Civil and Environmental Engineering Commons^™

Dust Susceptibility At Mine Tailings Impoundments: Thermal Remote Sensing For Dust Susceptibility Characterization And Biological Soil Crusts For Dust Susceptibility Reduction, Bonnie Zwissler

Dissertations, Master's Theses and Master's Reports

Mining operations produce massive volumes of mine tailings, which are deposited as slurry into permanent tailings impoundments. An important and heavily regulated environmental hazard associated with mine tailings impoundments is fugitive dust emissions. Wind erosion of mine tailings impoundments and the resulting dusting events, especially those caused by cold weather dusting, remain an on-going challenge for the mining industry. The overall goal of this research was to develop and evaluate effective, economical, and sustainable solutions to two major issues facing mine tailings impoundments with regards to dusting: (1) dust monitoring/detection and (2) dust reduction/prevention. Specifically, the research studied iron mine …

Extracting Physically Realistic Pore Network Features From Xct Data And Investigating The Impact Of Pore Topology On Flow In Porous Media, Godfrey Mills

LSU Doctoral Dissertations

Synchrotron XCT imaging approaches applied in this study provides crucial information on the impact of image voxel resolution on image based simulation results and the characteristic length scales that can be extracted from XCT image data sets. The methods and results in this work provides a holistic approach in generating reliable and representative porous media flow and transport properties via image processing and pore scale simulations through XCT image data sets of porous media. This study also shows how XCT imaging, coupled with pore topological and morphological measures can be utilized in quantifying the differences, and/or similarities between a 2.5D …

Effects Of Temperature Segregation On The Denisity And Mechanical Properties Of Asphalt Mixtures, Pranjal Pravin Phaltane

LSU Master's Theses

Temperature differentials (TD) between the target laydown and actual laydown temperatures of asphalt paving mixtures have been noticed and measured since the late 1990s. Since then, numerous research studies conducted on the phenomena found inconclusive conclusions regarding the effects of TD on the initial pavement quality and the long-term performance. The objective of this study was to evaluate the effects of different levels of TD on the initial quality and the long-term performance of asphalt pavements by evaluating the core density and laboratory measured performance characteristics, respectively. Through the evaluation, it was also aimed to ascertain and establish allowable TD …

Driver Engagement In Secondary Tasks: Behavioral Analysis And Crash Risk Assessment, Mengqiu Ye

LSU Master's Theses

Distracted driving has long been acknowledged as one of the leading causes of death or injury in roadway crashes. The focus of past research has been mainly on the change in driving performance due to distracted driving. However, only a few studies attempted to predict the type of distraction based on driving performance measures. In addition, past studies have proven that driving performance is influenced by the drivers’ socioeconomic characteristics, while not many studies have attempted to quantify that influence. In essence, this study utilizes the rich SHRP 2 Naturalistic Driving Study (NDS) database to (a) develop a model for …

Sulfate-Reducing Bacteria Community Analysis: Isco/Isb Coupled Remediation, Christopher K. Bartlett

Theses and Dissertations (Comprehensive)

Improved techniques for remediating groundwater systems are required for the more than 500,000 contaminated sites in North America. Many of these sites are the legacy of historical industrial operations, inappropriate disposal practices and accidental releases. The most widely observed contaminant at many of these sites is petroleum hydrocarbons (PHCs). Recently, remediation efforts that involve the sequential application of treatment technologies have gained widespread interest. One specific sequential technology application or treatment train employs the aggressive nature of a chemical oxidation followed by bioremediation for polishing. When persulfate is used as the chemical oxidant its natural degradation by-product is sulfate, an …

Numerical Modeling Of Wetland Hydrodynamics, Agnimitro Chakrabarti

LSU Doctoral Dissertations

Wave induced erosion accounts for as much as 26% of landloss in coastal Louisiana. This dissertation work, focuses on answering research questions relevant to the design of two shoreline protection methods (a) vegetated wetlands and (b) nearshore breakwaters. Two types of numerical models are used - the three-dimensional (3D) Navier Stokes Equation for small to medium scale experiments and a depth integrated, fully non-linear Boussinesq model for dispersive waves for larger, field scale studies. The former model provides insights into the 3D hydrodynamics of wave interaction with vegetation canopies and breakwaters, while the latter model focuses on the horizontal two …

Conjunctive Management Of Water Resources Under Climate Change Projection Uncertainty, Amir Mani

