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Civil and Environmental Engineering

Theses/Dissertations

2007

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Articles 211 - 239 of 239

Full-Text Articles in Engineering

Field And Laboratory Investigation Of Ozone-Indoor Surface Reactions: Secondary Emissions Inventory And Implications For Indoor Air Quality, Hong Wang Jan 2007

Field And Laboratory Investigation Of Ozone-Indoor Surface Reactions: Secondary Emissions Inventory And Implications For Indoor Air Quality, Hong Wang

Doctoral Dissertations

"Interfacial chemistry greatly influences human exposure to reactants and products in indoor environments. Emissions of volatile organic compounds, as a result of ozone-surface interactions, can lower an occupant's exposure to ozone, but increase indoor concentrations of odorous and carcinogenic compounds. Therefore, investigation of ozone-surface interactions are necessary for better understanding and controlling exposure to ozone and the products of indoor surface chemistry. In this dissertation, field experiments were conducted in five homes in three seasons to quantify ozone-initiated secondary emission rates (SERs), yields surface reaction probabilities and study their temporal trends"--Abstract, page iv.

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The Leaching Behavior Of Arsenic, Selenium And Other Trace Elements In Coal Fly Ash, Tian Wang Jan 2007

The Leaching Behavior Of Arsenic, Selenium And Other Trace Elements In Coal Fly Ash, Tian Wang

Doctoral Dissertations

"The goals of this study are four fold, they are: (1) to investigate the leaching behavior of arsenic and selenium from fly ash as well as their affecting factors; (2) to analyze the speciation of arsenic and selenium in fly ash leachate; (3) to develop a modeling approach to quantify the availability and stability of trace cationic elements in fly ash; (4) to apply this model to describe the leaching/adsorption behavior of arsenic and selenium on fly ash, as well as the calcium effect on arsenic (V) adsorption process"--Abstract, page iv.

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The Impact Of Drainage Ditches On Salt Marsh Flow Patterns, Sedimentation And Morphology: Rowley River, Massachusetts, Lynsey E. Lemay Jan 2007

The Impact Of Drainage Ditches On Salt Marsh Flow Patterns, Sedimentation And Morphology: Rowley River, Massachusetts, Lynsey E. Lemay

Dissertations, Theses, and Masters Projects

Salt marshes along many tidal systems in New England have been ditched since colonial times. These ditches have been thought to help control mosquito populations and increase salt marsh hay production by improving water drainage from the marsh. Although these ditches are prominent geomorphic features, little quantitative work has focused on how these man-made ditches may alter marsh hydrology and geomorphology. This study attempts to quantify the ways in which ditches alter sediment and water transport pathways and how that affects the overall morphology and surface geology. This study also addresses treatment affects on sedimentation from fertilization and fish removal …

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Ph Effect On Adsorption Of Saxititoxin On Powdered Activated Carbon, Jie Ding Jan 2007

Ph Effect On Adsorption Of Saxititoxin On Powdered Activated Carbon, Jie Ding

Masters Theses

"The presence of algal toxins, or cyanotoxins, in surface water has been increasingly reported. These highly hazardous toxins are potential threat to both human health and animals by contaminating drinking water sources over the world. In this study, the removal efficiency of saxitoxin from water using powered activated carbon was tested at different pH values for deionized water and natural surface water. The results of this study showed that pH has a strong impact on removal efficiency of saxitoxin using powdered activated carbon. Specifically, the removal efficiency of saxitoxin is significantly increased at higher pH from 5.7 to pH 10.7. …

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Analysis Of Soil Erosion Based On Soil Properties, Preetha Veeraraghavan Jan 2007

Analysis Of Soil Erosion Based On Soil Properties, Preetha Veeraraghavan

Masters Theses

"The objectives of this research were to identify the major soil parameter(s) that affect the erosion rate of soil and to estimate the erosion rate based on those soil parameters. Both prepared samples and natural samples were used in this research. The soil properties analyzed were the water content, unit weight, Atterberg limits, and soil cohesion. The erosion rate was determined using a rectangular flume and a linear relation between the erosion rate and shear stress was established from the flume experiment. The slope of the linear relation was a good indicator of the soil's erosion rate. The erosion rate …

