Civil Engineering Commons^™

Impedance Analysis Of Anodized Aluminum And Structural Bridge Tendons, Justin Silnutzer

USF Tampa Graduate Theses and Dissertations

This is a two-part thesis with the overall investigation technique being electrochemical impedance spectroscopy (EIS). In the first part, EIS is used to estimate the layer thickness of anodized aluminum oxide. This required the development of an appropriate electrical circuit model; that with parameters that correspond to physical properties of the oxide. In this work, it was found that for thicker oxides of which the outer porous layer is greater than 12 microns, impedance may be used to estimate the outer layer thickness. However, further research is required to understand the role of outer porous layer structure on the impedance …

An Improved Polynomial Chaos Expansion Based Response Surface Method And Its Applications On Frame And Spring Engineering Based Structures, Mhd A. Hafez

ETD Archive

In engineering fields, computational models provide a tool that can simulate a real world response and enhance our understanding of physical phenomenas. However, such models are often computationally expensive with multiple sources of uncertainty related to the model’s input/assumptions. For example, the literature indicates that ligament’s material properties and its insertion site locations have a significant effect on the performance of knee joint models, which makes addressing uncertainty related to them a crucial step to make the computational model more representative of reality. However, previous sensitivity studies were limited due to the computational expense of the models. The high computational …

Effects Of Slurry Type On Drilled Shaft Strength, Cesar Quesada Garcia

USF Tampa Graduate Theses and Dissertations

The main objective of this research is to identify how the strength of drilled shafts is affected by the use of various types of drill slurry. When concrete is placed in drilled shafts it flows out radially and a laitance interface forms creating a crease on the backside of the reinforcement cage due to the laitance trapped in concrete flowing around the rebar. This can cause concrete to not fully encapsulate the steel making the shafts prone to corrosion and the strength of the cover concrete is locally reduced. Over the past 9 years 58, 42-inch diameter shafts have been …

Tensile Strain And Damage Self-Sensing Of Flax Frp Laminates Using Carbon Nanofiber Conductive Network Coupled With Acoustic Emission, Yanlei Wang, Guipeng Chen, Yongshuai Wang, Baoguo Han, Baolin Wan, Qingduo Hao, Yulei Bai

Civil and Environmental Engineering Faculty Research and Publications

The strain and damage self-sensing properties of carbon nanofibers (CNFs)/flax fiber-reinforced polymer (FFRP) laminates under tension were investigated via simultaneously measuring the changes of electrical resistance (ER) and acoustic emission (AE) signals. The piezoresistive mechanisms together with the damage evolution of CNFs/FFRP laminates were also explored. The results revealed that both ER and AE responses to tensile strains in CNFs/FFRP laminates could be segmented into three stages, which confirmed their good damage self-sensing ability. The isochronous and reversible electrical resistance responses to tensile strains proved the stability and repeatability of strain self-sensing capability for CNFs/FFRP laminates. Moreover, in-situ ER measurement …

Characterizing The Chemical And Microbial Fingerprint Of Unsheltered Homelessness In An Urban Watershed, Daniel Gerrity, Katerina Papp, Eric Dickenson, Meena Ejjada, Erica Marti, Oscar Quinones, Mayra Sarria, Kyle Thompson, Rebecca A. Trenholm

Civil and Environmental Engineering and Construction Faculty Research

Unsheltered homelessness is rapidly becoming a critical issue in many cities worldwide. The worsening situation not only highlights the socioeconomic plight, but it also raises awareness of ancillary issues such as the potential implications for urban water quality. The objective of this study was to simultaneously leverage diverse source tracking tools to develop a chemical and microbial fingerprint describing the relative contribution of direct human inputs into Las Vegas' tributary washes. By evaluating a wide range of urban water matrices using general water quality parameters, fecal indicator bacteria (FIB), human-associated microbial markers [e.g., HF183, crAssphage, and pepper mild mottle virus …

Fault Tolerance Analysis Of An Adaptive Neuro-Fuzzy Inference System For Mandatory Lane Changing Decisions In Automated Driving, Matthew Vechione, Ruey Long Cheu

Civil Engineering Faculty Publications and Presentations

Past research has developed a binary decision model for mandatory lane changes based on the Adaptive Neuro-Fuzzy Inference System (ANFIS). This ANFIS Decision Model (simply called ADEM), developed and tested with the Next Generation Simulation (NGSIM) data, mimics the sensory inputs and decisions of human drivers. This research assumed that ADEM will be implemented as part of the automated lane changing system in Automated Vehicles (AVs). The system in AVs will depend on active radar sensors to make measurements. The sensor outputs will be converted into the input parameter values of ADEM. This research tested ADEM's performance when the sensors …

