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 …

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 …

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 …

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 …

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 …

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) …

Augmented Reality Enhancing The Inspections Of Transportation Infrastructure: Research, Education, And Industry Implementation, Fernando Moreu, Chris Lippitt, Dilendra Maharjan, Marlon Aguero, Xinxing Yuan

Publications

Transportation infrastructure needs continuous monitoring that is conducted by field inspectors regularly in the field. Currently, infrastructure inspectors climb, measure, and photograph structures annually to inform repair needs and prioritize decisions. In order to promote and accelerate early learner's expertise in decision-making capabilities during infrastructure inspections, this research project developed various software applications using augmented reality (AR) as an inspection tool for bridges and bridge management, more specifically. By objectively quantifying infrastructure field inspections, inspectors can make more accurate field assessments and managers can make better-informed decisions. This project collaborated with stakeholders, national laboratories, DOT agencies such as NCHRP and …

A Comprehensive Framework For Life-Cycle Cost Assessment Of Reinforced Concrete Bridge Decks, Mohamed Soliman, Samir Ahmed, Ligang Shen

Publications

Various environmental and mechanical stressors cause deterioration of concrete bridge decks. Normal wear and tear, freeze and thaw cycles, and chloride penetration due to deicing salts can cause aggressive deterioration that usually require frequent interventions during the life-cycle of the bridge. These interventions include deck maintenance and repairs (e.g., application of sealers or overlay placement) as well as bridge deck replacement. The quantification of the life-cycle cost of bridge decks considering maintenance and repair activities represents a significant challenge facing local and state transportation agencies. The life-cycle maintenance activities not only increase the direct life-cycle cost of the bridge, but …

Structural Vulnerability Of Coastal Bridges Under Extreme Hurricane Conditions, Arturo Montoya, Adolfo Matamoros, Firat Testik, Reza Nasouri, Adnan Shahriar, Arsalan Majlesi

Publications

This work presents the results of a numerical study evaluating the response of coastal bridges due to hurricane-induced waves. The analyses were conducted using the Coupled Eulerian-Lagrangian (CEL) approach, available on the commercial finite element software Abaqus, which allows modeling the interaction between water and the bridge. The work concentrated on (1) establishing an approach for modeling the desired wave characteristics (i.e., wave height, and frequency) within the CEL simulation, (2) conducting simulations using actual bridge dimensions of historically damaged bridges, (3) analyzing a range of foundation flexibilities to determine its effect on the uplift and shear forces acting on …

Disaster Resilient And Self-Assessing Multifunctional Transportation Structures, Ibrahim Karaman, Darren Hartl

Publications

This research designs and characterizes multifunctional materials, in particular inexpensive shape memory alloys, for transportation structures that possess excellent mechanical properties and self-sensing capabilities for strengthening and health monitoring. The properties are the Fe-SMAs are sensitive to part size in that the grain size of the material, which can be grown to several inches, should exceed the smallest dimension of the part. In the current work, maximum part size of the large dimension Fe-SMA rods were determined through detailed microstructural investigations. Samples were subjected to abnormal grain growth heat treatments and found out that part size be increased up to …

Workforce Development Symposiums For Uhpc, Brad Weldon, Craig Newtson, Grace Mcmurry, Leticia Davila

Publications

Ultra-high performance concrete (UHPC) is a cementitious material with a dense microstructure that contributes to high compressive strengths as well as enhanced durability properties. UHPC also possesses significant post-cracking strength and ductility due to the addition of fibers. These characteristics produce a material that provides advantages over conventional concrete; however, high costs attributed to materials and production, lack of industry familiarity and knowledge, and the absence of standardized design procedures have impeded its widespread use. To help disseminate knowledge on UHPC, two workforce development symposiums on UHPC were held in Las Cruces, New Mexico. The symposiums consisted of presentations and …

Performance Study Of Link Slab Continuity In Prestressed Concrete Bridges, Marco Tulio Canales Jr

LSU Doctoral Dissertations

Link slabs in bridges can be a cost-effective solution to increase the service life of bridge structures. The partial continuity condition in link slab bridges, however can be challenging to quantify. In this work link slab performance is studied by means of a parametric study, a long-term Structural Health Monitoring (SHM) System, and a detailed finite-element model.

