Engineering Commons^™

Buckling Analysis Of 0pen-Top Bridge Trusses, Ronald Hernandez, Mohammad Jonaidi

Symposium of Student Scholars

Finite Element Analysis (FEA) is a computerized method for determining the behavior of engineering elements under various loading and environmental conditions. Models can be comprehensively generated and sectioned into finite elements and the software can determine important stages such as buckling and failure of the structure. Computer based FEA offers significant benefits by cutting down cost and time to perform analysis on complex structures. In this research, the powerful software Abaqus is used to make models and perform buckling analyses for Half-Through trusses as specified by American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications. Some of the …

Review Of Finite Element Analysis (Fea) Of Concrete Reinforced Materials, George Williams, Mohammad Jonaidi

Symposium of Student Scholars

As a heterogeneous and generally anisotropic material with both brittle and ductile failure modes, concrete is a difficult material to simulate using finite element models. Coupled with discrete reinforcement interactions and different material properties depending on strain degradation, many different numerical models are available for accurately representing concrete with varying tradeoffs. This study provides a review of general Finite Element Analysis (FEA) techniques and methodologies, how concrete and reinforced concrete are unique, and examples of accurate modeling to assist in further understanding this subject. Finite element modeling of concrete and reinforced concrete structures offers considerable complexity due to concrete’s composite …

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, …

Computational Design Of Nonlinear Stress-Strain Of Isotropic Materials, Askhad M.Polatov, Akhmat M. Ikramov, Daniyarbek Razmukhamedov

Chemical Technology, Control and Management

The article deals with the problems of numerical modeling of nonlinear physical processes of the stress-strain state of structural elements. An elastoplastic medium of a homogeneous solid material is investigated. The results of computational experiments on the study of the process of physically nonlinear deformation of isotropic elements of three-dimensional structures with a system of one- and double-periodic spherical cavities under uniaxial compression are presented. The influence and mutual influence of stress concentrators in the form of spherical cavities, vertically located two cavities and a horizontally located system of two cavities on the deformation of the structure are investigated. Numerical …

Evaluation Of Masonry Materials And Structures Using Digital Image Correlation, Brittany Bullard

Civil Engineering Theses

Masonry structures are common throughout the world. Adobe is a masonry material found in the southwestern states of the United States in residential structures. Adobe is mostly used in brick form, where locally collected sand, clay, and silt are combined with natural fibers and water to create unfired bricks. The natural fibers provide the primary reinforcement of these bricks, and aid in the drying process, helping the bricks dry evenly. While this material has been used as a residential building material for many hundreds of years, much is still not understood regarding its mechanical properties, as they are dependent on …

Assessment Of Contract Terms And Conditions For Lump-Sum Contracts, Omar Othman

Theses and Dissertations

A Contract is a tool that defines the obligations of the contracting parties and assigns the risk between them. Contracts are usually drafted to meet the interests of the owner by addressing the legal issues and liabilities. Meanwhile, less emphasis is placed on clearly communicating the contract terms and ensuring that all contracting parties comprehend their risks and obligations. In a country like Egypt, which has faced drastic economic and political changes in the past few years, and yet is experiencing a boom in the construction sector, many developers tend to draft contracts that might be legally complicated or lacks …

Context-Aware Sensing And Fusion For Structural Health Monitoring And Night Time Traffic Surveillance, Xinxiang Zhang

Electrical Engineering Theses and Dissertations

Rapid developments in computer vision technologies have been transforming many traditional fields in engineering and science in the last few decades, especially in terms of diagnosing problems from visual images. Leveraging computer vision technologies to inspect, monitor, assess infrastructure conditions, and analyze traffic dynamics, has gained significant increase in both effectiveness and efficiency, compared to the cost of traditional instrumentation arrays to monitor, and manually inspect civil infrastructures and traffic conditions. Therefore, to construct the next-generation intelligent civil and transportation infrastructures, this dissertation develops a comprehensive computer-vision based sensing and fusion framework for structural health monitoring and intelligent transportation systems. …

