Engineering Commons^™

Enhancing Bridge Resilience And Overheight Vehicle Mitigation Through Innovative Sacrificial Cushion Systems, Aly Mousaad Aly, Marc Hoffmann

Faculty Publications

Transportation departments have made significant strides in addressing the challenges posed by the increasing weights of trucks on bridges. While there is a growing awareness of overheight vehicle collisions with bridges, implementing effective countermeasures remains limited. The susceptibility of bridges to damage from such collisions is on the rise, further exacerbated by unpredictable lateral impact forces. This study employs nonlinear impact analysis to assess the response of an unprotected vehicle-girder model, yielding realistic deformation outcomes comparable to observed impacts on the US-61 bridge. Predictions for a truck traveling at 112.65 km/h indicate deformations of 0.229 m, 0.161 m, and 0.271 …

Surrogate-Assisted Simulation-Optimization Framework For Groundwater Management In A Multi-Aquifer System, Melika Mani

LSU Master's Theses

Uncontrolled groundwater exploitation can lead to aquifer depletion, land subsidence, and saltwater intrusion. Effective groundwater management is challenging due to the intricate nature of subsurface hydrogeology and spatiotemporally variable pumping, especially in a multi-aquifer system. To ensure sustainable withdrawal, multi-objective optimization is an effective tool for balancing management goals and drawdown effects. However, running simulation-optimization using detailed groundwater models is computationally expensive, pushing decision-makers to decide based on limited scenarios. In this study, a hydrogeological framework was constructed for the Capital Area, Louisiana, allowing for individual assessment of each unit to better understand each aquifer's condition. Moreover, a surrogate-assisted simulation-optimization …

Integrating The Concept Of Complete Streets Into Pavement Preservation, Sirisha Gangireddy

LSU Master's Theses

This study is motivated by the evident gap in integrating Complete Streets principles into pavement preservation. Complete Streets opportunities, which aim to accommodate all road users, are typically encouraged in all kinds of projects including new construction, reconstruction, preservation, and rehabilitation. While the concept of Complete Streets is understood in terms of new construction (e.g., building sidewalks), its application through pavement preservation programs is not well-developed. To bridge the gap between the Complete Streets and pavement preservation, this study conducted a comprehensive review on how state Department of Transportation (DOTs) are currently incorporating Complete Streets into pavement preservation and identified …

Augmenting External Surface Pressures’ Predictions On Isolated Low-Rise Buildings Using Cfd Simulations, Md Faiaz Khaled, Aly Mousaad Aly

Faculty Publications

The aim of this paper is to enhance the accuracy of predicting time-averaged external surface pressures on low-rise buildings by utilizing Computational Fluid Dynamics (CFD) simulations. To achieve this, benchmark studies of the Silsoe cube and the Texas Tech University (TTU) experimental building are employed for comparison with simulation results. The paper is structured into three main sections. In the initial part, an appropriate domain size is selected based on the precision of mean pressure coefficients on the windward face of the cube, utilizing Reynolds Averaged Navier-Stokes (RANS) turbulence models. Subsequently, recommendations regarding the optimal computational domain size for an …

Investigating The Influence Of Portland Limestone Cement Combined With Sugarcane Bagasse Ash And Different Types Of Fly Ash On The Mechanical Properties Of Engineered Cementitious Composites, Samuel Guidroz

LSU Master's Theses

The ability to implement Engineered Cementitious Composites (ECC) within our transportation infrastructure systems has been limited because of increased costs associated with the material’s high cement quantity. To improve cost- effectiveness and to create a more sustainable footprint, the use of supplementary cementitious materials (SCMs) has been explored. This study evaluated the effects of utilizing cement interground with limestone, Portland limestone cement (PLC), as a replacement for ordinary Portland cement (OPC). Additionally, the performance of the composites was analyzed when mixed with sugarcane bagasse ash (SCBA) as well as different classes of fly ash (FA). In doing so, the experimental …

Optimization Of The Self-Healing Efficiency Of Bacterial Concrete Using Impregnation Of Three Different Precursors Into Lightweight Aggregate, Omar Omar