The parametric study was conducted using mathematical and a two-dimensional (2D) finite element model. The study considers bridge design factors such as number of spans, span length, span length ratio, girder separation, and temperature settings, in conjunction with the corresponding girder and support …

Reliability Of Corroding Reinforced Concrete Structures, Travis Honore

LSU Master's Theses

The enhanced performance due to the addition of steel within concrete elements has thrust reinforced concrete structures to be one of the most commonly used construction materials in the world. Reinforced concrete structures are exposed to a variety of deterioration mechanisms during their operational existence, each of which contributes to reducing their service life, durability, and load bearing capacity. The longevity of these reinforced concrete structures is strongly connected to degradation processes, whose origin is environmental and/or functional. Among these processes is the initiation and evolution of corrosion on the steel reinforcement. Steel reinforcement has direct effects on the durability, …

Cost-Effective Methods To Retrofit Metal Culverts Using Composites, Mahmoud Reda Taha, Susan Bogus Halter

Publications

One of the current pressing problems for all DOTs is the corrosion-oriented deterioration of existing metal culverts. These metal culverts typically are designed for a life of 50 years. However, corrosion is making them last no longer than 30 years. A Glass Fiber Reinforced Polymers (GFRP) pipe section has been evaluated as a fit-in GFRP profile liner for complete repair and rehabilitation of the corroded metal culvert with an expected life of 75 years. This is mainly because of the corrosion free nature of the GFRP material. A comprehensive rehabilitation methodology and laboratory scale three-point bending test was conducted to …

Aerodynamic Flutter And Buffeting Of Long-Span Bridges Under Wind Load, Shuqian Liu

LSU Doctoral Dissertations

With the continuous increase of span lengths, the aerodynamic characteristics of long-span bridges under external wind excitation have become much more complex and wind-induced vibration has always been a problem of great concern. The present research targets on the aerodynamic performance of long-span bridges under wind load with an emphasis on bridge flutter and buffeting.

For the aerodynamic flutter analysis of long-span bridges, the present research investigated the effects of the wind turbulence on flutter stability. The characterizations of the self-excited forces are presented in both the frequency-domain and in the time-domain, and the flutter analysis is conducted under both …

Sustainability-Based Long-Term Management Of Bridges Under Multi-Hazard Exposure, Mohamed Soliman

Publications

Bridges are under deterioration due to various mechanical and environmental stressors. Hydraulic-related hazards (e.g., flood and scour), aggressive environmental conditions, and seismic events (e.g., earthquake) are recognized as the most significant threats to the safety of bridges. In traditional risk assessment methods for structures susceptible to damage due to floods and other natural hazards (e.g., corrosion and seismic events), future hazard predictions are conducted using historic return periods and climate records. However, recent increase in flood intensity in central-southern states indicate that future hazard occurrence rate may not necessarily follow past trends. Accordingly, current design, assessment, and management methodologies should …

Development, Training, Education, And Implementation Of Low-Cost Sensing Technologies For Bridge Structural Health Monitoring (Shm), Fernando Moreu, Chris Lippitt, Dilendra Maharjan, Marlon Aguero, Roya Nasimi

Publications

Transportation infrastructure needs continuous monitoring. However, traditional inspections cost money and are conducted visually. New technologies for bridge monitoring are expensive and complex. This project involved developing cost-effective sensor technologies that can be applied towards the maintenance of railroad bridges by recording reference-free transverse displacement. More specifically, this project developed new applications of new technologies (Arduino, wireless smart sensors, drones, Hololens) and promoted workforce development with an emphasis on outreach of high-school students. This project was carried out in three main phases: (1) development and validation of technologies, (2) education and outreach to students, and (3) outreach to industry consisting …

Microstructural Characterization Of Shear Transformation Zones And Modeling Indentation Size Effect In Amorphous Polymers, Leila Malekmotiei

LSU Doctoral Dissertations

The first aim of this work is developing a procedure for experimental and analytical characterization of nano-scale microstructures which mediate large scale deformation in amorphous polymers. Glassy polymers are extensively used as high impact resistant, low density, and clear materials in industries. Nevertheless, their response under severe loading conditions is yet to be appropriately unraveled. Due to the lack of long-range order in the microstructures of glassy solids, their plastic deformation is different from that in crystalline solids. Shear Transformation Zones (STZs) are believed to be the main plasticity carriers in amorphous solids and defined as the localized atomic or …

Risk Assessment Of Concrete Gravity Dams Under Earthquake Loads, Ufuk Sen

LSU Master's Theses

Dams are important structures to supply water for irrigation or drinking, to control flood, and to generate electricity. In seismic regions, the structural safety of concrete gravity dams is important due to the high potential of life and economic loss if they fail. Therefore, the seismic analysis of existing dams in seismically active regions is very crucial to predict responses of dams to ground motions. In this thesis, earthquake response of concrete gravity dams is investigated using the finite element (FE) method. The selected dam is the Pine Flat Dam which is located in the Central Valley of Fresno County, …