Civil and Environmental Engineering Commons^™

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 …

Onsite Water Reuse: Fate Of Indicator Bacteria, Antibiotic Resistant Genes, Environmental Impacts, And User Perceptions, Michelle B. Henderson

USF Tampa Graduate Theses and Dissertations

Changes in water use, climate, and urbanization have shifted how water resources are used and defined. Wastewater is increasingly regarded as a viable resource to address challenges in non-potable and potable water applications. When dealing with water reuse, water quality and quantity are of the utmost importance; and the final product must be suitable for its intended purpose and acceptable to users. The first portion of this research analyzed the performance and environmental impacts of pilot-scale Hybrid Adsorption Biological Treatment Systems (HABiTS) for onsite wastewater treatment and reuse. Various configurations were investigated to increase HABiTS performance and ability to produce …

High-Risk Traffic Crash Pattern Recognition And Identification Using Econometric Models And Machine Learning Models, Runan Yang

USF Tampa Graduate Theses and Dissertations

Roadway crashes have become a major cause of human deaths and injuries and caused much economic damage. According to World Health Organization (WHO), about 1.35 million people died in traffic crashes and over 50 million people injured from traffic crashes in the year of 2016 (World Health Organization, 2020). Nationally, in the U.S., the latest decade witnessed an increase of over 10% in traffic fatalities (National Highway Traffic Safety Administration (NHTSA), 2019). Similarly, in state of Florida, the fatal crashes increased by 4.62% from 2019 to 2020 (Florida Department of Highway Safety and Motor Vehicles, 2021). To prevent injuries and …

Assessment Of Scoured Bridges Subjected To Vessel Impact Using Nonlinear Dynamic Analysis, Amir S. Irhayyim

USF Tampa Graduate Theses and Dissertations

Scour has been the number one cause of bridge failure in the United States with an average of 22 bridges collapsing or being closed owing to severe deformation each year [1]. This work attempts to deal with two important issues: (1) Potential bridge failures during the co-occurrence of scour and ship impact; (2) Incorporating IDA analysis to predict bridge responses based on barge and collision parameters, and to generate fragility curves to predict the probability of exceedance damage states.

For bridges, flooding is considered the most threatening hazard. According to the National Bridge Inventory (NBI) [2], 500,000 out of 615,000 …

Formation Of Trihalomethanes During Chlorination At South Cross Bayou Advanced Water Reclamation Facility, Pinellas County, Florida, Ian Grabo

USF Tampa Graduate Theses and Dissertations

South Cross Bayou Advanced Water Reclamation Facility (SCB) in Pinellas County, Florida, recently had a spike in effluent concentrations of bromodichloromethane (BDCM) and dibromochloromethane (DBCM) above the regulated limits, due to relying fully on chlorination instead of a combination of chlorination and ultraviolet light. The objective of this study was to determine the operating parameters most strongly affecting the formation of THMs. This was completed by analysis of long-term data sets obtained from SCB by multiple linear regression to create models describing THM formation. In addition, sampling of the chlorine contact chamber (CCC) was done to determine the effects of …

Carbon Diversion, Partial Nitritation/Anammox Enrichment, And Ammonium Capture As Initial Stages For Mainstream Ion Exchange-Deammonification Process, Sheyla Chero-Osorio

USF Tampa Graduate Theses and Dissertations

Eutrophication is a concerning environmental problem worldwide that results in algae blooms, oxygen depletion, damages to aquatic life and public health, water quality issues, and loss of aesthetics in water reservoirs. Nutrient (e.g., nitrogen and phosphorus) discharges from wastewater, agricultural, urban, and residential runoff promote eutrophication in receiving water bodies. In terms of nitrogen removal, conventional biological nitrogen removal (BNR) is a common technique used in many wastewater treatment plants (WWTP). However, BNR requires aeration for nitrification and organic carbon input for denitrification. In WWTP, the aeration represents a considerable investment in terms of energy costs. Recent technologies involve applying …