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Impact Of Ammonia On The Leaching Characteristics Of Mercury From Coal Fly Ash, Harmanjit Mallhi Jan 2007

Impact Of Ammonia On The Leaching Characteristics Of Mercury From Coal Fly Ash, Harmanjit Mallhi

Masters Theses

"Approximately half of the electricity produced in the United States is generated by coal-fired power plants. Coal combustion products (CCPs) such as fly ash, bottom ash, flue gas desulphurization (FGD) material, boiler slag are either disposed in landfills or impoundments, or beneficially used...It has been long known that fly ash contains many trace elements (As, Se, Hg Cr, Cd, Ni, Pb, Cu,Co, etc.) that can be of environmental concern. Mercury is of special interest since it is a known carcinogen and has the ability to bio-accumulate. The primary objectives of thesis research were to understand the leaching behavior of mercury …

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Vapor Phase Uptake Of Volatile Organic Contaminants By Hybrid Poplar Trees, Sally Rebecca Breite Jan 2007

Vapor Phase Uptake Of Volatile Organic Contaminants By Hybrid Poplar Trees, Sally Rebecca Breite

Masters Theses

"Phytoremediation, the use of plants to immobilize, degrade or remove contaminants from the environment, shows great promise as a remediation technique for many contaminated sites. Phytovolatilization in particular is of great interest for sites contaminated with chlorinated solvents and other volatile organic compounds (VOCs), many of which are recalcitrant to biodegradation. Hybrid poplar trees have been shown to uptake, translocate and volatilize numerous aqueous-phase VOCs, however vapor phase uptake of such compounds has only recently been observed and for only one contaminant, tetrachloroethylene (PCE). One semi-volatile and five volatile compounds were dosed to poplar trees in aqueous and vapor phase …

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Static Evaluation Of The Out-Of-Plane Behavior Of Urm Infill Walls Utilizing Modern Blast Retrofit Systems, Trevor D. Hrynyk Jan 2007

Static Evaluation Of The Out-Of-Plane Behavior Of Urm Infill Walls Utilizing Modern Blast Retrofit Systems, Trevor D. Hrynyk

Masters Theses

"Previous investigations have shown that the use of modern retrofit systems can significantly improve the behavior of URM infill walls subjected to variable out-of-plane loads. It has also been shown that the use of externally bonded retrofit systems can greatly reduce the amount of fragmentation and debris scatter that is found to occur in URM walls subjected to high intensity blast loads...The main objective of this study is to investigate, through static testing, the use of modern materials for the purpose of improving the behavior of URM walls subjected to blast loads. This study implemented externally bonded FRP grids and …

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The Importance And Influence Of Groundwater Fluctuations In Phytoremediation, Jeff A. Weishaar Jan 2007

The Importance And Influence Of Groundwater Fluctuations In Phytoremediation, Jeff A. Weishaar

Masters Theses

"The primary purpose of this research is to study the relationship between microbial degradation and plant uptake of volatile hydrocarbons, such as benzene, toluene, ethylbenzene and xylene. While these compounds are known to biodegrade and are capable of transport into plant tissue, any relationship between the two removal mechanisms remains largely unknown. The goal of this work is to better understand the interactions of these multiple biological processes within a phtytoremediation effort"--Introduction, page 3.

