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Title: The Effects of Silver Nanoparticles on Wastewater Treatment and Escherichia Coli Growth.
Creator: Perez, Michael, Department of Civil and Environmental Engineering
Abstract/Description: Nanomaterials and their increasing use in manufactured products are of great concern to wastewater treatment systems and the environment. Nanosilver has become one of the most popular nanoparticles due to its many applications and relatively low manufacturing costs. It is currently being used for a wide variety of commercial products including medical applications, water purification, antimicrobial uses, paints, coatings, food packaging. Impregnating other materials with silver nanoparticles...
Show moreNanomaterials and their increasing use in manufactured products are of great concern to wastewater treatment systems and the environment. Nanosilver has become one of the most popular nanoparticles due to its many applications and relatively low manufacturing costs. It is currently being used for a wide variety of commercial products including medical applications, water purification, antimicrobial uses, paints, coatings, food packaging. Impregnating other materials with silver nanoparticles is a practical way to exploit the germ fighting properties of silver (Nanotechnology 2006). In clothing such as socks, nanosilver may restrict the growth of odor causing bacteria (Benn, Nanoparticle Silver Released into Water from Commercially Available Sock Fabrics 2008). These impregnated socks however have been shown to release large amounts of n-Ag particles when washing. These free nanoparticles easily enter wastewater collection systems. The microbial inhibitory effects of nanosilver were evaluated by studying the effects Escherichia coli (E. coli) growth under nanosilver presence. Results showed that E. coli bacterial growth was inhibited when nanosilver was introduced. This may have detrimental impacts on aerobic wastewater treatment systems which rely on bacteria to break down organic material. Systems may become inefficient and obsolete with an increasing prevalence of nanosilver in sewage.
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Date Issued: 2012
Identifier: FSU_migr_uhm-0068
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: 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: 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: Accident-Based Model for Estimating User Costs on Florida Bridges.
Creator: Wang, Jianying, Sobanjo, John O., Ping, Wei-chou V., Spainhour, Lisa K., Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The Florida Department of Transportation (FDOT) is currently in the process of implementing the AASHTO Ware Pontis Bridge Management System (BMS) for planning and programming maintenance, repairs, rehabilitation, improvements, and replacement for bridges on the state highway network. One important task of BMS is to accurately estimate the user costs to help life-cycle planning of bridge investments and realize an optimal funding and timing that will keep roads and bridges in service at...
Show moreThe Florida Department of Transportation (FDOT) is currently in the process of implementing the AASHTO Ware Pontis Bridge Management System (BMS) for planning and programming maintenance, repairs, rehabilitation, improvements, and replacement for bridges on the state highway network. One important task of BMS is to accurately estimate the user costs to help life-cycle planning of bridge investments and realize an optimal funding and timing that will keep roads and bridges in service at minimum cost. The user costs primarily include travel time costs, vehicle operating costs, and accidents costs. Traditionally, travel time costs and vehicle operating costs are greatly influenced by detour lengths. This thesis examines the bridges features that would increase travel time through bridges without detour, and establishes Microsoft Excel spreadsheet templates for calculating travel time costs and vehicle operating costs for 5,219 Florida highway bridges based on bridge characteristics, pavement conditions, and level of services. These templates are integrated into Florida Pontis system to help better decision-making. At present, the accident cost employed in Pontis BMS is simply projected as a single function of the roadway width. However, this is inadequate in predicting bridge accident rates because it is widely believed that the rate strongly depends on other characteristics of bridges such as bridge length, number of lanes, and roadway conditions (Johnston et al, 1994, and Thompson et al, 1999). This thesis formulated discriminant functions and established regression models based on 2003-2007 Florida crash data at bridge sites in an effort to take the impacts of other bridge characteristics on accident costs into accounts. A discriminant function using logistic regression was established to determine whether a bridge has safety hazards. The results showed that the number of lanes, ADT, bridge length and urban arterials are key features affect the bridge safety. To model the accident rates on bridges, three models were investigated, including linear regression model, Poisson regression model, and negative binomial regression models. Compared to linear regression and Poisson regression, the negative binomial model appears to be better in accuracy, especially for predictions within an error of one count of accident, performing at above 80% accuracy for observed counts three or less.
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Date Issued: 2010
Identifier: FSU_migr_etd-1251
Format: Thesis

Title: Safety Analysis of Transit Bus Operators: Implications of Service Hours and Fatigue.
Creator: Mtoi, Enock T., Moses, Ren, Sobanjo, John, Razig, Yassir Abdel, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: This research study examines the safety impacts of the existing operator hours of duty policies in the state of Florida. Thus, this study uses questionnaire surveys, incident data archived by transit agencies and bus driver schedules to determine the relationship between crash involvement and operator schedules. It is obvious that long driving hours have a potential of causing fatigue, which is known as a contributing factor for collisions. This research examines the influence of bus operator...
Show moreThis research study examines the safety impacts of the existing operator hours of duty policies in the state of Florida. Thus, this study uses questionnaire surveys, incident data archived by transit agencies and bus driver schedules to determine the relationship between crash involvement and operator schedules. It is obvious that long driving hours have a potential of causing fatigue, which is known as a contributing factor for collisions. This research examines the influence of bus operator driving hours on the occurrence of preventable collisions by employing data from incident reports and operator schedules to evaluate the correlation between driving hours and operator involvement in collisions. Several methods of analysis including a statistical t-test, a comparative analysis, an overrepresentation analysis, Chi-square analysis and logistic regression analysis are employed. The results show a discernable pattern of an increased propensity of accident involvement with an increase in driving hours. Based on the analysis, on average, bus drivers who are involved in preventable collisions drive over six hours more than the general bus driver population. According to the findings of this study, it is clear that the present regulation that limits drivers' on-duty time to a maximum of seventy hours per week needs to be revised.
