Structural Engineering Commons^™

Equity-Aware Natural Hazards Resilience Assessment And Improvement Of Road Networks, Naqib Mashrur

LSU Doctoral Dissertations

As climate change intensifies the frequency and severity of hurricanes, the resulting flood events pose escalating threats to transportation infrastructure and community well-being. This dissertation addresses the intersection of flood resilience, network connectivity, and social equity by integrating principles from network analysis, equity planning, and disaster resilience. The research begins by examining the social dimensions of accessibility loss during hurricane-induced flooding. Spatial and demographic analysis reveals that Native American and Hispanic populations in the case study region experience the most significant reductions in access to essential service facilities, highlighting inequities in systems.

Investigating a region southern Louisiana road network demonstrates …

Wind-Resilient Solar: Harnessing Cfd For Enhanced Load Estimation, Aly Mousaad Aly

Faculty Publications

Solar panels are a cornerstone of renewable energy infrastructure, playing a pivotal role in global sustainability efforts. To ensure their resilience and long-term viability, accurate wind load estimations are essential for designing supporting structures, which account for nearly 50% of their total cost. However, traditional building codes lack comprehensive guidance for solar panels, resulting in inconsistent estimations due to discrepancies in scaled wall-bounded wind tunnel testing methodologies. These inaccuracies pose safety risks, increase costs, and hinder adoption. Emerging technologies like computational fluid dynamics (CFD) simulations offer a promising alternative by enabling full-scale analysis under realistic conditions of complete turbulence. This …

Advancing Solar Farm Resilience: Cfd-Driven Wind Load Optimization, Aly Mousaad Aly

Faculty Publications

This study investigates wind load design methods for ground-mounted solar panels and arrays by comparing Computational Fluid Dynamics (CFD) simulations with design standards. A case study of a solar farm impacted by Hurricane Maria examines the effects of elevation height, tilt angle, and variations in the American Society of Civil Engineers (ASCE) standards on wind loads and structural failure. Turbulence models, including Reynolds Stress Model, k–ε Model, and Large Eddy Simulation (LES), are used to analyze wind pressures, lift, drag, and peak pressures. Results show Phase 1 experienced higher wind loads than Phase 2 due to design differences. A cost-benefit …

Development Of Multifunctional Wood Composites With Integrated Phase Change Materials For Enhanced Thermal Management, Self-Healing, And Sustainability., Emmanuel Igbokwe

LSU Master's Theses

Abstract

This study focused on incorporating self-healing, flame retardancy, and energy harvesting capabilities into the wood composite to contribute to more sustainable and energy-efficient building practices. Oriented strand board has been widely used as sheath for roofing or dry walls in residential buildings. Residential buildings account for a large portion of energy consumption. Therefore, an oriented strand board with energy harvesting capability is highly desired. Additionally, flame retardancy and damage self-healing and end-of-life recycling are also critical features for buildings.

In this study, we prepared a novel oriented strand board by constructing sandwich structures. The face sheets of the sandwich …

Performance Assessment Of Aboveground Storage Tanks During Flood Events, Md Manik Mia

LSU Doctoral Dissertations

This research addressed the performance of aboveground storage tanks (ASTs) and connected pipelines during floods. ASTs, integral to the oil and gas industry, store hazardous materials like crude oil and chemicals. Positioned near coastal regions, especially the hurricane-prone Gulf Coast, these areas are vulnerable to natural hazards such as floods and hurricanes. This vulnerability can lead to potential environmental and economic disasters, as seen with past hurricanes.
The primary objectives were to investigate AST bottom plate failure mechanisms under flood conditions, assess material failure in tank shells and bottom plates using finite element models, examine the behavior of connected pipelines, …

Hurricane Vulnerability Of Above Ground Storage Tanks, Santosh Ghimire

LSU Master's Theses

The objectives of this research were to: 1) develop an approach to determine the effectiveness of regional storm surge reduction strategies and structural mitigation measures for aboveground storage tanks (ASTs), and 2) study the feasibility of controlled flotation of ASTs during flood and storm surge events. This study provided a comprehensive risk assessment strategy for regional portfolio of tanks, considering all dominant failure modes relevant to future planning initiatives aimed at reducing AST failures. Additionally, this research contributed a new methodology to prevent AST failures during flooding, offering a potential solution to prevent hazardous spills.