Estimating The As-Placed Grout Volume Of Auger Cast Piles, Tristen Mee

USF Tampa Graduate Theses and Dissertations

Augered Cast-in-Place (ACIP) piles are a geotechnical foundation element increasingly used to support large publicly funded structures as an alternative to drilled shafts or driven piles. ACIP piles are constructed by drilling an excavation to the full length of the designed pile with a continuous flight auger. Grout (cement, sand, and water mixture) is then pumped through the hollow auger stem to begin grouting the excavation. After establishing an initial head pressure, the auger is slowly extracted while the remainder of the pile is grouted. Once the auger is completely removed, the steel reinforcement cage is lowered into the grouted …

Effects Of Downdrag On Pile Performance, Malaak Omelia Araujo

USF Tampa Graduate Theses and Dissertations

All soils settle under the weight of newly constructed embankments. In the case of MSE wall-type embankments, piles are driven prior to embankment construction. Under the weight of the newly constructed embankment, the soil surrounding the piles may settle more than the piles themselves. This downward movement potentially drags the piles down and induces a force within the pile known as downdrag. The research on the downdrag phenomenon involving cohesionless granular soils is sparse, thus the focus of this study is to investigate the effects of downdrag on pile performance driven in Florida sandy soils. A site consisting of soil …

The Impact Of Land Use Change On Hydrology Using Hydrologic Modelling And Geographical Information System (Gis), Nattachan Luesaksiriwattana

USF Tampa Graduate Theses and Dissertations

Surface and groundwater conditions in west-central Florida are highly interactive, with shallow water table and sandy soil. Land use types including forests, agricultural areas, and urbanization affect water resources differently. Change in land use, associated with expanding the urban environment to support human needs, significantly impacts surface water infiltration and runoff characteristics. Construction of infrastructures such as buildings and housing can result less water to infiltrate through the soil, with increased surface water runoff and decline in evapotranspiration. A computerized hydrologic model, Hydrological Simulation Program-FORTRAN (HSPF), couple to a spreadsheet groundwater model and a Geographical Information System (GIS) were applied …

Development Of Membrane Assisted Recovery Of Solids (Mars) Technology For Nutrient Management In Decentralized Wastewater Treatment Systems, Itzé Alejandra Kenney

USF Tampa Graduate Theses and Dissertations

Increasing global populations will result in a rise of eutrophic wastewater and an increased need in food supply. Both problems share a commonality: nutrients. Not all communities are equipped to handle one or both of those challenges, considering that typical solutions require large and energy intensive technologies. Wastewater treatment in most major cities is done through centralized treatment plants, which is not feasible for places with limited resources. Decentralized wastewater treatment systems (DWTS) have been developed as an alternative solution for those communities, but they still struggle to sustainably treat nutrients such as ammonium (NH4) and phosphate (PO4^(3-)). Zeolite has …

Evaluation Of Hydrodynamic Effects Of Waterway Restoration On An Estuarine Ecosystem, Megan Kramer

USF Tampa Graduate Theses and Dissertations

Estuaries are hydrodynamically complex for they are influenced by tidal forces, freshwater flows, salinity variations, and often intricate coastal land morphology. Furthermore, many estuaries are subject to constant anthropogenic stresses due to dense coastal populations, which are expected to be exacerbated by changing climate trends. The 1,800 home residential Manchester Waterway (MW) community located in Charlotte Harbor (along the Gulf of Mexico in Southwest Florida), is interested in improving boat access by restoring a previous connection between the local waterway and the harbor, separated by a barrier peninsula. The proposed connections aim to reduce boat traffic and travel time through …

Coral Reef Restoration Monitoring Through An Environmental Engineering And Social-Ecological Lens, Michelle C. Platz

USF Tampa Graduate Theses and Dissertations

The Florida Reef Tract (FRT) has experienced catastrophic coral cover declines since the 1970s, and active coral restoration is therefore needed to recover ecosystem integrity, preserve intrinsic values, and guarantee the provision of ecosystem services on which humans rely. While the coral restoration field’s ability to grow and outplant coral has improved extensively in the last two decades, this growth has led to the development of research gaps pertaining to restoration monitoring, specifically regarding the technical capacity to perform long term monitoring, spatial and temporal resolution, and metrics with which to quantify changes in ecosystem function resulting from restoration. The …

Chlorine Taste Threshold And Acceptability As A Water Disinfectant Among Indigenous Ngäbe And Non-Indigenous In Rural Panama, Ashley Osler