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Date Issued: 2010
Identifier: FSU_migr_etd-2212
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: Verification, Validation and Optimization of Finite Element Model of Bus Structure for Rollover Test.
Creator: Bojanowski, Cezary, Wekezer, Jerry, El-Azab, Anter, Spainhour, Lisa, Mtenga, Primus V., Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Paratransit buses consist of a custom body mounted to a GM/Ford cutaway chassis by a secondary manufacturer called body builder. Paratransit buses form a significant segment of the bus market in the US nowadays. They are used as a complementary service for regularly scheduled routes and usually are prepared to transport disabled passengers in their wheelchairs. Their construction method and the lack of applicable national crashworthiness standards result in a wide variance of passenger...
Show moreParatransit buses consist of a custom body mounted to a GM/Ford cutaway chassis by a secondary manufacturer called body builder. Paratransit buses form a significant segment of the bus market in the US nowadays. They are used as a complementary service for regularly scheduled routes and usually are prepared to transport disabled passengers in their wheelchairs. Their construction method and the lack of applicable national crashworthiness standards result in a wide variance of passenger compartment structural strength amongst manufactures - as reported by the Florida Department of Transportation (FDOT). The primary objective of this dissertation was to develop a testing procedure with the performance rating system for paratransit buses acquired by the state of Florida. Sponsored by FDOT an assessment and improvement methodology was developed using joint computational and empirical approach. It prioritizes the strength of the structure in a rollover type accident utilizing as a basis the European Regulation ECE-R66. New measure of safety margin in rollover tests, a Deformation Index, was proposed. Detailed Finite Element (FE) model of selected paratransit bus was developed and used to perform explicit LS-DYNA simulations of the tilt table rollover test. Experimental tests on the bus subsections were conducted for validation purposes and weak spot identification. Discrete optimization using the Successive Response Surface Methodology in LS-OPT was also utilized to indentify parts of the structure critical to rollover performance. Improvements were suggested that minimize the addition of mass. Early results showed the connections between major structural components (floor/wall/roof) to be particularly weak. Proposed structural modifications increased the remaining safety margin from an initial level of 16% to 29% (In respect to the Deformation Index). The structural modifications resulting from the validation testing were incorporated in the currently produced buses. The proposed testing procedure was accepted by FDOT in August 2007 as the Crash and Safety Assessment Program. It received attention of the state and federal transportation agencies and support from the transit bus industry.
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Date Issued: 2009
Identifier: FSU_migr_etd-3610
Format: Thesis

Title: Optimal Design of Passive Fluid Viscous Dampers for Controlling Vibrations in Seismically-Excited Truss Towers.
Creator: Kalyanam, Sujatha, Rambo-Roddenberry, Michelle, Spainhour, Lisa, Jung, Sungmoon, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Truss towers form a vital part of the communication infrastructure, and the control of responses for such structures during adverse events such as an earthquake is of significant importance. The objective of this research venture is to combine the linear quadratic regulator (LQR) algorithm for optimal design of supplemental dampers of buildings with the bi-model method for a truss tower. Damping coefficients are calculated for the 3D truss model by analyzing the dynamically equivalent 2D...
Show moreTruss towers form a vital part of the communication infrastructure, and the control of responses for such structures during adverse events such as an earthquake is of significant importance. The objective of this research venture is to combine the linear quadratic regulator (LQR) algorithm for optimal design of supplemental dampers of buildings with the bi-model method for a truss tower. Damping coefficients are calculated for the 3D truss model by analyzing the dynamically equivalent 2D lumped mass model which is developed using the bi-model method. The dynamic responses of the structure for given seismic loads are computed for the conditions with and without dampers. The results are then compared to determine the efficiency of the method to design passive fluid viscous dampers (PFVD) to control the excess vibrations due to seismic loads in towers.
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Date Issued: 2009
Identifier: FSU_migr_etd-3359
Format: Thesis

Title: Safety Analysis of Florida Urban Freeways with Special Focus on the Influence of Truck Lane Restriction Policy.
Creator: Kobelo, Doreen, Moses, Ren, Spainhour, Lisa, Sobanjo, John, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Urban freeways and tollways in the United States are characterized by a significant number of truck traffic hauling freight between various origins and destinations. The truck traffic varies in size from single-unit trucks to multi-unit tractor trailers. Trucks also have different operational characteristics dissimilar to those of passenger cars such as low deceleration capabilities resulting in longer stopping distances. Statistics show over 200 percent increase in truck vehicle miles of...
