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Articles 301 - 330 of 406
Full-Text Articles in Civil and Environmental Engineering
Characterization And Development Of Axle Load Spectra To Enhance Pavement Design And Performance On The Basis Of New Mechanistic-Empirical Design Guide In Louisiana, Bharath Kumar Sridhar
Characterization And Development Of Axle Load Spectra To Enhance Pavement Design And Performance On The Basis Of New Mechanistic-Empirical Design Guide In Louisiana, Bharath Kumar Sridhar
LSU Master's Theses
For pavement design practices, several factors must be considered to ensure good performance of the pavement over the anticipated life cycle. Such factors include, but are not limited to, the type of paving materials, traffic loading characteristics, prevailing environmental conditions, and others. Traditional pavement design practices have followed the standards set by the American Society of State Highway and Transportation Officials (AASHTO) which require the use of an equivalent single axle load (ESAL - 18 kip single axle load) for design traffic input. Recently, a new mechanistic-empirical pavement design guide (MEPDG) was developed to improve pavement design practices. The guide …
Modeling Of Solute Transport And Retention In Upper Amite River, Hoonshin Jung
Modeling Of Solute Transport And Retention In Upper Amite River, Hoonshin Jung
LSU Master's Theses
Streams play an important role in a solute transport through a stream network. Transient storage is one of the important processes that control mass exchange between a main stream and transient storage zones because of increase in the residence time of solute. In order to take account of the effect of transient storage on solute transport in streams, a variable residence time (VART) model was developed. The model is characterized by several features: (1) actual varying residence time was used, (2) no-user specified residence time distributions (RTD) were required, (3) less calibration parameters were involved as compared to existing models, …
Exploring Stochastic Characteristics Of Freeway Traffic Breakdown And Recovery Conditions, Chaitanya Mamidala
Exploring Stochastic Characteristics Of Freeway Traffic Breakdown And Recovery Conditions, Chaitanya Mamidala
LSU Master's Theses
In recent times, the term ‘congestion’ has gained a lot of attention due to its negative impact on the mobility and efficiency of transportation network. Congestion control and mitigation of its effects has become a prime concern to many transportation agencies. With breakthroughs in transportation technologies, effective management and utilization of existing infrastructure capacities has been possible. One of the key functions of technological advancements is the ability to understand the different characteristics of traffic that prevail on major freeways and arterials, and to model short-term predictions of traffic conditions with reasonable accuracy. Providing accurate, real-time information makes travelers aware …
Nonlocal Gradient-Dependent Modeling Of Plasticity With Anisotropic Hardening, Gerald Pekmezi
Nonlocal Gradient-Dependent Modeling Of Plasticity With Anisotropic Hardening, Gerald Pekmezi
LSU Master's Theses
This work is concerned with the formulation of the thermodynamics of nonlocal plasticity using the gradient theory. The formulation is based on the nonlocality energy residual introduced by Eringen and Edelen (1972). Gradients are introduced for those variables associated with isotropic and kinematic hardening. The formulation applies to small strain gradient plasticity and makes use of the evanescent memory model for kinematic hardening. This is accomplished using the kinematic flux evolution as developed by Zbib and Aifantis (1987). Therefore, the present theory is a four nonlocal parameter-based theory that accounts for the influence of large variations in the plastic strain, …
Experimental Investigation Of Unsaturated Soil Stiffness, Ananth Bukkapatnam Tirumala
Experimental Investigation Of Unsaturated Soil Stiffness, Ananth Bukkapatnam Tirumala
LSU Master's Theses
Soil stiffness is a strain dependent non-linear parameter. Stiffness is the measure of soil deformation under a particular working load. It can used for predicting ground deformation in engineering earthworks such as highway embankments and foundations. Non-linear analyses for ground behavior have been widely used for developing models to predict the small –strain characteristics of the soil (Atkinson, 2000). This thesis provides a new insight into the behavior of soil stiffness. We used the wave propagation technique to determine the stiffness and term it as the small strain shear modulus (Gmax) of the soil. The objective of the thesis was …
Effect Of Hydrated Lime On The Laboratory Performance Of Superpave Mixtures, Md Sharear Kabir
