Binders: Feasibility As A Sustainable Alternative To Ordinary Portland Cement For Pre-~Cast Systems, Kimberly Sierra

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fresh, load-dependent, transport, and durability properties of alkali-activated fly ash mortars were studied. The influences of activator concentration, solution-to-binder ratio, curing condition, activator type, and sodium silicate-to-total solution ratio on the properties of the studied alkali-activated mortars were examined. This study was divided in two phases. The first phase dealt with the use of sodium hydroxide as the sole activator. The second phase of the study was divided into two parts, both of which used a combination of sodium hydroxide and sodium silicate as the activator solution. Part I of phase II used elevated temperature curing conditions, whereas part II …

Hydrodynamic Modeling Of The Green Bay Of Lake Michigan Using The Environmental Fluid Dynamics Code, Paula Estefania Cedillo

Theses and Dissertations

In this project we created a hydrodynamic model of the Lower Green Bay of Lake Michigan in Wisconsin, United States using the Visual Environmental Fluid Dynamics Code (EFDC). The model includes four tributary rivers to Lower Green Bay as well as the open boundary flow conditions at Chambers Island. This case study is used to: 1) compare the results obtained with a previous study of Lower Green Bay to validate the creation of the model 2) examine the hydrodynamics of the bay, and 3) create a framework for future studies at Lower Green Bay. The Geographic Information used to build …

Practical Robust Geotechnical Design- Methodology And Applications, Sara Khoshnevisan

All Dissertations

This dissertation advances the robust geotechnical design methodology by offering improvements, which makes it more efficient and practical for the design of geotechnical systems. Robust geotechnical design (RGD) methodology seeks an optimal design, which is insensitive to, or robust against, the variation in the uncertain input parameters (called “noise factors”) by only adjusting the easy to control parameters (called “design parameters”). The main goal of robust design is to consider safety, cost and robustness simultaneously. Because the cost and the robustness are conflicting objectives, the multi-objective optimization that considers these two objectives while enforcing the safety constraint yields not a …

Corrosion Of Steel In Submerged Concrete Structures, Michael Thomas Walsh

USF Tampa Graduate Theses and Dissertations

This investigation determined that severe corrosion of steel can occur in the submerged portions of reinforced concrete structures in marine environments. Field studies of decommissioned pilings from actual bridges revealed multiple instances of strong corrosion localization, showing appreciable local loss of steel cross-section. Quantitative understanding of the phenomenon and its causes was developed and articulated in the form of a predictive model. The predictive model output was consistent with both the corrosion rate estimates and the extent of corrosion localization observed in the field observations. The most likely explanation for the observed phenomena that emerged from the understanding and modeling …

An Analysis Of Partial-Depth, Floating, Impermeable Guidance Structures For Downstream Fish Passage At Hydroelectric Facilities, Kevin Mulligan

Doctoral Dissertations

Partial-depth, impermeable guidance structures (or guide walls) are used to enhance downstream passage effectiveness at a hydroelectric facility by actively guiding fish to a safe passage route (i.e. the bypass). Guide walls have been installed in a variety of ways and, like many fish passage devices, have resulted in variable efficiency rates. Currently, the most common type of installment is a steel panel guide wall attached to a floating boom. While less utilized than other guidance structure options (e.g. louvers and bar racks), guide walls have been gaining popularity, particularly within the Northwest United States. The aim of this dissertation …