Civil and Environmental Engineering Commons^™

Implementation And Testing Of Rans Turbulence Models For Stably Stratified Flows, Zachary A. Elliott, S. K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The presence of buoyancy forces due to stratification has a substantial effect on the flow development and mixing processes and hence influences the distribution of pollutants and suspended matter in environmental flows such as in reservoirs, lakes, and estuaries. In this study, we focus on the implementation and testing of proposed changes that explicitly account for buoyancy effects in Reynolds-averaged Navier-Stokes (RANS) turbulence models. Direct numerical simulation (DNS) data of stably stratified homogeneous turbulence are used to study the parameters in two-equation RANS turbulence models such as the buoyancy parameter Cε3, and the turbulent Prandtl number Prt in the k-ε …

Relating Climatic Attributes And Water Resources Allocation: A Study Using Surface Water Supply And Soil Moisture Indices In The Snake River Basin, Idaho, David J. Hoekema, Venkataramana Sridhar

Civil Engineering Faculty Publications and Presentations

Climate change forced by anthropogenic activities has been ongoing since at least the beginning of the industrial revolution. Part of the recent warming in the western United States has been attributed to anthropogenic climate change. This research seeks to answer the basic question of how declining streamflow, increasing temperatures, and fluctuation in precipitation have impacted water resource allocation in the Snake River Plain over the past 35 years (1971-2005). Understanding how changes in climatic attributes have historically impacted water allocation should help water managers better understand how projected climate change may influence allocation. Annual and monthly diversion trends from 62 …

Theoretical And Numerical Research On Sediment Transport In Pressurized Flow Conditions, Zhaoding Xie

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

Research of river bed erosion is an important part of designing bridges and transportation networks since the stability and hydrodynamic response of bridges critically depends on river bed scour. The engineering designers traditionally focus on the local scour around hydraulic structures, such as piers and abutments, in open channel flow. The pressurized scour under a submerged bridge deck is seldom researched.

In this study, the commercial CFD codes, FLOW3D and STARCCM+, are adopted to simulate pressure scour under a bridge deck with six girders. Several limitations for FLOW3D are found during its application of sediment transport model: a) the scour …

Buckling Of Profiled Steel Diaphragms, Rao V. Nunna

CCFSS Library (1939 - present)

No abstract provided.

Two-Dimensional Hydrodynamics Of Swimming Rainbow Trout Using Navier-Stokes And Large Eddy Simulation Models, Donovan R. Chipman

Theses and Dissertations

Energy efficiency and propulsive characteristics of a 10 cm undulatory rainbow trout (oncorhynchus mykiss) swimming in a stationary position are considered. Two CFD simulations are performed utilizing dynamic grid meshing (FLUENT 6.3). The first simulation uses a laminar flow model with an added hydrofoil shape in order to test if thrust and drag can be brought to unity. The second simulation uses a Large-Eddy Simulation (LES) turbulence model to determine if transition to turbulence along the fish's surface leads to boundary layer separation. The expected results caused by adding these two features to earlier simulations do not occur. …

Mapping And Modeling Chlorophyll-A Concentrations In Utah Lake Using Landsat 7 Etm+ Imagery, Victor Nii Afum Narteh

Theses and Dissertations

This study shows the results of testing previous research that used remote sensing techniques to determine chlorophyll-a concentrations in turbid surface waters, and developing similar methods and models for Utah Lake using Landsat 7 ETM+ satellite imagery and field measured concentrations of chlorophyll-a. The data for the study included images acquired on June 22 and July 8, 2009. The field data included ground measurements taken on June 22 and July 6, 2009 from seven water quality sampling locations. The 48 hour time difference between the Landsat image acquisition (July 8) and the field measurement (July 6), and the small sample …

Development Of Sstreamflow Projections Under Changing Climate Conditions Over Colorado River Basin Headwaters, W. P. Miller, Thomas C. Piechota, S. Gangopadhyay, T. Pruitt

Civil and Environmental Engineering and Construction Faculty Research

The current drought over the Colorado River Basin has raised concerns that the US Department of the Interior, Bureau of Reclamation (Reclamation) may impose water shortages over the lower portion of the basin for the first time in history. The guidelines that determine levels of shortage are affected by relatively short-term (3 to 7 month) forecasts determined by the Colorado Basin River Forecast Center (CBRFC) using the National Weather Service (NWS) River Forecasting System (RFS) hydrologic model. While these forecasts by the CBRFC are useful, water managers within the basin are interested in long-term projections of streamflow, particularly under changing …

Unintended Social And Economic Consequences Resulting From The Implementation Of New Construction Technologies In The Developing World, Andrew J. South

