Search results

Title: Dynamic and Stochastic Transition of Traffic Conditions and Its Application in Urban Traffic Mobility.
Creator: Kidando, Emmanuel, Moses, Ren, Duncan, Michael Douglas, Ozguven, Eren Erman, Sobanjo, John Olusegun, Sando, Thobias M., Florida State University, FAMU-FSU College of Engineering...
Show moreKidando, Emmanuel, Moses, Ren, Duncan, Michael Douglas, Ozguven, Eren Erman, Sobanjo, John Olusegun, Sando, Thobias M., Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Analytical models developed using field data can provide useful information with acceptable confidence to evaluate and predict the operational characteristics of a highway. As such, this study presents statistical models that can be used to estimate the travel time or speed distribution, cluster different traffic conditions, to model the dynamic transition of traffic regimes (DTR), and quantify the disparity-effects on the DTR associated with different lateral lane positions (i.e., lane near...
Show moreAnalytical models developed using field data can provide useful information with acceptable confidence to evaluate and predict the operational characteristics of a highway. As such, this study presents statistical models that can be used to estimate the travel time or speed distribution, cluster different traffic conditions, to model the dynamic transition of traffic regimes (DTR), and quantify the disparity-effects on the DTR associated with different lateral lane positions (i.e., lane near shoulder, middle lane(s) and lane near a median) as well as different days of the week. In the analysis, this study uses Bayesian frameworks to estimate the model parameters. These frameworks reduce the impact of model over-fitting and also incorporate uncertainty in the estimates. Data from a freeway corridor along I-295 located in Jacksonville, Florida were selected for analysis. It includes data from individual microwave vehicle sensors, segment level aggregated traffic data and data aggregated at a corridor level. The proposed probabilistic frameworks developed by this study can be a useful resource in detecting and evaluating different traffic conditions, which can facilitate the planning action to implement congestion-related countermeasures in urban areas. In addition, findings from the hierarchical regression model presented by the current study can be used in the application of intelligent transportation systems, mainly in the dynamic lane-management strategy.
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Date Issued: 2019
Identifier: 2019_Spring_Kidando_fsu_0071E_15049
Format: Thesis

Title: Hybrid Data Mining Models for Risk and Vulnerability Analysis of Traffic Safety.
Creator: Mafi, Somayeh, AbdelRazig, Yassir, Boot, Walter Richard, Ozguven, Eren Erman, Spainhour, Lisa, Florida State University, FAMU-FSU College of Engineering, Department of Civil and...
Show moreMafi, Somayeh, AbdelRazig, Yassir, Boot, Walter Richard, Ozguven, Eren Erman, Spainhour, Lisa, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: As the roadway networks have been developing gradually to improve transportation accessibility to various facilities, the probability of traffic crash occurrences has also increased consequently. With an increasing transportation demand, traffic safety needs to be improved in order to reduce the economic and societal expenses related to improper traffic safety measures. The identification and prediction of crash-prone regions is an essential task in highway safety management, particularly...
Show moreAs the roadway networks have been developing gradually to improve transportation accessibility to various facilities, the probability of traffic crash occurrences has also increased consequently. With an increasing transportation demand, traffic safety needs to be improved in order to reduce the economic and societal expenses related to improper traffic safety measures. The identification and prediction of crash-prone regions is an essential task in highway safety management, particularly when highway officials have a limited budget for mitigations. Generally, implementing effective methods for the prediction of high crash risk locations can facilitate research on contributing factors in traffic crashes to mitigate them, resulting in the efficient employment of federal, state and local government resources for enhancing transportation safety. In this regard, developing non-biased and accurate models capable of predicting crash risk is a vital task in transportation safety research. Another transportation issue, believed to have a close relationship with traffic safety and operation, is drivers’ gap acceptance behavior. Given the steady rise in the percentage of aging roadway users in the United States and their over-represented engagement in fatal crashes, there is a growing need for understanding how this population differs from their younger counterparts in driving performance and crash involvement. The general objective of this research is to develop hybrid data mining models for risk and vulnerability analysis of traffic safety. This research examines the feasibility of different data mining models in predicting the priority of intersections needing improvement for aging drivers by comparing their results with traditional models. It also investigates how injury severity differs between drivers of various age and gender groups by developing cost-sensitive data mining models which consider the consequences (cost) of incorrect predictions. Moreover, it examines the effect of time-based accessibility to on-premise alcohol outlets on the severity of alcohol-related crashes. This research also conducts Geographical Information System (GIS)-based hotspot analyses to identify the crash-prone locations for various occupant age groups during different time intervals of a day and predict the location of these hotspots using statistical and machine learning models. Besides, it conducts a spatiotemporal analysis to quantify the exposure of population of different age groups to crash-prone locations and to statistically analyze the decision-making process for possible improvement. This study also aims to investigate the differences in drivers’ gap acceptance behavior while performing permissive left and right turn maneuvers at four-legged intersections using the data extracted from a driving simulator. The results showed that the implemented machine learning models were superior methodologies for predicting crash risk. Moreover, the cost-sensitive learning classifiers outperformed regular classifiers at accurately predicting injuries and fatalities of crashes. Results of the crash severity models displayed substantial differences in injury severity determinants across the age/gender cohorts. Also, it was concluded that more accessibility to on-premise alcohol outlets results in more severe alcohol-related crashes. The hotspot prediction models also revealed considerable differences in crash hotspot determinants and their coefficients across the occupants’ age groups and time intervals of a day. Moreover, among the residents, the aging population were shown to be more exposed to the risk of being injured in a crash compared to other age groups. The results of driving simulation experiment also illustrated that aging drivers are more conservative in performing left turns than younger drivers, and accepted gap size, number of lanes, and the presence of pedestrians were significantly correlated with drivers’ gap acceptance behavior.
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Date Issued: 2019
Identifier: 2019_Spring_Mafi_fsu_0071E_14997
Format: Thesis

Title: Multilevel Competing Risks Models for the Performance Assessment of Transportation Infrastructure.
Creator: Inkoom, Sylvester Kwame, Sobanjo, John Olusegun, Chicken, Eric, AbdelRazig, Yassir, Spainhour, Lisa, Florida State University, FAMU-FSU College of Engineering, Department of...
Show moreInkoom, Sylvester Kwame, Sobanjo, John Olusegun, Chicken, Eric, AbdelRazig, Yassir, Spainhour, Lisa, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Natural disasters such as hurricanes, earthquakes, storm surges, wildfires among other hazards affect communities and large geographic areas of the United States resulting in negative repercussions on the environment and the economy. The impacts of these hazards on bridges and other civil infrastructure affect the structural integrity and functionality of bridges, highway pavements and overall efficiency of the transportation network. This study focuses on the hazards that affect bridges and...
Show moreNatural disasters such as hurricanes, earthquakes, storm surges, wildfires among other hazards affect communities and large geographic areas of the United States resulting in negative repercussions on the environment and the economy. The impacts of these hazards on bridges and other civil infrastructure affect the structural integrity and functionality of bridges, highway pavements and overall efficiency of the transportation network. This study focuses on the hazards that affect bridges and pavements, and the complex interactions and correlations among them, to evaluate the performance of civil infrastructure. Hazard scenarios are considered as competing risks impacting the health of bridges and highway pavements. The study derived stochastic distributions characterizing the behavior of bridge elements and pavement segments during natural deterioration process which are compared to their response in the presence of hazards. To achieve the above objective, competing risk models were developed for highway pavement in Florida in the presence of hurricane failures. Also, distributions and competing risk deterioration models for AASHTO Commonly Recognized (CoRe) bridge elements were developed using legacy data for bridges from the Florida Department of Transportation (FDOT). Annual probability of hazard occurrence data sourced from Federal Emergency Management Agency (FEMA – HAZUS) was employed to model hurricane induced pavement and bridge element failure. The expected service lives for highway pavement and bridge elements, transition and sojourn times from one condition state to another were obtained using the Cox Proportional Hazards, cumulative incidence functions, product-limit survival estimates and other survival functions. The method of likelihood estimation, weighting techniques and inference procedures were used to describe risk event data with censoring and truncation scenarios where necessary for the analyses. The cumulative incidence function and the Kaplan – Meier estimates were used to ascertain the effects of the modes of failures of bridge elements and highway pavements at the network levels in the presence of hurricanes. The results showed that three modes of failure (cracking, riding and rutting) are all significant to for pavements. As the roadway pavement section ages, the chance of failure is more likely to be due to cracking than the other competing modes. Based on the road functional classifications, the survival probabilities and the cumulative incidence estimates showed that the cracking defect was predominant on both interstate and non-interstate roadways. It was observed that urban and rural pavements deteriorated by the cracking and riding defects with the rutting failure mode being significant at the end of the service life of the pavement. The research also evaluated the significance of two competing risks events: “natural” crack deterioration of highway pavements in the presence of hurricane failure (Hurricane Categories 1, 2 and 3), for 6702 highway pavement sections using the nonparametric survival probability (Kaplan-Meier estimates) and the cumulative incidence function (CIF). The risks were compared using the Logrank Test (to indicate if the survival probabilities of the risks are significantly different), and the hazard ratio (ratio of hazard rates based on time to failure covariate). From the results, it was observed that the contribution of the Hurricane Category 3 as a competing risk was significantly higher and different from that of crack deterioration. For example, the hazard ratio indicated the effect of Hurricane Category 3 on pavement failure was twice as significant as that of the crack deterioration for the inland urban interstates roadways. Also, the hazard ratio between hurricane category 3 and crack deterioration was about 16 for rural interstates and 18 and 28 for urban non-interstates and rural non-interstates at the coastal locations respectively. The hazard ratios and CIF plots showed that impact of hurricanes on coastal roadways is more significant compared to how they affect the inland pavements. Finally, it was observed that the “natural” deterioration of bridge channels and hurricane induced channel failures generally yield significantly different impacts based on the logrank chi-square outputs. Also, it was observed the impact of hurricane categories 3 and 2 on bridge channel elements were more significant (based on the hazard ratios) at the coastal bridge locations than in the noncoastal areas, and also generally high for urban bridge channels compared to rural channels.
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Date Issued: 2019
Identifier: 2019_Spring_Inkoom_fsu_0071E_14979
Format: Thesis

Title: Modeling Biofilm on Reactive Surface.
Creator: Wang, Boya, Tang, Youneng, Ordóñez, Juan Carlos, Chen, Gang, Huang, Wenrui, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental...
Show moreWang, Boya, Tang, Youneng, Ordóñez, Juan Carlos, Chen, Gang, Huang, Wenrui, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Biofilms were first used to treat wastewater in the late 19th century, and still play an important role in today’s wastewater treatment plants. Biofilm model is one of the most essential and powerful tools for studying biofilm process, understanding the mechanisms both inside the biofilm and between the biofilm and outside environment, and controlling the performance of the biofilm reactors. Usually the biofilm grows on inert and impermeable surfaces, but sometimes it develops on ‘active’...
Show moreBiofilms were first used to treat wastewater in the late 19th century, and still play an important role in today’s wastewater treatment plants. Biofilm model is one of the most essential and powerful tools for studying biofilm process, understanding the mechanisms both inside the biofilm and between the biofilm and outside environment, and controlling the performance of the biofilm reactors. Usually the biofilm grows on inert and impermeable surfaces, but sometimes it develops on ‘active’ surfaces, which makes it more challenging to simulate. This dissertation is focused on modeling biofilm on reactive surface. It also develops a method to estimate kinetic parameters of biodegradation to be used in models. Homoacetogenesis and methanogenesis, which usually occur during anaerobic trichloroethene (TCE) dechlorination, affect the removal of TCE and its daughter products. This study develops a one-dimensional, multi-species H2-based biofilm model to simulate the interactions among six solid biomass species (Dehalococcoides, Geobacter, methanogens, homoacetogens, inert biomass (IB), and extracellular polymeric substances (EPS)) and 10 dissolved chemical species (TCE, dichloroethene (DCE), vinyl chloride (VC), ethene, hydrogen (H2), methane, acetate, bicarbonate, utilization associated products (UAP), and biomass associated products (BAP)). To evaluate and parameterize the model, parameter values from the literature were input into the model to simulate conditions reported for an experiment. The biomass species distribution in the biofilm and the chemical species concentrations in the reactor effluent at steady state were generally consistent between the experiments and the model. The predicted 15-µm biofilm consisted of three layers, each dominated by a different active biomass type: homoacetogens in the layer next to the membrane, Geobacter in the biofilm surface layer (next to the water), and Dehalococcoides in-between. About two thirds of the TCE was converted to ethene and one third to VC due to the large half-maximum-rate concentration of VC. The effluent concentration of VC is far beyond the drinking-water maximum contaminant level (MCL) of 2 µg/L. To achieve complete removal of TCE, DCE, and VC, we evaluated the influence of various operating conditions like H2 pressure, biofilm detachment rate (kdet), and multiple stages. Through all the simulation results, we demonstrated that VC could be completely removed from the reactor when the H2 pressure was between 0.01 and 0.1 atm and kdet was between 1 and 3.6 cm-1day-1. We also found that a 2-stage system was more efficient than a single-stage reactor. All biofilm models use kinetic parameters of biodegradation. For microbial consortia, the traditional method for kinetic parameter estimation is based on the total biomass concentration and assumes that all the microorganisms are capable of degrading the contaminant. This work proposed an improved method that selects the responsible microbial groups and uses their concentrations for parameter estimation. We conducted batch experiments to track the change of contaminant and biomass concentrations, and used 16s rRNA sequencing to analyze the microbial community. Based on the correlation between the contaminant and microbial abundance, we then found the groups that were likely responsible for bio-degradation of the contaminant. PEST, the industry standard software package for parameter estimation and uncertainty analysis of complex environmental and other computer models, was used to estimate biodegradation parameters. By comparing to the conventional method, we found that the accuracy of this method was higher than that of the conventional method.
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Date Issued: 2019
Identifier: 2019_Fall_Wang_fsu_0071E_15625
Format: Thesis

Title: Removal and Recovery of Selenium from Agricultural Drainage Using Microbial Processes.
Creator: Zhang, Zhiming, Tang, Youneng, Ye, Ming, Clark, Clayton J., Chen, Gang, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: Selenium is a nutrient for animals and human at low concentrations, but toxic at high concentrations. Agricultural drainage is one type of water that may contain selenium at a high concentration due to seleniferous agricultural soils, which presents hazards to its surrounding biosphere. Microbes can be used to remove selenium from agricultural water by converting dissolved selenate to elemental selenium nanoparticles, which may then be removed or recovered as a valuable resource. However,...
Show moreSelenium is a nutrient for animals and human at low concentrations, but toxic at high concentrations. Agricultural drainage is one type of water that may contain selenium at a high concentration due to seleniferous agricultural soils, which presents hazards to its surrounding biosphere. Microbes can be used to remove selenium from agricultural water by converting dissolved selenate to elemental selenium nanoparticles, which may then be removed or recovered as a valuable resource. However, sulfate is ubiquitous in water systems and the analogous reactions between selenate and sulfate affect the selenate reduction and the downstream elemental selenium purification and recovery. This presents one challenge for selenium recovery. The location of elemental selenium nanoparticles produced by the bacteria is closely relevant to the following recovery, since extracellular selenium nanoparticles are much easier to be recovered than intracellular selenium. Most microbial species either produce intracellular selenium nanoparticles or simultaneously produce extracellular and intracellular selenium nanoparticles. Few species produce only extracellular selenium nanoparticles, which leads to another challenge for selenium recovery. The overall objective of this dissertation is to address the two challenges. Being able to accurately measuring various selenium species is the precondition to addressing the two challenges. Particulate selenium is usually separated from dissolved selenium by centrifugation or filtration, but the separation conditions vary widely and are inconsistent in the literature. By systematically studying the effects of the relative centrifugation force and filter pore size on the separation of particulate selenium from dissolved selenium in typical environmental samples, we found that the relative centrifugation force of ≥ 20,000 g and filter pore size ≤ 20 nm led to complete separation of particulate selenium in general. The presence of other particles and the concentration of particulate selenium affect the separating efficiency by centrifugation and thus should be considered while choosing the appropriate centrifugation condition. To address the first challenge, the effects of sulfate on selenate reduction were studied in a H2-based membrane biofilm reactor. The composition and spatial distribution of biological selenate reduction products were affected by the operating conditions. At a hydraulic retention time (HRT) of 0.28 day, selenate was biologically reduced all the way to elemental selenium nanoparticles, which were embedded in the biofilm, suspended in the effluent and precipitated at the bottom of the reactor. With the HRTs decreasing to 0.14 and 0.07 days, selenium sulfides were the dominant particulate selenium products in the effluent, suggesting that the abiotic reaction between selenite (the intermediate of biological selenate reduction) and sulfide (the product of biological sulfate reduction) also occurred. To address the second challenge, a biocathode-based bioelectrochemical reactor was used to eliminate the need for separating intracellular selenium from biomass. The continuous-flow bioelectrochemical reactor removed > 99.6% of the selenate at a selenate surface loading rate of 330 mg Se/m2-day, which was higher than that in most of the conventional biological reactors. The inoculum was a microbial consortium containing both intracellular and extracellular selenium-producing bacteria, but only extracellular selenium nanoparticles were observed when the biocathode was imaged by a transmission electron microscope. To understand the extracellular selenium-producing mechanisms on the biocathodes, 16S rRNA sequencing was used to study the microbial community. Selenate reducing bacteria Azospira oryzae, Desulfovibrio, Stenotrophomonas, and Rhodocyclaceae dominated the cathodic electrode. They were reported to produce both intracellular and extracellular selenium nanoparticles in conventional reactors, but they produced only extracellular selenium nanoparticles on the biocathode. Raman spectrometry further demonstrated the existence of significant Cytochrome c (Cyt c) on the BIOcathode, an enzyme that plays a key role in extracellular electron transfer and subsequent extracellular selenium production. This dissertation is based on and adapted from published journal papers and manuscripts that are ready to submit.
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Date Issued: 2019
Identifier: 2019_Fall_Zhang_fsu_0071E_15643
Format: Thesis