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Using Principles Of Momentum Conservation To Develop A Coastal Storm Impulse Scale (Cosi), Chris Adam Klentzman Jan 2007

Using Principles Of Momentum Conservation To Develop A Coastal Storm Impulse Scale (Cosi), Chris Adam Klentzman

Civil & Environmental Engineering Theses & Dissertations

Coastal engineers have long recognized the need for a storm classification system that combines wave conditions, storm surge, and the length of time for the storm event. A new classification system has been developed that is based on the conservation of total horizontal momentum. This research concentrated on developing the theory and then applying that theory for a 10-year period of data from the Army Corps of Engineers Field Research Facility (FRF) in Duck, North Carolina. When fully developed, the Coastal Storm Impulse scale (COSI) may be applied to all previous Hurricane and Northeaster storm events along a coast and …

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Analysis Of Ultraviolet Energy Distribution In Uv Disinfection Systems Using Monte Carlo Ray -Trace Method, Khoi Trung Nguyen Jan 2007

Analysis Of Ultraviolet Energy Distribution In Uv Disinfection Systems Using Monte Carlo Ray -Trace Method, Khoi Trung Nguyen

Civil & Environmental Engineering Theses & Dissertations

Determination of fluence rate in ultraviolet (UV) disinfection systems is a crucial part in evaluating disinfection efficiency of the systems. A robust Monte Carlo Ray Trace (MCRT) method has been developed to determine fluence rates in three-dimensional space of the systems. This is a statistical sampling method in which millions of random light energy bundles are simulated from the axis of each UV lamp and traced through the system until their energies reduce to a minimum threshold level. Inherent phenomena including refraction through quartz tubes, specular reflection at quartz tube surfaces, and absorption by quartz and water, along with specific …

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Influence Of Temperature On The Performance Of Wetlands Treating Chlorinated Volatile Organic Compounds, Maria G. Murillo Jan 2007

Influence Of Temperature On The Performance Of Wetlands Treating Chlorinated Volatile Organic Compounds, Maria G. Murillo

LSU Master's Theses

Various studies have presented models to predict the performance of constructed wetlands at different temperatures focused on the removal of conventional pollutants, and common configuration of constructed wetlands. Investigations on the effect of temperature on the performance of constructed wetlands treating chlorinated volatile organic compounds are limited to microcosm studies. This study is meant to come up with kinetic and energy balance input data for mathematical models that can be used to predict the performance of upflow constructed treatment wetlands treating chlorinated ethenes and ethanes at different ambient temperatures. Bench scale continuous upflow columns will be conducted to investigate the …

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Evaluation Of Shear Strength Parameters Of Shale And Siltstone Using Single Point Cutter Tests, Mahendra Shewalla Jan 2007

Evaluation Of Shear Strength Parameters Of Shale And Siltstone Using Single Point Cutter Tests, Mahendra Shewalla

LSU Master's Theses

Detournay and Tan (2002) performed experiments with a rock cutting device to measure the load required to fail the rock under confining stress. They proposed models describing the correlation between the specific energy and confining stress for shear dilatant rocks as a function of unconfined specific energy at failure, cutter rake angle (θ), internal friction angle (φ) of the rock and an assumed interface friction angle (ψ) between the rock and the cutter. The aim of this research is to evaluate the model proposed by Detournay and Tan (2002), which states that specific energy varies linearly with bore hole pressure …

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Study Of Ranking Irregularities When Evaluating Alternatives By Using Some Electre Methods And A Proposed New Mcdm Method Based On Regret And Rejoicing, Xiaoting Wang Jan 2007

Study Of Ranking Irregularities When Evaluating Alternatives By Using Some Electre Methods And A Proposed New Mcdm Method Based On Regret And Rejoicing, Xiaoting Wang

LSU Master's Theses

Multi-criteria decision-making (MCDM) is one of the most widely used decision methodologies in the sciences, business, and engineering worlds. MCDM methods aim at improving the quality of decisions by making the process more explicit, rational, and efficient. One intriguing problem is that oftentimes different methods may yield different answers to the same decision problem. Thus, the issue of evaluating the relative performance of different MCDM methods is raised. One evaluating procedure is to examine the stability of an MCDM method’s mathematical process by checking the validity of its proposed rankings. The ELECTRE II and III methods are two well-known MCDM …

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Flow And Distribution Of Water In Fractional Wettability Unsaturated Porous Media, Zaydoun Turkey Abusalem Jan 2007

Flow And Distribution Of Water In Fractional Wettability Unsaturated Porous Media, Zaydoun Turkey Abusalem