A Practical Methodology To Detect, Quantify And Characterize Experimental Uncertainties In The Dynamic Testing Of Structures, James L. Woodall

Civil Engineering ETDs

This thesis investigates the uncertainty in the experimental context of structural dynamics. This thesis proposes a method to estimate both the effect of boundary conditions, as well as two different methods to detect the location of sensors on a specimen. Firstly, this thesis proposes a technique to predict the dynamic behavior of any point along a cantilever beam with an uncertain transverse elastic restraint. Secondly, this thesis investigates the estimation of the location of a sensor given the output data of a physical experiment with two different methods. Small errors in the sensor location may go unnoticed in the frequency …

Another Dangerous Fire Season Is Looming In The Western U.S., And The Drought-Stricken Region Is Headed For A Water Crisis, Mojtaba Sadegh, Amir Aghakouchak, John Abatzoglou

Civil Engineering Faculty Publications and Presentations

Just about every indicator of drought is flashing red across the western U.S. after a dry winter and warm early spring. The snowpack is at less than half of normal in much of the region. Reservoirs are being drawn down, river levels are dropping and soils are drying out.

It’s only May, and states are already considering water use restrictions to make the supply last longer. California’s governor declared a drought emergency in 41 of 58 counties. In Utah, irrigation water providers are increasing fines for overuse. Some Idaho ranchers are talking about selling off livestock because rivers and reservoirs …

Reliability Of Sfrp-Strengthened Rc Bridge Columns Subjected To Blast Loads, Ahmad Alsendi, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

The reliability of reinforced concrete bridge columns strengthened with externally bonded, steel-fiber reinforced polymer fabric subjected to blast loads was investigated. Columns were modeled with a nonlinear finite element approach that considers material damage, fracture, and separation. Different concrete strengths, longitudinal reinforcement ratios, and gravity and blast load levels were considered, while uncertainties in material strength and stiffness parameters, as well as load characteristics, were incorporated in the probabilistic analysis. It was found that the use of SFRP can allow significant increases in blast load while maintaining the same level of column reliability.

Examination Of The Correlation Between Shear Strength, California Bearing Ratio, And Index Properties Of Fine-Grained Soil, Billy W. Rushema

Master of Science in Civil Engineering Theses

Abstract

California Bering Ratio (CBR) is used to evaluate the strength of the pavement materials by comparing bearing capacity of the material with that of a high-quality crushed stone. This test adopted by transportation agencies and widely used in the design and analysis of pavement. Several agencies developed design thickness chart based on the CBR values of the subgrade. However, CBR test is time consuming and expensive to perform compared to shear strength test and therefore several studies have been conducted to establish correlation between shear strength and CBR. The published correlation models between CBR and shear strength of soil …

International Analysis On The Traffic Impact Of The Covid-19 Pandemic, Fanny Margaretha Kristiansson

Doctoral Dissertations and Master's Theses

The purpose of this research was to assess, compare, and contrast the impact of COVID-19 activity restrictions on road-based transportation activity in regions of the US, Sweden, and China from January 1st to December 31st, 2020. Roadway traffic volumes were used to relate the progression of reported COVID-19 cases and government directives for social separation in three countries with diverse governmental responses.

Among the contributions of this paper was the illustration of the timeline and level of public responses to closures, lockdowns, and reopening as represented through rapid traffic decreases and increases. Traffic was greatly impacted, showing that the pandemic …

Unveiling Women’S Needs And Expectations As Users Of Bike Sharing Services: The H2020 Diamond Project, Andrea Gorrini, Rawad Choubassi, Federico Messa, Wafaa Saleh, Augustus Ababio-Donkor, Maria Chiara Leva, Lorraine D'Arcy, Francesco Fabbri, David Laniado, Pablo Aragon

Articles

Within the objectives of the H2020 DIAMOND project, the paper investigates women’s needs and expectations as users of the bike-sharing service managed by Syndicat Mixte Autolib et Velib Métropole in the territory of Paris Region-Petite Couronne (France). The paper presents a thematic literature review focused on gender inclusion in bike-sharing schemes. The proposed methodological approach is based on (i) Geographic Information Systems for the analysis of geolocated open datasets related to land, sociodemographic and mobility characteristics of the areas surrounding each docking stations. This was aimed at identifying a short list of suitable bike-sharing docking stations, which were further characterized …