Effect Of Hydrated Lime On The Laboratory Performance Of Superpave Mixtures, Md Sharear Kabir
LSU Master's Theses
Permanent deformation and moisture damage are the most common distresses found in asphalt pavements today. Extensive experimental studies have revealed that the use of hydrated lime in Hot-Mix Asphalt (HMA) mixtures can reduce permanent deformation, long-term aging, and moisture susceptibility of mixtures. In addition, it increases the stiffness and fatigue resistance of mixtures. The objectives of this study were to evaluate (1) the fundamental engineering properties of HMA mixtures containing hydrated lime compared to conventional mixtures designed to meet the current Louisiana Superpave specifications and (2) the influence of the method of addition of hydrated lime on the mechanical properties …
Application Of The Hyman Model To Evaluate The Water And Salt Budgets In Three Mangrove Sites Along Shark River, Everglades, Cheng-Feng Tsai
Application Of The Hyman Model To Evaluate The Water And Salt Budgets In Three Mangrove Sites Along Shark River, Everglades, Cheng-Feng Tsai
LSU Master's Theses
Mangrove trees play an important role in the maintenance and sustainability of coastal wetlands due to their ability to adapt and survive in a wide range of saline and tidal conditions. Hydrologic processes (e.g., inundation frequency) and salinity are important regulators controlling the growth and productivity of mangrove forests. To quantify how changes in landscape-level hydrology will influence these regulators in mangrove forests, the hydrology model (HYMAN) was applied to three sites with distinct tidal forcings along the Shark River estuary in the Everglades National Park. HYMAN model uses mass balance equation to determine daily water and salt budgets as …
Influence Of Temperature On The Performance Of Wetlands Treating Chlorinated Volatile Organic Compounds, Maria G. Murillo
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 …
Hydrodynamic Modeling Of A Hypothetical River Diversion Near Empire, Louisiana, Nathan Lamont Dill
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 …
Evaluation Of Shear Strength Parameters Of Shale And Siltstone Using Single Point Cutter Tests, Mahendra Shewalla
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 …
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 …
Urban Stream Stabilization Using Regional Hydraulic Geometry Curves For Bankfull Floodplain Design, Jonathan Edward Fourrier
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 …
Production Well Operations Optimization In Water Distribution System Using Genetic Algorithm, Vineet Katiyar
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 …
Pile Capacity Utilization For Bridge Bents Designed Using Simplified Procedures, Md Rubiat Ferdous
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 …
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. …
Saltwater Intrusion Simulation In Heterogeneous Aquifer Using Lattice Boltzmann Method, Borja Servan Camas
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 …
Computer-Aided Weld Inspection By Fuzzy Modeling With Selected Features, Sean Najm Ghazavi
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 …
Evaluation Of Consolidation Parameters Of Cohesive Soils Using Pcpt Method, Rohit Raj Pant
Evaluation Of Consolidation Parameters Of Cohesive Soils Using Pcpt Method, Rohit Raj Pant
LSU Master's Theses
The piezocone penetration test (PCPT) has emerged as most widely used in situ method for obtaining soil profile as well as physical properties. The PCPT method provides three independent and nearby continuous measurements with the depth; they are: tip stress (qc), sleeve friction (fs) and pore pressure (u1, u2, or u3). These measurements have been successfully used to correlate various soil properties such as undrained shear strength, unit weight and consolidation parameters. This study presents the evaluation of the PCPT interpretation methods for their capability to reasonably estimate the consolidation parameters namely constrained modulus, overconsolidation ratio and vertical coefficient of …
Study Of Half-Order Bod Reactions, Nicole Plauche Lirette
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 …
Evaluation Of Media Influence And Practical Applications For The Use Of Static Low Density Media Filters In Domestic Wastewater Treatment, Steven Marty Bellelo
Evaluation Of Media Influence And Practical Applications For The Use Of Static Low Density Media Filters In Domestic Wastewater Treatment, Steven Marty Bellelo
LSU Master's Theses