LSU Doctoral Dissertations

In recent years, interest in fluid flow and transport in the unsaturated zone has gained more attention, due to growing concerns that the quality of the subsurface environment is adversely affected by agricultural, industrial, and municipal activities. The wettability properties (e.g., water repellency) of soil in the unsaturated zone play an important role in determining fluid movement and ultimate distributions. A number of studies have shown that preferential flow and spatially variable moisture content is likely to occur in water repellant soils. Development of appropriate constitutive relations for numerical modeling becomes even more difficult in systems that contain water repellant …

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Hydrodynamic Modeling Of A Hypothetical River Diversion Near Empire, Louisiana, Nathan Lamont Dill Jan 2007

Hydrodynamic Modeling Of A Hypothetical River Diversion Near Empire, Louisiana, Nathan Lamont Dill

LSU Master's Theses

Hydrodynamic models of a hypothetical Mississippi river diversion near Empire, LA are constructed using two popular finite element codes RMA2 and ADCIRC. In a series of simulations eddy viscosity parameters and bottom friction parameters are varied. Constant boundary conditions, discharge inflow and elevation outflow, are applied and water surface elevation and velocity solutions at fully developed flow are taken as steady-state results. A particle tracking code is developed and applied to the velocity solutions to aid in flow field comparisons. The results elucidate the model sensitivities to the varied parameters, and also provide for a comparison of the two different …

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Production Well Operations Optimization In Water Distribution System Using Genetic Algorithm, Vineet Katiyar Jan 2007

Production Well Operations Optimization In Water Distribution System Using Genetic Algorithm, Vineet Katiyar

LSU Master's Theses

The City of Chandler, Arizona lies in semi-arid area and the water resources management has been a major concern by the State citizen. There is always a need of optimizing the available water resources when the rate of demand constantly beats the rate of replenishment. In this study we have developed a management model to link the Chandler water distribution model (EPANET) with the Chandler groundwater flow model (MODFLOW) under an optimization framework (Genetic algorithm). The EPANET model supplied by the Chandler city municipal authority has several improper setting (pumping schedules, valves settings, pressure zones etc.). The original model has …

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Pre-Treatment Of Dynamically Varying Waste Gas Concentrations Using Activated Carbon Prior To Biofiltration: Effect Of Cycle Length On Degree Of Load Equalization, Kodi L. Collins Jan 2007

Pre-Treatment Of Dynamically Varying Waste Gas Concentrations Using Activated Carbon Prior To Biofiltration: Effect Of Cycle Length On Degree Of Load Equalization, Kodi L. Collins

LSU Master's Theses

Dynamically varying waste gas concentrations pose challenges to the operation and design of air pollution control techniques such as biofilters. Although design approaches are becoming well established for biofilters treating gases containing VOC concentrations that are constant as a function of time, many industrial processes emit gas streams contaminated with volatile organic compounds at concentrations that fluctuate with time. Application of an effective load equalization technique could eliminate some challenges associated with fluctuating pollutant concentrations. Recent research has demonstrated that granular activated carbon (GAC) can serve as a passively controlled system to provide load-equalization as a pre-treatment prior to biofiltration. …

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Characterization Of Unsaturated Soils Using Elastic And Electromagnetic Waves, Bashar Alramahi Jan 2007

Characterization Of Unsaturated Soils Using Elastic And Electromagnetic Waves, Bashar Alramahi

LSU Doctoral Dissertations

Recent advances in laboratory instruments and techniques enabled researchers to explore new aspects of the behavior of geomaterials and perform measurements that would be otherwise impossible to acquire using traditional geotechnical laboratory techniques. This dissertation is focused on utilizing elastic and electromagnetic wave measurements and SMCT imaging to non-destructively characterize different aspects of the behavior of unsaturated soils. A model that relates P-wave velocity in soils to the volumetric water content was used to develop a new methodology to determine the in situ density and moisture content of soils. It was numerically and experimentally verified to assess it validity and …

