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LSU Doctoral Dissertations

2003

Articles 1 - 9 of 9

Full-Text Articles in Civil and Environmental Engineering

Analytical Study On Flood Induced Seepage Under River Levees, Senda Ozkan Jan 2003

Analytical Study On Flood Induced Seepage Under River Levees, Senda Ozkan

LSU Doctoral Dissertations

A common and potentially dangerous phenomenon associated with flooding is seepage under levees and the formation of sand boils. Seepage flow due to hydrostatic head gradients of floods may cause deformation of pervious layers leading to heave, piping and sand boils. Underseepage may also cause irreversible changes in the characteristics of the porous medium. A series of independent flood events may have cumulative effects on pervious layers causing sand boils to grow. Current underseepage analyses for levees are based on steady-state flow. Transient seepage flow due to rapid changes in river head may contribute to cumulative effects and cause critical …

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Hydrodynamic And Sediment Transport Modeling Of Deltaic Sediment Processes, Hassan Shahid Mashriqui Jan 2003

Hydrodynamic And Sediment Transport Modeling Of Deltaic Sediment Processes, Hassan Shahid Mashriqui

LSU Doctoral Dissertations

This dissertation tests the hypothesis that the early phases of deltaic bar and distributary channel formation and sediment transport on an adverse slope could be simulated with a 2D finite element sediment transport model. The models used were RMA2 and SED2D modules of the TABS-MD model suite. A finite element mesh of the lower Atchafalaya River and the delta was developed, using the Surface Water Modeling System (SMS) software package. Calibration and validation of the model were performed, using data collected during field surveys and from available Atchafalaya River archived flow, suspended sediment, and dredging records. In a test simulation …

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Treatment Of Chlorinated Volatile Organic Compounds Using Wetland Systems, Gabriel Roderick Kassenga Jan 2003

Treatment Of Chlorinated Volatile Organic Compounds Using Wetland Systems, Gabriel Roderick Kassenga

LSU Doctoral Dissertations

Bench-scale continuous vertical flow column and microcosm studies were conducted to investigate the attenuation potential of chlorinated volatile organic compounds (CVOCs) in constructed wetland soil mixtures prepared from peat, compost and sand and in a pristine natural freshwater wetland soil. The study also determined geotechnical properties of potential synthetic peat mixtures for construction of treatment wetlands for CVOCs. Trichloroethene (TCE), cis-1,2-dichloroethene (cis-1,2-DCE) and 1,2-dichloroethane (1,2-DCA) were the main test chemicals used during the studies. Based on geotechnical and sorption characteristics, two mixtures (one comprised of sand and peat and the other comprised of sand, peat and compost product) were selected …

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Solute Transport In A Porous Medium: A Mass-Conserving Solution For The Convection-Dispersion Equation In A Finite Domain, William Golz Jan 2003

Solute Transport In A Porous Medium: A Mass-Conserving Solution For The Convection-Dispersion Equation In A Finite Domain, William Golz

LSU Doctoral Dissertations

This dissertation considers the proper mathematical description for the physical problem of a miscible solute undergoing longitudinal convective-dispersive transport with constant production, first-order decay, and equilibrium sorption in a porous medium. Initial and input concentrations may be any continuously differentiable functions and the mathematical system is articulated for a finite domain. This domain yields a mass balance which requires Robin (i.e., third-type) boundaries, which describe a continuous flux but a discontinuous resident-concentration. The discontinuity in the resident concentration at the outflow boundary yields an underdetermined system when the exit concentration is not experimentally measured. This is resolved by defining the …

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Rainfall-Runoff Control: Variably Saturated Transport For An Infiltration System Controlling Water Quality And Quantity, Zheng Teng Jan 2003

Rainfall-Runoff Control: Variably Saturated Transport For An Infiltration System Controlling Water Quality And Quantity, Zheng Teng