Title: Innovative Metaheuristic Algorithms for Efficient Berth Scheduling at Marine Container Terminals.
Creator: Kavoosi, Masoud, Dulebenets, Maxim A., Vanli, Omer Arda, Moses, Ren, Ozguven, Eren Erman, Wang, Hui, Florida State University, FAMU-FSU College of Engineering, Department of...
Show moreKavoosi, Masoud, Dulebenets, Maxim A., Vanli, Omer Arda, Moses, Ren, Ozguven, Eren Erman, Wang, Hui, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Maritime transportation has been continuously playing an undeniable role for the global trade and economy of many countries. Based on the fast growth of the maritime trade, the marine container terminal (MCT) operators should focus on improving the operations planning at the MCTs. Seaside operations have substantial impacts on the general throughput of the MCTs. The daily berth planning as a seaside operation is the point of focus herein. The daily berth planning is modeled as a berth...
Show moreMaritime transportation has been continuously playing an undeniable role for the global trade and economy of many countries. Based on the fast growth of the maritime trade, the marine container terminal (MCT) operators should focus on improving the operations planning at the MCTs. Seaside operations have substantial impacts on the general throughput of the MCTs. The daily berth planning as a seaside operation is the point of focus herein. The daily berth planning is modeled as a berth scheduling problem (BSP) in this dissertation. The BSP (as a decision problem) aims to assign the arriving vessels to the available berthing positions and can be reduced to the unrelated machine scheduling problem, which has NP-hard complexity. The large-size instances of decision problems with NP-hard complexity cannot be solved using exact optimization algorithms, while metaheuristic algorithms can effectively solve large-size problem instances and return good-quality solutions. Evolutionary Algorithms (EAs) are among the most popular metaheuristic algorithms deployed to solve the real-size BSPs. There are some algorithmic parameters in EAs (e.g., crossover probability, mutation probability, population size, etc.), which should be assigned the appropriate values to have the best possible performance of the algorithm for a given BSP. The process of determination of algorithmic parameters values is called the parameter selection. Several methodologies have been introduced in the EA literature for parameter selection, which can be classified as follows: (1) parameter tuning; and (2) parameter control. In parameter tuning, the algorithmic parameter values remain constant throughout the algorithmic evolution, while the parameter control strategy updates the algorithmic parameters considering different approaches. In this dissertation, an EA with a self-adaptive parameter control strategy is proposed to solve the developed BSP. Based on a self-adaptive parameter control strategy, the crossover and mutation probabilities are encoded in the solutions and evolve with the EA. The problem is formulated as a mixed-integer linear programming model, minimizing the total weighted vessel turnaround time and the total weighted vessel late departures. Comprehensive numerical experiments are conducted to assess performance of the proposed self-adaptive EA against the alternative EAs, which rely on the different parameter selection strategies. Results demonstrate that all the considered solution algorithms show a promising performance in terms of the objective function values at termination. However, application of the self-adaptive parameter control strategy substantially enhances the objective function values at convergence without a significant impact on the computational time. Furthermore, an EA with an augmented self-adaptive parameter control strategy is presented in this dissertation as another solution algorithm for the BSPs. Based on an augmented self-adaptive parameter control strategy, not only the crossover and mutation probabilities are encoded in the solutions but they are also updated based on the feedback from the search. A mixed-integer linear programming mathematical model is developed for the BSP, aiming to minimize the total costs for serving vessels at the MCT. The designed algorithm is evaluated against nine alternative state-of-the-art metaheuristic algorithms, which have been widely utilized in the BSP literature. The results show that all the developed algorithms have a high level of stability and return high-quality solutions at termination. The computational experiments also prove the superiority of the designed augmented self-adaptive EA over the alternative algorithms considering different performance indicators. Another innovative solution methodology is developed in this dissertation, which relies on the island-based concept. Specifically, a universal island-based metaheuristic algorithm is designed for the BSP, where four different population-based metaheuristics are executed simultaneously in order to effectively search for solutions. A mixed-integer linear mathematical model is developed for the BSP, minimizing the total cost to serve the arriving vessels at the MCT. Comprehensive numerical experiments are conducted to evaluate performance of the island-based algorithm against seven commonly used metaheuristics in the BSP literature. The stability and the capability of the adopted algorithms in providing high-quality solutions at convergence are proven. The results demonstrate that the island-based algorithm outperforms other adopted algorithms considering different performance indicators. To summarize, this dissertation proposes three different solution methodologies for various BSP mathematical formulations. The algorithms have been evaluated based on extensive numerical experiments against the alternative algorithms, which have been widely used in the MCT and freight terminal operations literature. Findings confirm effectiveness of the proposed solution methodologies. Therefore, the developed solution methodologies can serve as promising decision support tools and assist MCT operators with the development of berth schedules. The latter will also assist with serving the growing demand for containerized trade and ensure that the vessel service will be completed in a timely manner.
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Date Issued: 2019
Identifier: 2019_Fall_Kavoosi_fsu_0071E_15484
Format: Thesis

Title: Multi-Scale Hurricane Loss Estimation.
Creator: Kakareko, Grzegorz, Jung, Sungmoon, Liu, Xiuwen, Vanli, Omer Arda, Rambo-Roddenberry, Michelle Deanna, Ozguven, Eren Erman, Florida State University, FAMU-FSU College of...
Show moreKakareko, Grzegorz, Jung, Sungmoon, Liu, Xiuwen, Vanli, Omer Arda, Rambo-Roddenberry, Michelle Deanna, Ozguven, Eren Erman, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Hurricane risk assessment is an important research topic: accurate estimation of the potential loss helps guide mitigation efforts to decrease the loss in the future. In the past decade, researchers working on the loss analysis tried to improve the loss estimation by generally working on a specific scale, such as building scale or city scale. The overarching goal of this dissertation is to improve the hurricane risk analysis by advancing the components in different scales, starting from...
Show moreHurricane risk assessment is an important research topic: accurate estimation of the potential loss helps guide mitigation efforts to decrease the loss in the future. In the past decade, researchers working on the loss analysis tried to improve the loss estimation by generally working on a specific scale, such as building scale or city scale. The overarching goal of this dissertation is to improve the hurricane risk analysis by advancing the components in different scales, starting from improving the current vulnerability and fragility models used in risk analysis, exploring the new metrics in regional loss estimation, and quantifying Florida mitigation impact. The first objective is to investigate the approximate loss of low-rise buildings from hurricane damage considering a Bayesian capacity model. Due to the lack of methods that can combine physics principles with experimental data, many previous vulnerability models relied on estimating parametric statistical models solely from data. In this research, a Bayesian capacity model that combines physics-based analytical results with experimental results was proposed. The inclusion of analytical estimations can help to produce more accurate fragility function when the amount of available data is limited. The proposed approach provides a range of the fragility functions and their confidence intervals, which then is translated into upper and lower bounds in the vulnerability estimation. The second objective is the new methodology for time dependent fragility analysis. A gamma process is employed to model the stochastic degradation of building components. Time-dependent fragility function and failure probability of the roof system obtained from the component degradation can be applied in time-dependent reliability modeling and optimal maintenance planning. Another objective of this dissertation is to understand characteristics of hurricane loss in different regions of Florida. Two different structures with different components capacities were taken into consideration. The first structure does not meet the current building standards in terms of the high winds performance (“weak”), and the second structure is built from hurricane proved materials approved by Florida Building Code (“strong”). In order to bring a new insight into the regional differences in hurricane loss, Exceedance Probability of Loss (EPL) is introduced. The EPL is the probability that the total annual loss will exceed a certain level. The results of this research identified the most vulnerable parts of Florida in terms of the EPL. In order to quantify the loss, the main loss measures used in the past are normalized percentage loss and dollar value loss. In this dissertation, it is shown that these measures are useful but may not properly reflect the size of the population influenced by hurricanes. The first metric is the average annual loss (AAL) which represents the expected loss per year in percentage. The second is the average annual dollar loss (AADL) which represents the expected dollar amount loss per year. In addition, a new loss measure is proposed that reflects the hurricane impact on people occupying the structure, which is the average annual population-weighted loss (AAPL). Compared to the AAL, the AAPL reflects the number of people influenced by the hurricane. The advantages of the AAPL are illustrated using three different analysis examples: 1) conventional regional loss analysis, 2) mitigation potential analysis, and 3) forecasted future loss analysis due to the change in population.
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Date Issued: 2019
Identifier: 2019_Fall_Kakareko_fsu_0071E_15506
Format: Thesis

Title: Risk-Benefit Analysis and Optimization of LEED-Certified School Buildings Design and Construction: Statisitical and Machine Learning Approaches.
Creator: Doczy, Ryan Daniel, Boot, Walter Richard, Sobanjo, John Olusegun, Spainhour, Lisa, Florida State University, College of Engineering, Department of Civil and Environmental...
Show moreDoczy, Ryan Daniel, Boot, Walter Richard, Sobanjo, John Olusegun, Spainhour, Lisa, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: As the strategy of green building becomes more and more popular due to a combination of environmental and economic concerns, there develops a need for clearly being able to understand the potential implications for choosing green strategies over conventional building practices. Some of the regions of interest consist of the additional upfront costs associated with green practices, potential life-cycle benefits associated with green building components, potential energy savings, and the...
Show moreAs the strategy of green building becomes more and more popular due to a combination of environmental and economic concerns, there develops a need for clearly being able to understand the potential implications for choosing green strategies over conventional building practices. Some of the regions of interest consist of the additional upfront costs associated with green practices, potential life-cycle benefits associated with green building components, potential energy savings, and the ability to reduce emissions. Many of these areas can potentially be forecasted with a fair degree of certainty (e.g. energy consumption, additional upfront costs); however, some elements of green building are less well defined. One such area consists of the ability of green buildings to improve the productivity and well-being of its inhabitants through an improved indoor environmental quality (IEQ). It is difficult to grasp just how much a healthier and cleaner environmental can impact a person’s cognitive functions, mental state, and physical health. Several studies shown in the literature review of this paper lead show a positive correlation between green buildings and reductions in asthma symptoms, depression symptoms, improved well-being due to reductions in contaminants, a reduction in sick building syndrome (SBS) and building related illness (BRI). This paper aims to do what many have done before in attempting to quantify the potential impact that sustainable buildings can have on its occupants; however, the scope and methods to determine these potential correlations will differ. Perhaps the most noticeable difference will be in the paper’s focus on attempting to measure the potential impact that LEED (Leadership in Energy and Environmental Design) accredited schools have on their student occupants by measuring their productivity via the use of standardized test scores and attendance rates compared to those students in conventional (non-LEED) schools. To develop a balanced analysis, the paper will control for various school-related and socio-economic factors (e.g. economic status, race, percent of teachers with a Master’s degree or higher). To make a judgement on the effect that sustainability has on academic achievement and student wellbeing, 2 sample t-tests, regression analysis, and M5P decision trees will be implemented to determine if there are significant differences between LEED and conventional schools and to determine the relationship between LEED and non-LEED parameters on student achievement and wellbeing metrics. To ensure that a large population of students from across the nation are accounted for, the study intends on investigating at least three states-worth of student data. These states (Florida, New York and Virginia) are in different climates, thus allowing for an examination of the potential differences between the various climate zones and building codes. Lastly, a case study building information model (BIM) of College Park Elementary School (located in Virginia) will be run through the energy modeling (EM) software, Ecotect, to provide information related to the school’s annual energy consumption, acoustics, and daylight and lighting values. An optimization equation, developed using previous literature and findings from this study, will use information from the case study in an attempt to optimize its academic performance. The equation will attempt to minimize construction and operational costs while maximizing student performance metrics. The optimization equation will be run through NEOS server’s Nonlinearly Constrained Optimization, Knitro. The purpose of this study is to inform those decision-makers involved in the construction of schools, and who may be interested in obtaining LEED certification for the school, to what extent the LEED schools benefit the school’s student academic achievement levels. Accounting for soft benefits (e.g. productivity, morale, general wellbeing) in a cost-benefit analysis invites an element of risk due to the difficulties in soliciting, obtaining, and accurately measuring these performance metrics. When considering fields involving knowledge work, accurately measuring productivity is an inexact science that normally requires building occupants to perform self-examinations. The results from these examinations are reliant on the occupant’s perceptions and could be open to bias. This study avoids self-assessments through its use of standardized testing as a measure for productivity. The proposed outcome of this paper is that the impacts of LEED schools on their occupants’ academic achievement, health, and wellbeing will be better understood and easier to quantify. The authors hypothesize that LEED schools will outperform conventional schools, which can be attributed to improved IEQ due to tighter building envelopes, increased ventilation rates, better filtration, a reduction in building or cleaning products containing volatile organic compounds, etc. An absence of this data could point to the inability of LEED schools to directly impact their students in a meaningful way, particularly its Indoor Environmental Quality credits, which means that LEED could have to rethink its standards if it wishes to truly improve the productivity and wellbeing of its occupants.
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Date Issued: 2018
Identifier: 2018_Su_Doczy_fsu_0071E_14648
Format: Thesis

Title: Impact of Connected and Autonomous Vehicles on Freeway Traffic Operations.
Creator: Theophilus, Oluwatosin Paul, Sobanjo, John Olusegun, Ozguven, Eren Erman, Dulebenets, Maxim A., Florida State University, College of Engineering, Department of Civil and...
Show moreTheophilus, Oluwatosin Paul, Sobanjo, John Olusegun, Ozguven, Eren Erman, Dulebenets, Maxim A., Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: This project evaluates using traffic simulation, the performance of a mixed traffic composition of Connected and Autonomous Vehicles (CAV) and conventional or human-driven vehicles, in comparison with the performance of the existing traffic composition of only conventional vehicles on a freeway segment. The introduction of CAVs into the existing transportation system is a phase in the evolution of automobile traffic currently generating a lot of concerns and questions that needs to be...
Show moreThis project evaluates using traffic simulation, the performance of a mixed traffic composition of Connected and Autonomous Vehicles (CAV) and conventional or human-driven vehicles, in comparison with the performance of the existing traffic composition of only conventional vehicles on a freeway segment. The introduction of CAVs into the existing transportation system is a phase in the evolution of automobile traffic currently generating a lot of concerns and questions that needs to be answered before the full deployment of these vehicles. Traffic simulation presents a safer and cost-effective approach to evaluating this innovative technology when compared with real world testing. Connected and autonomous vehicles (CAV) are designed to improve traffic operations, as the difference in their driving behavior from regular vehicles suggests a reasonable tendency to change the traffic flow pattern. However the issue being examined in this project is whether there would be a significant change in traffic operations resulting from their deployment, and also to verify whether the change is an improvement of the existing traffic condition in terms of performance measures used for the evaluation. Data was collected from the I-95 Freeway in South Florida, and used in the development of a traffic microsimulation model, in VISSIM. The model was calibrated using minimum error algorithm implemented in MATLAB to determine the optimal value of the two model parameters considered -- stand still distance (CC0), and headway time (CC1). The calibrated model was used as the base model and CAVs are incorporated into the base model in 10% increment, to examine their effect on the base model. The performance measures are average hourly speed, hourly traffic volume, travel time, delay, and safety. Findings show that for every increment in CAV market penetration, there is a change of 6.52% - 48% in the capacity of the freeway, 40% reduction in travel time, more than 30% reduction in delay per vehicle, more than 26% increase in average speed of the traffic at high demand volumes.
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Date Issued: 2018
Identifier: 2018_Su_Theophilus_fsu_0071N_14809
Format: Thesis

Title: Accelerated Slab Replacement Using Temporary Precast Panels and Self Consolidating Concrete.
Creator: Squillacote, Steven C., Tawfiq, Kamal Sulaiman, Rambo-Roddenberry, Michelle Deanna, Spainhour, Lisa, Kampmann, Raphael, Florida State University, FAMU-FSU College of Engineering...
Show moreSquillacote, Steven C., Tawfiq, Kamal Sulaiman, Rambo-Roddenberry, Michelle Deanna, Spainhour, Lisa, Kampmann, Raphael, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: As it stands, many of Florida’s roads have already reached their designed service life and are now in the process of being renewed. The current method in rehabilitation of concrete pavement requires the expired piece of pavement to be cut and removed, place new dowel bars, and then epoxied into the surrounding slabs. Once the slab area has been prepared, fresh concrete is poured, and finished. The concrete is then cured and monitored to achieve a strength requirement of 2,200 psi in the...
Show moreAs it stands, many of Florida’s roads have already reached their designed service life and are now in the process of being renewed. The current method in rehabilitation of concrete pavement requires the expired piece of pavement to be cut and removed, place new dowel bars, and then epoxied into the surrounding slabs. Once the slab area has been prepared, fresh concrete is poured, and finished. The concrete is then cured and monitored to achieve a strength requirement of 2,200 psi in the shortest possible time before the lanes can be opened for traffic. This event has been known to take a long time and on major highways lane where lane closure may not exceed 8 hours. This restriction limits the number of slabs that can be replaced. The types of concrete used on these projects are also problematic. In the past, high amounts of cementitious material was used and this can lead to premature cracking. To improve production levels, accelerate construction time at a reduced cost, and provide long lasting pavement, the current research study presents an alternative method of using precast slab panels and self-consolidating concrete. This was accomplished by testing several SCC mixes in the laboratory to achieve concrete with high workability without, high early strength and without segregation. Then, precast panels were designed and built for quick installation and removal. This study also necessitated full scaled field tests where precast slab panels with the proper SCC mix were used. The slabs were tested by a loaded truck moving over it repeatedly and the slab was monitored for any movement and displacements caused by driving and braking on it. After the data was collected from the precast panels, the slabs were then removed and fresh SCC was then poured into the empty pit. The SSC slab was left to cure and the maturity of the concrete was monitored to achieve the required strength for lane opining. In this study, three techniques were used to monitor the concrete maturity. These techniques involved the use of the conventional thermocouples, thermal camera, and laser gun. The traffic load was then applied by driving a dump truck loaded to 25000 pounds over the track for 100 laps. The SCC mix behaved as designed and presented in this study. It achieved a high workability and retained a high slump for nearly an hour. It also exceeded the required FDOT strength requirement of 2200 psi for lane opening. The precast panels proved to be highly durable during the installation, testing, removal and can be reused for other similar applications. Results from this study proved proved that using this method has several benefits including greater productivity, reduced maintenance of traffic, shorter project completion time. Further, it may reduce the case of premature cracking due to the increase amount of curing time.
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Date Issued: 2018
Identifier: 2018_Su_Squillacote_fsu_0071N_13474
Format: Thesis

Title: Analysis of Composite Timber Studs: An Optimization of Tall Wall Structures.
Creator: Solek, Ashley, Rambo-Roddenberry, Michelle Deanna, Jung, Sungmoon, Kampmann, Raphael, Spainhour, Lisa, Florida State University, FAMU-FSU College of Engineering, Department of...
Show moreSolek, Ashley, Rambo-Roddenberry, Michelle Deanna, Jung, Sungmoon, Kampmann, Raphael, Spainhour, Lisa, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: The National Design Specification for Wood Construction (NDS) outlines different factors and equations necessary for designing structures exploiting timber. While analyzing a timber shear wall there are several specific equations and restraints that the design must satisfy. These limitations come from not only the NDS, but also the Minimum Design Loads for Buildings and Other Structures (ASCE7), the Florida Building Code (FBC), and the International Residential Code (IRC). ASCE7, paired with...
Show moreThe National Design Specification for Wood Construction (NDS) outlines different factors and equations necessary for designing structures exploiting timber. While analyzing a timber shear wall there are several specific equations and restraints that the design must satisfy. These limitations come from not only the NDS, but also the Minimum Design Loads for Buildings and Other Structures (ASCE7), the Florida Building Code (FBC), and the International Residential Code (IRC). ASCE7, paired with the NDS, provide a standard design methodology. The FBC and IRC focus their framework around the minimum requirements. These manuals focus on the design strength of the individual components, rather than how they react once affixed to one another. The sheathing is the foremost structural component which combats against the wind loads. Several different types of sheathing, as well as nail sizes and patterns were analyzed as a connected structure. The methodology used was similar to that of reinforced concrete, in that the properties of the nails and sheathing were transformed into that of the sawn lumber stud. This facilitated an analytical comparison between the standard design method and that of a "composite I-beam". Increases and decreases in strength were found, due to the complexity of the design equations, the addition of the sheathing component did not always enable a higher wall capacity. Deflection as the ultimate failure of the member still rang true for the new method of design.
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Date Issued: 2018
Identifier: 2018_Fall_Solek_fsu_0071N_14938
Format: Thesis