Show moreUrban freeways and tollways in the United States are characterized by a significant number of truck traffic hauling freight between various origins and destinations. The truck traffic varies in size from single-unit trucks to multi-unit tractor trailers. Trucks also have different operational characteristics dissimilar to those of passenger cars such as low deceleration capabilities resulting in longer stopping distances. Statistics show over 200 percent increase in truck vehicle miles of travel in the United States since 1970. The increase in truck vehicle miles of travel on US urban highways has posed significant challenges to policymakers given that truck traffic contributes to the reduction of efficiency and safety of the highway systems especially on limited access roadways. To address challenges and concerns posed by the growth of truck traffic on highways, policymakers have implemented a number of strategies including changing highway design standards to accommodate trucks, introduction of intelligent transportation systems, and the implementation of operational control policies aimed at heavy vehicles. One of the most prevalent operational control policies is the truck lane restriction. The implementation of truck lane restriction is mainly predicted on the principle that the restriction would increase the level of service and operational safety on limited access highways especially those located in urban areas. Like many other states, Florida has implemented truck lane restriction on approximately 430 miles of the state highway system. However, the effectiveness of this strategy in improving safety and efficiency of these highways has not been properly studied or documented. The objective of this study was therefore to analyze the effect of truck lane restriction on safety of the urban limited access highways in Florida. The analysis of safety was achieved through performing a before-after study that compared crash characteristics of highway sections before truck lane restriction was imposed to crash characteristics after the imposition of truck lane restriction. In addition, a negative binomial regression model was used to determine the influence of truck lane restriction as a modeling variable together with other variables derived from geometrics, traffic, and socio-economic characteristics related urban limited access highway sections in different metropolitan areas in the state of Florida. Data on geometric, traffic, and crash attributes were collected from various databases maintained by the Florida Department of Transportation including the Roadway Characteristics Inventory (RCI) database, the Crash Analysis Reprot (CAR) database and various other data provided by FDOT district offices and through field data collection. The before-and-after crash analysis data were from 200x to 200x while the geometric, traffic, and crash data used in the negative binomial regression modeling were from year 2005. All the data were checked for accuracy to eliminate sections that were under construction to avoid skewing the results. The results of the crash prediction model that was based on negative binomial regression model showed that the coefficient of the truck lane restriction variable in the model was negative but insignificant (p ≤ 0.808). The negativity of the variable indicates that highway sections with truck lane restriction had insignificantly less crashes than sections without truck lane restriction. A statistical marginal effect analysis was used to determine the percentage decrease in crashes that can be expected if truck lane restriction was implemented on a highway section. The results showed that in year 2005 there was a 4 percent decrease in crashes on sections with truck lane restriction compared to sections that did not have truck lane restriction. In addition, the results showed that when truck percentage variable was changed from minimum of 2 percent to a maximum of 15 percent in the model, there was a decrease of crashes by 22 percent. These results coupled with the results of the before-and-after analysis suggests that there is no clear cut safety benefits associated with the imposition of truck lane restriction. These results are in line with literature findings which showed mixed results arising from a number of studies conducted on different highways in different states in the United States. However, it should be noted that truck lane restriction has documented operational benefits such as decreasing lane changing by passenger cars and is generally popular with the traveling public.
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Date Issued: 2007
Identifier: FSU_migr_etd-2862
Format: Thesis

Title: Developing Crash Modification Factors for Urban Highway with Substandard Wide Curb Lane.
Creator: Mbatta, Geophrey, Moses, Ren, Niu, Xufeng, Sobanjo, John, AbdelRazig, Yassir, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Across the United States, a great deal of attention is being focused on promoting energy efficient and environmental friendly modes of transportation. Bicycling is an integral part of a sustainable transportation system that is one of the most efficient. The growing use of bicycles for commuting and leisure activities is creating conflicts with motorized traffic mainly due to deficient roadway facilities that were in the past designed to primarily accommodate motorized traffic.In 2008, 716...
Show moreAcross the United States, a great deal of attention is being focused on promoting energy efficient and environmental friendly modes of transportation. Bicycling is an integral part of a sustainable transportation system that is one of the most efficient. The growing use of bicycles for commuting and leisure activities is creating conflicts with motorized traffic mainly due to deficient roadway facilities that were in the past designed to primarily accommodate motorized traffic.In 2008, 716 bicyclists were killed in the USA which corresponds to 2 percent of total traffic fatalities reported. In the same year, over 52,000 bicyclists were also reported to have been injured in traffic crashes. When the data is broken down state by state, Florida ranked second with 6.82 bicyclist fatalities per million population. These statistics provide a grim reminder of the dangers faced by bicyclist riding on urban and rural highways.This study developed lane width crash modification factors (CMFs) for roads with wider outside lane narrower or equal to 14 ft, and inside lanes narrower or equal to 11 ft that were minimum recommended by the Florida Department of Transportation (FDOT) for arterial roadways in the state of Florida. The road segments used were urban four-lane with a divided median and four-lane two-way left turn lane (TWLT). Data used in the evaluation included 25 centerline miles of urban four-lane (TWLT) roads and 75 centerline miles of four-lane with a divided median roads. Two main types of crash modification factors and safety performance functions were developed in this study. The first type is crash modification factors and safety performance functions for all types of crashes, and the second is crash modification factors and safety performance functions for motor vehicle-bicyclist crashes only.In sum the results obtained from this study suggest that, maintaining of inside lane width to 11.5ft and outside lane width to 13 ft for 4D and 5T could results in less number of all types of crashes. Additionally, the decreases in motor vehicle-bicyclist crashes will also be achieved by outside lane width of 13 ft as the inside lane width was not found to contribute to the increase or decrease in motor vehicle-bicyclist crashes.
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Date Issued: 2011
Identifier: FSU_migr_etd-2627
Format: Thesis

Title: Developing Design and Evaluation Criteria for Transit Station with the Focus on Intermodal Connectivity Developing Design and Evaluation Criteriafor Transit Station .
Creator: Mbatta, Geophrey, Moses, Ren, Sobanjo , John, Ping , Wei Chou V., Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The continued population growth is continually challenging transportation officials to institute measures to meet travel needs at a desirable level of service. A customer-oriented transit service which provides intermodal travel would provide an alternative to the personal automobile mode of transportation hence reducing traffic congestion caused by high dependency on single occupancy vehicles. To ensure higher rates of ridership, station areas need to be designed with features known to...