Prestressed Concrete Slabs With Bonded And Unbonded Tendons, Jasmin Abdelhalim

Theses and Dissertations

Post-tensioning concrete technology increases the resistance of flexural concrete members. This technology allows for the production of slenderer sections, and sequentially less usage of material preserving the sustainability concept in construction engineering. Post-tensioning process can be done using bonded or unbonded steel tendons. The unbonded tendons are thought to have better resistance to corrosion for structures exposed to severe environmental conditions. The unbonded tendon’s steel strands are painted with grease and covered with plastic sheathing to prevent the moisture from reaching the steel strands thus they can provide high corrosion resistance. According to the ACI 318-19 and other codes of …

Valorization Of Secondary Agriculture Residues, Narendra Kumar

Master's Theses

Secondary agriculture residues have the potential to be major contributors as resources for energy and sustainably sourced materials production. Separating secondary agricultural residues, which have already been transported to processing centers, into individual biomass components could convert these wastes into bioproducts. Many types of pretreatments to achieve this separation involve chemicals that are hazardous for the environment. Several deep eutectic solvents (DES) that are biocompatible have been investigated for their ability to deconstruct rice hulls and sugarcane bagasse. Mass yield, enzymatic hydrolysis of the pretreated biomass, fiber analysis, and Fourier transform infrared spectroscopy have confirmed that the DES formic acid:choline …

Lateral Torsional Buckling Resistance Of Continuous Steel Stringers In Existing Bridges, Dinesha Malky Kuruppuarachchi Kuruppuarachchi Appuhamilage Don

Master's Theses

Some of the Louisiana’s bridges built in the 1950s and 1960s used two-girder or truss systems, in which floorbeams are carried by main members and the continuous (spliced) stringers are supported by the floorbeams. The main members are either two edge (fascia) girders or trusses. When the flexural capacity of continuous stringers is calculated, the moment gradient factor (Cb) is not accurately calculated considering the lateral torsional buckling (LTB) at the negative moment section. In particular, the bracing effect of the non-composite concrete deck is not accounted for, and as a result, the current practice has underestimated the LTB strength …

Environmental Geotechnics: Challenges And Opportunities In The Post-Covid-19 World, Arvin Farid

Civil Engineering Faculty Publications and Presentations

The outbreak of the coronavirus disease 2019 (Covid-19) pandemic not only has created a health crisis across the world but is also expected to impact negatively the global economy and societies at a scale that is maybe larger than that of the 2008 financial crisis. Simultaneously, it has inevitably exerted many negative consequences on the geoenvironment on which human beings depend. The current paper articulates the role of environmental geotechnics in elucidating and mitigating the effects of the current pandemic. It is the belief of all authors that the Covid-19 pandemic presents not only significant challenges but also opportunities for …

Lateral Torsional Buckling Resistance Of Continuous Steel Stringers In Existing Bridges, Dinesha Malky Kuruppuarachchi Kuruppuarachchi Appuhamilage Don

Doctoral Dissertations

Some of the Louisiana’s bridges built in the 1950s and 1960s used two-girder or truss systems, in which floorbeams are carried by main members and the continuous (spliced) stringers are supported by the floorbeams. The main members are either two edge (fascia) girders or trusses. When the flexural capacity of continuous stringers is calculated, the moment gradient factor (Cb) is not accurately calculated considering the lateral torsional buckling (LTB) at the negative moment section. In particular, the bracing effect of the non-composite concrete deck is not accounted for, and as a result, the current practice has underestimated the LTB strength …

Shallow 3d Shear Wave Velocity Model And Revised Site Period Prediction Map For The Mexico City Basin, Rendon Martin Rieth