Design guidelines such as API …

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 …

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 …

Evaluation Of Novel Jointless Engineered Cementitious Composites Ultrathin Whitetopping (Ecc-Utw), Ricardo Hungria

LSU Doctoral Dissertations

Ultrathin Whitetopping (UTW) is a rehabilitation technique that consists of placing a thin layer of concrete over a damaged asphalt pavement. While UTWs have demonstrated satisfactory performance in field tests, the inherent brittleness of concrete has led to the appearance of distresses. To address these distresses, Engineered Cementitious Composites (ECC) have been proposed for UTW applications, thanks to their exceptional attributes, including tensile ductility, flexural performance, and fatigue resistance. In this study, an ECC-UTW was constructed to investigate its potential as a viable solution. The project comprised two 18.3 m ECC sections with different thicknesses, namely 63.5 mm and 101.6 …

Failure Analysis Of Light Poles On Highway Bridges Exposed To Extreme Winds, Yanlin Chen

LSU Master's Theses

Light poles are critical secondary structural components that support the functionality and safety of transportation systems. However, they are tall slender structures vulnerable to wind load. This research attempts to analyze the mechanism of the widespread failure (69 poles failed) of light poles on an elevated highway bridge exposed to Category 4 Hurricane Laura (2020). To understand the mechanism of the failure, a comprehensive analysis is conducted. A nonlinear finite element model is created to simulate the structural responses. Wind pressures are obtained and applied to the FEM to perform nonlinear static and transient analysis. Research results indicate that, when …

Automated Reinforcement In Construction 3d Printing: An Investigation Of Mechanical And Macrostructural Performance Of Reinforced 3d-Printed Structures, Hassan Ahmed

LSU Master's Theses

Conventional construction with steel reinforcement is widely accepted and utilized worldwide for its proven strength, durability, design flexibility, cost-effectiveness, and due to available standards and design codes. Integration of reinforcement in construction 3D printing, however, presents multi-faceted challenges that may influence the structural properties of printed components and have hindered the widespread adoption of reinforced 3D-printed structures. This study explored two complementary reinforcement techniques, namely, steel fibers and threaded reinforcement, to reinforce 3D-printed structures. This study explored both the fresh and hardened properties of 3D-printed mixtures that contain very high steel fiber dosages of up to 2.5% by volume. Additionally, …

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 …

Machine Learning-Based Bridge Load Posting Prediction, Sai Naga Sasi Aditya Bandaru

LSU Master's Theses

1600 (12%) of Louisiana's 13,000 bridges that allow the passage of people, goods, and services are load posted, meaning they are deemed incapable of securely carrying all legal loads. A machine learning framework for estimating the number of load-posted bridges within a regional bridge portfolio would be extremely valuable in the future for allocating essential resources during long-term planning. A framework of this type is necessary since a significant proportion of the bridges are load posted. Furthermore, deterioration due to aging and future increases in legal loads can compound this situation. In this setting, there is a lack of data-driven …

Machine Learning-Based Bridge Load Posting Prediction, Sai Naga Sasi Aditya Bandaru

LSU Master's Theses

1600 (12%) of Louisiana's 13,000 bridges that allow the passage of people, goods, and services are load posted, meaning they are deemed incapable of securely carrying all legal loads. A machine learning framework for estimating the number of load-posted bridges within a regional bridge portfolio would be extremely valuable in the future for allocating essential resources during long-term planning. A framework of this type is necessary since a significant proportion of the bridges are load posted. Furthermore, deterioration due to aging and future increases in legal loads can compound this situation. In this setting, there is a lack of data-driven …

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 …

Optimizing The Self-Healing Efficiency Of Hydrogel Encapsulated Bacteria In Concrete, Ricardo Hungria