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Study Of Half-Order Bod Reactions, Nicole Plauche Lirette Jan 2007

Study Of Half-Order Bod Reactions, Nicole Plauche Lirette

LSU Master's Theses

Appropriate modeling of Biochemical Oxygen Demand, BOD, is an important part of understanding the character of a wastewater. Much necessary information is gleaned and extracted from the kinetic equation chosen for modeling, especially when a BOD model is included in a dissolved oxygen model. Some information includes the ultimate level of BOD exerted, the rate the BOD demand for dissolved oxygen is exerted, and the critical time at which the minimum level of dissolved oxygen occurs. Although widely used, the first-order kinetic BOD model is not suited for all situations. In some instances, as is the case with constituents found …

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Urban Stream Stabilization Using Regional Hydraulic Geometry Curves For Bankfull Floodplain Design, Jonathan Edward Fourrier Jan 2007

Urban Stream Stabilization Using Regional Hydraulic Geometry Curves For Bankfull Floodplain Design, Jonathan Edward Fourrier

LSU Master's Theses

The objective of this thesis was to determine the effectiveness of hydraulic geometry curves for designing bankfull floodplains to stabilize urban streams. In stable streams bankfull discharge is contained within the stream's banks. Higher flows spread out onto the floodplain where the water's velocity drops due to the increase in area and vegetation. This dissipation of energy promotes sediment deposition, decreases flow velocity, and reduces channel erosion. In cases like Galbraith Drain where historical gage data are not available and bankfull indicators are not present, a degraded stream's bankfull depth may be estimated with hydraulic geometry curves. Over forty cross …

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Pile Capacity Utilization For Bridge Bents Designed Using Simplified Procedures, Md Rubiat Ferdous Jan 2007

Pile Capacity Utilization For Bridge Bents Designed Using Simplified Procedures, Md Rubiat Ferdous

LSU Master's Theses

Bent substructure systems are being used increasingly in bridge construction. Among the various bent systems, pile bents are considered a popular choice due to their effectiveness in reducing time and cost. They are constructed by first driving piles to a specified elevation above the ground surface. Then, a cast-in-place reinforced concrete bent cap ties the piles together at their top end. The current Louisiana Department of Transportation and Development Bridge Design Manual provides guidelines for the structural analysis and construction details for general use in the preparation of plans for pile bents. The manual allows the use of a simplified …

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An Experimental Study On Characteristics And Behavior Of Reinforced Soil Foundation, Qiming Chen Jan 2007

An Experimental Study On Characteristics And Behavior Of Reinforced Soil Foundation, Qiming Chen

LSU Doctoral Dissertations

This research study aims at investigating the potential benefits of using the reinforcement to improve the bearing capacity and reduce the settlement of shallow foundations. To implement this objective, a total of one hundred seventeen tests were performed to study the behavior of reinforced soil foundation. The test results showed that the inclusion of reinforcement can significantly improve the soil's bearing capacity and reduce the footing settlement. The geogrids with higher tensile modulus performed better than geogrids with lower tensile modulus. The strain developed along the reinforcement is directly related to the settlement. The test results also showed that the …

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Saltwater Intrusion Simulation In Heterogeneous Aquifer Using Lattice Boltzmann Method, Borja Servan Camas Jan 2007

Saltwater Intrusion Simulation In Heterogeneous Aquifer Using Lattice Boltzmann Method, Borja Servan Camas

LSU Master's Theses

This study develops a saltwater intrusion simulation model using a lattice Boltzmann method (LBM) in a two-dimensional coastal confined aquifer. The saltwater intrusion is described by density-dependent groundwater flow and mass transport equations, where a freshwater-saltwater mixing zone is considered. The problem is formulated in terms of hydraulic head instead of pressure, which is recommended in those cases where static pressures dominate to reduce computational cost. The aquifer heterogeneity is explicitly a function of the speed of sound, relaxation parameter and time steps in the LBM. This study explores the equivalent squared sound speed to deal with the spatial-temporal heterogeneity …

