Civil Engineering Commons^™

Optimisation Of Cold-Formed Steel Purlin Cross-Sections, Matt Clifford

Theses

The subject of buckling of steel members is introduced and the critical nature of local buckling in slender members is highlighted.

The main thrust of work this semester is an investigation into the following buckling modes:

Flexural buckling;

Lateral torsional buckling;

Torsional buckling;

Shear buckling;

Web buckling;

Distortional buckling;

Local buckling.

This investigation has three main components:

1. Review of theory, books and appropriate published work;

2. Investigation into the relevant parts of Eurocode 3;

3. Finite element analysis using the LUSAS FE program to illustrate the various buckling modes.

Finally, the areas to be covered in the Realisation Stage …

Distribution Analysis Of Freight Transportation With Gravity Model And Genetic Algorithm, Jun Duanmu, Peter Foytik, Asad Khattak, R. Michael Robinson

VMASC Publications

The application of a gravity model in freight modeling work on both short-haul and long-haul trips is discussed. A commodity-based gravity model was developed to assess the distribution of freight by long-haul trucks in southeastern Virginia. Although gravity models have been used extensively in transportation studies, little work has been done to address the special characteristics of freight transportation, such as the definition of friction factors and the differences between long-haul and short-haul trips. Results of a recent study of these and similar problems provide valuable insight into freight distribution modeling. A new calibration method that used a genetic algorithm …

Structural Identification Through Monitoring, Modeling And Predictive Analysis Under Uncertainty, Hasan Burak Gökçe

Electronic Theses and Dissertations

Bridges are critical components of highway networks, which provide mobility and economical vitality to a nation. Ensuring the safety and regular operation as well as accurate structural assessment of bridges is essential. Structural Identification (St-Id) can be utilized for better assessment of structures by integrating experimental and analytical technologies in support of decision-making. St-Id is defined as creating parametric or nonparametric models to characterize structural behavior based on structural health monitoring (SHM) data. In a recent study by the ASCE St-Id Committee, St-Id framework is given in six steps, including modeling, experimentation and ultimately decision making for estimating the performance …

Engineering Characteristics Of Recyled Plastic Pin, Lumber And Bamboo For Soil Slope Stabilization, Faisal Shakib Ahmed

Civil Engineering Theses - Archive

Shallow slope failures are predominant in North Texas and pose a significant maintenance problem. The traditional slope repair and stabilization techniques become expensive in some instances with direct costs associated in maintenance and repair of landslides. A new approach for slope stabilization has been developed using Recycled Plastic Pins ( RPP) to reinforce slope movements. The engineering properties of RPP in compression and bending strength along with environmental considerations dictate the design and repair of slopes using RPP. Two other materials have also been considered as an alternative: (1) Wood lumber and (2) Bamboo. Wood has many advantages as an …

Development Of A Flexible Pavement Design Procedure Based On The Mechanistic - Empirical Pavement Design Guide: A Case Study, Ali Qays Abdullah

Civil Engineering Theses - Archive

This research developed design tables of new flexible pavement structures for New York State Department of Transportation based on the Mechanistic Empirical Design Guide (MEPDG). The design tables were developed using the MEPDG software for Regions 1, 3, and 7 for Upstate part of New York State and for Regions 8, 10, and 11 for the Downstate part of New York State. The MEPDG software was used to run design cases for combinations of: climate conditions, traffic volume, subgrade soil stiffness (Mr) and pavement structures. The conditions that the MEPDG was used to run were: the road structures classified as …

Shear Strength Of Web-Tapered I-Shaped Members, Ryan Paul Studer

Theses and Dissertations--Civil Engineering

Plate girders are fabricated in situations where standard structural shapes do not possess the required strength necessary to carry applied loads. In many instances, plate girders are tapered so that the resistance to bending is proportional to the bending moment, creating cost effective, aesthetically pleasing structures. The AISC 2010 Specifications accurately predict the flexural capacity of tapered plate girders but recent research has suggested that the required shear strength is overly conservative. The researchers postulate that the required shear strength is overly conservative due to an effect known as modified shear that has been neglected from the AISC 2010 Specifications …

An Innovative Approach To Mechanistic Empirical Pavement Design, Ronnie Clark Graves Ii

Theses and Dissertations--Civil Engineering

The Mechanistic Empirical Pavement Design Guide (MEPDG) developed by the National Cooperative Highway Research Program (NCHRP) project 1-37A, is a very powerful tool for the design and analysis of pavements. The designer utilizes an iterative process to select design parameters and predict performance, if the performance is not acceptable they must change design parameters until an acceptable design is achieved.