Theses and Dissertations

One of the key components of international development is to provide adequate shelter for citizens of developing countries. This is often accomplished by governmental, non- governmental, and private organizations that seek to lower the cost, increase the quality, and expand the availability of safe, sustainable housing through the use of innovative technologies. These new technologies can affect the social and/or economic structure within communities. This paper is a case study resulting from the construction of a seventy-one-home village, including infrastructure, near Yogyakarta, Indonesia by a foreign, aid-based non-governmental organization (NGO). The village was relocated less than two kilometers from its …

Civil Engineering And Construction News, Georgia Southern University

Civil Engineering & Construction: News & Publications (2011-2022)

• Georgia Southern University Civil Engineering Professor to Examine Performance of Rubberized Road Materials for Georgia Department of Transportation

Possibility Of Consolidated Wetland Mitigation In A Multi-Layered Legislated State, Juan P. Correa

Master's Theses

No abstract provided.

Friction Bit Joining Of 5754 Aluminum To Dp980 Ultra-High Strength Steel: A Feasibility Study, Britney Weickum

Theses and Dissertations

In this study, the dissimilar metals 5754 aluminum and DP980 ultra-high strength steel were joined using the friction bit joining (FBJ) process. The friction bits were made using one of three steels: 4140, 4340, or H13. Experiments were performed in lap shear, T-peel, and cross tension configurations, with the 0.070" thick 5754 aluminum alloy as the top layer through which the friction bit cut, and the 0.065" thick DP980 as the bottom layer to which the friction bit welded. All experiments were performed using a computer controlled welding machine that was purpose-built and provided by MegaStir Technologies. Through a series …

Green Building Policy, School Performance, And Educational Leaders’ Perspectives In Usa, Scott D. Kelting, Michael Montoya

Construction Management

The movement to construct high performance “green” buildings has had unprecedented market growth and continues to become mainstream practice for constructing schools in the United States. Green schools have economic, environmental and health benefits. Research provides information on the use of increased student performance found in green schools to justify building schools to a higher standard of indoor environment quality. There is clear and compelling evidence that schools currently built to specific green standards of indoor environmental quality, (e.g. thermal comfort, indoor air quality, acoustics and lighting,) result in healthier and more productive students and teachers. Current green building policies …

Fourier Finite Element Analysis Of Laterally Loaded Piles In Elastic Media Internal Geotechnical Report 2011-1, William Higgins, Dipanjan Basu

Technical Reports

Laterally loaded piles are analyzed using the Fourier finite element method. Pile response was observed to be a function of the relative stiffness of pile and soil and of the pile slenderness ratio. The analysis is mostly performed for piles embedded in elastic soil with constant and linearly varying modulus although the pile response in two-layer soil profiles is also investigated. Equations describing pile head deflection, rotation and maximum bending moment are proposed for flexible long piles and stubby rigid piles. The design equations were developed after plotting the pile responses as functions of pile-soil stiffness ratio and pile slenderness …

Sustainability In Geotechnical Engineering Internal Geotechnical Report 2011-2, Aditi Misra, Dipanjan Basu

Technical Reports

The built environment serves as a dynamic interface through which the human society and the ecosystem interact and influence each other. Understanding this interdependence is key to understanding sustainability as it applies to civil engineering. There is a growing consensus that delivering a sustainable built environment starts with incorporating sustainability thoughts at the planning and design stages of a project. Geotechnical engineering is the most resource intensive of all the civil engineering disciplines and can significantly influence the sustainability of infrastructure development because of its early position in the construction process. In this report, a review is made of the …

A Slurry Consolidation Approach To Reconstitute Low-Plasticity Silt Specimens For Laboratory Triaxial Testing, Shuying Wang, Ronaldo Luna, Richard Wesley Stephenson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Silt Specimen Reconstitution using a Slurry Consolidation Approach is Commonly Used for Laboratory Testing. This Paper Presents a New Slurry Consolidation Approach to Reconstitute Silt Specimens for Use in Triaxial Testing. Silt Specimens Were Reconstituted in a Split Vacuum Mold Mounted on a Special Experimental Setup. the Uniformity of the Reconstituted Specimens Was Verified by Measuring the Water Content and Grain Size Distribution throughout the Specimens. the Testing Program Was Expedited using a Special Sample Handling Technique to Move the Specimen from the Special Experimental Setup to the Triaxial Chamber Base Platen. the Handling Process Did Not Disturb the Specimens …

Climate Change Impacts: An Assessment For Water Resources Planning And Management In The Pacific Northwest Of The U.S, Venkataramana Sridhar, Xin Jin