Show moreThe continued population growth is continually challenging transportation officials to institute measures to meet travel needs at a desirable level of service. A customer-oriented transit service which provides intermodal travel would provide an alternative to the personal automobile mode of transportation hence reducing traffic congestion caused by high dependency on single occupancy vehicles. To ensure higher rates of ridership, station areas need to be designed with features known to enhance transit patronage. The long-term success of transit projects is closely linked to creating connectivity to all modes in the station areas. Of high importance is the station area design which encourages the use of all modes of transportation including pedestrian and bicycle connectivity. This can be accomplished by adopting a station area facility design which focuses on seamless movement of passengers as they change their modes of transportation at the stations. This study establishes minimum design and evaluation criteria for public transit stations which have been designed with special focus on intermodal connectivity. The proposed criteria will be used by designers and planners when evaluating station area plans for transit project such as bus rapid transit and rail projects in Florida
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Date Issued: 2008
Identifier: FSU_migr_etd-2629
Format: Thesis

Title: Mitigation of Vortex Induced Response in Long Span Bridges.
Creator: Patil, Atul Sudhakar, Jung, Sungmoon, Spainhour, Lisa, Rambo-Roddenberry, Michelle, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Span length of bridges is ever increasing. With the increase in span, bridges are becoming more slender, making them more prone to wind-induced forces and vibrations. Some bridges show significant wind-induced vibrations after the construction, which were not anticipated during the design. In order to improve the performance of these bridges, two strategies of retrofit are commonly used. First, tuned mass dampers (TMDs) may be added to dissipate the energy. Second, cross-section of the bridge...
Show moreSpan length of bridges is ever increasing. With the increase in span, bridges are becoming more slender, making them more prone to wind-induced forces and vibrations. Some bridges show significant wind-induced vibrations after the construction, which were not anticipated during the design. In order to improve the performance of these bridges, two strategies of retrofit are commonly used. First, tuned mass dampers (TMDs) may be added to dissipate the energy. Second, cross-section of the bridge may be retrofitted so that it is aerodynamically more favorable. Both methods are effective in reducing the magnitude of the wind-induced vibration. Among many types of wind-induced vibrations, this thesis deals with vortex-induced vibrations. The various parameters involved in retrofit have conflicting objective. For example if the maximum displacement is required to be reduced the cost involved is more. In such a case of conflicting objectives, multi-objective optimization can be used to find various solutions from the solution space. These solutions are termed as Pareto-optimal solutions. There is no specific solution which can be called as the best solution due to conflicting objectives. Multi-objective optimization gives the various options to choose from, to arrive at a decision for a particular real world problem. In our case, the problem is to decrease the magnitude of vortex-induced vibrations. The conflicting objectives are the cost of the retrofit and the displacement in terms of the performance. In thesis, the multi-objective optimization will be used to obtain various strategies of retrofit under conflicting objectives. The approach is illustrated with an example bridge modeled after Rio-Niterói Bridge.
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Date Issued: 2010
Identifier: FSU_migr_etd-2132
Format: Thesis

Title: Influence of Anomalies on Bond Layer to the Perfomance of Fiber Reinforced Polymer (FRP) Retrofit.
Creator: Shiyo, Wolta, Mtenga, Primus, Rambo-Roddenberry, Michelle, Tawfiq, Kamal, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: In recent decades, Fiber Reinforced Polymer (FRP) material has increased its importance in the construction industry. FRP is a non-metallic reinforcement material which has been used in the strengthening structures especially concrete structures. The applications of the FRP material in the construction industry brought about an interesting alternative for structural retrofitting. FRP materials are lightweight, high strength-to-weight ratio, stiffness-to-weight ratio has high chemical...
Show moreIn recent decades, Fiber Reinforced Polymer (FRP) material has increased its importance in the construction industry. FRP is a non-metallic reinforcement material which has been used in the strengthening structures especially concrete structures. The applications of the FRP material in the construction industry brought about an interesting alternative for structural retrofitting. FRP materials are lightweight, high strength-to-weight ratio, stiffness-to-weight ratio has high chemical resistance, ease to install, minimal labor cost and non-corrosive. These characteristics make FRP superior to traditional structural retrofit materials such as steel plates. Structural retrofit is a common phenomenon in the construction industry. Retrofitting is needed when one or a combination of the following situations are encountered: a) structural deterioration caused by the environmental changes, b) additional load carrying capacity needed due to occupancy change and c) when construction or design mistakes are made which result to inadequate reinforcement for a structure. FRP retrofit is done by mounting FRP to the tension side of a member to be retrofitted using epoxy which is used as the bonding agent. The nature and characteristics of the bond layer have some influence on the performance of a structure with anomalies in the bond layer, such as uneven thickness of epoxy or voids in structure itself which lead to debonding. Debonding is caused by high stress distribution on uneven location. These anomalies are usually a result of poor workmanship during the process of grinding the surface before the installation of FRP material. The objectives of this study were to assess the effects of anomalies on a structure that was retrofitted by FRP material and produce a remedy to the structure affected by these anomalies. The experiment conducted showed that anomalies affect structures that are retrofitted by FRP. One way of resolve this problem is by impregnating FRP material to a structure which is good in tension to avoid debonding. This method was found to be useful since it increases the load capacity for about 20%.
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Date Issued: 2008
Identifier: FSU_migr_etd-1745
Format: Thesis

Title: Application of SCS CN Method in HEC-HMS in Shihmen Watershed Simulation of Rainfall-Runoff Hydrologic Model.
Creator: Chang, Chi-Wen, Huang, Wenrui, Hu, Bill X., Hilton, Amy Chan, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: A catchment is usually delineated as many sub-basins by using Geographical Information System (GIS) before HEC-HMS is applied. How many sub-basins should be delineated by the users is always a problem. If the range of sub-basins is too large, the spatial heterogeneity will be too difficult to recognize. On the other hand, it will be too complicated to process the spatial data for too many sub-basins. The purpose of this study is to apply cluster analysis for catchment delineation and to study...