LSU Doctoral Dissertations

Rainfall-runoff impacted by anthropogenic activities transports significant quantities of particulate, aqueous and complexed constituents. These diffuse, unsteady and stochastic event-based loadings are unique challenges for water quality and quantity control. The design, water quality and quantity functions of a partial exfiltration reactor (PER) utilizing Fe-coated-sand and porous pavement (CPP) is examined specifically across three representative rainfall-runoff events. Total concentrations and mass for metals (Zn, Pb, Cu and Cd), suspended solids, and Chemical oxygen demand were reduced significantly. Rainfall-runoff volume and peak flow were reduced and time to peak was extended. Influent dm/dp ratios based on particle analyses suggest that the …

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Granulometry, Chemistry And Physical Interactions Of Non-Colloidal Particulate Matter Transported By Urban Storm Water, Hong Lin Jan 2003

Granulometry, Chemistry And Physical Interactions Of Non-Colloidal Particulate Matter Transported By Urban Storm Water, Hong Lin

LSU Doctoral Dissertations

Urban rainfall-runoff is a major source of anthropogenic pollutions to the natural water bodies. Particulate matter generated from anthropogenic environments and activities is a constituent of environmental concern as well as a carrier substrate for reactive contaminants such as metals. Partitioning, transport and transformation of particulate-bound contaminants are determined by the granulometry, physical and geochemical properties of the particulate carriers. Previous research emphasized in the transport of colloidal and suspended particles in rainfall-runoff. The settleable and sediment material were ignored though they are a major granulometric fraction which may contain most of the sorbed or transported constituents such as metals, …

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Investigation Of Bond Slip Between Concrete And Steel Reinforcement Under Dynamic Loading Conditions, John Henry Weathersby Jan 2003

Investigation Of Bond Slip Between Concrete And Steel Reinforcement Under Dynamic Loading Conditions, John Henry Weathersby

LSU Doctoral Dissertations

Structural failures during recent earthquakes and terrorist attacks have demonstrated shortcomings in the design procedures for reinforced concrete structures. Earlier research has demonstrated that a major limitation of the Finite Element (FE) modeling of the response of reinforced concrete is the accurate modeling of the interaction of the concrete with the steel reinforcement. Presently, there are insufficient data on the dynamic nonlinear interaction between the concrete material and the steel reinforcement to develop a numerical model of this interaction. The primary objective of this study was to experimentally investigate the dynamic interaction (bond slip) of reinforcement with concrete and gain …

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Optimization Of The Light Dynamics In The Hydraulically Integrated Serial Turbidostat Algal Reactor (Histar), Barbara Christine Benson Jan 2003

Optimization Of The Light Dynamics In The Hydraulically Integrated Serial Turbidostat Algal Reactor (Histar), Barbara Christine Benson

LSU Doctoral Dissertations

The research objective was the optimization of light dynamics in a Hydraulically Integrated Serial Turbidostat Algal Reactor (HISTAR). A deterministic model of HISTAR productivity that was responsive to manipulations of photosynthetic photon flux fluence rate (PPFFR) was developed, calibrated, and applied. A series of experiments was conducted to define the mathematical equations that best describe three relationships. The first relationship was between the elevation (E) of the light source and the culture surface PPFFR (Io). The second relationship was between the biomass concentration (X) in the experimental unit and the average PPFFR in the reactor (Ia). …

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Clay Landfill Liners Subject To Variable Interfacial Redox And Ph Conditions-Heavy Metal And Clay Interactions, Ping Zhou Jan 2003

Clay Landfill Liners Subject To Variable Interfacial Redox And Ph Conditions-Heavy Metal And Clay Interactions, Ping Zhou

LSU Doctoral Dissertations

Municipal landfill leachate contains high levels of metal species, including Cu, Zn, Cd and Pb generating competitive interactions between these metal species and the landfill clay liner materials. Characterization of the clay fraction, physical and chemical characteristics of landfill clay liner materials, the competitive interaction of metal species with clay liner materials, the kinetic modeling of metal species transport in clay liner, and the effect of cyclic interfacial redox potential on the structural changes to the clay liner and leachate metal transport were investigated in this study. The clay liner materials studied included Na-bentonite, kaolinite and Amite soil (sandy silty …

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