Characterization And Performance Enhancement Of Cement-Based Thermoelectric Materials, Ruchita Jani, Niall Holmes Dr., Roger West, Kevin Gaughan, Xiaoli Liu, Ming Qu, Esther Orisakwee, Lorenzo Stella, Jorge Kohanoff, Hongxi Yin, Bartlomiej Wojciechowski

Articles

Thermoelectric materials enable the direct conversion of thermal to electrical energy. One application of this is ambient heat energy harvesting where relatively stable temperature gradients existing between the inside and outside of a building could be utilized to produce electricity. Buildings can thus change from energy consumers to energy generators. This could ultimately help reduce the surface temperatures and energy consumption of buildings, especially in urban areas. In this paper, research work carried out on developing and characterizing a cement-based thermoelectric material is presented. Cement-based samples are doped with different metal oxides (Bi2O3 and Fe2O3) to enhance their thermoelectric properties, …

Discrepancies In Changes In Precipitation Characteristics Over The Contiguous United States Based On Six Daily Gridded Precipitation Datasets, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Variability and spatiotemporal changes in precipitation characteristics can have profound socioenvironmental impacts. Several studies have shown that the frequency and/or magnitude of precipitation events have changed over the contiguous United States (CONUS) in the past decades. Most previous studies used only one precipitation dataset and only investigated mean or extreme precipitation. Here, using 6 gridded daily precipitation datasets, we show that there are substantial discrepancies in the changes in characteristics of both extreme and non-extreme precipitation events from 1983 to 2017. Our results highlight that using a single record to study precipitation changes can potentially lead to biased results. Using …

Coevolution Of Machine Learning And Process-Based Modelling To Revolutionize Earth And Environmental Sciences: A Perspective, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Machine learning (ML) applications in Earth and environmental sciences (EES) have gained incredible momentum in recent years. However, these ML applications have largely evolved in ‘isolation’ from the mechanistic, process-based modelling (PBM) paradigms, which have historically been the cornerstone of scientific discovery and policy support. In this perspective, we assert that the cultural barriers between the ML and PBM communities limit the potential of ML, and even its ‘hybridization’ with PBM, for EES applications. Fundamental, but often ignored, differences between ML and PBM are discussed as well as their strengths and weaknesses in light of three overarching modelling objectives in …

Measuring Accessibility For Pedestrians, Bicyclists, And Transit Riders To Grocery Stores In The Excelsior/Outer Mission Neighborhoods Of San Francisco, Alexandra Lee-Gardner

Master's Theses

Grocery stores are an important amenity in neighborhoods and access to grocery stores is important for health and well-being. While grocery store accessibility is a popular topic of research, studies measuring access for pedestrians, bicyclists, and transit riders are extremely rare. When a new store opened in the Excelsior/Outer Mission districts of San Francisco on a street lacking basic infrastructure for pedestrians, bicyclists, and transit riders, the importance of this study became apparent. The Excelsior/Outer Mission neighborhood has a shocking number of collisions (over 1,100 between 2015 and 2019), elevated levels of walking, biking, and transit ridership, and minimal safe …

Feasibility Report On Water Recycling And The Housing Crisis, Tally A. Perry

City and Regional Planning

The western United States is experiencing increasing population, a housing shortage, and a drought. These challenges demand creative and unprecedented changes to development. Water recycling is slowly emerging as a viable solution for developers, home owners, and cities as a way to continue much-needed housing development while mitigating unnecessary water depletion. With all change, policy, feasibility, and awareness can be the largest influencers. Drought-ridden western-American states require additional and revised regulatory requirements to promote recycled water in new development. Currently, water reuse is largely used for agricultural and industrial purposes. To motivate and encourage housing development, water recycling needs to …

Evaluation Of An Equivalent Mean Grain Size Diameter To Rationally Predict The Erodibility Of Fine Riverbed Soils In Nebraska, Basil Abualshar

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The erosion of riverbed soils under the bridges is one of the major reasons that cause bridge closure or failure leading to a significant effect on the local economy. One of the commonly used methods to predict the erosion rate of soils is the excess shear stress method, which is based on two parameters describing the erodibility behavior; the erodibility coefficient and the critical shear stress. On the other hand, studies showed that the mean grain size diameter D₅₀ could be correlated to the erosion resistance of soils, usually for cohesionless soils but not for cohesive soils. It is …

Investigating Pedestrian Distraction By Phone At Intersection Crossings, Safety Implications And Potential Treatments, Lusanni Mercedes Acosta Rodriguez

Dissertations

Road user distraction is a major safety concern. The issue is not only for drivers, but also for vulnerable road users such as pedestrians. Every year people are involved in potential and real crashes due to being distracted while walking/crossing streets. Although there are several ways by which pedestrians are distracted, phone use while crossing streets is among the riskier and growing behaviors. Crossing an intersection, especially those with heavy traffic, requires full attention from the individual. Inattentiveness to traffic while on a phone call, texting, web-surfing, listening to music before crossing a street can lead to a fatal crash. …