LSU Master's Theses

Calcium carbonate precipitation through microbial means is a promising pathway for concrete self-healing technologies, mainly for its microcrack sealing attributes. The main goal of this project was to study and optimize the crack healing efficiency of hydrogel encapsulated bacteria in concrete. To achieve this purpose, Bacillus pseudiformus was implemented as the bacteria strain at a concentration of 10⁸ cells/ml. This bacterium strain along with yeast extract was combined along with three different mineral precursors corresponding to magnesium acetate, calcium lactate, and sodium lactate. All these three precursors were evaluated at two concentrations (67.76 mM/l and 75 mM/l). For each …

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 …

Structural Vibration Control Of Offshore Wind Turbines, Vahid Jahangiri

LSU Doctoral Dissertations

Offshore wind turbines (OWTs) are becoming more attractive than their onshore counterparts due to advantages such as high wind speed, less visual impact and less noise constraints in the marine area. However, the combined wind, wave and seismic loading and other environmental effects render the offshore wind turbines suffering from excessive vibration which adversely influences the system performance and structural integrity. In this regard, the present dissertation aims to develop effective structural control techniques to mitigate three-dimensional structural vibrations of offshore wind turbines. Analytical models of a fixed-bottom and floating offshore wind turbine are established using Euler-Lagrangian equation wherein the …

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.

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 …

Reliability Analysis Of Concrete Gravity Dams Under Earthquake Loads, Anu Abraham

LSU Master's Theses

Dams are infrastructure assets of extreme importance; the failure of which can have catastrophic consequences on adjacent communities. Therefore, it is prudent for authorities to evaluate the safety of existing dams in seismically active regions. This thesis focuses on carrying out a reliability analysis of concrete gravity dams under earthquake loads using an enhanced finite element model. For many years, reliability studies on concrete gravity dams were performed using a finite element model that considered a massless foundation and assumed that water is incompressible. Moreover, the design ground motion was applied without any modification either at the bottom fixed boundary …

Over Height Impact Avoidance And Incident Detection System, Suvash Chapain, Aly Mousaad Aly

Faculty Publications

During the construction and repair of bridges, work platforms or construction-related containment may result in restricted vertical clearances at a work location. Some tractor-trailer combinations are prone to over-height collisions at these locations. Collisions are a hazard to all drivers, and repair of the damage typically causes traffic delays. Appropriate solutions to this problem will focus on the prevention of collisions by detecting over-height vehicles and directing the drivers to take an alternate safe route. This presentation addresses the design and functionality of smart detection/alert systems that can be set up well in advance of a known vertical clearance restriction …

Liability Of The Structural Engineer: Establishing, Quantifying, And Managing Risks, Justin Thomas Ittmann

LSU Doctoral Dissertations

Liability is an important topic to all practicing professionals—including practicing engineers. However, the topic of liability does not receive the necessary attention required relative to other professions. Further, engineers that desire to learn more about liability in relation to their practice do not have many university options within an engineering curriculum or from outside materials available to a non-legally trained engineer. The goal of the study is to provide a comprehensive overview of liability directed towards an intelligent practicing engineer, while avoiding unnecessary over-simplification of the material. This study initially provides an in depth survey of the legal standard of …

Peak Pressures On Low Rise Buildings: Cfd With Les Versus Full Scale And Wind Tunnel Measurements, Aly Mousaad Aly, Hamzeh Gol-Zaroudi

Faculty Publications

This paper focuses on the processes of wind flow in the atmospheric boundary layer, to produce realistic full-scale pressures for the design of low-rise buildings. CFD with LES turbulence closure is implemented on a scale 1:1 prototype building. A proximity study was executed computationally in CFD with LES that suggests new recommendations on the computational domain size, in front of a building model, apart from common RANS-based guidelines (e.g. COST and AIJ). Our findings suggest a location of the test building, different from existing guidelines, and the inflow boundary proximity influences pressure correlation and reproduction of peak loads. The CFD …