Static Low Density Media filters have been used over the past two decades for nitrification and solids removal in high-density recirculating aquaculture systems. The SLDM filters are submerged biofilters which contain a plastic media with a density less than that of water. The media beds remain packed, or static, during operation except for periodic expansion of the bead bed during a backwash. More recently SLDM filters have been evaluated for secondary clarification of domestic wastewater where concurrent biological treatment and particulate removal occur within one unit. Recirculation is accomplished using airlifts which provide external aeration coupled with multiple pass removal …
Frictional Interaction Properties Between Geomaterials And Geosynthetics, Julian Javier Coronel
Frictional Interaction Properties Between Geomaterials And Geosynthetics, Julian Javier Coronel
LSU Master's Theses
Soil reinforcement interaction is a primary issue for designing reinforced soil structures. The soil to geosynthetic interaction parameters are influenced by a) Interaction mechanism between geomaterials and geosynthetics (pull-out or direct shear), b) Physical and mechanical properties of geomaterials (density, grain shape and size, grain size distribution, water content, and plasticity of clayey soils), and c) Mechanical properties (tensile peak strength), shape and geometry of geosynthetics. The soil to geogrid interface friction parameters (interface friction angle "δ" and adhesion "ca") for different plasticity indexes, moisture contents, and dry densities were investigated. For this purposes, a large scale direct …
Partial Continuity In Prestressed Concrete Girder Bridges With Jointless Decks, Ram Naren Mothe
Partial Continuity In Prestressed Concrete Girder Bridges With Jointless Decks, Ram Naren Mothe
LSU Master's Theses
Jointless multi-simple span deck-girder (composite concrete deck with steel or prestressed concrete girders) bridge construction has been accepted as an alternative to jointed construction. Bridge deck joints add to the construction and maintenance costs of the bridge. Bridge support bearing pads deterioration is a common problem in bridges with jointed bridge decks. One of the methods used for building a jointless bridge is to provide a link slab that connects the decks of the adjacent spans. This study mainly focuses on the behavior of the link slab and its effect on the behavior of the bridge system as a whole. …
Refurbishment Of Louisiana State University Calibration Chamber, Ardita Dushi
Refurbishment Of Louisiana State University Calibration Chamber, Ardita Dushi
LSU Master's Theses
This thesis focuses on the refurbishment of Louisiana State University calibration chamber. The testing equipments were checked and connected together to complete the calibration chamber system. The data acquisition system was upgraded to National Instruments (NI) SCXI system. Therefore, a compatible computer program language in LabVIEW was developed. LabVIEW is a programming language developed by NI that reads the data from the instruments, displays the data in graphical form, calculates the desired parameters, commands the transducer to apply the required pressure to the specimen, and saves the data at the desired frequency. The Anisotropic Modified Cam Clay Model (AMCCM) following …
Development And Application Of Methods For Evaluation Of Hurricane Shelters, James P. Gregg
Development And Application Of Methods For Evaluation Of Hurricane Shelters, James P. Gregg
LSU Master's Theses
With the population of hurricane prone regions increasing, it has become more difficult to evacuate entire communities, increasing the need for hurricane shelters in coastal areas. Community officials generally use American Red Cross Standard ARC 4496 to evaluate the suitability of buildings for use as shelters.. ARC 4496 uses a least-risk process that evaluates many building and site characteristics. However, it does not address characteristics of the approaching storm and does not provide insight to the expected hazards and performance of the facility under different hurricane conditions. A new method for evaluating facilities for use as hurricane shelters is proposed. …
Effect Of Speed Limit Increase On Crash Rate On Rural Two-Lane Highways In Louisiana, Athira Swarna Jayadevan
Effect Of Speed Limit Increase On Crash Rate On Rural Two-Lane Highways In Louisiana, Athira Swarna Jayadevan
LSU Master's Theses
Though the rural two lane roads are the low volume-less traveled roads, the majority of the crashes occur on these roads and the high speed of motor vehicles on these roads is suspected to be one of the main causes for this. This study focused on the development of a methodology to study the impact of a speed limit increase on the crash rate on the rural two lane roads in Louisiana. The Louisiana crash database obtained from the Louisiana Department of Transportation (LADOTD) was used to carry out the analysis. The analysis consisted of the comparison of crash rates …