LSU Doctoral Dissertations

Goal of this study is to investigate the impacts of climate change projection uncertainty on conjunctive use of water resources. To pursue this goal first, a conjunctive-use model is developed for management of groundwater and surface water resources via mixed integer linear fractional programming (MILFP). The conjunctive management model maximizes the ratio of groundwater usage to reservoir water usage. A conditional head constraint is imposed to maintain groundwater sustainability. A transformation approach is introduced to transform the conditional head constraint into a set of mixed integer linear constraints in terms of groundwater head. A supply network is proposed to apply …

Numerical Simulation Of Pile Installation And Following Setup Considering Soil Consolidation And Thixotropy, Firouz Rosti

LSU Doctoral Dissertations

During pile installation, the stresses and void ratios in the surrounding soils change significantly, creating large displacements, soil disturbance and the development of excess porewater pressures. The disturbed soils, especially fine grain soils, tend to regain their strength over time due to both the consolidation of the excess porewater pressure and thixotropic behavior of soil particles. In this research, the pile installation process and the subsequent consolidation, the thixotropy and load tests for several test piles were modeled using finite element (FE) model. A new elastoplastic constitutive model, which was developed based on the disturbed state concept (DSC) and critical …

Analysis Of Right-Turn Lane Length In Left-Hand Traffic Countries At Signalised Intersections Of Urban Roads, Noura Thomas

Theses: Doctorates and Masters

Analysis of the right turn lane length of urban roads in left-hand traffic countries, such as Australia, UK and India (left-turn lane length in right-hand traffic countries such as USA), at signalised intersections encounters two main geometric features namely, deceleration length and storage length. The literature shows that in routine practice, the deceleration length is generally estimated by using constant deceleration rate. Many researchers consider this assumption for all design speeds unrealistic as it does not reflect the influence of the pavement condition. Hence, it may be desirable to consider the pavement’s condition in terms of its longitudinal coefficient of …

Evaluation Of Ultra-High Performance Concrete (Uhpc) In Joints Of Bridge Girders, Saipavan Rallabhandhi

Masters Theses

"Joints are often considered as the weak link in a structure and often deterioration of the structure initiates from the joints. Joints transfer the stresses from super-structure to sub-structure and in this process are subjected to large transfer stresses. Not much attention is given to the design of joints as they are positioned in low moment regions and typically a 4 to 6 ksi (28 to 41 MPa) concrete is used to fill the joints. One of the solution to this problem is Ultra-high performance concrete (UHPC). In the recent past significant research has been done to use UHPC in …

Shear Behavior Of Reinforced Fly Ash-Based Geopolymer Concrete, Noor S. Yacob

Masters Theses

"The geopolymerisation of aluminosilicate materials such as fly ash has been a radical change in construction material's chemistry and composition, compared to the portland cement-based concrete calcium silicate-hydrate chemistry. The adoption of fly ash in concrete industry is a good use of by-product ashes to reduce emissions of the greenhouse gas implicitly. However, in this research, the replacement of portland cement by fly ash is 100%, which makes it a zero-cement concrete with no proprietary chemical additives.

Geopolymer concrete (GC) is a revolutionary synthetic material that combines sustainability and high engineering properties, and it is relatively cost-effective compared to portland …

Microwave Material Characterization Of Alkali-Silica Reaction (Asr) Gel In Cementitious Materials, Ashkan Hashemi

Doctoral Dissertations

"Since alkali-silica reaction (ASR) was recognized as a durability challenge in cement-based materials over 70 years ago, numerous methods have been utilized to prevent, detect, and mitigate this issue. However, quantifying the amount of produced ASR byproducts (i.e., ASR gel) in-service is still of great interest in the infrastructure industry. The overarching objective of this dissertation is to bring a new understanding to the fundamentals of ASR formation from a microwave dielectric property characterization point-of-view, and more importantly, to investigate the potential for devising a microwave nondestructive testing approach for ASR gel detection and evaluation. To this end, a comprehensive …

Geotechnical State-Of-The-Art In Guatemala -- Ground Stabilization, Fernando Rafael Callejas Benitez

Doctoral Dissertations

"History provides an understanding of the present and in a way, a guide for the future. The state-of-the-art is often referred to as a snapshot of the most significant works and contributions made in a field of study; In this case the focus is on Guatemalan geotechnical engineering. This study presents a comprehensive description of the different events that impulse geotechnical engineering in Guatemala.