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Computer-Aided Weld Inspection By Fuzzy Modeling With Selected Features, Sean Najm Ghazavi Jan 2007

Computer-Aided Weld Inspection By Fuzzy Modeling With Selected Features, Sean Najm Ghazavi

LSU Master's Theses

This thesis develops a computer-aided weld inspection methodology based on fuzzy modeling with selected features. The proposed methodology employs several filter feature selection methods for selecting input variables and then builds fuzzy models with the selected features. Our fuzzy modeling method is based on a fuzzy c-means (FCM) variant for the generation of fuzzy terms sets. The implemented FCM variant differs from the original FCM method in two aspects: (1) the two end terms take the maximum and minimum domain values as their centers, and (2) all fuzzy terms are forced to be convex. The optimal number of terms and …

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Locally Derived Nonpoint Loading Estimates For The Boeuf River/Bayou Lafourche Watershed, Emerald Purser Roider Jan 2007

Locally Derived Nonpoint Loading Estimates For The Boeuf River/Bayou Lafourche Watershed, Emerald Purser Roider

LSU Doctoral Dissertations

There is currently a great demand for data and models that can be used to quantify nonpoint source pollutant loads from different land-use types. The Louisiana Department of Environmental Quality (LDEQ) is in the process of implementing management programs for impacted water bodies based on the Total Maximum Daily Load (TMDL) of a pollutant. Pollutants of concern include total suspended solids (TSS), nitrogen, and phosphorus. One of the key parameters in determining the TMDL of a water body is the nonpoint source pollutant load from different land-use types. To date, such load estimates in Louisiana are lacking. The primary objective …

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Effects Of Capping On Biodegradation Of Organic Contaminants In Sediments, Eun Ju Lee Jan 2007

Effects Of Capping On Biodegradation Of Organic Contaminants In Sediments, Eun Ju Lee

LSU Doctoral Dissertations

Sediment capping remains an effective remediation technique for contaminated sediments due to its capability to contain contaminants and provide a sound habitat for indigenous biota. This research investigated the effect of capping on biodegradation of organic contaminants in Anacostia River sediments using both experimental and modeling techniques. 14C–Phenanthrene mineralization was monitored under various redox conditions in Anacostia River sediments. Mineralization of 14C–phenanthrene was strongly linked to sulfate reduction, which was the more energetic process than any other anaerobic condition in Anacostia sediments. Sulfate is a more promising terminal electron acceptor for intrinsic degradation in Anacostia River and other PAH contaminated …

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Wind Loads For Petrochemical Structures, Samuel Amoroso Jan 2007

Wind Loads For Petrochemical Structures, Samuel Amoroso

LSU Doctoral Dissertations

Techniques currently available to practicing engineers for estimating wind loads for petrochemical structures have little theoretical or experimental basis. This dissertation research is an effort to expand the understanding of wind effects on petrochemical and other, similar structures. Petrochemical structures introduce geometric scales into wind tunnel model simulations below what are common for enclosed structures. Wind tunnel experiments were performed to help determine whether this will introduce problems in achieving dynamic similarity between models and prototypes. The experiments did not reveal any clear indication that petrochemical structures cannot be modeled in wind tunnels at scales similar to those used for …

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Laboratory Characterization And Numerical Modeling Of Geogrid Reinforced Bases In Flexible Pavements, Munir Darwish Nazzal Jan 2007

Laboratory Characterization And Numerical Modeling Of Geogrid Reinforced Bases In Flexible Pavements, Munir Darwish Nazzal

LSU Doctoral Dissertations

This dissertation documents the results of an extensive research study that was conducted to characterize the behavior of geogrid reinforced base course materials. The research was conducted through an experimental testing and numerical modeling programs. The experimental testing program included performing different laboratory tests to evaluate the effect of various factors on the performance geogrid reinforced base course materials. Finite element models were also developed to investigate the benefits of placing geogrids within the base course layer in a flexible pavement structure. The results of the experimental testing demonstrated that the inclusion of the geogrid reinforcement layer(s) improved the compressive …

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