Show moreA catchment is usually delineated as many sub-basins by using Geographical Information System (GIS) before HEC-HMS is applied. How many sub-basins should be delineated by the users is always a problem. If the range of sub-basins is too large, the spatial heterogeneity will be too difficult to recognize. On the other hand, it will be too complicated to process the spatial data for too many sub-basins. The purpose of this study is to apply cluster analysis for catchment delineation and to study whether the SCS curve number (SCS CN) method is appropriate for estimation of direct runoff in Taiwan. The DaHan Creek, a tributary of the DanShui River, is chosen for case study. In the cluster analysis, the values of curve number, surface slop, and the specified rain gages weighting for each sub-basin are used as variables. According to the discharge hydrograph of 3 selected rainfall events, the hydrologic parameter characteristics of the basin can be chosen by the trial and error process. The results show that CN value has correlated to hydro-geo factors and has positive correlation with peak flow.
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Date Issued: 2009
Identifier: FSU_migr_etd-3900
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: Unconventional Intersection Designs for Improving Through Traffic along the Arterial Road.
Creator: Hildebrand, Thomas E., Moses, Ren, Sobanjo, John, Ping, W. Virgil, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: With an increase in demand on the current roadway system, intersections are beginning to fail before the end of the design period. Generally, an intersection is formed when two roadways cross. One of the roads usually services higher traffic volume than the other. This roadway is designated as the major or arterial road. The second road, which services a lower traffic volume, is called the minor or collector road. The purpose of the major road at the intersection is to provide a high level of...
Show moreWith an increase in demand on the current roadway system, intersections are beginning to fail before the end of the design period. Generally, an intersection is formed when two roadways cross. One of the roads usually services higher traffic volume than the other. This roadway is designated as the major or arterial road. The second road, which services a lower traffic volume, is called the minor or collector road. The purpose of the major road at the intersection is to provide a high level of service for the through traffic. When the level of service of an intersection has reached an unacceptable level, the typical treatment to increase both the capacity and level of service is to add another through lane. Unfortunately, this treatment does not add as much time to the life cycle of the intersection as it did in the past. In an attempt to improve the performance of an intersection and to increase the life cycle, several unconventional intersections have been designed. The unconventional designs examined during this study include the bowtie, continuous flow intersection, jughandle, median U-turn, and superstreet. These designs remove exclusive left turn lanes from the major road at the intersection in order to provide a longer green phase for the through traffic. The unconventional designs as well as the conventional designs were examined based on area required, traffic simulation, and estimated cost of construction. After reviewing and analyzing the data obtained during this study, it can be concluded that the continuous flow intersection and median U-turn designs provide the highest level of service. However, the estimated construction cost of the continuous flow intersection is approximately 50% more than the conventional solution and the construction cost of the median U-turn is approximately 35% more than the conventional solution.
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Date Issued: 2007
Identifier: FSU_migr_etd-4052
Format: Thesis

Title: Comparison of Fatal Traffic Crashes in Southern and Northern Regions of the State of Florida a Study of Fatal Traffic Crashes in Florida from 1998-2000.
Creator: Kadabagere, Nirup H., Spainhour, Lisa K., Mtenga, Primus V., Sobanjo, John O., Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The highway fatality rate in the state of Florida is very high, with 40 percent more facilities per vehicle mile than the national average in 1999. Crashes involving trucks are fatal more than crashes involving passenger cars. The State Safety Office of the Florida Department of Transportation proposed conducting a review and analysis of traffic fatalities and truck crashes on the state roads of Florida to tackle these problems. The goal of this project was to go beyond the data currently...
Show moreThe highway fatality rate in the state of Florida is very high, with 40 percent more facilities per vehicle mile than the national average in 1999. Crashes involving trucks are fatal more than crashes involving passenger cars. The State Safety Office of the Florida Department of Transportation proposed conducting a review and analysis of traffic fatalities and truck crashes on the state roads of Florida to tackle these problems. The goal of this project was to go beyond the data currently available from the Florida traffic crash report (FTCR) and homicide reports to create a comprehensive database of contributing causes of fatal crashes. The outcome of the study identified engineering and behavioral issues. The results will be used to guide future design standards as well as to develop education and enforcement programs. The objective of the research was to provide the analysis of the causes of fatal traffic crashes and traffic fatalities. The major tasks were: 1. Identifying data elements deemed to be potential contributors for fatal crashes. 2. Investigating all fatal crashes in the year 2000 for the study regions and fatal crashes involving trucks for the year 1998 and 1999 in the study regions. 3. For each crash, identifying factors contributing to both the crash and the fatalities. 4. Developing a computerized database and querying tool. This report contains the results of a component of the statewide study. The primary purpose of the study was to compare the nature of crashes in two different regions. One region in northern Florida consisted of six counties; Suwannee, Madison, Gilchrist, Hamilton, Lafayette and Alachua counties in FDOT District 2; the second region was southern, consisting of Miami-Dade County in FDOT District 6. The southern region is primarily urban, with over 26 million daily vehicle miles traveled, while the northern region is primarily rural, with fewer than 8 million daily vehicle miles travelled. Both regions have approximately 2500 lane miles. Parameters considered included driver behavior, roadway characteristics and other factors, contributing to both crashes and fatalities. It was concluded that the primary contributing factor in the majority of the fatal crashes was human error, including driver errors in negotiating intersections and pedestrians violating the right of way of the vehicle. Driver defects, vehicle defects, and weather were not found to be common in the crashes in both the regions. Crashes occurred most frequently at intersections in both the regions. There was also significant number of run-off the road crashes in both the regions. Male drivers and young drivers were involved in fatal crashes most frequently. Most of the pedestrian crashes in the study occurred in the southern region. Intersection crashes in the southern region frequently involved left turn crashes, often where the driver misjudged the gap in the oncoming traffic. Rear-end crashes were found to be more common in the northern region. Overall, forty-four percent of pedestrians in the fatal were found to be under the influence of alcohol and drugs. In the southern region, approximately one in every four at-fault drivers were under the influence of alcohol and drugs. Influence of alcohol and drugs was less common in the northern region found to be common. Twenty-six percent of at-fault drivers in the northern region were below age 21, compared with less than 8 percent in the southern region. On the other hand, 58 percent of the 51-60 year old drivers in the southern region were found at-fault, compared with only 24 percent in the northern region. Eighty-six percent of the at-fault drivers were from the county of the crash in the southern region whereas only 34 percent of at-fault drivers in northern region were from the county of the crash. Heavy truck crashes are overrepresented in northern region: the most common type of crashes involving trucks were rear-end crashes. A total of sixty percent and forty-seven percent of occupants in the fatal crashes were using seat belts or child restraints in the southern and northern regions respectively. Wearing seat belts reduced the likelihood of dying in the crash from 73 percent to 45 percent
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Date Issued: 2003
Identifier: FSU_migr_etd-3394
Format: Thesis

Title: Quantification of Methane Emissions via the Use of an Optical Remote Sensing Technique in a Landfill Setting.