Title: Biomechanics of Older Drivers in Vehicular Crashes.
Creator: Fung, Kakit, Jung, Sungmoon, Zeng, Changchun (Chad), Sobanjo, John Olusegun, Tawfiq, Kamal Sulaiman, Florida State University, FAMU-FSU College of Engineering, Department of...
Show moreFung, Kakit, Jung, Sungmoon, Zeng, Changchun (Chad), Sobanjo, John Olusegun, Tawfiq, Kamal Sulaiman, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: The aging population is expected to increase substantially in the future. The fatal crash rates (per mile traveled) involving older drivers (65+) are considerably higher than those of younger drivers. This research involved conducting computational experiments involving dummy models to investigate the biomechanics of older drivers in vehicular crashes. Before conducting these experiments, the concepts of biological changes in older populations needed to be addressed. This allowed us to first...
Show moreThe aging population is expected to increase substantially in the future. The fatal crash rates (per mile traveled) involving older drivers (65+) are considerably higher than those of younger drivers. This research involved conducting computational experiments involving dummy models to investigate the biomechanics of older drivers in vehicular crashes. Before conducting these experiments, the concepts of biological changes in older populations needed to be addressed. This allowed us to first find out what makes the older drivers different from younger drivers. It was found that driving posture is one of the two key differences between the two age groups. The Hybrid III computational dummy model was used to investigate the effect of driving posture. The other key finding shows that older drivers are affected by aging factors such as material properties decrease and thickness decrease of bones. The Total Human Model for Safety (THUMS) was used because it can be modified to represent an aged driver to be used in the crash simulations. For the posture investigation, the idea is that driving posture for older drivers tend to be closer to the steering wheel whereas younger drivers are more laid back was incorporated. All computational work was completed in LS-DYNA; a finite element code used for non-linear impact analysis. The Finite Element (FE) simulation was validated by comparing the FE results with physical crash test results. These results were found in the Federal Motor Vehicle Safety Standards and Regulations (FMVSS) Report 208 for Frontal Crash Test. For subsequent simulations, posture changes based on the idea of aging according to literature review were implemented. For the Head Injury Criteria, the extended shoulders of an older driver yielded percent differences as high as 16%. The arms acted like braces to restrain the torso while the head continued forward. The extended knees also yielded a 16% increase in head injury. As for the chest acceleration, the extended hip and torso joints showed increased values. It was concluded that sitting closer was beneficial for the Head Injury Criteria but the opposite was true for the chest acceleration. The posture changes did not affect the pelvis acceleration. This investigation gave us a better understanding of what occurs in automobile accidents specific to older occupants. This knowledge can be useful in designing engineering approaches to mitigate injuries. Using the aged model, the material properties decrease yielded the highest chest deflection of 13.3%. For the bone thickness decrease, the chest acceleration showed the highest increase of 12.5%. The head acceleration and chest deflection showed noticeable increases. Overall with all three aging factors in place, the head and chest accelerations yielded high increases. Whereas for the deflection, it remains the same. The thoracic rotation increased the head resultant acceleration. The rotation decreased the deflection of the thorax because the ribs were more in line with the force imposed by the crash. It can withstand more force when the ribs are more parallel with the force. As for the chest acceleration, no significant change was present. It can be concluded that the older drivers in rear impacts experienced higher (Neck Injury Criterion) NICmax than younger drivers as much as 6.9% percent for the material property decrease and bone thickness decrease. The thorax rotation yielded a 4.7% decrease in NICmax. It is possible that this aging factor caused the thorax to conform more into the seatback thus reducing the injury. The bone thickness decreased affected the NICmax greatly whereas the material property decreased did show signs of minimal positive influence. The material property decreased yielded 0.8% increase while the thickness decreased yielded a 3.0% increase.
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Date Issued: 2017
Identifier: FSU_FALL2017_Fung_fsu_0071E_14227
Format: Thesis

Title: Driver Behavior in Mixed Connected-Automated and Conventional Vehicle Traffic at a Freeway Merge.
Creator: Chityala, Sneha, Sobanjo, John Olusegun, Ozguven, Eren Erman, Spainhour, Lisa, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: Wireless communication through automated and connected vehicles is an evolving technology. This ameliorates the driving conditions, reduces time spent in traffic and curtails the crash occurrences. One of the most challenging areas, where these interactions can be most useful, are freeway merge ramps. Both the drivers on mainline and the drivers merging would be skeptical about their decisions at this location. The drivers who want to merge to the freeway mainline would seek to find an...
Show moreWireless communication through automated and connected vehicles is an evolving technology. This ameliorates the driving conditions, reduces time spent in traffic and curtails the crash occurrences. One of the most challenging areas, where these interactions can be most useful, are freeway merge ramps. Both the drivers on mainline and the drivers merging would be skeptical about their decisions at this location. The drivers who want to merge to the freeway mainline would seek to find an appropriate gap to enter the mainline of the freeway. While the technology of connected and automated vehicles is being promoted, the reality now is that for the foreseeable future, the traffic would not comprise 100% of such connected and automated vehicles. In other words, there will be a mixed traffic of manually-driven and connected/automated vehicles, with various levels of automation in the latter types of vehicles. Capturing the driver behavior at the merge locations into a freeway with such mixed traffic, will be useful in learning and improving safety on the roadways. The Driving Simulator is a useful device in capturing driver behaviors. In this study scenarios are developed in the Driving Simulator which allows mixed traffic on mainline and also observe the driver behaviors from the ramp onto the merge. Overall there were three variations in the mixed traffic flow for the mainline freeway: 0%, 50% and 75% penetration rates. The freeway traffic was generated for the mixed traffic by first developing a mixed probability distribution which assumes exponential distributions for the inter-arrival times of manually-driven vehicles and a constant headway (uniform distribution) is assumed between connected vehicles. The mixed distribution was then used to randomly generate vehicles through Monte Carlo simulation, with assigned headways in the Driving Simulator for the various connected vehicle penetration rates. The subject driver’s speed along the ramp is monitored, as well as the speeds of those vehicles on the freeway. The gaps between freeway vehicles, which were accepted by the subject driver, were recorded for the various situations and scenarios. There were a total of 41 participants, with 29 young drivers (younger than 65 years) and 12 elderly drivers (65 years and older, amongst which 2 were between 55 and 65 years old). Three scenarios were presented to the drivers. The first driving task was to determine headway gap acceptance for the three penetration rates, based on the perception of the subject drivers (without driving). The second test involved the subjects actually driving on the ramp and implementing a suitable gap to merge on the freeway traffic at each ramp. From the data collected, the critical gaps were estimated based on perception. The gaps accepted while driving were also tabulated analyzed. It was observed that the critical gap for the young drivers in 0%, 50%, 75% penetrations rate are 2.9 sec, 1.8 sec, and 1.7 sec respectively. The critical gaps observed for elderly drivers aged over 65 are 3.5 sec, 2.0 sec, and 1.9 sec respectively. Based on an Analysis of Variance (ANOVA), there is no evidence to prove the equality of means for different groups classified by age, gender and driving experience in both perception and actual driving conditions for 0% and 50% penetration rates. It was observed that the headway gaps accepted by young and drivers, both by perception and driving in 0% penetration rate were 2.39 sec and 2.35 sec respectively. The headway gaps accepted by elderly drivers both by perception and driving in 0% penetration rate were 2.4 sec and 2.72 sec respectively. When the ANOVA was performed between the 0% and 50% penetration rates of driving conditions, it was observed that there is a lot of variation in the mean headway gaps accepted. The values of average headway gaps accepted for young drivers were estimated as 2.36 sec and 1.53 sec respectively, in the 0% and 50% penetration rates. For the elderly drivers the average headway gap values observed were 2.72 sec and 1.55 sec respectively, in the 0% and 50% penetration rates traffic. The results also indicated the subject driver acceleration and deceleration behavior at the merge ramp. The results also showed that when the (aggressive) drivers accelerated to match the velocity of mainline traffic and merged in between connected-automated vehicles with the shortest gap, effects were noticed on the mainline traffic, where the main line traffic had to decelerate rapidly. Overall, it was observed that the subject drivers accepted shorter headway gaps as the penetration rates increases.
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Date Issued: 2017
Identifier: FSU_SUMMER2017_Chityala_fsu_0071N_14121
Format: Thesis

Title: Optimization of Alternative Wind Turbine Towers in Low Wind Resource Regions.
Creator: Al-Kaimakchi, Anwer, Jung, Sungmoon, Rambo-Roddenberry, Michelle Deanna, Spainhour, Lisa, Florida State University, FAMU-FSU College of Engineering, Department of Civil and...
Show moreAl-Kaimakchi, Anwer, Jung, Sungmoon, Rambo-Roddenberry, Michelle Deanna, Spainhour, Lisa, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Taller wind turbines with big wheel area have been proposed for low wind speed sites, where conventional 80m tower cannot produce enough electricity. Hub height of 140m gives the potential to all 50 states to produce power from wind. However, it is not clear which tower (steel, concrete or hybrid) is economically attractive beyond 80m, or which design parameter is most critical in enabling tall yet economic tower. The aim of this paper is to come up with optimum designs for steel, concrete...
Show moreTaller wind turbines with big wheel area have been proposed for low wind speed sites, where conventional 80m tower cannot produce enough electricity. Hub height of 140m gives the potential to all 50 states to produce power from wind. However, it is not clear which tower (steel, concrete or hybrid) is economically attractive beyond 80m, or which design parameter is most critical in enabling tall yet economic tower. The aim of this paper is to come up with optimum designs for steel, concrete and hybrid towers while minimizing wind turbine cost and maximizing power production and then study the influence of changing one design variable on optimum designs. Also, it was of interest to study the effect of defining rotor dimeter of turbine as an independent design variable or as function of height. Multiple optimal solutions were obtained, which are called Pareto-optimal solutions. The design variables were chosen to be diameter, thickness, height of tower and blade radius. Design constraints were buckling, yielding, shear stresses for steel tower and ultimate and service limit states for the concrete tower. Those constraints have been used to control the stability of the tower. Different linear constraints have been applied for each tower, e.g. radius of the rotor should be less than the height of the tower. The design problem is conceptual design so detailed design is beyond scope of this research, such as the flange for the steel tower, connection between the concrete parts, and connection between the steel and concrete for the hybrid tower. Nonetheless, the cost of these parts was added to the design problem. Due to the highly constrained, non-convex and non-linear nature of the design problem, Genetic algorithm has been chosen as a solver for the problem. The towers were analyzed for operational and nonoperational aerodynamic conditions according to IEC 61400-1. A comparison of steel, concrete and hybrid towers was analyzed for heights ranging (80m-150m). Results showed that up to 95m, the cost difference was negligible between all towers options. Beyond 95m hybrid towers were dominating the solutions. For 150m hub height, concrete tower saved 12% when it is compared to its steel counterpart. Concrete base diameter decreases to less than 10m, industry preferred, when average concrete wall thickness was equal or greater than 0.4m or compressive strength of concrete increases. Increasing compressive strength of concrete by 10% also resulted in cost reduction of 2.18% for 150m hub height. Results showed that defining rotor diameter as a design variable was better than defining it as a function of height because the optimization problem had fewer constraints.
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Date Issued: 2017
Identifier: FSU_SUMMER2017_ALKAIMAKCHI_fsu_0071N_13989
Format: Thesis

Title: Removal of Powdered Activated Carbon by Cloth Tertiary Filters.
Creator: Madden, Brandon Cale, Ahmad, Hafiz, Chen, Gang, Tang, Youneng, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: Water conservation, wastewater treatment regulations, and the use of reclaimed/reuse water supplies have been on a collision course since society’s demand began outstripping the supply of fresh water. As potable water demand has risen, engineers have looked toward Waste Water Treatment Plants (WWTP) to alleviate the stress placed upon aquifers and surface water sources. Direct Potable Reuse (DPR), Indirect Potable Reuse (IPR) and Reuse/Reclaimed systems all conserve water; however, they also...
Show moreWater conservation, wastewater treatment regulations, and the use of reclaimed/reuse water supplies have been on a collision course since society’s demand began outstripping the supply of fresh water. As potable water demand has risen, engineers have looked toward Waste Water Treatment Plants (WWTP) to alleviate the stress placed upon aquifers and surface water sources. Direct Potable Reuse (DPR), Indirect Potable Reuse (IPR) and Reuse/Reclaimed systems all conserve water; however, they also unintentionally conserve pollutants. The widespread use of WWTP effluent conservation requires additional treatment options such as Activated Carbon treatment to further treat plant effluent. Powdered Activated Carbon (PAC) has shown promise as a treatment method to reduce pollutants but challenges remain in effectively applying PAC to a wastewater stream. Of particular concern is the application of PAC to existing facilities in which the existing hydraulic profile does not allow the use of large sedimentation tanks normally associated with PAC use in potable water applications. Cloth Media Filtration (CMF) is an existing treatment process that has seen significant saturation into the WWTP market in the United States since being introduced in 1991. While mostly targeted at tertiary treatment, alternate processes such as primary filtration and storm water treatment are now being pursued. It is suspected that CMF will capture and retain Powdered Activated Carbon (PAC) in which the two processes could be combined in order to produce an energy friendly and cost competitive approach to pollutant reductions. This research examines the feasibility of application of PAC into existing hydraulic profiles by using inline injection and its quick removal by Cloth Media Filtration (CMF). One of the most challenging aspects of PAC usage is its removal, which can be facilitated by a commercial CMF. A bench sized cloth media filter was constructed and then operated in a side stream manner with a real-world wastewater treatment train. The results show excellent performance of the designed CMF. The removal of two commercially available PACs was more than 70% within a short time using the existing hydraulic conditions of the plant. Additionally, using the backwash rates and solids removal rates, it was determined that CMF performs as an acceptable means of removal for PAC in a WWTP.
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Date Issued: 2017
Identifier: FSU_SUMMER2017_Madden_fsu_0071N_14114
Format: Thesis

Title: Modeling of Complex Behaviors of Submarine Debris Flows.
Creator: Saha, Bikash C. (Bikash Chandra), Ye, Ming, Niedoroda, Alan W., Misra, Vasubandhu, Shanbhag, Sachin, Wang, Xiaoqiang, Florida State University, College of Arts and Sciences,...
Show moreSaha, Bikash C. (Bikash Chandra), Ye, Ming, Niedoroda, Alan W., Misra, Vasubandhu, Shanbhag, Sachin, Wang, Xiaoqiang, Florida State University, College of Arts and Sciences, Department of Scientific Computing
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Abstract/Description: Submarine debris flows are hazards when they threaten the facilities that are built on sea floor to facilitate submarine transportation. The dynamics of submarine debris flow is simple once the debris material gets in the flow motion and that it can be represented using simple physics. A two-dimensional model with two-layer Bingham fluid representations, SDFlow2D, was developed by using an Eulerian frame of reference to predict the consequences of complex submarine debris flows. The model was...
Show moreSubmarine debris flows are hazards when they threaten the facilities that are built on sea floor to facilitate submarine transportation. The dynamics of submarine debris flow is simple once the debris material gets in the flow motion and that it can be represented using simple physics. A two-dimensional model with two-layer Bingham fluid representations, SDFlow2D, was developed by using an Eulerian frame of reference to predict the consequences of complex submarine debris flows. The model was viscoplastic in nature based on depth-averaged approximation to the Shallow Water Equations (SWE), and it assumes that the flow consists of a non-deforming upper layer riding on a deforming layer. The model was verified by comparing the numerical solution with experimental observations as well as with an analytical solution. The comparison shows a good agreement with analytical solution and an acceptable agreement with experimental observations. The model was found to be capable of simulating real-word submarine debris flows. The consequence of bed material entrainment is worth studying as this process adds antecedent sediment to the debris flow mass that in turn increases the intensity of hazard. The modeling code SDFlow2D was enhanced by using simple physics to include the capability of computing bed material entrainment. It was assumed that no inertial force was involved in the process, and that the entrainment was instantaneous. The modified SDFlow2D was applied to two idealized cases and to a prognostic case. A total variation diminishing (TVD) scheme with flux limiter was applied with MacCormack predictor-corrector scheme to smooth out the spurious solution near the source area of debris flow. While the TVD scheme served that purpose to some extent, it was not helpful to make the model robust as the computational time was 15 times greater than that of using the code without TVD scheme. The Bayesian inverse modeling was implemented to quantify the Bingham parameters uncertainty. The technique helps find not only the most probable pair of Bingham parameters but also the distribution of the parameters by conducting a small number of model simulations. The overall outcome of the study benefits the deep sea explorers as well as the designers and planners in charge of designing the submarine structures.
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Date Issued: 2017
Identifier: FSU_2017SP_Saha_fsu_0071E_13595
Format: Thesis