Graduate Theses and Dissertations

The goal of this study was to revise the existing site period prediction map and to develop a shallow 3D shear wave velocity model of the Mexico City Basin. To accomplish this goal, an extensive literature review was performed to compile as much pertinent shear wave velocity and site period data for the region. In total, 75 sites were used to revise the site period prediction map and 40 sites were used to develop the shear wave velocity model. The 2004 Complementary Technical Standards of Mexico site period prediction map was adjusted with new site period measurements across the basin …

Comparison Of The Resistance Of Belitic Calcium Sulfoaluminate Cement And Portland Cement To Sulfate Attack And Sulfuric Acid, Rilye Dillard

Graduate Theses and Dissertations

Microbially induced corrosion (MIC) is a fairly common concrete deterioration mechanism with many negative effects. MIC is a complex chemical and biological process that occurs in sewage systems and is nearly impossible to replicate in a laboratory setting. For this study, sulfate and sulfuric acid attack on concrete were studied to mimic two stages of the MIC process. The ASTM C1012, Standard Test Method for Length Change of Hydraulic-Cement Mortars Exposed to a Sulfate Solution and a modified ASTM C1012 accelerated method were used to compare the sulfate resistance of belitic calcium sulfoaluminate (BCSA) cement, portland cement (PC), and PC-fly …

Experimental Design And Preliminary Testing For Skewed Special Moment Frame Prequalification, Sara Alimirzaei

Graduate Theses and Dissertations

Special moment frames having specially detailed connections are common in high seismic regions, providing architectural flexibility for passageways and views without brace obstructions. In situations where the building framing layout requires deviation from typical rectangular framing, skew in the moment frame connections may be required. Currently, the AISC prequalified connections only include testing of orthogonal moment frame connections and it is unclear whether the existing design methods can accommodate skew at the beam-to- column connections. To investigate the effect of out-of-plane skew on the performance of reduced beam section special moment frame connections, an experimental test is designed and a …

Development Of An Ultraviolet Absorbance Assay To Estimate Air Entrainer Dosing For Concrete Containing Fly Ash, James Spencer

Graduate Theses and Dissertations

Fly ash is a coal combustion byproduct that can be used as a supplementary cementitious material (SCM) in concrete, offering benefits such as increased workability, durability, and strength. Fly ash can be used as a partial replacement to cement, reducing concrete productions costs and decreasing disposal in landfills. However, variability of fly ash properties (e.g., carbon content, adsorption site density) confounds estimates of the air entraining admixture (AEA) dose needed to achieve a specified air content in concrete. Air entrainment is needed to improve freeze-thaw resistance and limit concrete cracking. The foam index (FI) test is currently used to estimate …

Vistas: Vocational Immersive Storytelling Training And Support Framework For Augmenting Work Performance, Sanika Doolani

Civil Engineering Theses - Archive

Training and assessment of novice workers are the most vital part of any vocational industry. Innovations in science and technology have led to the creation of new industries and occupations, enhanced productivity and quality of work-life, and increased the potential for more people to participate in the workforce. However, these come at the risk and disadvantage of an increased cost of training and lack of proper training in industries, such as manufacturing. Recently, the use of Extended Reality (XR) systems has been on the rise to tackle various domains such as training, education, safety, etc. With the recent advances in …

Numerical Simulation Of Anchor Group Effects On Concrete Breakout Strength Within Steel Fiber Reinforced Concrete, Harjasdeep Singh Chauhan

Civil Engineering Theses - Archive

This study aims to investigate numerically, the effect of anchor groups on concrete breakout strength using nonlinear finite element analysis. Steel headed studs were cast in place within concrete of different amounts of steel fibers. Different proportions of steel fibers (0%, 0.5%, 1%, 1.5%) were utilized within steel fiber reinforced concrete (SFRC) for the numerical simulation. The physical properties of SFRC were modelled with respect to its composite compressive and tensile strength obtained from the experiments. The analysis was conducted on the concrete breakout strength of anchor bolts within SFRC. A good agreement was achieved between the numerical and the …

Effect Of Modified Moisture Barrier In Mitigating Pavement Distresses Due To Expansive Subgrade, Pratibha Pandey