Safety Assessment Of Road Vehicle In Crosswind Considering Driver Behavior, Jiexuan Hu

LSU Doctoral Dissertations

With expansion of the economy, more and more highway networks extend to coastal areas and mountain valley areas. Vehicles will be exposed to strong crosswinds when driven on these highway roads, especially in hurricane season and in winter in these two different topographic areas. Strong crosswinds threaten the safety of transportation infrastructure and passing vehicles in forms of vehicle accidents that usually result in traffic blockage and driver injury, posing negative effects on economic growth. This dissertation aimed to evaluate the vehicle safety when running through crosswinds in consideration of driver behaviors.

Firstly, the aerodynamic characteristics of road vehicles were …

Soil-Recycled Aggregate-Geopolymer Road Base/Subbase Mixtures: Steps Towards Sustainability, Mohammad Khattak, Daniel Odion

Data

Corresponding data set for Tran-SET Project No. 18GTLSU10. Abstract of the final report is stated below for reference:

"This study deals with the development of Soil-Geopolymer mixtures using flyash, alkali activator and recycled aggregates (RAG) including recycled concrete (RCA) and reclaimed asphalt (RAP) as an alternative to soil-cement for pavement base and subbase layers. Several mix constituents were varied such as flyash type and content, RCA and RAP content and ratio of sodium silicate and sodium hydroxide. Experiment design was established and mechanical and durability characteristics of Soil-RAG-Geopolymer mixtures were evaluated and then compared to the conventional soil-cement mixtures. The …

Toward Non-Corrosion And Highly Sustainable Structural Members By Using Ultra-High-Performance Materials For Transportation Infrastructure, Shih-Ho Chao, Ashish Karmacharya

Data

Corresponding data set for Tran-SET Project No. 18STUTA01. Abstract of the final report is stated below for reference:

"This research focused on investigating a highly sustainable and efficient reinforced concrete structural member for future infrastructure by utilizing emerging high-performance materials. These materials include ultra-high-performance fiber-reinforced concrete (UHP-FRC) and corrosion-resistant high-strength fiber-reinforced polymer (FRP) bars. Four reduced scale UHP-FRC specimens were tested under large displacement reversals to prove the proposed new ductile-concrete strong-reinforcement (DCSR) design concept by fully utilizing these ultra-high-performance materials. Micro steel fibers were incorporated into three specimens and ultra-high molecular weight polyethylene fibers were blended into the fourth …

Performance Of Drilled Shaft Under Combination Of Complicated Loads Under Hurricane Event, Jie Huang, Sazzad Bin-Shafique

Publications

This project includes experimental and numerical studies to investigate and assess the impact of vertical loads on a laterally loaded drilled shaft under various conditions. The experimental study includes lab testing and lab-scale load test to examine a drilled shaft subjected to vertical and lateral loads at a reduced scale. With the data obtained from the lab-scale testing, a numerical model was calibrated, which was used to perform a parametric study to scrutinize the effect of many possible factors such as soil stiffness, soil friction angle, and drilled shaft geometry. With all the factors considered in this study, the vertical …

Toward Non-Corrosion And Highly Sustainable Structural Members By Using Ultra-High-Performance Materials For Transportation Infrastructure, Shih-Ho Chao, Ashish Karmacharya

Publications

This research focused on investigating a highly sustainable and efficient reinforced concrete structural member for future infrastructure by utilizing emerging high-performance materials. These materials include ultra-high-performance fiber-reinforced concrete (UHP-FRC) and corrosion-resistant high-strength fiber-reinforced polymer (FRP) bars. Four reduced scale UHP-FRC specimens were tested under large displacement reversals to prove the proposed new ductile-concrete strong-reinforcement (DCSR) design concept by fully utilizing these ultra-high-performance materials. Micro steel fibers were incorporated into three specimens and ultra-high molecular weight polyethylene fibers were blended into the fourth specimen. One specimen with ASTM A1035 MMFX high-strength steel rebars, one with high-strength glass fiber reinforced polymer (GFRP) …