Title: Gas Emissions in Landfills.
Creator: Melaouhia, Haykel, Abichou, Tarek, Chanton, Jeffrey M., Tang, Youneng, Tawfiq, Kamal Sulaiman, Chen, Gang, Florida State University, College of Engineering, Department of Civil...
Show moreMelaouhia, Haykel, Abichou, Tarek, Chanton, Jeffrey M., Tang, Youneng, Tawfiq, Kamal Sulaiman, Chen, Gang, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Environment and natural resources can be polluted and consequently human beings, animals and plants can be impacted. Then, waste management plays an important role in human's life. Landfilling is one of the most common technology for solid waste management (MSW) as an alternative to waste burning and composting. A complex series of biological and chemical reactions is initiated with the burial of solid waste in a landfill, resulting in the production of methane (CH4) and carbon dioxide (CO2)...
Show moreEnvironment and natural resources can be polluted and consequently human beings, animals and plants can be impacted. Then, waste management plays an important role in human's life. Landfilling is one of the most common technology for solid waste management (MSW) as an alternative to waste burning and composting. A complex series of biological and chemical reactions is initiated with the burial of solid waste in a landfill, resulting in the production of methane (CH4) and carbon dioxide (CO2) as the major end products of biological decomposition. With a global warming potential 25 times as high as than carbon dioxide on a century time scale, methane is an important greenhouse gas in the climate system. The fate of this CH4 varies widely depending on typical landfill practice in a specific country. Ideally, all generated CH4 would be captured and used beneficially as an energy source. However, even at modern landfills, some CH4 is released before installation of gas collection systems and some CH4 is released because it is not captured in a collection system. A fraction of the uncollected CH4 is oxidized in the landfill cover through bacterial activities and the rate of CH4 oxidation has recently been reviewed. Thus, estimation of methane emissions from landfills is a crucial task. Several models have been developed through the history for such a task, however, none of them represent the reality of the different phases that methane goes through in the landfill. Moreover, methane oxidation capacity estimation has been only based on stable isotopes method. The objective of this work is to develop new methodologies to quantify methane oxidation capacity within landfill covers and to develop a holistic gas estimation model based on the different phases that gas goes through, generation, collection and oxidation, and this model will be calibrated based on field measurements and historical data available over the United States.
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Date Issued: 2017
Identifier: FSU_2017SP_Melaouhia_fsu_0071E_13859
Format: Thesis

Title: Evaluation of Florida-I Beam Bridges with Precast Concrete Deck Panels (Non-prestressed and Prestressed).
Creator: Chipperfield, Jonathan Darren, Rambo-Roddenberry, Michelle Deanna, DeBrunner, Linda S., Sobanjo, John Olusegun, Spainhour, Lisa, Florida State University, FSU-FAMU College of...
Show moreChipperfield, Jonathan Darren, Rambo-Roddenberry, Michelle Deanna, DeBrunner, Linda S., Sobanjo, John Olusegun, Spainhour, Lisa, Florida State University, FSU-FAMU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Four (4) new bridges were constructed by the Florida Department of Transportation (FDOT) to replace four (4) deteriorated bridges on U.S. Highway 90 between Tallahassee and Quincy, Florida. The new bridges were built using new construction methods which can be designated as Accelerated Bridge Construction (ABC) processes. This research focuses on the bridges' superstructures which were constructed using prefabricated elements from a precast concrete facility. The superstructure elements...
Show moreFour (4) new bridges were constructed by the Florida Department of Transportation (FDOT) to replace four (4) deteriorated bridges on U.S. Highway 90 between Tallahassee and Quincy, Florida. The new bridges were built using new construction methods which can be designated as Accelerated Bridge Construction (ABC) processes. This research focuses on the bridges' superstructures which were constructed using prefabricated elements from a precast concrete facility. The superstructure elements included precast pretensioned Florida-I Beams (FIB), precast pretensioned concrete deck panels and precast reinforced (non-prestressed) concrete deck panels. The two (2) westbound bridges were constructed using pretensioned concrete deck panels, whereas the two (2) eastbound bridges were constructed using reinforced concrete deck panels. The bridge panels were connected to the FIBs using a high-strength grout. Closure joints between the panels were filled with cast-in-place concrete. Before this new construction method can be adopted by the FDOT, it is necessary to evaluate the feasibility, construction process, and overall structural integrity of the new bridges. Therefore, load tests took place to evaluate the similarities and differences of the two (2) different types of panels. The testing showed that they both behave similarly to each other, and that composite action between the panels and FIBs was achieved. The test results were also used to compare the American Association of State Highway and Transportation Officials (AASHTO) distribution factors with those calculated from load test data. A portion of the load test focused on how much the barrier affects the overall load distribution, by load testing before and after the barriers were placed on one of the bridges.
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Date Issued: 2016
Identifier: FSU_FA2016_Chipperfield_fsu_0071E_13615
Format: Thesis

Title: High Alkalinity Cement: The Use of High Alkalinity Cement in FDOT Class IV Concrete.
Creator: Beckwith, Lauren Ann, Rambo-Roddenberry, Michelle Deanna, Spainhour, Lisa, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental...
Show moreBeckwith, Lauren Ann, Rambo-Roddenberry, Michelle Deanna, Spainhour, Lisa, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: High alkali cements are not used in the state of Florida because of its supposed deleterious effects to concrete. The alkali-silica reaction forms a gel in the voids of the concrete and the increase in internal pressure created by the gel causes the concrete to crack. Other states across the United States have implemented the use of high alkali cements. The purpose of this research was to supply the Florida Department of Transportation an initial investigation of the effects high alkali...
Show moreHigh alkali cements are not used in the state of Florida because of its supposed deleterious effects to concrete. The alkali-silica reaction forms a gel in the voids of the concrete and the increase in internal pressure created by the gel causes the concrete to crack. Other states across the United States have implemented the use of high alkali cements. The purpose of this research was to supply the Florida Department of Transportation an initial investigation of the effects high alkali cement in Class IV concrete. A total of twelve mixes, four control mixes and eight test mixes, were prepared and tested to compare the fresh and hardened properties. Class IV concrete has requirements that it must be met in order to be used in Florida and the goal of this research was to determine if the test mixes met these requirements. As it stands, the high alkali cement did appear to have an effect on the fresh and hardened properties of the concrete. A final conclusion was made that high alkalinity cements could be use but only with supplementary cementitious materials such as fly ash and slag.
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Date Issued: 2016
Identifier: FSU_FA2016_Beckwith_fsu_0071N_12986
Format: Thesis

Title: Evaluation of Florida Vehicle Classification Table.
Creator: Masaki, Jaqueline Eliabu, Moses, Ren, Ozguven, Eren Erman, Sobanjo, John Olusegun, Florida State University, College of Engineering, Department of Civil and Environmental...
Show moreMasaki, Jaqueline Eliabu, Moses, Ren, Ozguven, Eren Erman, Sobanjo, John Olusegun, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Accurate vehicle classification data is fundamental to pavement design and road safety analysis. In addition, vehicle classification data is important for Florida Department of Transportation’s Transportation Statistics Office’s clients including consultants, researchers, designers, and planners who use the data to perform various analyses. In the mid-1980s, the Federal Highway Administration (FHWA) developed a standardized vehicle classification system which was designed to meet the needs of...
Show moreAccurate vehicle classification data is fundamental to pavement design and road safety analysis. In addition, vehicle classification data is important for Florida Department of Transportation’s Transportation Statistics Office’s clients including consultants, researchers, designers, and planners who use the data to perform various analyses. In the mid-1980s, the Federal Highway Administration (FHWA) developed a standardized vehicle classification system which was designed to meet the needs of many traffic data users. This resulted in the FHWA 13-category classification rule set presently used for most Federal reporting requirements. Furthermore, this serves as the foundation for most State vehicle classification reporting efforts.The Florida Department of Transportation (FDOT) uses the FHWA F-Scheme to classify vehicles throughout the state highway system. This scheme relies mainly on the number of axles and the axle spacing, but on some Weigh-in-Motion (WIM) sites, vehicle weights are also used to improve classification. This thesis evaluates the performance of the Florida vehicle classification table of non-WIM sites using video data as the ground truth.This thesis has two main parts. Part I compares the performance of different data recorders that use FDOT vehicle classification table for WIM and non-WIM sites in classifying vehicles and evaluate the misclassification rates for each recorder. Part II evaluates the accuracy of the Florida vehicle classification table, determines the sources of misclassification, describes the changes recommended in the classification table to improve the classification accuracy, proposes and validates the improved vehicle classification table. This report will be of interest to Florida Department of Transportation and consultants, researchers, engineers, designers, and planners who require accurate vehicle classification information for planning, designing and maintenance of transportation infrastructures.
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Date Issued: 2016
Identifier: FSU_2016SU_Masaki_fsu_0071N_13458
Format: Thesis

Title: Aging Driver Focused Traffic Crash Frequency and Severity Analyses.
Creator: Omidvar, Aschkan, Vanli, Omer Arda, Ozguven, Eren Erman, Shrivastava, Abhishek Kumar, Park, Chiwoo, Florida State University, FAMU-FSU College of Engineering, Department of...
Show moreOmidvar, Aschkan, Vanli, Omer Arda, Ozguven, Eren Erman, Shrivastava, Abhishek Kumar, Park, Chiwoo, Florida State University, FAMU-FSU College of Engineering, Department of Industrial and Manufacturing Engineering
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Abstract/Description: The aim of this thesis is to investigate the effect of environmental and traffic-related factors on the frequency and severity of highway crashes with a focus on different age groups including the aging populations. Existing studies in the traffic safety have not specifically focused on aging driver-involved crashes. Aging drivers are more vulnerable to the roadway crashes than other adult age groups due to their cognitive, physical and health limitations. This problem becomes more...
Show moreThe aim of this thesis is to investigate the effect of environmental and traffic-related factors on the frequency and severity of highway crashes with a focus on different age groups including the aging populations. Existing studies in the traffic safety have not specifically focused on aging driver-involved crashes. Aging drivers are more vulnerable to the roadway crashes than other adult age groups due to their cognitive, physical and health limitations. This problem becomes more challenging due to the drastic variation in the traffic patterns that especially happen on the major highways. In this thesis, several data sets from different sources, such as the National Oceanic and Atmospheric Administration (NOAA) and Florida Automated Weather Network (FAWN), the Florida Department of Transportation (FDOT) and the United States Naval Observatory (USNO), are collected, refined and combined. With the aid of statistical correlation analysis and logistic regression, a top down analysis is performed in order to analyze the occurrence of crashes via a case study application on the I-95 highway corridor in the State of Florida. Using logit curves, a sensitivity analysis is carried out to quantify the effect of traffic volume on the crash frequency. In addition to the crash frequency analysis, factors influencing the crash severity are also analyzed in an integrated manner for two metropolitan areas in the City of Jacksonville and Miami, Florida. Both frequency- and severity-focused analyses have led to several important conclusions. Results suggest that the variation in the hourly traffic volume significantly affects the crash occurrences for both aging and non-aging drivers depending on the geographical location; however, the crash occurrence for aging drivers is less sensitive to the flow than other age groups in congested locations. Results indicate that crash severity for all other age groups decrease on roadways with narrower shoulders and at night unlike those of aging drivers. Furthermore, driving at night on I-95 in Jacksonville seems to be problematic for both age classes whereas that risk is less for Miami locations. Higher roadway surface width also appears to increase the chance of having a severe crash for aging drivers. The DUI-influenced crashes have also been detected considerably high on the I-95 highway corridor in the City of Miami, Florida. This problem seems critical both in terms of crash frequency and severity. The proposed methodology can help transportation officials to understand the nature of the aging driver-involved crashes, and formulate better safety-oriented decisions.
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Date Issued: 2016
Identifier: FSU_2016SU_Omidvar_fsu_0071N_13464
Format: Thesis

Title: Weibull-Based Deterioration and Preservation Models for Florida Bridges.
Creator: Ackah, Kojo Essuman, Sobanjo, John Olusegun, Spainhour, Lisa, Tawfiq, Kamal Sulaiman, Florida State University, FAMU-FSU College of Engineering, Department of Civil and...
Show moreAckah, Kojo Essuman, Sobanjo, John Olusegun, Spainhour, Lisa, Tawfiq, Kamal Sulaiman, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: In the past decade, FDOT has carried out network-level decisions through the utilization of AASHTO Pontis Bridge Management System. Like most states, Florida DOT had been previously using a customized version of the 1997 AASHTO CoRe Element Guide and developed its inspection, deterioration and cost frameworks using the 1997 capabilities. In compliance with the MAP-21 directive, Florida modified its procedures of bridge inspection data collection, cost, and deterioration and preservation...
Show moreIn the past decade, FDOT has carried out network-level decisions through the utilization of AASHTO Pontis Bridge Management System. Like most states, Florida DOT had been previously using a customized version of the 1997 AASHTO CoRe Element Guide and developed its inspection, deterioration and cost frameworks using the 1997 capabilities. In compliance with the MAP-21 directive, Florida modified its procedures of bridge inspection data collection, cost, and deterioration and preservation models development based on the new AASHTO 2013 manual. This thesis research was aimed at developing a Semi-markov based preservation model based on the revised bridge inspection process. The changes however, required a revision of past deterioration models, both Markov and Semi-markov. Thus, transition probabilities based on the two-parameter Weibull distribution describing the natural deterioration of each element were generated and consequently, optimized preservation policies. This task required a review of Florida bridge data, creating a time-based deterioration model and thereafter, generating preservation actions to be taken on the bridge elements. A literature review of state DOT inspection and preservation manuals, the NBIS requirements, AASHTO BrM 5.2.1 documentation and other helpful publications was also conducted in the process. The network-level optimization model was established with the application of linear programming algorithms and stochastic theories.
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Date Issued: 2016
Identifier: FSU_2016SU_Ackah_fsu_0071N_13292
Format: Thesis

Title: Aerated Recirculation and Pressurized Suspended Fiber Biofiltration for the Treatment of Landfill Leachate.
Creator: Wang, Boya, Chen, Gang, Huang, Wenrui, Tang, Youneng, Florida State University, FAMU/FSU College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: ABSTRACT Landfilling is widely adopted as one of the most economical processes for solid waste disposal. At the same time, landfill leachate is also a great environmental concern because of its complex composition and high contaminant concentrations. Recirculating leachate appears to be one of the least expensive methods for partial treatment and disposal of leachate at properly designed and operated landfill sites. The leachate recirculation not only improves the leachate quality, but also...
Show moreABSTRACT Landfilling is widely adopted as one of the most economical processes for solid waste disposal. At the same time, landfill leachate is also a great environmental concern because of its complex composition and high contaminant concentrations. Recirculating leachate appears to be one of the least expensive methods for partial treatment and disposal of leachate at properly designed and operated landfill sites. The leachate recirculation not only improves the leachate quality, but also shortens the time duration required for landfill stabilization. In addition, aerated leachate recirculation can bring air into the landfill, leading to aerobic organic decomposition, as well as iron precipitation. It has been discovered that up to 84% BOD, 86% COD, 90% iron and manganese can be removed after 4 months' recirculation. In Northwest Florida, high concentrations of iron have been observed in the landfill leachate, which is believed to be released to the landfill leachate from iron-rich soil owing to changes in pH and redox conditions induced by organic waste decomposition. Therefore, aerated leachate recirculation has obvious benefits in this region. Although aerated leachate recirculation has these advantages, leachate is only partially treated. The leachate must be further treated in order to meet the discharge requirements. Among all the treatment methods, biological treatment of wastewater with a biofilter is the most promising and most well characterized technology. During biofiltration operations, the growth of microorganisms develops biofilms on the medium surfaces and the microorganisms in the biofilms absorb soluble and colloidal waste materials in the wastewater as it percolates over the medium surfaces. The BOD can nearly be completely removed if the wastewater retention time in the media is sufficiently long for the microorganisms to absorb wastewater constituents. In this research, aerated recirculation and pressurized suspended fiber biofiltration were tested for the treatment of leachate from landfills in Northwest Florida. The pressurized suspended biofilter can efficiently achieve the filtration function with limited space. The suspended fiber provide a tremendous amount of surface areas in a small volume. Therefore, microorganisms can grow around the fibers at a density of greater than 1 × 108 cells per ml, the only means to culture cells at in vivo-like cell density. Another advantage of the pressurized suspended fiber filtration is that the oxygen transfer barrier can be overcome and consequently significantly increased dissolved oxygen level can be achieved. As an innovative technology for wastewater treatment, the pressurized suspended fiber biofilters also makes biological contact oxidation possible, which can significantly improve BOD and COD removal and decrease the sludge yield. For iron removal, contact oxidation is achieved by microbial mediated iron oxidation and fixation during which ferrous iron is oxidized to ferric iron and fixed onto the filter media. Consequently, there is minimal ferric iron suspending in the solution that can escape the filter. Using the combined aerated leachate recirculation and pressurized fiber biofiltration, chemical oxygen demand (COD) of the landfill leachate can be reduced to as low as 8 mg/l and iron content can be reduced to as low as 0.02 mg/l under appropriate dissolved oxygen and alkalinity conditions.
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Date Issued: 2016
Identifier: FSU_2016SP_Wang_fsu_0071N_13128
Format: Thesis

Title: Effect of Friction on Vehicle Crashworthiness during Rollover.
Creator: Gleba, Michal, Jung, Sungmoon, Rambo-Roddenberry, Michelle Deanna, Spainhour, Lisa, Wekezer, Jerry W., Florida State University, College of Engineering, Department of Civil and...
Show moreGleba, Michal, Jung, Sungmoon, Rambo-Roddenberry, Michelle Deanna, Spainhour, Lisa, Wekezer, Jerry W., Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: The State of Florida acquires over 300 cutaway buses every year. The increasing popularity of such buses raised concerns about passenger safety and overall crashworthiness of this transportation mode. Dimensions of the cutaway buses and their two-stage manufacturing process made them exempted from safety standards which were developed for smaller passenger cars as well as for large coaches. To fill this gap, cutaway bus manufacturers try to demonstrate the strength of their bus roof...
Show moreThe State of Florida acquires over 300 cutaway buses every year. The increasing popularity of such buses raised concerns about passenger safety and overall crashworthiness of this transportation mode. Dimensions of the cutaway buses and their two-stage manufacturing process made them exempted from safety standards which were developed for smaller passenger cars as well as for large coaches. To fill this gap, cutaway bus manufacturers try to demonstrate the strength of their bus roof structures by using FMVSS 220 standard, which follows conservative quasi-static load tests for school buses in the US. However, more advanced, dynamic based safety standard - Regulation 66, was developed in Europe. It is based on a dynamic rollover test which more closely resembles an actual rollover accident. A cutaway bus is placed on a tilt table 800 mm above a concrete slab. The bus is tilted until it falls and impacts the concrete deck and the deformation of the sidewalls is measured in order to check if there is any intrusion into a so called 'survival space'. This standard was endorsed by 44 countries through the United Nation resolution. However, the Regulation 66 standard does not specify all the parameters regarding the rollover test. From multiple tests it can be observed that the friction between the vehicle and the concrete slab which is being impacted by the bus has an influence on the outcomes of the experiment and has great contribution to either a positive or negative assessment of the crashworthiness of a tested vehicle. This Master thesis focuses on the friction parameters between the impacting cutaway bus and a concrete slab used in the Regulation 66 standard. Due to dynamic nature of the experiment, the impact of the bus exerts a high normal force on the concrete slab. Together with an uneven and non-standard geometry of the elements in contact with the concrete deck the standard coefficient of friction found in the literature or obtained using standard tests may not hold. The proper assessment of this coefficient is important since many rollover tests are carried out numerically using Finite Element Methods. The use of numerical analysis reduces the cost of an expensive full scale rollover test. However, it requires verified and validated parameters in order to consider the results trustworthy. The experimental part of this thesis consists of designing and carrying out experiments to evaluate the coefficient of friction for an impacting cutaway bus and a concrete slab. The results from the experiments are incorporated into an explicit computer code LS-DYNA, which is used for numerical analysis of the cutaway buses. The final outcome of this thesis will be validating the coefficient of friction used in the Finite Element Analysis which will lead to improvement of the Finite Element models and will be used to check the influence of the coefficient of friction on vehicle structure deformation (Deformation Index) during rollover accidents.
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Date Issued: 2015
Identifier: FSU_2015fall_Gleba_fsu_0071N_12953
Format: Thesis