Civil Engineering Dissertations - Archive

Surficial distresses in roadways of Texas are very common due to presence of high plastic clayey soil in the subgrade. Increased sensitivity of high plastic clay towards seasonal moisture change results in repeated swelling and shrinkage, and ultimately the development of pavement cracks. Annual expenses of such distresses impose huge financial liability to maintenance authorities. Studies have indicated rainwater intrusion into underlying expansive subgrade soil coupled with inadequate drainage as the main cause of pavement damage in semi-arid regions. The inability of drainage layer to laterally drain the excess moisture may lead to moisture accumulation within the base layer which …

Evaluation And Retrofitting Of Prestressed Concrete Girder Bridge With Excessive Vibration, Ikram Hasan Efaz

Civil Engineering Dissertations - Archive

Vibration of a highway bridges is a serviceability issue according to American Association of State Highway and Transportation Officials (AASHTO). Though vibration is one of the primary reasons of bridge deck cracking, AASHTO only has a deflection limit to counterpart vibration which is not adequate according to many researchers. For instance, SH-75 SB Bridge over Wilson Creek in McKinney, Texas was observed to have excessive vibration and cracking on the concrete deck. To evaluate the condition of the bridge, Ground Penetrating Radar (GPR) and Impact Echo (IE) were used on the deck as Non-Destructive Evaluation (NDE) methods. A diagnostic load …

Effect Of Sludge Content On Different Types Of Food Waste Degradation In Anaerobic Digester, Mumtahina Binte Latif

Civil Engineering Theses - Archive

Food waste (FW) is the second-largest component in landfills which impacts environments adversely by generating excessive leachate and greenhouse gas. Generally, conventional anaerobic digester and composting can be used for FW disposal. However, the former is highly expensive while the latter is energy inefficient. In contrast, household or community level underground anaerobic digester offers a cost-efficient solution as well as retrieves valuable energy from FW. The addition of nutrients such as sludge to organic waste especially FW accelerates the production of energy by limiting volatile fatty acid (VFA) accumulation. The objective of the current study is to find out the …

An Analytical, Numerical, And Experimental Study Of Automated Damage Assessment For Concrete Structures, Sanggoo Kang

Civil Engineering Dissertations - Archive

This dissertation presents the automated damage assessment studies for concrete structure. Three major studies are performed to: 1) understand the theoretical wave scattering model to evaluate the internal vertical crack, 2) to validate the theoretical wave scattering model through FE simulations with experimental measurements, and 3) to advance practical automated crack evaluation (ACE) system for vertical crack and delamination detection. Firstly, singular integral solutions are studied to investigate scattering of Rayleigh waves by subsurface cracks. Defining a wave scattering model by objects, such as cracks, still can be quite a challenge. The model’s analytical solution uses five different numerical integration …

Understanding Process Controls On Flow Duration Curves Through A Novel Framework, Saba Ghotbi

Electronic Theses and Dissertations, 2020-2023

Flow duration curve (FDC) is a hydrologically representation of the statistical distribution of daily streamflows. For a long time, hydrologists have sought deeper understanding of the process controls on the shape of FDC, which has been a challenge due to contrasting processes controlling the fast flow and slow flow components of streamflow and their interactions. This dissertation addresses the challenge by outlining a novel framework to explore the physical controls on FDC. The framework involves separating streamflow into fast flow and slow flow and studying their duration curves separately then combining them statistically to obtain FDC. Initially, the potential of …

Characterization Of Msw And Plastic Waste Volume Estimation During Covid-19 Pandemic, Sehneela Sara Aurpa

Civil Engineering Theses - Archive

COVID-19 has appeared and shook all aspects of our life. Starting from panic buying prior lockdown to the availability of vaccine, the whole world has gone through a pandemic situation which bounded people to live a life that never seemed normal before. Lockdown and risk of spreading disease forced people to stay at home and generate more waste, especially plastic waste. The effect on municipal solid waste characteristics due to this shift in the way of living is assessed in this study. In this study, municipal solid waste was collected from the working face of Irving Hunter Ferrell landfill. Waste …