Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Groundwater (2)
- Reliability (2)
- Uncertainty (2)
- Aquifer (1)
- Asphalt mixtures (1)
-
- Baton Rouge (1)
- Biodegradation (1)
- Bridge scour monitoirng (1)
- Bridges (1)
- Chlorinated ethanes and ethenes (1)
- Clay Minerals (1)
- Cohesive element (1)
- Crack propagation model (1)
- Damage detection (1)
- Dechlorination rates (1)
- Dehalobacter (1)
- Dehalococcoides (1)
- Dissolved Oxygen (1)
- Dynamic modulus test (1)
- Engineered wetland systems (1)
- Exopolymer (1)
- Extreme value (1)
- FBG sensors (1)
- FRP (1)
- Fault (1)
- Fine-grained sediment (1)
- Finite element method (1)
- Floc mechanics (1)
- Heterogeneous modeling (1)
- Hurricane storm surge (1)
Articles 1 - 9 of 9
Full-Text Articles in Engineering
Characterization And Uncertainty Analysis Of Siliciclastic Aquifer-Fault System, Ahmed Saad Elshall
Characterization And Uncertainty Analysis Of Siliciclastic Aquifer-Fault System, Ahmed Saad Elshall
LSU Doctoral Dissertations
The complex siliciclastic aquifer system underneath the Baton Rouge area, Louisiana, USA, is fluvial in origin. The east-west trending Baton Rouge fault and Denham Springs-Scotlandville fault cut across East Baton Rouge Parish and play an important role in groundwater flow and aquifer salinization. To better understand the salinization underneath Baton Rouge, it is imperative to study the hydrofacies architecture and the groundwater flow field of the Baton Rogue aquifer-fault system. This is done through developing multiple detailed hydrofacies architecture models and multiple groundwater flow models of the aquifer-fault system, representing various uncertain model propositions. The hydrofacies architecture models focus on …
Modeling Temporal And Spatial Variations In Dissolved Oxygen In Amite River, Vahid Zahraeifard
Modeling Temporal And Spatial Variations In Dissolved Oxygen In Amite River, Vahid Zahraeifard
LSU Doctoral Dissertations
A watershed-based modeling framework is developed in this dissertation for simulating temporal and spatial variations in DO in lowland rivers with organic-rich fine-grained sediment. The modeling framework is based on three major contributions/new models, including (1)VART-DO model for improved estimation of reaeration coefficient (K2) in natural streams, (2)VART-DOS model for simulation of temporal variations in DO in response to sediment resuspension, and (3)VART DO-3L model for simulation of spatial variations in DO. A major advantage of VART-DO model is the capability of simulating DO exchange across the water-sediment interface through the hyporheic exchange mechanism in addition to the air-water exchange. …
Finite Element Modeling Of Hot-Mix Asphalt Performance In The Laboratory, Hao Ying
Finite Element Modeling Of Hot-Mix Asphalt Performance In The Laboratory, Hao Ying
LSU Doctoral Dissertations
The theoretical investigation of Hot-Mix Asphalt (HMA) response in the dynamic modulus and the semi-circular bending (SCB) laboratory test procedures is necessary to understand the influence of various design parameters on the performance of the mix. In addition, laboratory tests such as the dynamic complex modulus assume that this material can be dealt with as a homogeneous material while overlooking the particulate nature of this composite. The ultimate goal of this study is to develop an advanced theoretical framework, based on three-dimensional (3D) finite element (FE) methods and digital image analysis techniques to describe the behavior of HMA in two …
Framework Of Damage Detection In Vehicle-Bridge Coupled System And Application To Bridge Scour Monitoring, Xuan Kong
LSU Doctoral Dissertations
Most vibration-based damage identification methods make use of measurements directly from bridge structures with attached sensors. However, the vehicle moving on the bridge can serve as both an active actuator and a response receiver. This dissertation aimed to develop new methodologies to eventually detect bridge damages such as scour using the dynamic response of the vehicle. To reach the final objective, a framework of damage identification was developed first, which gave a guideline on the three crucial steps for damage detection. An optimization method was proposed that combines the Genetic Algorithm (GA) and the First Order (FO) method. It has …
Bioremediation Of Chlorinated Ethanes And Ethenes In Vertical Flow Engineered Wetland Systems, Christopher Akudo
Bioremediation Of Chlorinated Ethanes And Ethenes In Vertical Flow Engineered Wetland Systems, Christopher Akudo
LSU Doctoral Dissertations