USF Tampa Graduate Theses and Dissertations

More than two billion people globally still lack access to safely managed drinking water (WHO & UNICEF, 2021). Although gains in access to water service over the past two decades have been large, universal access to safe and affordable drinking water (SDG 6, target 6.1) is not on track to be achieved. In Panama, safely managed drinking water access has not been measured. However, the data on basic water access illustrates the large disparities between rural and urban areas of Panama. While 98% of urban Panamanian households have basic access to water, only 86% of rural Panamanian households, and 54% …

Trajectory Optimization For Connected And Autonomous Vehicle Platooning And Split Operations: Modeling And Experiments, Qianwen Li

USF Tampa Graduate Theses and Dissertations

Emerging connected and autonomous vehicle (CAV) platoon technology holds great potential in improving mobility, enhancing riding comfort, reducing fuel consumption, and mitigating congestion. It reduces car-following gaps via cyber connections. Further, it smooths vehicle trajectories via automated control. Smoothed trajectories and improved aerodynamic efficiency from reduced car-following gaps improve fuel and space efficiency, thus improving traffic performance.

Motivated by such promising advantages, this dissertation investigates trajectory optimization for two basic CAV platoon operations, i.e., platooning and split, which are the premise to implement this technology to benefit society. Two two-stage optimization problems are formulated to solve the platooning and split …

Cross-Checking Automated Passenger Counts For Ridership Analysis, Simon Berrebi, Sanskruti Joshi, Kari Watkins

Journal of Public Transportation

Due to concerns about data quality, Automated Passenger Counting technology has rarely been used to analyze local ridership trends. This paper presents a novel framework to test the consistency and completeness of passenger count data in four cities. The data are aggregated at the system level and compared with the National Transit Database between 2012 and 2018. In all four agencies, passenger counts closely follow the fluctuations observed in the national transit database. There is, however, a slight drift in two of the four agencies. At the stop-level, missing and duplicate vehicle-trips are identified using schedule data from the General …

Efficient Management Of Nitrogen And Phosphorus At Centralized Water Reclamation Facilities, Helene Kassouf

USF Tampa Graduate Theses and Dissertations

A variety of process configurations are employed at municipal water reclamation facilities (WRFs), such as 5-stage Bardenpho, oxidation ditch, modified Ludzack-Ettinger (MLE) process, and sidestream recycle. However, all of these configurations face certain challenges in achieving optimum treatment of nitrogen and phosphorus. In this dissertation, the driving objectives were to: (1) quantitatively assess the fate of nitrogen and phosphorus (mass fluxes) at a treatment facility that employs biological nutrient removal, aerobic digestion, and sidestream recycle, (2) evaluate the performance of a microbial fuel cell (MFC) as a technology to remove nitrogen from sidestreams at a treatment plant that employs that …

Pressure Retarded Osmosis: A Potential Technology For Seawater Desalination Energy Recovery And Concentrate Management, Joshua Benjamin

USF Tampa Graduate Theses and Dissertations

Currently, a significant challenge with reverse osmosis-based desalination is reducing the energy consumption and environmental impacts of the process. This project analyzed the viability of using pressure-retarded osmosis (PRO) for energy recovery in seawater desalination facilities using brine concentrate (the draw solution) and other water sources (the feed solution) such as wastewater effluent. The primary goal of this project is to decrease the cost and overall energy consumption of seawater desalination through PRO-based energy recovery. Process modeling, statistical and sensitivity analysis, energy and cost analysis, geospatial and GIS analysis, laboratory-scale testing, water quality analysis, SEM-EDS microscopy, computational fluid dynamics (CFD), …

Shortcut Nitrogen Removal In Photo-Sequencing Batch Reactor, Experiments, Dynamic Model And Full-Scale Design, Sahand Iman Shayan

USF Tampa Graduate Theses and Dissertations

Nitrogen is one of the essential elements for life; however, inefficient use of nitrogen creates major environmental problems. Nitrogen-rich streams from urban areas, farms, and wastewater treatment plants (WWTPs) lead to surface and groundwater contamination, resulting in eutrophication, hypoxia, and notable environmental, public health and economic damage. Ammonia is a form of nitrogen that can be created during industrial or biological nitrogen fixation or decomposition of biomass. Anaerobic digesters (ADs) in WWTP generate biogas from collected sludge from primary and secondary clarifiers to achieve energy recovery in the plant. However, sidestream effluent from dewatering AD sludge contains high concentrations of …