As part of the description of the state-of-the-practice an investigation of the different human (engineers/contractors) and physical resources (laboratories/field equipment) and their capabilities are presented. An overview of the civil engineering programs is presented. Then, the …

Static And Dynamic Characterization Of Tied Arch Bridges, John Edward Finke

Doctoral Dissertations

"Tied arch bridges have been designed and constructed since the late 19th century. With their open vista owing to minimalist features tied arch bridges continue to appeal the public. Tied arch bridges are both aesthetic and economical alternates to long span bridges holding a place in the hierarchy of major bridges. They fit in a niche between viable and economical plate girder spans and short cable stayed bridge spans. There are several variations of the tied arch with the most common form being those having vertical hangers, stiff tie girders and slender arch ribs. This tied arch variation is examined …

Enhancing Project Management With Lean World Class Manufacturing In Construction, Jacob Randles

College of Graduate Studies: Theses & Dissertations

In construction, the goal of commercial projects is to turn a profit. This is achieved by minimizing inputs and maximizing outputs while building a product that meets the customer’s perception of value. Value is determined through pre-negotiated specifications, plans, and material quality. Even in U.S. military construction, the unit executing the construction wants to complete the task on time and on budget, which can be difficult to do. Studies on project completion showcase a surprisingly high rate of failure in reaching the aforementioned “on time, on budget” goal. It is important to understand the nuances and details of U.S. Army …

Discrepancy Analysis Between Close-Range Photogrammetry And Terrestrial Lidar, Sam R. Newsome Jr

College of Graduate Studies: Theses & Dissertations

This study presents a comparison of building measurements performed on 3D models generated by two different approaches. In one approach, the models were produced via close-range photogrammetry. Such models are based on still-frame photographs that are, post-processed with commercially available photogrammetric software. In the second approach, 3D point-cloud models were generated via laser scanning. For this purpose, three case studies were conducted. The first was a simple one story structure, the second was a multi-story Maya ruin, and the third was an earth filled terrace. Several benchmarks within a closed traverse were established to serve as standard georeference points for …

Coastal Flood Risk In A Changing Climate Along The Northern Gulf Of Mexico, Matthew Vernon Bilskie

LSU Doctoral Dissertations

Coastal regions around the world are experiencing increased vulnerability from natural and manmade disasters. It is anticipated that coastal flood risk will increase due to the effects of climate change, and sea level rise (SLR) in particular. A dynamic, physics-based, framework to compute coastal flood inundation maps under various climate change scenarios was developed. The novel modeling system includes not only SLR, but considers future projections of shoreline evolution and primary dune morphology, upland migration of intertidal marsh, and land use land cover change. A present day hurricane storm surge model was generated for the Mississippi, Alabama, and Florida panhandle …

Strengthening Shear Deficient Thin-Walled Steel Beams By Bonding Pultruded Gfrp Sections, Tuna Ulger

LSU Doctoral Dissertations

Rehabilitation and retrofitting methods offer economical and feasible alternatives for upgrading aged and deficient structures. Structural strengthening using Fiber Reinforced Polymer (FRP) composites have been widely investigated by researchers and used in field applications. The main advantage of FRP composites is the superior mechanical properties they offer over traditional structural materials. One novel alternative of these retrofitting methods was developed at Louisiana State University and called “Strengthening-by-Stiffening” (SBS). In SBS, the external strengthening of shear deficient thin-walled steel structures is achieved by bonding pultruded FRP sections to buckling prone web panels. Contrary to the commonly used uniaxial tension resistance of …

Bridge Rating Based On In-Situ Weigh-In-Motion And Health Monitoring Data, Dana Feng

LSU Doctoral Dissertations

Parallel to the bridge design methodology changes from the Allowable Stress Design to the Load Factor Design, and then to the reliability based Load and Resistance Factor Design (LRFD), bridge load rating method has also been evolving. Applying the reliability theory to the bridge load rating is more complex than applying to the LRFD since any conservatism can have a significant effect on the assessment of bridge capacity, particularly in load posting and bridge replacement. Although the current Load and Resistant Factor Rating (LRFR) method applying the concept of reliability analyses, it uses very limited site-specific data due to practical …

Performance Evaluation Of Instrumented Geosynthetics Reinforced Paved Test Sections Built Over Weak Subgrade Using Accelerated Load Testing, Shadi Hanandeh

LSU Doctoral Dissertations

Weak soil is a common problem in road construction. Whether it is a temporary access road or a permanent road built over a weak subgrade, a large deformation of the subgrade can lead to deterioration of the paved or unpaved surface. Geosynthetics offer a potentially economical solution for stabilizing roads built over weak soil. Three sets of testing programs were be conducted in this study.The first testing program includes conducting accelerated load testing of full-scale geosynthetic reinforced test lanes using rolling wheel load facility; the second program included conducting laboratory cyclic plate loading test on geosynthetic reinforced test sections constructed …