LSU Master's Theses

Concrete is the most broadly used construction material; thus, developing sustainable concrete is essential to decrease greenhouse gas (GHG) emissions from concrete production. Implementation of self-healing concrete technologies is a promising approach to enhance the durability and sustainability of the transportation infrastructure. Among these technologies, bacterial concrete has the potential to seal microcracks through microbial induced calcite precipitation (MICP). Bacterial protection is essential to ensure the viability of this technology due to concrete’s harsh environment. Additionally, the success of this technology depends on the presence of an adequate mineral precursor compound and nutrient for the bacteria. As such, the main …

Physics-Based Crystal Plasticity Model For Predicting Microstructure Evolution And Dislocation Densities, Juyoung Jeong

LSU Doctoral Dissertations

This work presents three different studies investigating plastic deformation mechanisms in metals and alloys using crystal plasticity finite element (CPFE) modeling. The first study presents a new nonlocal crystal plasticity model for face-centered cubic single crystals under heterogeneous inelastic deformation. The model incorporates generalized constitutive relations that incorporate the thermally activated and drag mechanisms to cover different kinetics of viscoplastic flow in metals and describes the plastic flow and yielding of single-crystals using dislocation densities. The model is compared to micropillar compression experiments for copper single crystals and clarifies the complex microstructural evolution of dislocation densities in metals. The second …

Numerical Investigation Of Heat Generation And Accumulation Contributing To Elevated Temperature In Msw Landfills, Alborz Fathinezhad

LSU Doctoral Dissertations

Landfills are complex geostructures which contains organic and inorganic municipal, and in some cases industrial, wastes and are expected to remain operational for long times. Due to the complex nature of physical, chemical, biological, and thermal reactions that carry on within the depths of a landfill, unexpected incidents such as elevated temperatures could become inevitable. While uncommon to happen, elevated temperatures cause health and environmental issues such as odors, rapid settlements, slope instabilities. In addition, elevated temperatures can negatively impact engineered components in composite bottom liners, cover systems, leachate collection, and gas extraction and recovery systems.

Air intrusion into municipal …

Incorporating Geopolymer Binders To Fully Utilize Recycled Concrete Aggregates, Matthew Upshaw

LSU Doctoral Dissertations

This study aims to develop a geopolymer concrete binder that will yield desirable strength and durability characteristics when applied to recycled aggregate concrete. In order to achieve this, a geopolymer binder consisting of a metakaolin-silica fume aluminosilicate source material blend activated by potassium-based alkaline solutions is developed and used in place of ordinary Portland cement (OPC) with four different levels of recycled aggregate replacement ratios. The properties of these concretes were analyzed and compared with the properties of OPC concretes produced with the same replacement ratio levels. The results showed that the geopolymer recycled aggregate concrete (GRAC) achieved greater than …

Wetland Soil Development Along Salinity And Hydrogeomorphic Gradients In Active And Inactive Deltaic Basins Of Coastal Louisiana, Amanda Fontenot

LSU Master's Theses

Coastal wetlands provide an abundance of ecosystem services that benefit society, such as essential habitat for commercial species, storm protection, nutrient cycling, and carbon storage. Louisiana faces rapid rates of relative sea level rise (natural subsidence and eustatic sea levels) that threaten wetland survival, which are amplified by a reduction of riverine sediment input. An important determining factor of marsh survival is the formation of wetland platform elevation, known as vertical accretion, which is determined by several processes including sediment deposition & erosion, below ground biomass (BGB) productivity, decomposition of organic matter, shallow & deep subsidence, and soil compaction. Feldspar …

A Case Study Of Protecting Bridges Against Overheight Vehicles, Aly Mousaad Aly, Marc Hoffmann

Faculty Publications

Most transportation departments have recognized and developed procedures to address the ever-increasing weights of trucks traveling on bridges in service today. Transportation agencies also recognize the issues with overheight vehicles’ collisions with bridges, but few stakeholders have definitive countermeasures. Bridges are becoming more vulnerable to collisions from overheight vehicles. The exact response under lateral impact force is difficult to predict. In this paper, nonlinear impact analysis shows that the degree of deformation recorded through the modeling of the unprotected vehicle-girder model provides realistic results compared to the observation from the US-61 bridge overheight vehicle impact. The predicted displacements are 0.229 …

A New Generation Of Open-Graded Friction Course For Enhanced Durability And Functionality, Hossam Abohamer