A System Architecture For Water Distribution Networks, Noha Abdel-Mottaleb

USF Tampa Graduate Theses and Dissertations

This dissertation examines structure-function relationships of water distribution networks (WDNs), with focus on improving the decision-making process for water utilities. WDNs are lifeline infrastructure systems, necessary for the functioning of cities. Yet water utilities around the world struggle with emerging challenges that include but are not limited to aging infrastructure components, limited budgets, increased interdependencies between infrastructure systems, increased rates of urbanization, and increasing extreme weather conditions. This is why enhancing the performance of WDNs is a priority for water utilities around the world. This research begins to delineate a system architecture for WDNs and evaluates the use of various …

Driver Perceptions On Taxi-Sharing And Dynamic Pricing In Taxi Services: Evidence From Athens, Greece., Christina Milioti, Konstantinos Kepaptsoglou, Konstantinos Kouretas, Eleni Vlahogianni

Journal of Public Transportation

The taxi industry has changed dramatically during the last decade, as ride-sourcing applications, ride-sharing and alternative pricing schemes have emerged, either as complementing or competitive services and strategies. After some years of familiarity with such trends, it is interesting to explore where the taxi industry stands with respect to possible service innovations. This paper explores behavioral patterns of drivers, focusing on issues such as their preferred way of conducting business, and their views on introducing taxi-sharing and dynamic pricing. Data collected from a face-to-face questionnaire survey in Athens, Greece are exploited, and appropriate econometric models are developed for the purposes …

An Assessment And Exploration Of Recent Methodological Advances In Safety Data Analysis, Suryaprasanna Kumar Balusu

USF Tampa Graduate Theses and Dissertations

The injury severity and frequency of traffic crashes can be further reduced by implementing appropriate traffic safety measures. Several advanced methodologies have been developed in the recent decades to more accurately identify the factors affecting road safety. Such methodologies have helped policy makers formulate appropriate safety measures directed toward increasing seatbelt and helmet use, reducing speed limits in school zones, implementing adolescent driver programs, and so on. However, each methodological approach has its own strengths and weakness and could lead to different inferences. This dissertation assesses and explores a number of recently developed methodologies and their application to traffic safety …

Sanitation Marketing In Uganda: The Impact Of Gender On Participation And Outcomes, Elizabeth Vicario

USF Tampa Graduate Theses and Dissertations

Uganda aims to reach universal access to basic sanitation under Sustainable Development Goal #6, but achieving this target by 2030 would require doubling the annual rate of progress. Women are disproportionately affected by poor sanitation due to their health needs and risk of facing violence, but they have historically been excluded from sanitation planning. Low household demand and poor service delivery have stalled progress in Uganda. Market-based sanitation (MBS) is a novel method of developing a sanitation market through stimulating demand and supporting a competitive atmosphere for product and service providers. This research studies the sanitation marketing activities implemented by …

Use Of Biochar And Zeolite For Landfill Leachate Treatment: Experimental Studies And Reuse Potential Assessment, Thanh Thieu Lam

USF Tampa Graduate Theses and Dissertations

Leachate is a highly colored liquid waste product of landfills that contains high concentrations of ammonia nitrogen (NH4+-N), refractory organic matter, and heavy metals. It is commonly disposed to local publicly owned treatment works (POTWs). With these potent characteristics, it interferes with the physical, biological, and chemical treatment processes within POTWs. Sequencing batch biofilm reactors (SBBR) and hybrid subsurface flow constructed wetlands (CW) have been used in the past to treat landfill leachate, but their design and performance can still be optimized. Addition of low-cost adsorbent materials to SBBRs and CWs, such as biochar and zeolite, have the potential to …

Community Assessment Of Water Perceptions And Household Point-Of-Use Treatment Methods In Madagascar, Isabella Rose Silverman

USF Tampa Graduate Theses and Dissertations

One in four people around the world do not have access to safe drinking water, which means that two billion people globally lack access. In high-income countries, 0.02% of yearly deaths are attributed to unsafe water sources; however, an alarming 10.6% of deaths occur in Madagascar, for the same reason.