Civil Engineering Faculty Publications and Presentations

Assessing the hydrological impacts of climate change in the Pacific Northwest (PNW) region of the United States is important. Many global circulation models (GCMs) have a wide range of temperature and precipitation predictions for the PNW region (Bureau of Reclamation, 2011). Numerous studies have reported that decreasing snow pack, increasing temperatures and decreasing streamflow for many basins. For instance, Mote (2003) indicates that annual average temperatures in the Northwest rose faster than the global average during the 20th century. This warming occurred mostly during the winter and spring. The predominance of winter and spring warming, especially in regard to extreme …

Dynamics Of Oxidized And Reduced Iron In A Northern Hardwood Forest, Colin B. Fuss, Charles T. Driscoll, Chris E. Johnson, Robert J. Petras, Timothy J. Fahey

Civil and Environmental Engineering - All Scholarship

Iron (Fe) is ubiquitous in forest ecosystems and its cycle is thought to influence the development of soil, particularly Spodosols (podsolization), and the biogeochemistry of macronutrients such as carbon (C), nitrogen (N), and phosphorus (P), as well as many trace metals. The cycle of Fe in northern hardwood forests remains poorly understood. To address some of these uncertainties, we constructed a biogeochemical budget of Fe for a small catchment at the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire, USA. Horizonal, temporal, and elevational patterns of concentrations and fluxes of oxidized and reduced Fe species were assessed …

Electromagnetic Waves In Contaminated Soils, Arvin Farid, Akram N. Alshawabkeh, Carey M. Rappaport

Civil Engineering Faculty Publications and Presentations

Soil is a complex, potentially heterogeneous, lossy, and dispersive medium. Modeling the propagation and scattering of electromagnetic (EM) waves in soil is, hence, more challenging than in air or in other less complex media. This chapter will explain fundamentals of the numerical modeling of EM wave propagation and scattering in soil through solving Maxwell’s equations using a finite difference time domain (FDTD) method. The chapter will explain how: (i) the lossy and dispersive soil medium (in both dry and fully water-saturated conditions), (ii) a fourth phase (anomaly), (iii) two different types of transmitting antennae (a monopole and a dipole), and …

A Study On Facility Planning Using Discrete Event Simulation: Case Study Of A Grain Delivery Terminal, Sarah M. Asio

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

The application of traditional approaches to the design of efficient facilities can be tedious and time consuming when uncertainty and a number of constraints exist. Queuing models and mathematical programming techniques are not able to capture the complex interaction between resources, the environment and space constraints for dynamic stochastic processes. In the following study discrete event simulation is applied to the facility planning process for a grain delivery terminal. The discrete event simulation approach has been applied to studies such as capacity planning and facility layout for a gasoline station and evaluating the resource requirements for a manufacturing facility. To …

Design, Behavior, And Performance Of Precast Concrete Bridge Barriers, Walid Rajab Alaywan

Doctoral Dissertations

The guidelines proposed by the NCHRP Report 350 pertaining to the safety of roadway hardware devices necessitated the evaluation of those devices. This study deals with the strength evaluation of precast concrete bridge railing.

A literature review was performed before the start of the study. Though many articles, reports, and publications were found regarding the testing of cast-in-place concrete barriers, such similar publications pertaining to precast concrete bridge railing were almost non-existent.

The theoretical work was performed using the yield line theory to predict the strength of the precast barrier. Though the theory was developed for cast-in-place barriers where the …

Remote Monitoring Of Bridges, Rajan Sen, Gray Mullins, Alberto Sagues, Julio Aguilar, Danny Winters

Civil and Environmental Engineering Faculty Publications

This report summarizes findings from a 24-month study in which the performance of cathodic protection systems for substructures of two interstate bridges was remotely monitored. The two bridges #860050 and #860054 are located on the “Alligator Alley” toll portion of eastbound I-75 in Broward County, FL. Each bridge spans two pilesupported piers inside a drainage canal. The seven steel H-piles supporting the piers are jacketed in concrete to a level just below the water surface and are cathodically protected by three magnesium anodes spaced uniformly over their submerged length.

Nitrogen Mass Balance In A High Rate Algal Pond, Kevin Jones

Biomedical Engineering

The objective of the study described herein was to perform a mass balance on nitrogen in four small high rate algal ponds (HRAPs) in order to determine the fate of the nitrogen. The total percentage of nitrogen lost via ammonia volatilization was calculated via the mass balance.