Title: Hydrogen Sulfide Attenuation within Landfill Covers.
Creator: Green, Stefan Larae, Abichou, Tarek, Clark, Clayton J., Chen, Gang, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: There has been much research done on the reduction, or attenuation, of hydrogen sulfide (H2S), particularly within landfill cover soils, as H2S can cause many issues when exposed to the atmosphere. The objective of this research study was to understand hydrogen sulfide (H2S) attenuation within landfill cover soils, and to use mass balancing to determine how much sulfur was retained within each layer of test pad. Both of these were completed through 403 days of monitoring three 65 feet by 35...
Show moreThere has been much research done on the reduction, or attenuation, of hydrogen sulfide (H2S), particularly within landfill cover soils, as H2S can cause many issues when exposed to the atmosphere. The objective of this research study was to understand hydrogen sulfide (H2S) attenuation within landfill cover soils, and to use mass balancing to determine how much sulfur was retained within each layer of test pad. Both of these were completed through 403 days of monitoring three 65 feet by 35 feet lysimeter test pads constructed at the Riverbend Landfill. Test Pad 1 was constructed with 18 inches of local soil and an underlying 6 inch gravel layer. Test Pad 2 was constructed with 12 inches of compost, 6 inches of local soil and an underlying 6 inch gravel layer. Test Pad 3 was constructed with 6 inches of local soil and an underlying 6 inch gravel layer. Monitoring on Test Pad 3 was stopped on April 27th, 2015 due to erosion of the 6 inch soil layer, while Test Pads 1 and 2 were monitored until July 20th, 2015. Readings of landfill gas and H2S inflow, and bottom landfill gas and H2S concentrations were taken in each testing pad on a weekly basis. Bottom H2S loading into the soil layer and top H2S emissions from the soil layer were also measured to determine the removal efficiency of H2S. The average H2S removal efficiency of the test pads is 95%, with Test Pad 1 having a removal efficiency of 99%, Test Pad 2 having a removal efficiency of 99%, and Test Pad 3 having a removal efficiency of 82%. Six soil samples and five water samples were taken to measure sulfur concentration within the testing pads. Soil samples were also taken within each of the layers of each testing location within each test pad to determine the soil type and the water content of each soil layer. Mass balance was calculated by taking the amount of sulfur loaded into the bottom of each testing pad, and subtracting the sum of sulfur loaded into the soil cover, sulfur emitted from the soil cover into the atmosphere, and sulfur removed from the system with water as sulfate. Test Pads 1 and 2 yielded similar results, both retaining about 6000 grams of sulfur within their cover layers, while the results from Test Pad 3 suggest that more sulfur was removed from the system than was originally pushed into the system, which is not possible and suggests errors with either testing methods or the testing pad itself. While the concentrations of sulfur within each test pad layer were measured, there were concerns with their dependability that caused them to not be used to determine the amount of sulfur in each layer.
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Date Issued: 2015
Identifier: FSU_2015fall_Green_fsu_0071N_12959
Format: Thesis

Title: Analysis of Route Choice and Activity Scheduling Dynamics in Multi-Agent Transport Simulation Environment for Efficient Network Demand Estimation.
Creator: Mtoi, Enock T., Moses, Ren, Horner, Mark W., Ozguven, Eren Erman, Sobanjo, John Olusegun, Park, Chiwoo, Florida State University, College of Engineering, Department of Civil and...
Show moreMtoi, Enock T., Moses, Ren, Horner, Mark W., Ozguven, Eren Erman, Sobanjo, John Olusegun, Park, Chiwoo, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: The study of user-behavior and decision-making dynamics in transportation network are vital in modeling and simulation of user interactions. Different users access transportation network in order to accomplish different activities. Such activities can be regular commuting, transit services, commercial taxicabs, deliveries, long distance trips, logistics or fleet services, etc. While the world is becoming increasingly urbanized reliable and cost effective movement of people and goods is...
Show moreThe study of user-behavior and decision-making dynamics in transportation network are vital in modeling and simulation of user interactions. Different users access transportation network in order to accomplish different activities. Such activities can be regular commuting, transit services, commercial taxicabs, deliveries, long distance trips, logistics or fleet services, etc. While the world is becoming increasingly urbanized reliable and cost effective movement of people and goods is important for the productivity and economic growth at large. Urbanization and population growth have created the shift in how travel activities are tied to the economy. In today's economy, businesses and individuals are looking for ways of making their fiscal resources and workforce more efficient. However, traffic congestion dampens the efficiency and prosperity by imposing additional operating costs, slowing mobility and causing wastage of time and by hindering efficient metropolitan services such as deliveries, public safety and maintenance. Traffic congestion in the United States in 2011 for instance, caused urban commuters to travel 5.5 billion hours more and to purchase an extra 2.9 billion gallons of fuel (enough to fill Superdome in New Orleans, two times) for a congestion cost of $121 billion. In larger cities and in busy expressways, traffic infrastructures are already operating at near or full capacity. With today's shrinking budgets, often no funding is available to rebuild or expand an aging public transportation infrastructure, making it crucial to devise ways to optimize the performance of existing transportation assets. Since the recurring congestions in large metropolitan areas are mainly due to predictable behavioral activity scheduling, traffic management efforts should be geared towards behavior analysis and modeling. Modeling behavior and decisions, pertinent to route choice and activity scheduling dynamics are crucial for capturing microscopic and mesoscopic nature of traffic flow patterns. In this research, the focus is placed on the development of multi-agent transportation demand estimation and simulation framework to be used by the public entities for performance optimization of existing transportation network and scenario evaluation of new investments. The framework employs several mathematical and statistical methods for the derivation of sampling distributions of users' (i.e., agents') behavior and travel characteristics for the initial network demand generation. The processes of deriving sampling distributions of agents' behavior and travel characteristics largely rely on the quantity, quality and resolution of the available data of the region under study. Travel characteristics/travel surveys data from South East Florida Regional Planning Model (SERPM) region and the National Household Travel Survey (NHTS) data contained individuals' travel characteristics such as origin, destination, departure and arrival time, chain of activities and tours within the trip. These are micro-information needed for the derivation of household and individual agent's travel behavior. The data was processed to develop probability distributions for groups of agents with similar travel behavior, given the agents' household characteristics. In a similar fashion, with agents' household characteristics given, the logit models for agents' activity and locations choices were developed. Besides behavior simulation and demand estimation, the developed framework included an ad-on module for lane choice and pricing approaches applicable to dynamic high occupancy toll (HOT) lanes pricing. The reinforcement learning (RL) approach was used for updating the optimal pricing strategy in a given traffic condition. The pricing controller was configured to start with a predefined base price at a given traffic level, and then in the process of learning, it varies the price in accordance with the acceptable price levels at a given level of service (LOS). In this way, the pricing controller learns the states in which a higher price is more beneficial and those in which a lower price is more beneficial, and then adjusts the parameters of the pricing function to minimize the difference between the current computed price and the posted price. The framework was tested and validated for the scenario based on the data from SERPM region. The scenario was simulated in Multi-Agent Transport Simulation (MATSim). In MATSim, the simulation is constructed around the notion of agents that make independent decisions about their actions. Each traveler of the real system is modeled as an individual agent. Generally, the observation of network traffic evolution from the simulation showed the expected traffic patterns for both morning peak and afternoon peak traffic. One of the most important aspects of travel behavior is the characterization of travel activities by trip duration. The distribution of travel activities by trip duration is the reflection of user behavior in the study area. This determines the expected users departing, en-route, stuck, and arriving to their destinations at a particular time interval. In this research, the simulation results show that network users in our case consist mainly of regular commuters (≥ 20%) whose trips take about 15 minutes. As any other research study, there are some limitations with this work. Due to lack of relevant data, transit use and other modes other than personal vehicle were not considered. Future directions for this research include the inclusion of other data sources and optimization of the demand estimation framework in order to scale-down the computation cost. In addition to the reduction of computation cost, focus will be on development and implementation of modules for simulating dynamic toll pricing on high occupancy toll lanes and assessing the effects of social media information exchange among the agents on mobility.
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Date Issued: 2015
Identifier: FSU_migr_etd-9419
Format: Thesis

Title: Pressure Drag Reduction on Patterned Cylindrical Models Inspired by Biomimicry.
Creator: Ferreira, Larissa Mendes, Jung, Sungmoon, Rambo-Roddenberry, Michelle Deanna, Spainhour, Lisa, Florida State University, College of Engineering, Department of Civil and...
Show moreFerreira, Larissa Mendes, Jung, Sungmoon, Rambo-Roddenberry, Michelle Deanna, Spainhour, Lisa, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Extensive research has been previously conducted on cylindrical models with different surface patterns. These experiments were generally performed with the intention of passively reducing friction drag on aerodynamic structures exposed to laminar flows. Incorporating knowledge from this, the present research aims to quantify the effectiveness of similar surface patterns in reducing pressure (form) drag for structures exposed to turbulent flow through wind tunnel experiments. The surface...
Show moreExtensive research has been previously conducted on cylindrical models with different surface patterns. These experiments were generally performed with the intention of passively reducing friction drag on aerodynamic structures exposed to laminar flows. Incorporating knowledge from this, the present research aims to quantify the effectiveness of similar surface patterns in reducing pressure (form) drag for structures exposed to turbulent flow through wind tunnel experiments. The surface patterns selected are originally inspired from marine animal anatomy. V-grooved riblets mimic the miniscule patterns found on a sharks' skin, which aid sharks in reducing drag while propelling forward in the water. U-grooved riblets (ie: bumps) mimic the tubercles located on the leading edge of a humpback whale's pectoral fins, which serve to increase maximum lift and reduce drag. In addition to patterned cylinders, pressure tests will also be conducted on a smooth-surfaced cylinder, serving as the control of the experiment. Since the length of the wind tunnel test section is short in comparison to the length of wind tunnels regularly used for this type of testing, having a 0.61m x 0.61m x 2m test section, there needs to be an array of roughness elements placed at the upstream end of the test section. These elements will serve to induce a thicker atmospheric boundary layer (ABL) within the test section before interacting with the test specimen. After a series of experimental tests, this project successfully generated an ABL in a short tunnel which allowed for a detailed study of the effects of surface patterns on scaled-down versions of high-rise structures. The results indicated that the cylinder covered in V-grooved riblets was most effective in reducing pressure drag when subjected to a turbulent flow characteristics.
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Date Issued: 2015
Identifier: FSU_migr_etd-9332
Format: Thesis

Title: Response of a Wind Turbine Structure to Strong Ground Motions and High Velocity Winds.
Creator: Patil, Atul Sudhakar, Jung, Sungmoon, Liang, Zhiyong Richard, Rambo-Roddenberry, Michelle Deanna, Wekezer, Jerry W., Florida State University, College of Engineering, Department...
Show morePatil, Atul Sudhakar, Jung, Sungmoon, Liang, Zhiyong Richard, Rambo-Roddenberry, Michelle Deanna, Wekezer, Jerry W., Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Wind turbines are getting bigger to extract more power from wind. In the past decade, the wind turbines heights increased up to 135 m (Enercon E126, 7.5MW capacity). Many wind turbines are constructed in earthquake prone and high velocity wind regions. The taller wind turbine structures are more susceptible to high loading events such as high intensity earthquake and high velocity wind such as hurricane wind. Wind turbines are not catered for a particular type of high loading events. The same...
Show moreWind turbines are getting bigger to extract more power from wind. In the past decade, the wind turbines heights increased up to 135 m (Enercon E126, 7.5MW capacity). Many wind turbines are constructed in earthquake prone and high velocity wind regions. The taller wind turbine structures are more susceptible to high loading events such as high intensity earthquake and high velocity wind such as hurricane wind. Wind turbines are not catered for a particular type of high loading events. The same wind turbine could be installed in earthquake prone regions as well as high velocity wind regions. Though, these high loading events could impart comparable loading magnitude, the nature and the characteristics of these loads are different. The failure of one turbine in the wind farm could disrupt the operation of an entire wind farm. This makes it imperative to evaluate performance of the wind turbine towers under the action of high loading events. The objective of the present study is to evaluate the performance of the wind turbine tower for earthquake and high velocity wind loading events. The performance was evaluated by probabilistic approach by employing fragility analysis. For earthquake fragility analysis four displacement based limit states: a) global buckling b) yielding c) permanent deformation d) foundation overturning were defined. The wind fragility analysis was performed by defining three limit states: a) global buckling b) yielding, c) foundation overturning. The demand data, as required for fragility analysis, comes from the full scale nonlinear analysis by applying earthquake and wind loads. The capacity data comes from the pushover analysis by applying loads along the different directions. Few studies in the recent past include creating the simplified wind turbine model, and analyzing the particular type of response. In the present study, a full scale model of a wind turbine tower based on Vestas 1.65 MW was created with details such as door and cable opening at the bottom. The height of the tower was 80 m. The nacelle and rotor were simplified as concentrated mass at the top of the tower. The finite element model comprises of shell and solid elements for main body of the structure, the point mass elements for nacelle and rotor assembly. The turbine model was validated for geometric, engineering and dynamic properties. The seismic loadings were applied as earthquake accelerations availed from PEER (Pacific Earthquake Engineering Research) center database. The earthquake loads were the time history acceleration records in orthogonal directions. The preliminary analysis performed by applying original earthquake loads did not fail the turbine tower. The earthquake records were scaled by the factor of 2.5 so as to fail the structure. The near and far fault acceleration loadings were applied at the base of the wind turbine tower. The wind loadings were applied as wind fields generated by TURBSIM for various mean wind velocities. The wind loads were applied with the attack angles of 0 and 30 degrees with respect to the rotor axis. In the case of near fault earthquake loading, the maximum magnitude for the response spectral acceleration in the present study was 1.715 g. When the response spectral acceleration reaches to 1.715 g, the exceedance probability for global buckling was found to be 5.7%. The exceedance probability for yielding was found to be 68%. The exceedance probability for permanent deformation was found to be 26.4%, whereas the exceedance probability for foundation overturning was found to be 99.4%. In case of far fault loading, the maximum magnitude of spectral acceleration was 0.57 g. When the response spectral acceleration reaches this value the exceedance probability was found to be 0% for global buckling, 0.4% for yielding, 0.25 % for permanent deformation and 10.8% for foundation overturning limit state. For both the near and far fault loading, the foundation overturning was found to be the most critical limit state. This foundation was not designed for an earthquake prone region. The analysis was performed by improving the foundation by increasing the width from 15 m to 16.56 m. The exceedance probability rendering to failure was found to be reduced significantly. In the case of high velocity wind, the maximum mean wind velocity was 70 m/s. In case of 0 degree wind direction, the exceedance probability for all the three limit states were found to be 0% even when the mean wind velocity reaches to the maximum value of 70 m/s. In case of 30 degree wind direction, when the mean wind velocity reaches to 70 m/s, the exceedance probability for global buckling was found to 0%, the exceedance probability for yielding was found to be 88%, the exceedance probability for foundation overturning was found to be 100%. This foundation also was adopted from a hazard-free region and shown to be susceptible to failure. The exceedance probability leading to the failure was found to be reduced when the foundation was improved by increasing the width from 15 m to 16.56 m. For the wind turbine studied in this research, it could be concluded that the foundation overturning is the most critical limit state, and needs a due consideration while designing the wind turbine tower system. In case of earthquake, the near fault earthquake loading is the most detrimental to the stability of the wind turbine structures. The first mode failure governs the safety and satiability of the wind turbine structures. The 30 degree wind direction loading is more critical wind direction compared to 0 degree wind direction loading. Repeating the analysis for different wind turbine types, capacities and sizes would give more data, and more comprehensive conclusion could be drawn.
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Date Issued: 2015
Identifier: FSU_migr_etd-9666
Format: Thesis

Title: GIS-Based Spatial and Temporal Analysis of Aging-Involved Crashes in Florida.
Creator: Vemulapalli, Sai Saylesh, Ozguven, Eren Erman, Sobanjo, John Olusegun, Moses, Ren, Florida State University, College of Engineering, Department of Civil and Environmental...
Show moreVemulapalli, Sai Saylesh, Ozguven, Eren Erman, Sobanjo, John Olusegun, Moses, Ren, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Roadway crashes claim more than 30,000 lives each year in the United States, and they continue to affect the lives of people adversely. This problem becomes even more challenging when aging populations are considered due to their vulnerability and fragility to crashes. This is especially a major concern in Florida since the crash risk for the aging populations is increasing day by day proportional to the population growth of aging Floridians. This study investigates the spatial and temporal...
Show moreRoadway crashes claim more than 30,000 lives each year in the United States, and they continue to affect the lives of people adversely. This problem becomes even more challenging when aging populations are considered due to their vulnerability and fragility to crashes. This is especially a major concern in Florida since the crash risk for the aging populations is increasing day by day proportional to the population growth of aging Floridians. This study investigates the spatial and temporal patterns of aging-involved crashes using Geographical Information Systems (GIS)-based methods with a case study on three urban counties in Florida. These counties are selected based on the high aging-involved crash rates, as identified by the Safe Mobility for Life Coalition of Florida. Among the methods studied, a network distance-based kernel density estimation method, namely SANET, is identified as a very effective tool since it provides an unbiased distribution of the crashes by calculating the actual distances between the crashes over the roadway network. GIS-based results are also supported with a binary logistic regression analysis in order to identify the significant factors affecting the aging-involved crashes. Results indicate that high risk locations for aging-involved crashes show different spatial and temporal patterns than those for other age groups. These pattern specific differences include the following: (a) Intersections have an adverse effect on the 65+ populations more than other adult age groups, (b) Aging-involved population crashes occur during the mid-day rather than the peak hours, which is not a similar pattern for other adult age groups, especially for the working populations, and (c) Weekdays have more aging-involved crashes than the weekends contrary to the other age group crashes. Investigating these distinct patterns thoroughly can lead to better aging-focused transportation plans and policies.
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Date Issued: 2015
Identifier: FSU_migr_etd-9516
Format: Thesis