The design process has more than 100 input parameters across many areas, including, climatic conditions, material properties for each layer of the pavement, and information about the truck traffic anticipated. Many of these parameters are known to have insignificant influence …

Risk Management In Reservoir Operations In The Context Of Undefined Competitive Consumption, Yunus Salami

Electronic Theses and Dissertations

Dams and reservoirs with multiple purposes require effective management to fully realize their purposes and maximize efficiency. For instance, a reservoir intended mainly for the purposes of flood control and hydropower generation may result in a system with primary objectives that conflict with each other. This is because higher hydraulic heads are required to achieve the hydropower generation objective while relatively lower reservoir levels are required to fulfill flood control objectives. Protracted imbalances between these two could increase the susceptibility of the system to risks of water shortage or flood, depending on inflow volumes and operational policy effectiveness. The magnitudes …

Biogeochemical Cycling And Nutrient Control Strategies For Groundwater At Stormwater Infiltration Basins, Andrew M. O'Reilly

Electronic Theses and Dissertations

Elevated concentrations of nutrients, particularly nitrate, in groundwater and springs in Florida are a growing resource management concern. Stormwater infiltration basins, which are a common stormwater management practice in the well-drained karst terrain areas of Florida, are a potentially important source of nutrients to the groundwater system because stormwater exits the basin by only evaporation or infiltration. To better understand the biogeochemical processes integrating stormwater infiltration impacts on groundwater resources in a field-scale setting, a combination of hydrologic, soil chemistry, water chemistry, dissolved and soil gas, isotope, and microbiological data was collected from 2007 through 2010 at two stormwater infiltration …

Microscopic Assessment Of Transportation Emissions On Limited Access Highways, Hatem Abou-Senna

Electronic Theses and Dissertations

On-road vehicles are a major source of transportation carbon dioxide (CO2) greenhouse gas emissions in all the developed countries, and in many of the developing countries in the world. Similarly, several criteria air pollutants are associated with transportation, e.g., carbon monoxide (CO), nitrogen oxides (NOx), and particulate matter (PM). The need to accurately quantify transportation-related emissions from vehicles is essential. Transportation agencies and researchers in the past have estimated emissions using one average speed and volume on a long stretch of roadway. With MOVES, there is an opportunity for higher precision and accuracy. Integrating a microscopic traffic simulation model (such …

Effluent Water Quality Improvement Using Silt Fences And Stormwater Harvesting, Ikiensinma Gogo-Abite

Electronic Theses and Dissertations

Construction sites are among the most common areas to experience soil erosion and sediment transport due to the mandatory foundation tasks such as excavation and land grubbing. Thus, temporary sediment barriers are installed along the perimeter to prevent sediment transport from the site. Erosion and sediment transport control measures may include, but not limited to, physical and chemical processes such as the use of a silt fence and polyacrylamide product. Runoff from construction sites and other impervious surfaces are routinely discharged into ponds for treatment before being released into a receiving water body. Stormwater harvesting from a pond for irrigation …

Incorporating Remotely Sensed Data Into Coastal Hydrodynamic Models: Parameterization Of Surface Roughness And Spatio-Temporal Validation Of Inundation Area, Stephen Conroy Medeiros

Electronic Theses and Dissertations

This dissertation investigates the use of remotely sensed data in coastal tide and inundation models, specifically how these data could be more effectively integrated into model construction and performance assessment techniques. It includes a review of numerical wetting and drying algorithms, a method for constructing a seamless digital terrain model including the handling of tidal datums, an investigation into the accuracy of land use / land cover (LULC) based surface roughness parameterization schemes, an application of a cutting edge remotely sensed inundation detection method to assess the performance of a tidal model, and a preliminary investigation into using 3-dimensional airborne …

A Framework For Process Data Collection, Analysis, And Visualization In Construction Projects, Reza Akhavian

Electronic Theses and Dissertations

Automated data collection, simulation and visualization can substantially enhance the process of designing, analysis, planning, and control of many engineering processes. In particular, managing processes that are dynamic in nature can significantly benefit from such techniques. Construction projects are good examples of such processes where a variety of equipment and resources constantly interact inside an evolving environment. Management of such settings requires a platform capable of providing decision-makers with updated information about the status of project entities and assisting site personnel making critical decisions under uncertainty. To this end, the current practice of using historical data or expert judgments as …

Geospatial Assessment Of Sustainable Built Infrastructure Assets And Flood Disaster Protection, Alper Durmus