Creator: Clark, Jeremy Matthew, Abichou, Tarek, Chanton, Jeff, Watts, Michael, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The United States Environmental Protection Agency (USEPA) has proposed a method that will be used to quantify fugitive emissions from large area sources such as landfills. The method is presented in the USEPA's Other Test Method-10 (OTM-10) manual. The method utilizes non-intersecting multiple-beam paths, scanning equipment, and Optical Remote Sensing (ORS) instruments in a variety of radial configurations. The use of an ORS instrument to scan in a radial configuration introduces radial plume...
Show moreThe United States Environmental Protection Agency (USEPA) has proposed a method that will be used to quantify fugitive emissions from large area sources such as landfills. The method is presented in the USEPA's Other Test Method-10 (OTM-10) manual. The method utilizes non-intersecting multiple-beam paths, scanning equipment, and Optical Remote Sensing (ORS) instruments in a variety of radial configurations. The use of an ORS instrument to scan in a radial configuration introduces radial plume mapping (RPM) to the OTM-10. There are several RPM methods discussed in the OTM-10, such as horizontal radial plume mapping (HRPM), vertical radial plume mapping (VRPM), and 1-D radial plume mapping (1D-RPM). The VRPM is the only method discussed in the OTM-10 that is capable computing pollutant flow rates for a large area source such as a landfill, so this study looks into the reliability of the VRPM's ability to quantify methane emissions from a landfill setting. The VRPM is used as a tool to quantify pollutant concentrations measured in the vertical plane downwind from the emissions source. In conjunction with the concentration data, which is computed by the vertical plane, wind speed and direction data is monitored to convert pollutant concentration values to pollutant flow rates by multiplying the concentration data to a trigonometric function of the wind speed. The objective of this study was to investigate uncertainties associated with the use of the VRPM method in a landfill setting. Once deficiencies in the method are found, users of the VRPM in a landfill setting will be provided with accurate guidelines on the reliability of the method under a variety of conditions. Several uncertainties associated with the VRPM method in a landfill setting include; the location of hot spots in comparison to vertical plane location, the reliability of the of the optimization algorithm used in quantification to correctly compute emission concentration when multiple hot spots are present, and the area contributing to flux (ACF). Through this study it was found that the spatial variability of emissions in the emitting domain can lead to uncertainties of -34 to 190% in the measured flux value when idealistic scenarios were simulated. The level of uncertainty can be reduced by improving the vertical planes location in comparison to the hot spots. The variability in wind direction during VRPM testing can introduce an uncertainty of 20% of the measured flux value. This study also provides an estimate to the ACF for each meteorological stability class defined in the field and has an uncertainty of 10 to 30% associated with it.
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Date Issued: 2010
Identifier: FSU_migr_etd-3592
Format: Thesis

Title: Finite Element Analysis on the Effect of Fire for Specified Duration, on a Reinforced Concrete Beam with Varied Boundary Conditions.
Creator: Chythanya, Meghana, Spainhour, Lisa K., Rambo-Roddenberry, Michelle, Jung, Sungmoon, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Concrete is a poor conductor of heat due to its incombustible nature and low thermal diffusivity, which guarantee a slow propagation of thermal transients within the structural members. Despite exhibiting a good behavior at high temperatures, it can suffer considerable damage when exposed to fire. The knowledge of high-temperature properties of concrete is critical for fire resistance assessment because the fire performance of structural members like beams depends on the properties of the...