LSU Doctoral Dissertations

This study aims at (1) enhancing Open Graded Friction Course (OGFC) mixes durability using additives and other by-products; (2) investigating the impacts of selected factors on OGFC pavements seepage characteristics; (3) developing a quantitative tool to model the deterioration in OGFC pavements functional performance; and (4) developing new guidelines of Air Void (AV) content for OGFC for optimum functionality and durability. For the durability objective, eight mixes were prepared with a PG 76-22 binder and two sources of aggregate (i.e., # 78 limestone and # 67 sandstone). Three Warm Mix Additives (WMA), one by-product (i.e., crumb rubber [CR]), and two …

Investigation Of Groundwater Depletion And Leveel Underseepage With Unstructured-Grid Modeling Approach, Ye-Hong Chen

LSU Doctoral Dissertations

Unstructured grid is a tessellation of geometric shapes in irregular patterns that provides flexibility in grid design for groundwater modeling. However, groundwater modeling is mostly developed with uniform grid tessellation and layer, which could simplify model structure or cause expensive computational costs in high-resolution simulations. Unstructured grid incorporates non-uniform horizontal and non-uniform vertical discretizations providing the capability to replicate complex hydrostratigraphy, capture geologic features that are crucial for groundwater flow simulation, and reduce computational costs while maintaining a high resolution for areas of interest. This study contains three parts to investigate unstructured-grid approach on constructing high-fidelity groundwater models, comparisons with …

Investigation Of Sand-Biochar Mixtures As A Potential Roadway Fill Material, Katia J. Lele Lagmago

LSU Master's Theses

Biochar is a sustainable and lightweight carbon-rich material with a high surface area and porosity. Previous studies reported that biochar can reduce soil erosion and cracking, retain contaminants, and enhance soil aggregation. Given these favorable properties, soil-biochar mixtures have the possibility to serve as a multifunctional lightweight fill material for roadway embankment applications. The purpose of this research is to develop sand-biochar mixtures as a sustainable and multifunctional lightweight fill material for roadway embankment applications.

This research investigated the consolidation and hydraulic properties of sand-biochar mixtures by (1) performing 1D consolidation tests, (2) performing permeability tests, and (3) assessing the …

A Conceptual Framework For Phase-Dependent, Composite Flood Risk Index (Fri) Curves Based On The Relationship Between Temporal Probability Of Flood Occurring (Ph) And Flood Vulnerability Index (Fvi) Along With Maps Of Fvi Within The Amite River Basin Based On The August 2016 Flood., Austin S. Guerin Mr.

LSU Master's Theses

Efforts directed at determining community vulnerability to flooding are limited and only include economic (dollar damages) and public safety impacts and do not consider the phase dependency of the system, i.e., pre-, during- and post-storm, both critical shortcomings for more broadly assessing community risk and developing comprehensive plans and mitigation strategies. This thesis first develops a framework based on a Flood-Vulnerability Index (FVI) approach and then demonstrates its usefulness, at the census tract level of detail, for three parishes in the Greater Baton Rouge, LA area, based on the August 2016 flood. FVI’s indicators are multidimensional and phase dependent: “Pre-Flood” …

Finite Element Numerical Modeling And Parametric Study Of Geosynthetic Reinforced Pile-Supported Embankments, Abdallah Ikbarieh

LSU Master's Theses

This study directed at investigating the performance of the pile-supported embankment system utilizing a geosynthetic reinforced load transfer platform (GRLTP) using Finite Element numerical modeling. A 2D Finite Element Modeling (FEM) methodology was first developed using PLAXIS 2D 2021 computer software and verified by well-documented case studies in the literature of this system. Second, a performance prediction was made for a field case study of the Amite River Project near French Settlement, which is located along Route LA 16 Livingston Parish in Louisiana State. A comprehensive FEM parametric study was then carried out to evaluate the performance of the system …

An Improved Earned Value Management Method Integrating Quality And Safety, Brian Briggs

LSU Doctoral Dissertations

The construction industry invests significant time and money to improve quality and safety while reducing cost and schedule impacts. The industry has a sincere desire to improve construction project management methods to improve efficiency. Historically, quality and safety underperformances result from undermanaged quality control and safety activities. The cost and schedule impacts associated with poor quality work have always had an impact on construction operations. The unprecedented challenges and uncertainties of COVID-19 highlighted the need to improve the Earned Value Management (EVM) method within construction to reflect these quality and safety activities. The central goal of this dissertation is to …

Assessment Of Long-Term Performance Of Pavements Containing Warm Mix Asphalt Technologies In Louisiana, Kwadwo Ampadu Boateng

LSU Master's Theses

This study focused on the assessment of long-term performance of asphalt pavements containing warm mix asphalt technologies in Louisiana. A total of five rehabilitation projects were studied in the state of Louisiana. The study consisted of engineering desk analyses of field performance indicators, indices and the initial laboratory performance indicators measured for five rehabilitation projects.