Electronic Theses and Dissertations

This research was initiated with a review and synthesis of infrastructure related to city and urban growth, built infrastructure to meet transportation needs and travel demand, and role of mass transit in reducing adverse impacts on the environment and greenhouse gas emissions. Floods are the most frequently occurring natural disaster in the world, which so far claimed millions of lives and resulted in billion-dollar economic costs. Built infrastructure assets in urban and rural areas are not spared from floods' aftermath. A major motivation for this thesis was the 2011 megaflood disaster of Thailand which devastated the green campus of Asian …

Geohazard Potential Of Rainfall Induced Slope Failure On Expansive Clay, Jubair Hossain

Civil Engineering Dissertations - Archive

Each year, rain induced slope failures cause significant damages in highway infrastructures and environments, as well as tragic losses of human lives around the world. Rainfall-induced slope failure is a common problem in areas with slope constructed on high plasticity clays. These post failure costs can be significantly reduced if precautions are taken ahead of time. Development of an early hazard warning system based on weather forecast data can help identify potential slopes susceptible to failure due to rainfall. But development of such system will require a better understanding of the in situ behavior of soil due to rainwater infiltration …

An Evaluation Of Large Diameter Steel Water Pipelines, Tushar Joshi

Civil Engineering Theses - Archive

Steel water pipelines, as a part of America's underground infrastructure, play a key role in maintaining the quality of life and well-being of communities. Thousands of miles of steel water pipelines make up a huge and complex water transmission system. This complexity generates the necessity for research on underground infrastructure in general and steel pipelines in particular. The objective of this research is to evaluate performance of large diameter (24 in. and larger) steel water pipelines. This research objective was achieved by use of a survey of various North American water utilities to provide details about their inventory. This data …

Degradation Of Triclosan By Sulfate Radicals Generated By Metal-Mediated Activation Of Oxidants, Prince Albert Nfodzo

Civil Engineering Dissertations - Archive

The presence of persistent and toxic compounds, especially pharmaceuticals and personal care products (PPCPs) in water resources has generated considerable scientific, regulatory, and public interests, requiring the development of cost-effective technologies for the management of PPCPs-contaminated water resources. In particular, triclosan (TCS, 5-chloro-2-(2,4-dichlorophenoxy)phenol), an important antimicrobial agent widely used in many PPCPs, has attracted significant attention due to its potential endocrine disrupting capabilities. In order to address these concerns, advanced oxidation processes (AOPs), resulting in the generation of stronger oxidizing species, typically hydroxyl radicals (HRs) and sulfate radicals (SRs), have been studied and proposed to be effective to degrade a …

An Improved Model For Predicting Methane Emissions From Landfills Based On Rainfall, Ambient Temperature And Waste Composition, Richa Vijay Karanjekar

Civil Engineering Dissertations - Archive

Accurately estimating the emissions of methane (CH4) and carbon dioxide (CO2) in a landfill is important for quantifying its greenhouse gas (GHG) emissions and power generation potential. Previous studies have shown that variation in waste composition, rainfall and ambient temperature of a landfill significantly influences its methane generation potential. Current methane generation models, namely U.S. Environmental Protection Agency's (EPA) Landfill Gas Generation Model (LandGEM) and Intergovernmental Panel on Climate Change's (IPCC) methane generation model, are overly simplified and do not account for the variations in waste composition, rainfall and ambient temperature. The goal of this research was to improve our …

Development Of A New Device To Evaluate Stabilization Durability Of Expansive Soils By Addressing Wetting/Drying And Leachate Issues, Priya Pravin Lad

Civil Engineering Theses - Archive

Expansive soils have been known to cause deterioration among all aspects of civil infrastructure for many years primarily due to the presence of clay minerals like Montmorillonite. Replacing these problematic soils is not a viable solution in that it is costly and time consuming.Although many stabilization techniques are available, chemical stabilization has proven to be an important tool in arresting the swell/shrink behavior of expansive soil, which is a major source of distress problems for most infrastructures built on this type of soils. Of the chemical stabilizers available in the market, lime and cement stabilizers are the two most widely …

Evacuee Route Choice Decisions In A Dynamic Hurricane Evacuation Context, R. Michael Robinson, Asad Khattak

VMASC Publications

Very high traffic volumes may lead to extensive congestion during hurricane evacuations. Evacuation planners reduce this congestion by careful planning for multiple hurricane scenarios and assignment of evacuation routes and timing. This planning may be for naught if obstructions block key roadways. An advanced traveler information system (ATIS) may be used to guide evacuees to alternate routes, but how effective will that guidance be? Should the use of alternate routes be encouraged? How are drivers likely to respond to delays and information? Will information shorten or improve the reliability of travel times in emergency conditions? Integration of a dynamic evacuation …