Show moreConcrete is a poor conductor of heat due to its incombustible nature and low thermal diffusivity, which guarantee a slow propagation of thermal transients within the structural members. Despite exhibiting a good behavior at high temperatures, it can suffer considerable damage when exposed to fire. The knowledge of high-temperature properties of concrete is critical for fire resistance assessment because the fire performance of structural members like beams depends on the properties of the constituent materials. To predict the conditions within the RC beams subjected to fire, knowledge is required of the behavior of concrete subjected to high temperatures. To ensure the safety of RC structural systems in the event of fire, concrete members should be designed against fire. The temperature dependent properties that are important for establishing an understanding of the fire-response of RC structures include thermal and material properties at elevated temperatures. In this research, a finite element model was developed using ALGOR® to study the impact of fire on an RC beams. This model provides information about temperature distributions in the beam for given initial and boundary conditions. Using finite element analysis, the entire beam was meshed into small segments called elements. The elements hold information about the physical properties of their corresponding materials. Each element was bounded by nodal points. Boundary conditions were included on the appropriate nodes in the model. The different boundary conditions on which the analysis was conducted are pin-roller, pin-pin, fixed on both ends and cantilever. All the results obtained from the analyses are time dependent, including displacement, stresses and strains. The location and magnitude of maximum stress, strain and displacement for each boundary condition were determined with the analysis. The maximum principal stress in each case when compared to the compressive strength of normal strength concrete, implied that failure has occurred in all the four cases i.e. pin-roller, pin-pin, fixed on both ends and cantilever. The results obtained from the Transient Heat Analysis were compared with the temperature distribution from other studies. It was found that the temperature distribution determined in Kodur et al is very similar to the temperature distribution which results from the transient heat transfer analysis.
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Date Issued: 2009
Identifier: FSU_migr_etd-3609
Format: Thesis

Title: Risk and Liability Analysis Modeling for Hurricane Damage on Florida Bridges: A Geographical Information System Application.
Creator: Lachance, Michelle M., AbdelRazig, Yassir, Sobanjo, John, Mussa, Renatus, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The 2004 and 2005 hurricane seasons have proved to be critical turning points in society's view of such destructive storms. Bridges are not exempt from such destruction. The economic impacts of damage to bridges can be dramatic since bridges are the keystone of mobility and accessibility. Looking at the events of past years provides a great deal of information to help plan for future events. This model is based on the most widely and easily available information, the National Bridge Inventory...
Show moreThe 2004 and 2005 hurricane seasons have proved to be critical turning points in society's view of such destructive storms. Bridges are not exempt from such destruction. The economic impacts of damage to bridges can be dramatic since bridges are the keystone of mobility and accessibility. Looking at the events of past years provides a great deal of information to help plan for future events. This model is based on the most widely and easily available information, the National Bridge Inventory. With the use of Geographic Information Systems, it has been developed in hopes of helping prioritize funding for repair and replacement of bridges that are structurally unprepared for such events as well as improving emergency response after an event. This model and the analysis that follows also provides considerable insights on economic impacts which are based on both total risk due to scour and wind (two common elements of storm damage) as well as total economic costs of rebuilding and traffic detouring. The analysis of the output of the model illustrates the important role average daily traffic and detour length play in economic impacts. The analysis also demonstrates that these impacts, or liabilities, closely follow a lognormal distribution.
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Date Issued: 2005
Identifier: FSU_migr_etd-3328
Format: Thesis

Title: Analytical Modeling of Fiber Reinforced Post-Tensioned Concrete Anchorage Zones.
Creator: Johnson, Stacy, Tawfiq, Kamal, Mtenga, Primus, Wekezer, Jerry, Spainhour, Lisa, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The use of post-tensioning in bridge girders causes tensile bursting stresses to occur some distance ahead of the anchorage device in a region known as the general zone. Large amounts of mild steel reinforcement are placed in this area of the bridge girder in order to resist these highly tensile stresses. This causes congestion in the area of the steel and poses difficulty during concrete placement. The objectives of this study were to determine the feasibility of reducing the mild steel...
Show moreThe use of post-tensioning in bridge girders causes tensile bursting stresses to occur some distance ahead of the anchorage device in a region known as the general zone. Large amounts of mild steel reinforcement are placed in this area of the bridge girder in order to resist these highly tensile stresses. This causes congestion in the area of the steel and poses difficulty during concrete placement. The objectives of this study were to determine the feasibility of reducing the mild steel reinforcement by adding fibers to the general zone and to determine the impacts of doing so. Fiber reinforced concrete (FRC) improves the mechanical properties of non-fibrous concrete. So it is expected to support the proposed reduction of mild steel reinforcement in the post-tensioned anchorage zone. The first phase of the study involved researching past studies on the use of FRC in order to determine the material and mechanical properties pertaining to the fibers. Steel fiber was deemed to be the most useful for enhancement of non-fibrous concrete properties. The second phase of the study was to determine a realistic and reasonable specimen for FRC application. The pier segment of a currently used bridge in Florida was chosen. This selection was based on having common and less complex geometry. After selection, information was gathered about the segment such as the volume of concrete, mild steel reinforcement details, and post-tensioning system details. In the final phase of this study, a finite element model was developed for the segment using design required mild steel reinforcement. Using the initial model, duplicate models were analyzed with varying steel fiber volumes. The theoretical results indicate that a maximum reduction of 65% of the design mild steel reinforcement can occur when replaced by 0.50% steel fiber to the concrete volume of the general zone. However, it is recommended that a mild steel reinforcement reduction of 50% be replaced by 0.50% steel fiber in order to stay conservative and safe. It was also observed that higher volumes of steel fiber could increase stresses in the general zone. Therefore, it is recommended that experimental testing of these procedures be done for complete verification.
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Date Issued: 2006
Identifier: FSU_migr_etd-3651
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: Engineering Properties of Florida Concrete Mixes for Implementing the Aashto Recommended Mechanistic Empirical Rigid Pavement Design Guide.
Creator: Kampmann, Raphael, Ping, Wei-Chou V., Rambo-Roddenberry, Michelle, Abichou, Tarek, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The coefficient of thermal expansion (CTE) is a fundamental property of Portland cement concrete (PCC). The magnitude of temperature-related pavement deformations is directly proportional to the CTE during the pavement design life. Because of its critical effect on PCC performance, it is proposed to be considered for distress and smoothness prediction by the newly developed Mechanistic-Empirical Pavement Design Guide (M-E PDG). To account for M-E PDG implementation in Florida, three typical...