The engineering desk study consisted of a review of literature from previous WMA technology projects done in Louisiana. Additionally, data was acquired and validated from the Louisiana Pavement Management System (PMS). Pavement performance indicators (i.e., cracking (transverse, longitudinal, and fatigue cracking), roughness, rutting, and pavement …

Vertical Feature Delineation For Flood Hazard Assessments At The Coastal Land Margin, Shu Gao

LSU Doctoral Dissertations

Coastal and riverine flooding constitutes a major environmental hazard that affect millions of people residing along the world’s coastline. Improved understanding of the driving mechanisms that can cause flooding within coastal watersheds requires advanced hydrologic and coastal storm surge simulation. Such advanced simulation is dependent upon an accurate digital elevation model (DEM) for the optimal topographical representation of the true domain in the discretized model grid (mesh). However, it is not possible to afford mesh resolution as fine as contemporary DEMs, resolved at sub-10 meters, due to the impractical computational expense. Therefore, significant elevation barriers such as roadbeds, levees, railroads, …

Simulation Of Compound Flood Events In Low-Gradient Coastal Watershed, Felix Luis Santiago-Collazo

LSU Doctoral Dissertations

Low-gradient coastal watersheds are susceptible to flooding caused by various flows such as rainfall, tides, and storm surge. Compound flooding occurs when at least two of these mechanisms happen simultaneously or in close succession. Different inundation models, observed data, and/or a combination of these are coupled through varying techniques involving one-way, loosely, tightly, or fully coupled approaches to assess compound flooding. This study presents a one-dimensional (1-D), fully coupled compound inundation model based on the Shallow Water equations. This model approach simultaneously simulates the free water surface variations in the ocean domain (i.e., tide and storm surge modeling), rainfall-runoff in …

Quantifying Discharge On The Lower Mississippi River Physical Model, Taylor S. Cagle

LSU Master's Theses

The Lower Mississippi River Physical Model (LMRPM) is a distorted, movable-bed physical model that replicates the hydraulics and bedload (sand) transport of the lower 195 miles of the Mississippi River. One year of flow and sediment transport on the prototype can be modeled in approximately one hour. With the ability to simulate long periods of time on the Lower Mississippi River in such a short time frame, the model can provide unique insight into subjects such as the potential effects from relative sea level rise on the lower river’s hydraulics and sediment transport. Quantifying discharge on the LMRPM is an …

Bio-Mediated Ground Improvement For Fine-Grained Soil, Guantao Cheng

LSU Master's Theses

The research explored the use of microbially induced carbonate precipitation (MICP) to improve the mechanical properties of fine-grained soil and rapidly repair soil cracks on embankment slopes. Slope failures are often induced by surface cracks on the embankment slopes. To date, most rapid repair methods for slope failures (e.g., geosynthetics, soil nails, plastic pins, and lime treatment, etc.) involve large earthwork, special installation equipment, and unique construction processes, which may require extended construction time, disturb traffic, or increase the total construction cost. This research explored the feasibility of using bio-cement (MICP) to improve soil mechanical properties, seal the soil cracks, …

On The Computational Efficiency Of Les And Hybrid Rans-Les Models In Building Aerodynamics, Aly Mousaad Aly, Faiaz Khaled

Faculty Publications

Large-eddy simulation (LES) has proven to offer superior accuracy in regards to predicting surface pressures compared to the Reynolds-averaged Navier Stokes (RANS) models. However, the primary impediment is the high computational cost associated with LES. The authors attempt to investigate the computational cost and accuracy by employing different sub-grid scale (SGS) models in LES and hybrid RANS-LES models. One of the prerequisites of accurate pressure estimations is to ensure a horizontally homogeneous empty computational domain. This study aims to compare the computational competence qualitatively and quantitatively using an empty domain in regards to the ability to maintain horizontal homogeneity. The …

On The Computational Efficiency Of Les And Hybrid Rans-Les Models In Building Aerodynamics, Faiaz Khaled, Aly Mousaad Aly

Faculty Publications

No abstract provided.