To achieve Sustainable Development Goal 6: Ensure access to water and sanitation for all, a collaboration between public health and engineering is critical. Within the public health sector, social marketing is commonly utilized to address a problem by using commercial marketing principles to change behavior for the good of society. …

Laboratory Examination Of Lead Weights Harvested From Pitcher Pumps In Eastern Madagascar, Madelyn Wilson

USF Tampa Graduate Theses and Dissertations

Previous sampling campaigns in Tamatave, Madagascar, conducted by the University of South Florida (USF) have identified lead contamination in drinking water sourced from self-supply pitcher pumps. The pitcher pump piston and foot valves were identified as the primary source of lead contamination since they are often manufactured from recycled lead acid batteries. The previous field sampling technique consisted of collecting an aliquot of a 10-15-liter composite sample from the pitcher pump for dissolved lead analysis; however, this technique (1) neglects the contribution of particulate lead, (2) does not properly account for the effects of water stagnation inside the pitcher pump …

Using Fuzzy Clustering Of User Perception To Determine The Number Of Level-Of-Service Categories For Bus Rapid Transit, Yueying Huo, Jinhua Zhao, Xiaojuan Li, Chen Guo

Journal of Public Transportation

The concept of level of service (LOS) is meant to reflect user perception of the quality of service provided by a transportation facility or service. Although the LOS of bus rapid transit (BRT) has received considerable attention, the number of levels of service of BRT that a user can perceive still remains unclear. Therefore, in this paper, we address this issue using fuzzy clustering of user perception. User perception is defined as a six-dimension vector of the perceived arrival time, perceived waiting time, bus speed perception, passenger load perception, perceived departure time, and overall perception. A smartphone-based transit travel survey …

Minimum Cut-Sets For The Identification Of Critical Water Distribution Network Segments, Xiliang Mao

USF Tampa Graduate Theses and Dissertations

To ensure adequate performance of water distribution networks, utilities must identify critical segments within the network that will adversely affect users when failures occur. Currently, time consuming hydraulic simulations are used for such criticality analyses. A method can be of great benefit for utilities if it can easily evaluate the criticality of water distribution network segments. This research applies topology-based methods for the preliminary screening of critical segments. This study evaluated the connectivity between sources and each demand segment in water distribution networks using minimum cut-sets. Through topological analysis, the minimum cut -set between the source node and each demand …

Effects Of Nitrate On Arsenic Mobilization During Aquifer Storage And Recovery, Hania Hawasli

USF Tampa Graduate Theses and Dissertations

Aquifer storage and recovery technology is used to sustain water resources and to prevent saltwater intrusion. The injected water can come from various resources, including treated wastewater. In pilot ASR studies in the Tampa Bay region, researchers found high As concentrations in the recovered water from the oxidation of the arsenopyrite that is embedded in the aquifers. The presence of dissolved O2 in the injected water is a major factor in the arsenopyrite oxidation during ASR, however the effects of NO3- on the arsenopyrite has not been studied yet. This is an important knowledge gap because injected water may contain …

Understanding Transantiago Users’ Motivations For Paying Or Evading Payment Of Bus Fares, Carolina Busco, Felipe González, Yamil Jaqueih, Felipe Jiménez, Borja Alonso

Journal of Public Transportation

Transantiago, the public transport system implemented in Santiago, Chile, remains a controversial subject of public debate due to constantly increasing fare evasion rates throughout its decade-long existence. The

Transantiago, the public transport system implemented in Santiago, Chile, remains a controversial subject of public debate due to constantly increasing fare evasion rates throughout its decade-long existence. The research question under consideration in this paper is as follows: What motivates individuals to evade or pay bus fares? To answer this question, we developed a multidisciplinary study that combined relevant engineering expertise with a sociological perspective and combined quantitative analyses with qualitative methodologies …

People-Focused And Near-Term Public Transit Performance Analysis, Alex Karner

Journal of Public Transportation

Public transit ridership forecasts have long played a role in understanding the potential success of a policy or investment, but their limitations have led researchers and practitioners to identify other performance analysis approaches. Accessibility, or the ease of reaching opportunities, has become very popular and widely used for this purpose. But commonly used accessibility measures also embody weaknesses that are seldom acknowledged; these limit their utility for truly understanding the benefits of transit investments. In this paper, we identify the pros and cons of these competing approaches and offer a third strategy. Specifically, we describe how revealed travel behavior data, …