A Deterministic Method Of Predicting Long-Term Pile Capacity In Cohesive Soils After The Dissipation Of Excess Pore Water Pressure, Eric J. Steward

Doctoral Dissertations

Pile setup or freeze is a phenomenon where the bearing capacity of a pile increases over time both during and after the dissipation of pore pressure and the stabilization of lateral earth pressure. Driven piles gain capacity after installation because of the dissipation of excess pore pressure and soil aging. Incorporating accurate setup prediction into the design of the piles can significantly reduce the cost of many projects by reducing the size or number of required piles. Various simple, empirical mathematical models have been developed to predict pile setup. However, these models are often unreliable, resulting in very conservative designs. …

Predicting Deterioration Rate Of Culvert Structures Utilizing A Markov Model, Chenguang Yang

Doctoral Dissertations

A culvert is typically a hydraulic passage, normally placed perpendicular to the road alignment, which connects the upstream and downstream sections underneath an embankment, while also providing structural support for earth and traffic loads. The structural condition of culverts continues to deteriorate due to aging, limited maintenance budgets, and increased traffic loads. Maintaining the performance of culverts at acceptable levels is a priority for the U.S. Department of Transportation (DOT), and an effective maintenance of culvert structures can be greatly improved by introducing asset management practices. A priority list generated by traditional condition assessment might not provide optimum solutions, and …

Improved Bridge Expansion Joints, Sudhir Palle, Theodore Hopwood Ii, Bobby W. Meade

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) has both open and closed bridge expansion joints and associated details that are problematic. Several state highway agencies (SHA) have joints that they believe are superior performers to other types and have prepared guidance documents for their use. A literature search indicated that several previous research studies, including national surveys, addressing SHA joint practices have been conducted over the past 10 years. For up-to-date information, a new set of surveys were developed and distributed to all the SHAs by email through the AASHTO Subcommittee on Maintenance-Bridge Technical Working Group chairman in June 2010. There were …

Towards A Unified Definition Of Supply Chain Management, Edward Sweeney

Articles

A wide range of definitions of supply chain management (SCM) have been developed over the last three decades. The philosophy of SCM is based firmly on a recognition that it is only by working in a more integrated manner that competitive advantage can be maximised. However, for this to become a reality the development of common definitions and understandings between supply chain partners is a critical success factor. The corollary of this is that a lack of definitional consistency and a common understanding is an inhibitor to the successful adoption of SCM thinking in practice. This paper reviews a number …

A Case Study Analysis Of The Kentucky Transportation Cabinet’S Design/Build Pilot Projects, Paul M. Goodrum, Mohammad Moin Uddin, Bradley J. Faulkenberg

Kentucky Transportation Center Research Report

The current economic climate has forced transportation agencies to evaluate opportunities to save money. One possible opportunity lies in Design/Build (DB) delivery. In 2006, with the approval of the Kentucky General Assembly, The Kentucky Transportation Cabinet selected ten projects to be developed through the Design/Build method. DB delivery offers many attainable advantages, the most notable being expedited delivery. The research described herein presents a case study of these DB pilot projects in order to capture lessons learned on the use of the DB delivery method on future projects. In order to determine which projects are suitable for DB delivery, a …

The Effects Of Pedestrian Countdown Timers On Safety And Efficiency Of Operations At Signalized Intersections, Jacob N. Schmitz

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

Pedestrian countdown timers are becoming common at urban and suburban intersections. The added information that pedestrian countdown timers provide to pedestrians can also be used by approaching drivers. A before and after case study on the effects that pedestrian countdown timers have on safety and efficiency of operations was performed at two signalized intersections in Lincoln, Nebraska. The effects on both drivers and pedestrians were analyzed. Performance measures for pedestrian analysis include pedestrian compliance and average pedestrian walking speed. Performance measures for the driver analysis include probability of stopping and speed at the stop bar of vehicles during the yellow …

A Simplified Method For Analyzing Factors Contributing To Motorcyclists’ Fatal Injuries In Ohio, Deogratias Eustace, Vamsi Krishna Indupuru

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

The aim of this paper was to analyze traffic crash data by using a simplified method in determining significant factors that increase the risk of a motorcyclist being fatally injured once involved in a motorcycle crash in Ohio. The concept of overrepresentation, which is similar to relative risk, was used in identifying significant variables associated with the elevated risk of a motorcycle crash resulting into a fatality. The overrepresentation factor (ORF) was calculated for each variable of interest. The ORF offers a simple but powerful procedure of determining whether a certain factor significantly occurs more or less frequently in one …

Identification Of Risk Factors Associated With Motorcycle-Related Fatalities In Ohio, Deogratias Eustace, Vamsi Krishna Indupuru, Peter W. Hovey

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

Out of the 7,138,476 motorcycles operating on U.S. roads, 346,925 were registered in the state of Ohio in the year 2007. Although motorcycles represent only 2.8% of all registered vehicles in the state of Ohio, motorcycling accounts for more than 13% of Ohio highway traffic fatalities. Since 2005, Ohio has had a distressing distinction of being among the fifteen states that have sustained more than half of all motorcycle fatalities recorded in the USA (NHTSA 2007; NHTSA 2008a). For the past ten years, the overall motorcycle crash fatalities have been increasing while the motor vehicle occupant crash fatalities have been …