Increasing Strength Of Plywood Shear Walls, Elizabeth Claypool, Michelle Dennin

Architectural Engineering

In a recent iteration of an upper-division engineering design lab course at Cal Poly SLO, students were challenged to identify and understand the probable failure mechanism of conventionally built plywood shear walls and hypothesize how they could delay or prevent common failure mechanisms to increase the overall lateral load capacity. After observing the results of a test on a conventional, code specified wall, a solution to integrate metal gauge strapping into edge nailing was developed to address the common failure mechanisms of nail head pull through and panel edge tear out. A shear wall with metal strapping installed between the …

Development Of Probabilistic Failure Pressure Models For Pipelines With Single Corrosion Defect, Kiswendsida J. Kere, Qindan Huang

Civil and Environmental Engineering Faculty Research and Publications

Many models have been developed in the past to predict the failure pressure of a pipeline with a single corrosion defect. However, most of the existing models are conservative and may lead to unnecessary repairs and maintenance in the pipeline risk management. The aim of this study is to develop probabilistic failure pressure prediction models that are suitable for risk assessment of corroded pipelines. The proposed models are developed at three levels of pipe ultimate strength based on a comprehensive database (consist of both experimental and numerical data) established in this study. When comparing with the existing models, it is …

Using Metal-Organic Frameworks (Mof) To Reduce The Carbon Footprint Of Concrete, Mona Ibrahim El-Hallak

Theses

The production of concrete by the construction industry has a massive impact on the environment. The process of manufacturing its main component, cement, releases a considerable amount of anthropogenic carbon dioxide. This thesis is concerned with the production of sustainable and eco-friendly concrete that integrates metal-organic frameworks (MOF) to capture and offset the CO₂ emissions emitted during the production of cement. The main objective is to synthesize a MOF capable of capturing CO₂ in concrete through accelerated carbonation curing and to assess its impact on concrete performance. Different parameters were examined, including the MOF content, initial curing duration, …

Numerical Modelling Of Externally-Bonded Fiber Reinforced Polymer Shear-Strengthened Reinforced Concrete Beams Subjected To Fatigue Loading, Nagwa Ibrahim Fares

Theses

An extensive number of existing structures persistently exposed to fatigue loading such as bridges, offshore structures, pavements, and highways, are in urgent need of repairing and strengthening. This may be attributed to the continuous increase in the load requirements, change of the structure’s function, and meeting current load standards. Among the potential methods of rehabilitation and strengthening of existing reinforced concrete structures, the externally bonding fiber reinforced polymers (FRP) composites are gaining massive popularity and becoming a viable and cost-effective method. Shear failure of reinforced concrete (RC) beams is known to be brittle, which occurs without prior sufficient warnings; therefore, …

Effects Of Experimental Scale On The Adsorption Of Two Pharmaceutical Drugs Detected In Municipal Wastewater Effluent, Michael Moore

Master's Theses

Pharmaceutical drugs are being produced and consumed in increasing quantities every year and are poorly treated by conventional wastewater treatment processes, leading to increasing detection of such compounds in surface water, groundwater, and municipal drinking water. Soil aquifer treatment (SAT) is a promising method for treating these emerging compounds through combined adsorption and degradation of target compounds in soil. This thesis examines the consistency of results from typical studies like adsorption isotherms and soil columns utilized in analysis of SAT performance, across varying experimental scales. The adsorption behavior of two pharmaceuticals was investigated as a function of experimental scale and …

The Impact Of Material And Environmental Properties On The Ettringite - Metaettringite Thermochemical Reaction, Aaron Strand

Dissertations

The use of energy is an essential need for people, with demand constantly increasing due to an increasing population and an increase in living and comfort standards. Since 1965, world energy consumption has quadrupled. During peak utilization, the strain on the grid infrastructure can be immense. As energy demand fluctuates during different times of the day and year, the energy production needs to scale accordingly This creates inefficiencies within the system such as over building generation capacity or losses from start up or ramping up production. This can be alleviated through load leveling where excess energy generated during low demand …

Partial Systems' Analysis Of Traffic Noise Reduction In Tarik Al Jadidah, Beirut, Ibtihal Y. El-Bastawissi, Nour El Baba, Shireen Khalil, Nour El Hage, Rouba Joumblat, Franz Gatzweiler

BAU Journal - Creative Sustainable Development

Traffic noise is considered one of the main pollutants in an urban space and has multiple side effects regarding the physical and mental health of the human being. Tarik Al Jadidah, one of the most densely populated neighborhoods in Beirut City- Lebanon, is selected as urban area for a project-based initiative and the focal point of different studies in BAU Urban Lab. The area suffers from various urban problems, but prominently traffic noise that highly damages the urban residents' quality of life due to its high levels of traffic noise that surpasses the World Health Organization (WHO) guidelines.

BAU Urban …