Effects Of Historical Land-Use Change On Surface Runoff And Flooding In The Amite River Basin, Louisiana, Usa Using Coupled 1d/2d Hec-Ras–Hec-Hms Hydrological Modeling, Alexandre G. H. Cowles

LSU Master's Theses

The Amite River Basin is a largely rural watershed spanning parts of four counties in southern Mississippi and seven parishes in southeast Louisiana, with basinwide imperviousness increasing from 0.82% in 1938 to 3.85% in 2016. The Basin has been the subject of significant research interest since catastrophic flooding in 2016 caused 13 deaths and widespread damages. Rapid development in recent decades has led to an expansion of impervious surfaces in Baton Rouge and surrounding areas, encroaching on floodplains and wetlands. At the basin scale, differences in flooding due to impervious cover changes were found to be somewhat limited, particularly along …

Development Of Cracking Resistance Prediction Model Of Long-Term Aged Asphalt Mixtures, Peyman Barghabany

LSU Doctoral Dissertations

With the increasing complexity of asphalt mixture composition, the current volumetric-based Superpave mixture design would not be sufficient to address durability concerns. To address this limitation, performance-based testing is introduced to supplement conventional volumetric mixture design in assessing the cracking resistance of asphalt mixtures. To perform cracking tests, samples need to be aged to represent the most embrittlement case. The current AASHTO standard for asphalt mixture long-term aging (LTA) is a 5-day oven-aging at 85°C. Quality control/assurance practices require samples to be long-term aged prior to a cracking test which is a time-consuming process. Therefore, it would be beneficial to …

Stream Power Analysis Of The Mid-Barataria Conveyance Channel Model, Jack Graham

LSU Master's Theses

Louisiana’s coast is disappearing at an alarming rate. Erosion, subsidence, sea level rise, and the devastating impacts from hurricanes have contributed to the loss of thousands of square miles of land that was once a thriving ecosystem. The Louisiana government is taking action to help protect and restore these coastal habitats, which are a home to some two million people and numerous species of animals, birds, and fish. The Mid-Barataria Sediment Diversion is a new type of project to help create land in Barataria Basin. Conceptually, the diversion is designed to use the available sediment and stream power provided by …

Non-Newtonian Model Development For Post-Wildfire Flood Risk Management, Ian Eli Floyd

LSU Doctoral Dissertations

Wildfire effected regions of the western U.S. frequently produce non-Newtonian floods (or floods that have a non-linear relationship between stress and deformation) in response to moderate to severe precipitation events. This research presents the development, evaluation, and demonstration of a post-wildfire hydrodynamic one-dimensional and two-dimensional diffusive wave and shallow-water numerical modeling approach that can be used to predict post-wildfire downstream runout of debris flows and floodplain inundation conditions. While researchers have developed a variety of Non-Newtonian approaches to simulate debris flows and mudflows, there has been very limited application to post-wildfire flooding. This can make it difficult to understand the …

Temperature Gradient Effects On Behavior And Design Of Prestressed Concrete Girder Bridges, Ahmed Saad Elsayed Mohamed Elshoura

LSU Doctoral Dissertations

Temperature variation is an inevitable environmental loading type that affects bridges. Considering temperature effects during structural design is deemed essential for short, medium, and long span bridges. Temperature loading can be categorized into three components; uniform temperature, vertical temperature gradient, and transverse temperature gradient. Temperature variation causes additional movements, stresses, and internal forces that should be considered in the design of bridges. In this study, the temperature effects of vertical and transverse temperature gradients are investigated for continuous prestressed concrete bridges.

Thermal restraint moments induced by vertical temperature gradients on prestrssed concrete bridges are investigated by performing three-dimensional (3D) finite …

Accelerated Controller Tuning For Wind Turbines Under Multiple Hazards, Aly Mousaad Aly, Milad Rezaee

Faculty Publications

During their lifecycle, wind turbines can be subjected to multiple hazard loads, such as high-intensity wind, earthquake, wave, and mechanical unbalance. Excessive vibrations, due to these loads, can have detrimental effects on energy production, structural lifecycle, and the initial cost of wind turbines. Vibration control by various means, such as passive, active, and semi-active control systems provide crucial solutions to these issues. We developed a novel control theory that enables semi-active controller tuning under the complex structural behavior and inherent system nonlinearity. The proposed theory enables the evaluation of semi-active controllers’ performance of multi-degrees-of-freedom systems, without the need for time-consuming …