Title: Health Index and Deterioration Models for Florida Bridges.
Creator: Inkoom, Sylvester Kwame, Sobanjo, John Olusegun, AbdelRazig, Yassir A., Spainhour, Lisa, Florida State University, FAMU-FSU College of Engineering, Department of Civil and...
Show moreInkoom, Sylvester Kwame, Sobanjo, John Olusegun, AbdelRazig, Yassir A., Spainhour, Lisa, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Florida has been actively implementing the AASHTO Pontis Bridge Management System (BMS) to support network-level and project-level decision making in the headquarters and district offices. As a concerted effort of the FDOT to improve the quality of asset management information, Pontis is used as a tool to provide decision making recommendations. The credulity and usefulness of this information is also essential for satisfaction of the requirements of the government accounting standards board...
Show moreFlorida has been actively implementing the AASHTO Pontis Bridge Management System (BMS) to support network-level and project-level decision making in the headquarters and district offices. As a concerted effort of the FDOT to improve the quality of asset management information, Pontis is used as a tool to provide decision making recommendations. The credulity and usefulness of this information is also essential for satisfaction of the requirements of the government accounting standards board statement 34 (GASB 34) regarding the reporting of capital assets, and the federal MAP-21 requirements for performance management and development of asset management plans. Anticipating the new MAP-21 requirements, AASHTO in 2013 approved a new bridge element inspection manual (BRM manual), which was published as the AASHTO Manual for Bridge Element Inspection. Like most states, in order to comply with the new MAP-21 requirements, Florida will need to redefine its methods of obtaining bridge inspection data, developing deterioration models, cost models, and other preservation analysis capabilities. This thesis research seeks to develop data and models based on the bridge inspection process. First, an extensive literature review has been conducted, including but not limited to, the AASHTO Manual for Bridge Element Inspection (2013 edition); reports of state DOT experiences implementing the new inspection process; federal guidance on the collection and use of the new data, such as new NBIS requirements; BrM versions 5.1.2 and 5.2.1 software and documentation; and other relevant materials. Next the research has developed a new set of condition health index models to fit the new bridge element inspection data. A Bridge Health Index (BHI) is a calculated number between 0 and 99 percent that can be used as a rating to represent the overall deteriorated condition of a bridge element. The report looks at various methodologies of determining the health index (based on relative importance levels or factors) of bridge elements. Stochastic analysis and element historical data have been used to generate health index of elements through the risk and vulnerability (hazard) information as well as replacement cost data. Also a reliability methodology was considered as a new approach to compute importance weights and health index of bridge components. This thesis research also reviewed the Florida Department of Transportation (FDOT) Bridge Field Inspection Guide, including a comparison on element condition state tables from the FDOT manual, with the AASHTO manual and manuals from other state DOTs. Expert opinions on the importance of bridge elements were elicited and used to compute the health index of the bridge. This BHI has been compared to other methodologies already mentioned. Due to the revised bridge element definitions and meaning of condition states, necessary studies on the use of the AHP method and the Delphi survey analysis have been suggested for future research.
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Date Issued: 2015
Identifier: FSU_migr_etd-9620
Format: Thesis

Title: Evaluation of Florida Asphalt Mixtures for Crack Resistance Properties Using the Laboratory Overlay Test Procedure.
Creator: Sheng, Biqing, Ping, Wei-Chou Virgil, Niu, Xufeng, Tawfiq, Kamal Sulaiman, Rambo-Roddenberry, Michelle Deanna, Moses, Ren, Florida State University, College of Engineering,...
Show moreSheng, Biqing, Ping, Wei-Chou Virgil, Niu, Xufeng, Tawfiq, Kamal Sulaiman, Rambo-Roddenberry, Michelle Deanna, Moses, Ren, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Cracking is a primary distress on flexible pavements in Florida. Therefore, it is necessary to evaluate the crack resistance of proposed asphalt mixtures on Florida Department of Transportation (FDOT) projects. A comprehensive literature review was conducted on the evaluation of reflective cracking of HMA mixtures. Mechanisms of reflective cracking, crack models, and crack resistance evaluation was reviewed based on research studies performed by other researchers. The ability of the overlay...
Show moreCracking is a primary distress on flexible pavements in Florida. Therefore, it is necessary to evaluate the crack resistance of proposed asphalt mixtures on Florida Department of Transportation (FDOT) projects. A comprehensive literature review was conducted on the evaluation of reflective cracking of HMA mixtures. Mechanisms of reflective cracking, crack models, and crack resistance evaluation was reviewed based on research studies performed by other researchers. The ability of the overlay test for characterizing the cracking-resistance performance of asphalt mixtures was methodically reviewed. Available information, such as test procedures, results, and findings, were collected and examined. The variability and effects of different factors on the overlay test, such as test setup, opening width, sample thickness, asphalt binder, and Reclaimed Asphalt Pavement (RAP) materials, were also evaluated. Cracking performance of common Florida asphalt mixtures were evaluated using laboratory Overlay Test (OT). A test procedure based on Tex-248-F test method was developed to accommodate the Florida test methods on asphalt mixtures. Nine standard mix designs for traffic level C & E, which included SP-12.5, SP-9.5, and SP-4.75 mix designs, were selected to conduct the Overlay Test. Granites, which were from different sources, were used as the aggregate in the mixtures. In addition, the mixtures were prepared using both virgin asphalt binder (PG 67-22) and polymer modified asphalt (PMA) binder (PG 76-22). The effects of material characteristics, polymer modified binder, and RAP on the crack resistance of Florida asphalt mixtures were investigated. Additionally, a lower maximum opening displacement, 0.0125 inch, was tried out on one type of mixture (SP-12.5 with 20% RAP) to determine the significance of displacement rate on the crack resistance of the Florida asphalt mixture. Three replicate samples were tested for each type of mixture. The test results had a good agreement on the three replicate samples. The coefficients of variation (COV) were less than 20%. It was found that granite from different aggregate source did not have a strong influence on the test results, while the aggregate size did have a significant effect. SP-9.5 mixtures had the best cracking performance compared to SP-12.5 and SP-4.75 mixtures. Considerable effects were found on the asphalt binder and RAP. Crack resistance of Florida asphalt mixtures was significantly improved if PG 76-22 PMA binder was used instead of PG 67-22 virgin asphalt binder. However, the crack resistance was reduced when 20% RAP was included in the mix designs. Fracture mechanics analysis was conducted on the overlay test results based on the Paris' Law. Besides of fracture properties A and n, crack indexes A' and n', which can be easily obtained from the overlay test load reduction curve, were introduced to evaluate the crack resistance of asphalt mixtures. The correlation relationships between the crack indexes and the fracture properties were developed. It was found that the asphalt mixtures with greater n'/n values had better crack resistance than the asphalt mixtures with lower n'/n. The computed fracture properties can be compared to the results from the other tests, such as IDT. The laboratory test results can also be compared to the field observations to better predict the cracking performance of asphalt mixtures in the field. Some criteria based on the laboratory test results can be adopted into the design guide to evaluate the cracking performance of the asphalt mixtures.
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Date Issued: 2015
Identifier: FSU_migr_etd-9680
Format: Thesis

Title: Pyrolysis and Activation of an Invasive Species.
Creator: Mayers, Jordan, Chen, Gang, Ahmad, Hafiz, Clark, Clayton J., Huang, Wenrui, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Invasive plants are a nuisance and a hazard across the United States. Many states spend large amounts of money in an attempt to control and prevent the spread of these plants. This study seeks to take these invasive, low value plants and process them into higher value products. The first step is pyrolysis in which the plant, albizia, is converted into bio-gas, bio-oil, and bio-char. The bio-gas is released while the bio-char and bio-oil are collected. Their basic properties are studied and...
Show moreInvasive plants are a nuisance and a hazard across the United States. Many states spend large amounts of money in an attempt to control and prevent the spread of these plants. This study seeks to take these invasive, low value plants and process them into higher value products. The first step is pyrolysis in which the plant, albizia, is converted into bio-gas, bio-oil, and bio-char. The bio-gas is released while the bio-char and bio-oil are collected. Their basic properties are studied and presented. The bio-char is then further processed to produce activated carbon. Both physical activation with steam and chemical activation with phosphoric acid were evaluated. The carbon showed significantly increased surface area and iodine adsorption. Both physical and chemical activation achieved significant activation with iodine numbers as high as 1000 mg. of I per g. of activated carbon. The results also showed that the yield was significantly increased with the addition of phosphoric acid while maintaining high iodine numbers. As phosphoric acid increased, the yield increased.
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Date Issued: 2014
Identifier: FSU_migr_etd-8841
Format: Thesis

Title: Behavior of Plywood and Fiberglass Steel Composite Tube Structures Subjected to Impact Loading.
Creator: Armaghani, Seyamend Bilind, Jung, Sungmoon, Spainhour, Lisa, Tawfiq, Kamal, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Paratransit buses are custom built as the major vehicle manufacturer produces the custom built passenger cage installed on the chassis for the Paratransit bus. In order for these Paratransit bus members to be sufficient, they have to be evaluated for crashworthiness and energy absorption. This has prompted Florida Department of Transportation (FDOT) to fund research for the safety evaluation of Paratransit busses consisting of crash and safety analysis. There has been a large body of research...
Show moreParatransit buses are custom built as the major vehicle manufacturer produces the custom built passenger cage installed on the chassis for the Paratransit bus. In order for these Paratransit bus members to be sufficient, they have to be evaluated for crashworthiness and energy absorption. This has prompted Florida Department of Transportation (FDOT) to fund research for the safety evaluation of Paratransit busses consisting of crash and safety analysis. There has been a large body of research done on steel subjected to static loads, but more research is needed for steel applied under dynamic loading and high speeds in order to improve crashworthiness in events such as rollovers and side impacts. Bare steel Hollow Structural Section (HSS) tubing are used a lot as structural members of Paratransit buses because of their lightness and progressive buckling under loading. The research will be conducted on quantifying the tubing's behavior under bending by conducting static three point bending and impact loading tests. In addition to the bare tubing, plywood and fiberglass composites are investigated because they are both strong and lightweight and their behavior under dynamic loading hasn't been quantified. As a result, the main purpose of this research is to quantify the differences between the dynamic and static behavior of plywood steel composite and fiberglass steel composite tubing and compare these findings with those of bare steel tubing. The differences will be quantified using detailed and thorough experiments that will examine the composites behavior under both static and dynamic loading. These tests will determine if there are any advantages of using the composite materials and thus allow for recommendations to be made to the FDOT with the goal of improving the safety of Paratransit busses. Tensile tests were conducted to determine the material properties of the tested specimens. Before the static and dynamic experiments are run to investigate the differences between static and dynamic behavior, Preliminary three point bending testing was conducted to determine the parameters for the final experiments. Static bending testing was conducted on the bare, plywood composite, and fiberglass composite steel tubing. The point of these experiments was to produce a Moment vs. Rotation plot to determine the specimens' maximum moments and their associated rotation, as that is when the steel buckles and fails. The dynamic three point bending experiments were conducted using the impact loading apparatus and had the same purpose as the static experiments. For both static and dynamic experiments, the performances of the different types of specimens were compared based upon their Moment vs. Rotation plots. This will determine the effect that the composite has on the rotation and maximum moment at which the tubing fails. After conducting these experiments, amplification factors were established for each specimen by comparing the maximum moment and their associated rotation between static and dynamic testing. λ was calculated to quantify the ratio between the static and dynamic maximum moments. β was used to quantify the ratio between the rotation needed to produce the maximum moment between static and dynamic events. A small amplification factor denotes that material performs well under impact loading and the material doesn't experience dramatic change in behavior during dynamic events. Amplification factors were compared between the bare, plywood, and fiberglass composite steel tubing in order to evaluate the performance of the composites. After comparing the amplification factors of the different types of tubing, recommendations can be made. Fiberglass and plywood composite were shown to be valuable because it decreased the effect of dynamic forces as β was reduced by a factor of 2 in comparison to bare tubing. Based upon the amplification factors, it was recommended to use 14 gauge fiberglass composite tubing as Paratransit bus structural members because it was affected the least by dynamic loading.
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Date Issued: 2014
Identifier: FSU_migr_etd-8933
Format: Thesis

Title: E.Coli Growth and Transport in the Presence of Nanosilver under Variable Growth Conditions.
Creator: Xie, Weijie, Chen, Gang, Huang, Wenrui, Clark, Clayton, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Nanosilver has the ability to anchor to the bacterial cell wall and subsequently penetrate it, thereby causing structural changes in the cell membrane and death of the cell. The bacterial responses to the presence of nanosilver usually vary depending on the concentration of nanosilver particles, exposure conditions and the bacterial physiological stage. Since bacterial anabolism dependents upon a stoichiometric ratio of carbon and inorganic nutrients, the carbon to nitrogen ratio (C/N) thus...
Show moreNanosilver has the ability to anchor to the bacterial cell wall and subsequently penetrate it, thereby causing structural changes in the cell membrane and death of the cell. The bacterial responses to the presence of nanosilver usually vary depending on the concentration of nanosilver particles, exposure conditions and the bacterial physiological stage. Since bacterial anabolism dependents upon a stoichiometric ratio of carbon and inorganic nutrients, the carbon to nitrogen ratio (C/N) thus plays an important role of bacterial responses to the exposure of nanosilver. This study investigated the responses of Escherichia coli to the exposure of nanosilver under variable growth conditions. It was discovered that E. coli grown under different growth conditions had least resistance to the toxicity of nanosilver when cultured under carbon limited conditions. However, the presence of rhamnolipid, a commonly utilized biosurfactant for soil remediation increased the resistance of E. coli to nanosilver. The transport of E. coli cultured under carbon limited conditions was further studied in silica sand columns. E. coli adsorption in silica sand increased when cultured in the presence of nanosilver. On the contrary, E. coli adsorption in silica sand was significantly reduced when cultured in the presence of rhamnolipid. The results suggest that the resistance of E.coli to nanosilver can be improved by diminishing the carbon limitation in growth condition and the transport impact of nanosilver can be diminished by adding rhamnolipid.
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Date Issued: 2014
Identifier: FSU_migr_etd-8921
Format: Thesis

Title: Buildings' Sustainability Analysis: Analytical Hierarchy Process to Analyze Cost, Leed Credits, and Carbon Neutrality Utilizing a Building Information Modeling Platform.
Creator: Doczy, Ryan, AbdelRazig, Yassir A., Sobanjo, John O., Spainhour, Lisa, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: For building owners, there are several factors that they must consider when thinking about whether or not a building has achieved the goals set up for it. With increases in energy prices, knowledge about the damage being done to our atmosphere by humanity, and an increased drive towards environmental stewardship, sustainability has become more and more of a priority for building owners. A problem that building owners face when designing a building is trying to create a proper balance between...
Show moreFor building owners, there are several factors that they must consider when thinking about whether or not a building has achieved the goals set up for it. With increases in energy prices, knowledge about the damage being done to our atmosphere by humanity, and an increased drive towards environmental stewardship, sustainability has become more and more of a priority for building owners. A problem that building owners face when designing a building is trying to create a proper balance between reducing immediate costs and increasing the "greenness" of a building. The construction industry's technological breakthroughs and growing experience constructing green buildings is causing even those without sustainable inclinations to have to consider the possibility of going green due to the perceived benefits. Owners now have to consider that while sustainable construction drives up the upfront costs of costs of buildings, it also reduces long term costs (e.g. utility bills) while also increasing potential benefits associated with building green (e.g. increasing worker productivity). Due to the implications that these decisions will have on the owner and the building's occupants, the owner needs to have a tool to be able to assist them in determining what building design alternatives are helping the owner achieve his or her goals. The objectives of this research consist of the following (1) develop a decision making tool that is a hybrid of the analytical hierarchy process and the multiple attribute utility theorem; (2) design the decision making tool to take user inputs and determine how close a project came to meeting its goals; (3) set up the model to allow the user to be able to compare alternatives and chose the one that best meets the cost, LEED, and net-zero/carbon neutral goals
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Date Issued: 2014
Identifier: FSU_migr_etd-8767
Format: Thesis

Title: Prediction of Wind Induced Damage Using Prior Knowledge and Monitored Data.
Creator: Alduse, Bejoy Paruthyvalappil, Jung, Sungmoon, Liang, Zhiyong Richard, Vanli, Omer Arda, Mtenga, Primus V., Rambo-Roddenberry, Michelle Deanna, Florida State University, College...
Show moreAlduse, Bejoy Paruthyvalappil, Jung, Sungmoon, Liang, Zhiyong Richard, Vanli, Omer Arda, Mtenga, Primus V., Rambo-Roddenberry, Michelle Deanna, Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: Wind induced damage is observed in different types of civil engineering structures. There are several methods in use to predict damage. Researchers and stakeholders rely on these methods to quantify damage, which helps to schedule maintenance and to estimate financial loss. These damage prediction methods utilize the knowledge on properties of the wind or the wind load resistance of the material that constitutes the structure. However, recently, researchers have pointed out several...
Show moreWind induced damage is observed in different types of civil engineering structures. There are several methods in use to predict damage. Researchers and stakeholders rely on these methods to quantify damage, which helps to schedule maintenance and to estimate financial loss. These damage prediction methods utilize the knowledge on properties of the wind or the wind load resistance of the material that constitutes the structure. However, recently, researchers have pointed out several shortcomings in these approaches. One such shortcoming is the inability of these methods to address the uncertainty in the data. A typical method for damage prediction rely on the accuracy of statistic of the wind load or the material property used in the analysis. If uncertainty exists in the data, then the statistic obtained from the data will give overconfident inferences. As a result the final predicted damage, will be biased and will not reflect the uncertainties involved in the actual data. In this research, an approach is proposed to enhance the damage prediction model. In order to address the uncertainties in damage prediction, the approach integrates monitored data and existing knowledge, which gives probabilities of damages rather than a single number. The advance in sensors and wireless technologies has enabled much easier access to high-quality monitored data. The monitored data can be used to enhance the accuracy of damage prediction. While using monitored data, the proposed approach also seeks to fully utilize existing damage prediction models. These models provide a strong framework based on theories of mechanics and knowledge gained from many years of research. In order to integrate existing damage models and additional monitored data, a Bayesian approach is adopted. The Bayesian approach provides a sound framework for integrating the existing model and the additional data. In the Bayesian approach the existing model is termed as the prior. The prior is systematically updated using additional monitored data, in order to provide the posterior. In this research two case studies are considered. These are complete sealant failure of three tab asphalt shingles under wind load and fatigue damage of slender structures due to turbulence and wind structure interaction. In case of asphalt shingles, wind vulnerability is determined using a sensor based strength monitoring and integrating the existing data. The sealant in the shingle, helps to resist the wind load acting on the shingle. After installation of asphalt shingle, the sealant deteriorates over time and loses bond with the shingle. Consequently the wind uplift capacity is reduced and larger area of the shingle is exposed to higher wind load. A complete failure of sealant due to the wind load acting on it is defined as the failure of the shingle. A sensor mechanism is proposed to monitor the deterioration of the sealant and wind vulnerability of the asphalt shingle. Existing knowledge and monitored data is integrated to estimate the uplift capacity and the wind load acting on the shingle. The vulnerability of the shingle at each wind speed is expressed in terms of the sensor reading. MC simulation is carried out to determine the failure contour on the roof and fragility curves of roof at different ages. It is observed that, the fragility curve for a 2% area of roof failure at 100 mph for a 10 year old roof from this study compares well with the results of fragility of roof cover from Cope, 2014. In case of long span bridges, the wind data from existing and monitored data are integrated to determine the possible statistic of wind data and damage is predicted using this data. Accuracy of fatigue damage prediction depends on the accuracy of the wind speed and direction statistic. Conventional approaches rely on initial wind statistics only, which result in a single fatigue damage value. The proposed approach systematically updates the prior and wind statistic using the monitored data of wind for one year. This is used to determine the possible values of wind speed and direction statistic at the location. Fatigue analysis provides the probability distribution of different fatigue damage values. A long span bridge and long span beam were studied using the conventional and proposed approach. For the long span bridge, the fatigue damage from conventional approach is 0.002 and the mean fatigue damage from proposed analysis is 0.002. For the long span beam it is 0.392 and 0.397 respectively. The results from the proposed approach will give the designers and retrofitters a comprehensive view of the possible values of damage at any location on the bridge, thus helping in planning a maintenance task.
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Date Issued: 2014
Identifier: FSU_migr_etd-9226
Format: Thesis