A Comparative Analysis Of Hurricane Evacuation Traffic Conditions Using Static And Dynamic Traffic Assignments, Santosh Kumar Andem
A Comparative Analysis Of Hurricane Evacuation Traffic Conditions Using Static And Dynamic Traffic Assignments, Santosh Kumar Andem
LSU Master's Theses
This study compares link flows of evacuation traffic using Static Traffic Assignment (STA) with those obtained from Dynamic Traffic Assignment (DTA) and observed traffic counts. The analysis is conducted on a sample of households from South Carolina who evacuated in the face of hurricane Floyd in 1999. The results indicate that traditional static models have the potential to significantly underestimate congestion levels in the network, and DTA models account for nonuniform demand and traffic dynamics in hurricane evacuation much more realistically. From observed traffic counts, traffic volumes vary considerably during an evacuation and the DTA flow estimates generally reproduced these …
Calibration Of Flexural Design Of Concrete Members Reinforced With Frp Bars, Sujata Nandkumar Kulkarni
Calibration Of Flexural Design Of Concrete Members Reinforced With Frp Bars, Sujata Nandkumar Kulkarni
LSU Master's Theses
Fiber Reinforced Polymer (FRP) composites have been increasingly accepted in the construction industry as a promising substitute for steel. Bridge deck deterioration is one of the most common deficiencies in a bridge system. The use of FRP bars as reinforcement for concrete bridge decks provides a potential for increased service life, economic, and environmental benefits. This research presents the development of resistance models for concrete members (beams and slabs) reinforced with FRP bars (FRP-RC), for carrying out reliability analysis. The scope of this model is limited to the flexural behavior only; i.e. the failures are not shear failure and debonding. …
Fundamental Characterization Of Louisiana Hma Mixtures For The 2002 Mechanistic-Empirical Design Guide, Sandeep Obulareddy
Fundamental Characterization Of Louisiana Hma Mixtures For The 2002 Mechanistic-Empirical Design Guide, Sandeep Obulareddy
LSU Master's Theses
The main objective of this research was to develop a catalog for dynamic modulus values inputs in the 2002 Empirical and Mechanistic Guide for Design of New and Rehabilitated Pavement Structures (2002 M-E Design Guide) and to examine the permanent deformation characteristics of Louisiana hot mix asphalt (HMA) mixtures based on four laboratory tests, namely dynamic modulus |E*|, flow number, flow time and hamburg wheel tracker test. In addition, the sensitivity of rut prediction from the 2002 M-E Design Guide, using the dynamic modulus |E*| test results was evaluated and the Witczak and Hirsch models were also evaluated, for the …
Acoustic Emission Monitoring And Quantitative Evaluation Of Damage In Reinforced Concrete Members And Bridges, Archana Nair
Acoustic Emission Monitoring And Quantitative Evaluation Of Damage In Reinforced Concrete Members And Bridges, Archana Nair
LSU Master's Theses
A considerable proportion of highway bridges in the US, are made of reinforced concrete. The vulnerability of these structures during their long service life is a cause of major concern for civil engineers. Since there is a need to detect and recuperate the condition of the bridge structures numerous innovative non-destructive testing (NDT) techniques have come into the forefront. Of the many available technologies, acoustic emission (AE) monitoring has been the most popular non-destructive technique used on highway bridges. Acoustic emission is a passive monitoring technique. Thus, it can be appropriately used for field bridge monitoring applications. Usually AE monitoring …
Influence Of Typha Latifolia And Phragmites Communis Root Matter On Degredation Of Aged 1,2,3,4-Tetrachlorobenzene In Bayou Sediments, Elaiza Maria Alvarez
Influence Of Typha Latifolia And Phragmites Communis Root Matter On Degredation Of Aged 1,2,3,4-Tetrachlorobenzene In Bayou Sediments, Elaiza Maria Alvarez
LSU Master's Theses
The purpose of this study was to investigate the effects of Typha latifolia and Phragmites communis root matter in degradation of sediments contaminated with aged 1,2,3,4- Tetrachlorobenzene (1,2,3,4-TeCB). In the present study, complete reductive dechlorination of 1,2,3,4-TeCB was observed in root matter systems, contrasting sediment with no roots present. Microcosms amended with Phragmites communis roots achieved the greatest first-order reaction rate constant over a 4-week period (0.113 d-1, half-life time of 6.13 days). Typha latifolia roots also played an important role in reductive dehalogenation of 1,2,3,4-TeCB, although the first-order reaction rate constant observed within the same period of …