Sustainable treatment of chlorinated ethanes and ethenes contaminated groundwater using vertical flow engineered wetland systems were investigated in microcosm and column studies. Experiments on environmental and biogeochemical factors that affect system performance were conducted, and a numerical model involving advection, sorption, and sequential biodegradation was developed to describe the fate and transport of the contaminants of concern in the treatment wetland bed. 1,1-dichloroethane (1,1-DCA) and cis-1,2-dichloroethene (cis-1,2-DCE) were used as the chemicals of interest. The presence of cis-1,2-DCE inhibited dechlorination of 1,1-DCA but cis-1,2-DCE dechlorination was not affected by the presence of 1,1-DCA. Simulation runs showed that the treatment bed …
Size Kinetics And Mechanics Of Clay-Biopolymer Flocs, Hang Yin
Size Kinetics And Mechanics Of Clay-Biopolymer Flocs, Hang Yin
LSU Doctoral Dissertations
The suspended cohesive sediments, mostly clay minerals with negative surface charges, usually interact through an array of intermolecular/surface forces (e.g., Coulomb force, van der Waals attractions, and hydrogen bonding) with waterborne organic matter (e.g., exopolymers) and dissolved salts, resulting in fractal, tenuous, and hybrid organic-inorganic flocs or “marine snow”. A pilot and systematic laboratory and theoretical work have been conducted towards a synthetic nanoscale understanding of the flocculation kinetics and mechanics of the clay-exopolymer micro-sized flocs. This systematic study has achieved two impressive objectives: (1) the effect of exopolymer polarity and concentration on the particle size kinetics of clay-exopolymer mixtures …
Assessing Levels Of Reliability For Design Criteria For Hurricane And Storm Damage Risk Reduction Structures, Christopher Leslie Dunn
Assessing Levels Of Reliability For Design Criteria For Hurricane And Storm Damage Risk Reduction Structures, Christopher Leslie Dunn
LSU Doctoral Dissertations
In the wake of Hurricane Katrina, the U.S. Army Corps of Engineers (USACE) updated design methodologies and required factors of safety for hurricane and storm damage risk reduction system (HSDRRS) structures to incorporate lessons-learned from the system performance during Katrina and results of state-of-the-art research in storm surge modeling and foundation behavior. However, the criteria (USACE 2008) were not calibrated to a target reliability, which creates the need to understand the reliability provided by designs using those criteria, especially for pile-founded structures subject to global instability. This dissertation presents a methodology for quantifying the reliability of pile-founded structures that can …
Nanoindentation Characterization Of Clay Minerals And Clay-Based Hybrid Bio-Geomaterials, Rohit Raj Pant
Nanoindentation Characterization Of Clay Minerals And Clay-Based Hybrid Bio-Geomaterials, Rohit Raj Pant
LSU Doctoral Dissertations
Layered hydrous aluminosilicates are key constituent minerals in rocks, soils, and other parts of the Earth crust. Understanding mechanical properties of these aluminosilicates is crucial for seismic study, stability of parent rocks and geomaterials, and for geophysical subsurface exploration. Recently, growing prospects of clay based nanocomposites have renewed further interest in understanding the fundamental elastic and plastic properties of hydrous aluminosilicates. Their distinct, nanoscale layered crystal structure is known to result in anisotropic responses to loading, however, owing to their tiny sizes; it is a significant challenge to determine the anisotropic properties. There is a little data available in the …
Time-Variant Performance Assessment And Improvement Of Existing Bridges, Miao Xia
Time-Variant Performance Assessment And Improvement Of Existing Bridges, Miao Xia
LSU Doctoral Dissertations
The serviceability and safety of buildings and bridges are expected to be maintained within a reasonable safety level throughout their lifetimes. However, the increase of the applied loads and degradation of structural performances reduce the safety of these structures over time. Therefore, the performance assessment of existing bridges with reliability theories is a worldwide problem in civil infrastructure systems. Theoretically, the bridge reliability, usually expressed by a reliability index, is quantified by comparing the structural capacity (R) with the load effects (Q), using the predefined limit state functions. A limit state function is a mathematical description of a boundary between …