Title: The Development of the Gas Push-Pull Test for Landfill Cover Soil Applications.
Creator: Higgs, Bently Hillory, Abichou, Tarek, Chanton, Jeffrey P., Chen, Gang, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
Abstract/Description: The purpose of this thesis was to develop the Gas Push-Pull Test (GPPT) for landfill cover soil applications to measure H2S oxidation. This thesis begins with an overview of solid waste management in the USA, and describes the alternatives for discarding and handling of solid waste. Also, discussions about the components that makeup a landfill to help resist the exposure of contaminants from the solid waste to the environment is elaborated upon. In addition, the ways in which landfill gas is...
Show moreThe purpose of this thesis was to develop the Gas Push-Pull Test (GPPT) for landfill cover soil applications to measure H2S oxidation. This thesis begins with an overview of solid waste management in the USA, and describes the alternatives for discarding and handling of solid waste. Also, discussions about the components that makeup a landfill to help resist the exposure of contaminants from the solid waste to the environment is elaborated upon. In addition, the ways in which landfill gas is generated by placing solid waste into landfills along with mitigation techniques to help attenuate H2S is discussed. Then the most suitable test to quantify in-situ rates of chemical or microbial reactions in the vadose zone or unsaturated zone which is the GPPT, is introduced. As a part of the development of the Gas Push-Pull Test (GPPT), chapter three presents a new methodology that allows for sound implementation of the GPPT in diverse subsurface environments such as a landfill to better understand the transport of gaseous components during the GPPT. For this to be accomplished, many GPPTs were run in fine sand and clayey fine sand with non-reactive gases methane (CH4) and sulfur hexaflouride (SF6) with molecular weights of 16.04 g/mol and 146.06 g/mol. With the data from the GPPTs, an equation or function called the correction factor was formulated to correct for the difference in molecular weights. The correction factor was applied to the GPPTs data and was successful in correcting CH4 and SF6 the non-reactive gases to have a molecular weight equal to the reactive gas Hydrogen Sulfide (H2S) with a molecular weight of 34 g/mol. Now one does not have to search for a tracer with equal transport capabilities like the reactive gas, one need only apply the correction factor. Now you are able to account for how much reactive gas was lost because of transport through the cover soils and by reactions within the cover soils. Once the correction factor was applied, the reacted portion can be used to calculate oxidation or reaction rates of landfill cover soils which is shown in chapter four. Also, to optimize H2S reduction in various soil types, it was important to be able to accurately quantify the reaction rate coefficient, k. Therefore, chapter four focuses on the use of lab and field techniques to examine reaction rates of H2S with fine sand, silty fine sand, clayey fine sand, compost and landfill cover soil. First, a series of laboratory flask experiments were conducted to assess the reaction rates of various soil types with no moisture, and then with varying water content from 10% to 60%. Next, the Gas Push-Pull Test (GPPT) was conducted in the field in different soil types to assess reaction rates. The laboratory results showed that the landfill cover soil had the highest reaction rate of 41.87 hr-1 when the soil had no moisture. Whereas compost had the highest reaction rate from 5.84 hr-1 to 9.98 hr-1 when moisture content increased from 10% to 60%, respectively. The laboratory results showed that lab-measured reaction rates of dry soils are strongly related to total iron content. For instance, the landfill cover soil had the highest reaction rate of 41.87 hr-1 with an iron content of 31,000 mg/kg of soil. On the other hand, fine sand had the lowest reaction rate of 1.47 hr-1 with an iron content of 100 mg/kg. The reaction rate with water was also measured to be 1.44 hr-1. It was noticed that water causes the reaction k to decrease for soils that had high k values with 0% water content. Whereby water causes the reaction k of compost to increase. The GPPT well-mixed and plug-flow reactor models' reaction rates for fine sand ranged from 1.63 hr-1 to 3.02 hr-1 and from 0.45 to 2.02, respectively. The GPPT well-mixed and plug-flow reactor models reaction rates for clayey fine sand ranged from 63.80 hr-1 to 144.49 hr-1 and from 47.77 hr-1 to 74.08 hr-1, respectively. Lastly, the GPPT well-mixed and plug-flow reactor models reaction rate values for landfill cover soil ranged from 55.83 hr-1 to 318.18 hr-1 and from 32.69 hr-1 to 110.14 hr-1, respectively. Also, fine sand tested for reaction rates in the flask and with the GPPT was not significantly different because of the homogeneity of the soil. However, the clayey fine sand and landfill cover soil tested for reaction rates was significantly different because of the heterogeneity of the soils. Both the flask test and the GPPT are easy and convenient to perform, but the GPPT is the most reliable because it quantifies in-situ reaction rates. Furthermore, to understand the attenuation of H2S, chapter five looks at lab and field scale studies that were conducted with potential landfill cover soils. For the laboratory experiment a rigid translucent plastic cylinder with a diameter of 5 1/2 inches and a height of 24 inches was constructed. The inside of the column from bottom to top was composed of a 2mm geotextile underlayment, a five-inch layer of course gravel, another two pieces of 2mm geotextile underlayment, twelve inches of 50-50 compost peat (by volume) mixture, and a six-inch air space. Then landfill gas (LFG) was injected into the column to assess the mitigation of H2S. After pumping 28,000 L of LFG was introduced into the column, which indicated the average instantaneous removal efficiency during the monitoring period was 85.7%. Also, the total mass of H2S introduced into the column was approximately 3.12g, the total mass emitted was 0.28g, and the total mass retained by the 1 foot soil mix was 2.84g. Therefore cumulative removal efficiency was 91%. In addition, to check for physical and chemical adsorption in the column, the saturated four-inch bottom layer of the soil mix was removed and tested for total sulfur. The sulfur adsorption capacity of the soil mixture was 2.2 g of total S per kg of dry mass of soil mix. The Michaelis-Menten kinetics parameters to understand the biological oxidation of H2S was determined to be Vmax of 450 nmol/s/kg of dry soil mix and a half saturation constant Km of 30 ppm. Also, a field scale study was conducted by constructing three 65x35 lysimeter test pads at the Riverbend Landfill. The test pads were made up of a composition of local soil and compost. As of October 2014, the average removal efficiency of the test pads is 99%. Test pad II with 6 inches of local soil on the bottom and 12 inches of local soil on the top had the highest H2S removal efficiency of 100%. Whereby test pad I with 18 inches of local soil and test pad III with 6 inches of local soil, both had 99% H2S removal efficiency. Also, continual monitoring of the test pads will persist, because of the increase of LFG flow into the test pads by increasing the orifice plates to 1 inch. In addition, the total sulfur and iron content of the test pads will be examined especially since LFG is still being introduced to the test pads. Lastly the newly developed GPPT will be utilized to study the field scale H2S oxidation of each test pad.
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Date Issued: 2014
Identifier: FSU_migr_etd-9187
Format: Thesis

Title: Rollover Procedures for Crashworthiness Assessment of Paratransit Bus Structures.
Creator: Gepner, Bronislaw Dominik, Wekezer, Jerry W., Jung, Sungmoon, Liang, Zhiyong Richard, Mtenga, Primus V., Plewa, Tomasz, Florida State University, FAMU-FSU College of Engineering...
Show moreGepner, Bronislaw Dominik, Wekezer, Jerry W., Jung, Sungmoon, Liang, Zhiyong Richard, Mtenga, Primus V., Plewa, Tomasz, Florida State University, FAMU-FSU College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: The following dissertation presents the initial stages of the development of the new rollover safety assessment protocol developed for paratransit buses. Each year, the State of Florida purchases over 300 paratransit buses. In 2011, the purchased buses came with over 40 different floor/wheelbase/chassis configurations. Such variety of purchased vehicles gives the ordering agencies a flexibility of ordering vehicles optimized for desired purpose, but also creates a challenge for the rollover...
Show moreThe following dissertation presents the initial stages of the development of the new rollover safety assessment protocol developed for paratransit buses. Each year, the State of Florida purchases over 300 paratransit buses. In 2011, the purchased buses came with over 40 different floor/wheelbase/chassis configurations. Such variety of purchased vehicles gives the ordering agencies a flexibility of ordering vehicles optimized for desired purpose, but also creates a challenge for the rollover safety assessment procedures. Currently, there are two standards available to be used for rollover crashworthiness assessment of buses, the FMVSS 220 standard and the UN-ECE Regulation 66. The FMVSS 220 is commonly used in the United States to evaluate rollover crashworthiness of wide variety of buses. Its quasi-static nature offers an attractive, easy to perform test that provides good repeatability of results. Nevertheless, due to the nature of applied load, this procedure may not be the best choice for evaluating the dynamic behavior of a bus during a rollover accident. In contrast, the UN-ECE Regulation 66 employs a full scale, dynamic rollover test to examine response of buses in rollover accidents. The dynamic rollover, which forms the basis of the ECE-R66 approval procedure closely resembles the real world rollover accident and this regulation has been adopted by over 40 countries in the world. However, the dynamic nature of this test makes it expensive, time consuming and difficult to perform. This situation calls for an update of an approval procedure, in order to test the purchased buses within the available time and budget. The initial development of the new assessment protocol, the Equivalent Rollover Testing (ERT) procedure, was carried out in this dissertation. The ERT procedure is conceived as an alternative approval method for the experimental or virtual full scale rollover testing. The new protocol was developed based on collected experimental experience, extensive numerical studies and theoretical considerations. The ERT procedure establishes a set of experimental tests, on the components of bus structure, that if satisfied give a high level of confidence that the tested bus will pass the requirements of the ECE-R66 rollover procedure. The proposed ERT procedure is further tested through the parametric studies on five detailed finite element models of paratransit buses. The models, developed in the Crashworthiness and Impact Analysis Laboratory (CIAL), cover a wide range of buses, from small 138 in to a large 255 in wheelbase configurations. Through the modifications of structural components of each of the buses, a set of 132 bus designs and corresponding 132 rollover tests was established. Each of the developed buses was also subjected to the provisions of the ERT procedure. The comparison of results showed that ERT procedure presents a conservative approach to paratransit bus safety evaluation. Out of all 132 test cases there was not a single bus that passed the provisions of the ERT procedure, but has failed the full scale ECE-R66 rollover test. The proposed ERT procedure, complemented by future validation experimental study presents a promising alternative for the paratransit bus rollover safety evaluation.
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Date Issued: 2014
Identifier: FSU_migr_etd-9176
Format: Thesis

Title: Ground Tire Rubber as a Component Material in Concrete Mixtures for Paving Concrete.
Creator: Twumasi-Boakye, Richard, Sobanjo, John, Tawfiq, Kamal, Spainhour, Lisa, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The management of solid waste is a major environmental concern in the United States. Waste tire rubber forms a major part of this problem and a rather severe one since tire rubbers are not biodegradable hence its disposal into landfills are of great concern. This research primarily focused on finding the best way of producing paving concrete with the use of ground tire rubber as a component material. Tests on rubber concrete were performed in two stages. Preliminary tests were performed using...
Show moreThe management of solid waste is a major environmental concern in the United States. Waste tire rubber forms a major part of this problem and a rather severe one since tire rubbers are not biodegradable hence its disposal into landfills are of great concern. This research primarily focused on finding the best way of producing paving concrete with the use of ground tire rubber as a component material. Tests on rubber concrete were performed in two stages. Preliminary tests were performed using both 40-mesh GTR and 3/8-inch rubber chips (RC) to replace fine aggregates and coarse aggregates respectively by weight in the concrete mix. This stage of testing considered zero to 40 percent GTR replacement of fine aggregates by weight at 10 percent increment and for zero to 30 percent RC replacement of coarse aggregates by weight at 10 percent increment. Observations from this stage guided the formulation of a second and final stage of testing which involved only zero to 20 percent GTR replacement of fine aggregate by weight at 5 percent increment. The mix design for this stage involved the use of water reducers, air-entrainer and fly-ash. In addition to concrete mechanical property tests, coefficient of thermal expansion (CTE), plastic shrinkage and drying (free) shrinkage tests were also conducted. Results from preliminary tests indicated that GTR and RC concrete specimens were of relatively low strength, improved toughness and showed more elasticity when compared to normal concrete specimens. The final stage of laboratory testing however showed improved strength characteristics, with the initial observations of improved toughness and low modulus of elasticity still evident. Coefficient of thermal expansion (CTE) test results did not show significant difference between mix-types, with the range of results falling within the typical limit for normal concrete. Plastic shrinkage test results showed that the inclusion of GTR helped in reducing plastic shrinkage cracks in concrete. Preliminary results at the second stage testing on drying shrinkage using 10% GTR concrete indicated a reduction in free shrinkage when compared to the control specimens.
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Date Issued: 2014
Identifier: FSU_migr_etd-9107
Format: Thesis

Title: Damage Detection in Reinforced Concrete Structures with In-Situ Triboluminescent Optical Fiber Sensors.
Creator: Kliewer, Kaitlyn, Department of Civil and Environmental Engineering
Abstract/Description: With the increased aging and deterioration of civil infrastructure systems, it is crucial to develop an effective and economical structural health monitoring system. Current structural health monitoring systems are burdened by disadvantages rendering them inefficient or not economically viable. In response to this problem, the in-situ triboluminescent optical fiber (ITOF) sensor has been developed for applications within cementitious structures. Four point bend tests were carried out on...
Show moreWith the increased aging and deterioration of civil infrastructure systems, it is crucial to develop an effective and economical structural health monitoring system. Current structural health monitoring systems are burdened by disadvantages rendering them inefficient or not economically viable. In response to this problem, the in-situ triboluminescent optical fiber (ITOF) sensor has been developed for applications within cementitious structures. Four point bend tests were carried out on reinforced concrete beams with integrated ITOF sensors so as to evaluate the performance of the sensor. With this study, the ITOF sensor's potential to provide in-situ and distributed real time damage detection within concrete structures has been demonstrated. Reinforced concrete beams instrumented with the ITOF sensor provided warning signals and real time feedback prior to the failure of the beam through triboluminescent signal peaks and demonstrated the potential as a viable SHM system. Both the length and sensor location within the reinforced beams were tested. Test results indicated that a longer sensitized region of the ITOF sensor and a sensor placed closer to the tension face of the beam yielded higher damage (triboluminescent) response signals.
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Date Issued: 2013
Identifier: FSU_migr_uhm-0236
Format: Thesis

Title: Development of the Gas Push Pull Test for Hydrogen Sulfide Oxidation.
Creator: Lawson, Jacob Brinton, Abichou, Tarek, Chanton, Jeffery, Clark, Clayton, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: ABSTRACT A limited number of studies using various types of cover materials to attenuate H2S emissions have been performed both at the laboratory and field scales. These results have demonstrated that H2S emissions can be effectively reduced using compost, fine concrete, and lime-amended sandy soils as cover materials using several mechanisms (Plaza et al. 2007, Xu, 2005, Sungthong 2010). These mechanisms are: (1) Hydrogen sulfide is consumed by bacteria found in soil that oxidizes hydrogen...
Show moreABSTRACT A limited number of studies using various types of cover materials to attenuate H2S emissions have been performed both at the laboratory and field scales. These results have demonstrated that H2S emissions can be effectively reduced using compost, fine concrete, and lime-amended sandy soils as cover materials using several mechanisms (Plaza et al. 2007, Xu, 2005, Sungthong 2010). These mechanisms are: (1) Hydrogen sulfide is consumed by bacteria found in soil that oxidizes hydrogen sulfide to elemental sulfur or sulfate, (2) Clay or organic matter in soils may also sorb hydrogen sulfide (soil microorganisms are not involved in the sorption process), and (3) H2S may be oxidized by reaction with soil minerals, particularly ferric iron. Such mechanisms are well understood from the significant amount of research performed on H2S gas removal using biofiltration. Additionally, under aerobic landfill cover conditions, considerable research has been performed using microbiological methane oxidation to mitigate methane emissions from municipal solid waste. One of the main issues regarding the implementation of approaches for the reduction of H2S emissions from landfills is the lack of a proper technique to assess the level of H2S oxidation and reaction under field conditions. Developing such a technique would allow the determination of H2S oxidation capacity of different cover materials and different cover designs under different climatic conditions. One possible technique that could be employed is the Gas Push Pull Test (GPPT). The general aim of this thesis is to develop the GPPT method for a reactive gas like H2S, which has not been done before. GPPT is a single well gas-tracer test in which inert gases are used as non-reactive tracers for the reactive gas (methane) or in this case, H2S. During the test, a mixture of tracer and reactive gases is injected (pushed) into the soil. During a transition phase, the soil "air" mixes with the injected gases where it is available to microorganisms or minerals. The mixture of soil "air" and injected gas is then extracted (pulled) from the same location. The quantification of oxidation is then based on the analysis of the breakthrough curves (relative concentrations) of the reactive and the tracer gases. It is expected that the tracer concentrations at the injection/extraction points decrease as a result of physical transport processes, whereas the attenuation of the reactive gas is a result of physical transport processes, chemical oxidation, and microbial (and others) activities. A lab study was completed to assess the reactivity of H2S by different soil types typically used in landfill cover construction. The reactivity of H2S was characterized by zeroth-order kinetics as well as correlating the reactivity to water and iron content of the soil materials. The lab study only investigated physical and chemical processes that attenuate H2S. In addition to the laboratory study, a field study was completed to develop proper methods in performing a (GPPT) to measure the capacity of soil materials to oxidize H2S. The objectives were to experimentally compare transport of the reactant gas H2S and tracer gases during GPPTs as a function of varying injection/extraction flow rates in a porous medium and in the absence of microbial activity. Additionally, the relative importance of molecular diffusion, advection, and transfer into the water phase of H2S during GPPTs was also evaluated as well as developing a correction ratio that would allow the use of tracers with dissimilar molecular weights.
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Date Issued: 2013
Identifier: FSU_migr_etd-7878
Format: Thesis

Title: Empirical Deck for Phased Construction and Widening.
Creator: Fuentes, Javier Alexander Muniz, Tawfiq, Kamal, Sobanjo, John O., Spainhour, Lisa K., Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: A standard deck is defined as a deck slab on longitudinal beams with main reinforcement placed perpendicular to traffic. As outlined in Article 9.6.1 of the AASHTO-LRFD Bridge Design Specifications, it allows three design methods or procedures of bridge decks with primary reinforcement perpendicular to the main bridge beams Approximate Elastic or "Strip" Method of Analysis (AASHTO 4.6.2.1) Traditionally bridge deck designs have always been made by analyzing assumed transverse slab strips...
Show moreA standard deck is defined as a deck slab on longitudinal beams with main reinforcement placed perpendicular to traffic. As outlined in Article 9.6.1 of the AASHTO-LRFD Bridge Design Specifications, it allows three design methods or procedures of bridge decks with primary reinforcement perpendicular to the main bridge beams Approximate Elastic or "Strip" Method of Analysis (AASHTO 4.6.2.1) Traditionally bridge deck designs have always been made by analyzing assumed transverse slab strips within the concrete deck as flexure members and supported by the existing girders. This method is called the Approximate Method of Analysis. To simplify the length and complexity of the design, it is assumed that the girders are rigid supports. In addition, AASHTO specifications allow the maximum positive moment and the maximum negative moment to apply for all positive moment regions and all negative moment regions in the slab, respectively. Refined Methods of Analysis (AASHTO 4.6.3) - Refined Methods of Analysis are generally acceptable methods for analyzing concrete bridge decks. These methods are based mainly on finite element analysis, which requires a more complicated and lengthy set of calculations. Thus, these various methods are not typically used to analyze a standard or "typical" bridge deck. A refined analysis method would be better suited for a more complex deck slab structure, which would require a more detailed analysis. Empirical Method of Analysis (AASHTO 9.7.2) - Empirical Method of Analysis is generally based on the concept of internal "arching action" within concrete slab. In other words, the deck behaves more like a "continuous membrane" than a series of contiguous beams. This method takes into account in plane stresses generated by applying load to the deck. These in plane forces, which in traditional design are ignored, act to strengthen the overall response of the deck. This design procedure is generally accepted and is widely adopted and employed by many other countries and in-state agencies. This project was initiated with the goals of assessing the current and possibly future design methodologies to be used by the Florida Department of Transportation in future bridge deck design projects. This thesis focuses on evaluating and contrasting the benefits and disadvantages of the Traditional Method of Analysis (currently in general use by the FDOT) and the empirical method of analysis. This objective is achieved by conducting a Finite Element Analysis parametric study using specialized computer software, where a typical bridge is designed and tested based on designs derived from said methods. The analysis yielded data that was then collected, analyzed and used for benchmark purposes. This study allowed an extensive range of specimens to be tested, and a broad range of loads and reinforcement combinations to be analyzed using both methodologies. From the results obtained, potential recommendations were then formulated in contrast to current design practices.
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Date Issued: 2013
Identifier: FSU_migr_etd-8609
Format: Thesis

Title: Development Device for Prestressing Strands in Beams.
Creator: Wagner, David J., Roddenberry, Michelle, Tawﬁq, Kamal, Mtenga, Primus, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: A grouted sleeve device for gripping prestressing steel, developed and tested in previous research by Potter 2009, was embedded into the end regions of prestressed concrete bridge beams in an attempt to anchor the terminal ends of the strands. The goal was to produce enough bond strength in the device to effectively act as a strand anchor and reduce the development length of the strand. Anchored strand could also serve to increase ductility, improve ultimate capacity and reduce the number of...
Show moreA grouted sleeve device for gripping prestressing steel, developed and tested in previous research by Potter 2009, was embedded into the end regions of prestressed concrete bridge beams in an attempt to anchor the terminal ends of the strands. The goal was to produce enough bond strength in the device to effectively act as a strand anchor and reduce the development length of the strand. Anchored strand could also serve to increase ductility, improve ultimate capacity and reduce the number of stirrups required in the end region. Four test series were performed, each focusing on separate aspects of the research. Test Series 1 focused on prestress release testing using 0.6-in.-diameter prestressing strand with different steel sleeve sizes and grout types; the results of these tests were used to finalize the anchorage device design. Series 2 incorporated two different designs into the fabrication of two half-scale AASHTO Type II prestressed concrete beams. These beams were fitted with strain gauges for monitoring the transfer length during detensioning. In Series 3, the beams from the previous test series were tested in a shear test configuration to failure, and results were compared to a control specimen. For Series 4, unstressed pull-out specimens were created to test the bond performance of the second anchorage type embedded in a beam of Series 2 and 3. Finalization of device design and field installation method in Test Series 1 provided a path for the research to take. The transfer length testing that followed established that reducing the transfer length (Lt) in a prestressed beam by means of an embedded anchor was possible. Improvement of the transfer length due to the grouted device is considered negligible after accounting for concrete strength, but the second anchor type (coil confinement) showed a reduction in Lt of 30%. Both types of embedded anchors showed an improvement in ductility and ultimate capacity, but proper end region detailing using shear steel would be beneficial in future tests to more thoroughly test the performance of the anchor.
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Date Issued: 2013
Identifier: FSU_migr_etd-7642
Format: Thesis

Title: Side Impact of a Paratransit Bus.
Creator: Turley, Joshua, Jung, Sungmoon, Wekezer, Jerry, Rambo-Roddenberry, Michelle, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The Florida Department of Transportation--Transit Office has endeavored to quantify the safety of a paratransit bus in a side impact collision. They have provided funded to produce this work. The goal of this work is to determine the likeliness that an occupant in a paratransit bus will experience an unacceptable amount of harm during a side impact collision. A side impact experiment was performed. An impactor weighing 4,400 lbs consisting of a crash cart with an attached IIHS deformable...
Show moreThe Florida Department of Transportation--Transit Office has endeavored to quantify the safety of a paratransit bus in a side impact collision. They have provided funded to produce this work. The goal of this work is to determine the likeliness that an occupant in a paratransit bus will experience an unacceptable amount of harm during a side impact collision. A side impact experiment was performed. An impactor weighing 4,400 lbs consisting of a crash cart with an attached IIHS deformable barrier was suspended between two steel towers. The impactor was raised to a height of 31 ft and let swing into the side of a stationary paratransit bus in a pendulum motion impacting at an angle of 90 degrees. Inside the bus a Hybrid III 50th percentile Anthropomorphic Test Dummy (ATD) was seated near the region of impact. The ATD recorded values that were all below Injury Assessment Reference Values (IARV) which indicates a favorable crashworthiness result for a side impact of similar paratransit bus. There was a significant amount of crush in the deformable barrier where it contacted the bus deck and indicates that should the impactor impact the bus higher or the bus have a low deck construction the results may be significantly different. This should be investigated in future research.
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Date Issued: 2013
Identifier: FSU_migr_etd-7632
Format: Thesis

Title: Analysis of Tilt-Up Building Design and Industry Standard Practices in Tornado-Prone Regions.
Creator: Maldonado, Desiderio, Rambo-Roddenberry, Michelle, Jung, Sungmoon, Mtenga, Primus, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Tilt-up buildings are a popular building construction method used across the United States. These structures offer many benefits, but can also present unique design challenges when compared to other building types. Recent tornado outbreaks have caused over $20 billion in total damages and killed hundreds of people. As with most structures, tilt-up buildings tend to be susceptible to tornado events. These events have brought building performance and safety in tornado-prone regions to the...
Show moreTilt-up buildings are a popular building construction method used across the United States. These structures offer many benefits, but can also present unique design challenges when compared to other building types. Recent tornado outbreaks have caused over $20 billion in total damages and killed hundreds of people. As with most structures, tilt-up buildings tend to be susceptible to tornado events. These events have brought building performance and safety in tornado-prone regions to the forefront of consideration by residents, building owners, code officials, and design professionals. The research for this thesis was performed to study the major components and connections used in typical tilt-up buildings using current standard wind analysis methods and to identify limiting factors in building performance in hopes of improving future building designs. Standard wind design and analysis methods were used for this research, not tornado-specific wind design criteria. The components focused on are generally regarded as current industry standards and follow local building codes and manufacturer recommendations. Existing retrofit options traditionally used in high seismic regions were also studied to see if any available methods were suitable for preventing tilt-up building failure in tornado events. The construction of internal storm shelters was also investigated as a potential additional method of reducing injuries and deaths in tornado-prone regions. While large tornado-proof buildings may be impractical or cost prohibitive, it is important for design professionals to continue to take proactive approaches to region specific hazards in future designs to reduce property damage and casualties.
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Date Issued: 2013
Identifier: FSU_migr_etd-7484
Format: Thesis

Title: Determination of Optimum Lengths of Active and Inactive Elements of a Segmented Sensor for Discriminating Among Single, Super Single, and Dual Tires.
Creator: Conrad, Adam, Moses, Ren, Sobanjo, John, AbdelRazig, Yassir, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Monitoring traffic through extensive collection and efficient storage of traffic data is crucial for improving safety and efficiency of Florida Highways. To this end, the Florida Department of Transportation operates temporary and permanent count stations strategically placed at various locations on the state highway system. The data collected by electronic equipment installed at these stations include individual vehicle records composed of a number of axles per vehicle, axle spacing, overall...
Show moreMonitoring traffic through extensive collection and efficient storage of traffic data is crucial for improving safety and efficiency of Florida Highways. To this end, the Florida Department of Transportation operates temporary and permanent count stations strategically placed at various locations on the state highway system. The data collected by electronic equipment installed at these stations include individual vehicle records composed of a number of axles per vehicle, axle spacing, overall vehicle length, and operating speed. The Florida Department of Transportation operates other sites categorized as weigh-in-motion (WIM) sites that are set up to additionally collect individual axle weights and overall gross vehicle weight. In general, the traffic count program managed by the FDOT Statistics Office is operating very well and serves a vital purpose of supporting federal, state, and private user needs. Nevertheless, the FDOT Statistics Office continues to experience a number of challenges in operating the count sites, in assuring the quality of data collected by these sites, and in complying with continually changing federal reporting requirements. The following research aims to provide the FDOT Statistics Office with an improved device to classify vehicles on all desired roadways. The research effort consisted of collecting vehicular data, conducting statistical analyses and developing equations. It was determined that a segmented sensor would provide FDOT with an improved system by having the capability to determine the class of vehicle driving over it. A sensor length recommendation was made that will accurately determine the type of tire running overhead. This paper will take the reader through the process of coming to the aforementioned conclusions.
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Date Issued: 2013
Identifier: FSU_migr_etd-8686
Format: Thesis

Title: The Efficacy of Aeration and GAC Filtration at Reducing Microtoxicity of Water.
Creator: Michaud, Gustave, Chen, Gang, Barbu, Adrian, Huang, Wenrui, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Chlorination of water is among the cheapest and mostly widely used drinking water disinfection methods. It also produces many disinfection by-products (DBPs) that are considered carcinogenic. DBPs are the result of chlorine reaction with dissolved organic carbon (DOC) in water. This study seeks to evaluate a solution for the removal of DBPs, namely bubble column aeration in conjunction with granulated activated carbon (GAC) filtration. Trihalomethanes (THMs), which are one of the two major...
Show moreChlorination of water is among the cheapest and mostly widely used drinking water disinfection methods. It also produces many disinfection by-products (DBPs) that are considered carcinogenic. DBPs are the result of chlorine reaction with dissolved organic carbon (DOC) in water. This study seeks to evaluate a solution for the removal of DBPs, namely bubble column aeration in conjunction with granulated activated carbon (GAC) filtration. Trihalomethanes (THMs), which are one of the two major types of DBPs produced by chlorination, are volatile and therefore can be removed by aeration. This study also seeks to evaluate the effectiveness of aeration as a form of pre-treatment, if removal of DOC is achieved. The results show that GAC filtration is very efficient at removing DOC, and microtoxicity in neutral pH synthetic surface water. Bubble Column aeration alone, however, is not effective at removing DOC. The results also show that aeration improves the efficiency of GAC filtration at reducing microtoxicity of water. The t-test between toxicity values for the GAC filtration set-up, and the GAC/Bubble column aeration set-up indicate that the two methods give a difference in values that is statistically significant. It is concluded that chlorination followed by a GAC/Bubble column aeration filtration system is a viable treatment method. Alternative treatment technologies such as ozone and chlorine dioxide create DBPs that are carcinogens, or considered potential carcinogens.
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Date Issued: 2013
Identifier: FSU_migr_etd-8603
Format: Thesis

Title: The Use of O₃ Advanced Oxidation Processes for Landfill Leachate Pretreatment.
Creator: Ghazi, Niloufar Mirsaeid, Chen, Gang, Clark, Clayton, Abichou, Tarek, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The final discharge point for collected landfill leachates is frequently the local municipal wastewater treatment facility. The salinity, color, and/or nutrient and organics contamination of leachates often necessitate some form of pre-treatment. When advanced oxidation processes (AOPs) are considered for pre-treatment, the unique composition of dissolved organic matter (DOM) and the relatively high concentrations of some inorganic solutes in leachate will inhibit treatment efficiency. The...
Show moreThe final discharge point for collected landfill leachates is frequently the local municipal wastewater treatment facility. The salinity, color, and/or nutrient and organics contamination of leachates often necessitate some form of pre-treatment. When advanced oxidation processes (AOPs) are considered for pre-treatment, the unique composition of dissolved organic matter (DOM) and the relatively high concentrations of some inorganic solutes in leachate will inhibit treatment efficiency. The most important benchmark for design of AOPs is the expected steady-state production of free radical (*OH). Without a quantitative assessment of total *OH consumption in high-strength waste water, like a landfill leachate, efficient AOP treatment is uncertain. For this reason, two landfill leachates, distinct in color, DOM, population served by municipal solid waste facility, and age of landfill, were characterized for *OH-scavenging using a well-established competition kinetics method. After stripping the samples of inorganic carbon, the DOM in leachate from mature (stabilized) landfill was found to react with *OH at a rate of 9.76 x 108 M-1s-1. However, DOM in leachate from newer landfill was observed to scavenge available *OH at a faster rate (8.28 x 109 M-1s-1). The combination of fast rate of reaction with *OH and abundance of DOM in the sampled leachate severely limited the contribution of *OH to degradation of an O3- and *OH-labile organic probe compound (bisphenol-a) in the ozonated mature leachate (f*OH= 0.03). Substantial dosing of both O3 and H2O2 (> 70 mg/L and >24 mg/L, respectively) may be required to see at least 1-log-removal (>90%) of an *OH-selective leachate contaminant (parachlorobenzoic acid) in a mature landfill leachate.
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Date Issued: 2013
Identifier: FSU_migr_etd-8606
Format: Thesis

Title: Power Generation and Nitrogen Removal of Landfill Leachate Using Microbial Fuel Cell Technology.
Creator: Lee, Yongwoo, Chen, Gang, Clark, Clayton J., Ahmad, Haﬁz, Huang, Wenrui, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Microbial fuel cell (MFC) technology has been practiced in the treatment of landfill leachate. However, it is a big challenge for the usage of MFCs to treat landfill leachate with high ammonium content. The purpose of this study was to design and test two MFC reactors, i.e., an ammonium oxidation/MFC re- actor and a MFC/Anammox reactor for the treatment of landfill leachate with high ammonium content in terms of power generation and nitrogen removal. Using the ammonium oxidation/MFC reactor,...
Show moreMicrobial fuel cell (MFC) technology has been practiced in the treatment of landfill leachate. However, it is a big challenge for the usage of MFCs to treat landfill leachate with high ammonium content. The purpose of this study was to design and test two MFC reactors, i.e., an ammonium oxidation/MFC re- actor and a MFC/Anammox reactor for the treatment of landfill leachate with high ammonium content in terms of power generation and nitrogen removal. Using the ammonium oxidation/MFC reactor, the landfill leachate collected from Leon County Landfill of Northwest Florida generated a power density of 8 mW/m2 together with 92% of nitrogen removal. For the MFC/Anammox reactor, a power density of 12 mW/m2 was achieved with 94% of nitrogen removal. Compared with the ammonium oxidation/MFC reactor, 50% more energy was generated because in the MFC/Anammox Reactor, nitrite served as the electron acceptor; while in the Ammonium Oxidation/MFC reactor, nitrate served as the electron acceptor. In this research, power generation was also found to be directly linked to the microbial species that were involved in organic decomposition, i.e., the greater the microbial concentration, the more power generated.
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Date Issued: 2013
Identifier: FSU_migr_etd-8588
Format: Thesis

Title: Investigation of Carbon Fiber Composite Cables (CFCC) in Prestressed Concrete Piles.
Creator: Joshi, Kunal, Rambo-Roddenberry, Michelle, Mtenga, Primus, Jung, Sungmoon, Spainhour, Lisa, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The Florida Department of transportation most commonly uses prestressed concrete piles as foundation in bridges. It has been observed since past few years that the piles installed in aggressive marine environments are subjected to corrosion which generates a need to retrofit them. Although many solutions have been applied to address this issue, these solutions have seem to be ineffective in long term and hence use of advanced materials in piles, to avoid degradation due to corrosion, is...
Show moreThe Florida Department of transportation most commonly uses prestressed concrete piles as foundation in bridges. It has been observed since past few years that the piles installed in aggressive marine environments are subjected to corrosion which generates a need to retrofit them. Although many solutions have been applied to address this issue, these solutions have seem to be ineffective in long term and hence use of advanced materials in piles, to avoid degradation due to corrosion, is necessarry. The ACI and AASHTO equations used to determine the bond properties of a prestressing strand, need to be satisfied by this material, to render this material's suitability as replacement to steel strands. 5--24 in. square prestressed concrete piles which included 3--40 ft. piles and 2--100ft. piles, were cast using 0.6in. diameter carbon fiber composite cables manufactured by Tokyo Rope Mfg. Co. to asses the performance of CFCC as reinforcement. A different anchoring system was used to anchor the CFCC to the abutment in order to prestress the strands. Transfer length was monitored on each pile end and compared to the ACI and AASHTO equations to evaluate the bond characteristics of the CFCC. In addition to that, development length tests and flexural tests were performed at the Marcus. H. Ansley research laboratory to further judge the bond properties of the CFCC with concrete. The results of these tests show if the performance of CFCC is comparable to steel and also describe the technique used to prestress these strands. The 2--100 ft. piles were cast to be driven on site to monitor the static resistance of the piles and would be long term monitored to asses the performance of CFCC against corrosion.
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Date Issued: 2013
Identifier: FSU_migr_etd-8578
Format: Thesis

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