Show moreThe coefficient of thermal expansion (CTE) is a fundamental property of Portland cement concrete (PCC). The magnitude of temperature-related pavement deformations is directly proportional to the CTE during the pavement design life. Because of its critical effect on PCC performance, it is proposed to be considered for distress and smoothness prediction by the newly developed Mechanistic-Empirical Pavement Design Guide (M-E PDG). To account for M-E PDG implementation in Florida, three typical Florida concrete mixtures were experimentally measured for compressive strength, flexural strength, splitting tensile strength, Young's modulus, Poisson's ratio, and CTE according to AASHTO TP-60. The test results revealed that PCC's CTE rapidly increases within the first week but stabilizes after 28 days. However, to accurately analyze the mix designs using the new mechanistic-empirical concept considering all three hierarchy levels, nine different JPCP models were generated. Their PCC layer thicknesses were iteratively determined before the resultant pavement structures were evaluated based on the predicted distresses (faulting and cracking) and smoothness (IRI). It was found, that cracking is the most critical pavement performance criterion for Florida JPCP. Moreover, top-down fatigue damage was isolated to be the controlling failure mechanism because of insignificant faulting and minor smoothness reduction. Based on the thickness idealized JPCP models, a CTE sensitivity matrix was developed for adequate comparison of predicted pavement performance under interchanging CTE values. Despite wide ranging properties, clear patterns were exposed and distinctive performance envelopes arose for certain criteria. It was established that the new M-E PDG, is minimally CTE sensitive to faulting, CTE sensitive to bottom-up damage (for thin PCC layers), and extremely CTE sensitive to top-down damage, cracking, and smoothness.
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Date Issued: 2008
Identifier: FSU_migr_etd-3358
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: 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: Risk and Vulnerability Analysis of Civil Infrastructure: Florida Highway Bridges Case Study.
Creator: Lazo, Eric, AbdelRazig, Yassir, Moses, Ren, Sobanjo, John, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The last few years have had very active storm seasons and have had much damage on the nation's infrastructure. Along with destructive storms are the chances of a terrorist attack. Since the attacks of September 11, 2001 the nation's infrastructure has been under large scrutiny to make sure it as safe as it can be. Included in the nation's infrastructure are bridges in a roadway network. Bridges are key parts to roadway networks, being connecting features to either over other roadways or over...
Show moreThe last few years have had very active storm seasons and have had much damage on the nation's infrastructure. Along with destructive storms are the chances of a terrorist attack. Since the attacks of September 11, 2001 the nation's infrastructure has been under large scrutiny to make sure it as safe as it can be. Included in the nation's infrastructure are bridges in a roadway network. Bridges are key parts to roadway networks, being connecting features to either over other roadways or over water to islands. Examining events that have occurred in the prior years can give great feedback to help plan for issues that might arise in the future. This research will discuss the ideas and calculations in order to find the risk and vulnerabilities of bridges in Florida. This model is based on data gathered from many different sources. The statistical bridge data was collected through the Florida Department of Transportation. Weather data such as hurricane and tornado history was collected through the National Oceanic and Atmospheric Administration. The fire data being used was received from the Florida Department of Agriculture and Consumer Services, Division of Forestry. The flood data and state population data was received through the United States Census Bureau. With the use of Geographical Information Systems, showing which bridges in the state of Florida relative to their locations, have the greatest risk to a natural or man-made disaster. The model and analysis that is to follow provides insight to how vulnerable Florida Bridges are to natural and man-made disasters. The same concepts and analysis can be applied throughout the country in order to help government officials realize where the problem areas are in order to be better prepared before an incident occurs. The analysis and the outputs of the model illustrates the important role of average daily traffic along with geographical location of these bridges and how they play a role in both natural disasters and man-made disasters.
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Date Issued: 2008
Identifier: FSU_migr_etd-3216
Format: Thesis

Title: Sequential O3 Anaerobic Activated Sludge Treatment of Municipal Landfill Leachate.
Creator: Mumm, Andrés A. Lastra, Watts, Michael, Chen, Gang, Hilton, Amy Chan, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: In this study, laboratory experiments were conducted to compare the efficiency of using O3 and O3+H2O2 as precursor to anaerobic biological treatment of the treatment of landfill leachate. Both oxidation systems were proven efficient in increasing the overall biodegradability of the leachate. At an ozone dose of 7.5ppm biodegradability of the leachate was increased by 25%, while a combination of 7.5ppm of ozone with 5ppm of hydrogen peroxide resulted in a 35% increase in biodegradability of...
Show moreIn this study, laboratory experiments were conducted to compare the efficiency of using O3 and O3+H2O2 as precursor to anaerobic biological treatment of the treatment of landfill leachate. Both oxidation systems were proven efficient in increasing the overall biodegradability of the leachate. At an ozone dose of 7.5ppm biodegradability of the leachate was increased by 25%, while a combination of 7.5ppm of ozone with 5ppm of hydrogen peroxide resulted in a 35% increase in biodegradability of the treated leacahte. Furthermore, this study investigated the efficiency of using the mentioned oxidation processes for overall enhancement of landfill leachate water quality and the degradation of endocrine disrupting compounds (EDCs) present in the leachate. The research proved the studied oxidants were able to decrease overall total organic carbon (TOC) concentrations and were responsible for the removal of a fraction of the total ammonia concentration from the studied landfill leachate. Furthermore, the research showed that ozone and the peroxone process had the ability to degrade EDCs that were present in leachate. Second order rate constants for the degradation of EDCs both in water and in leachate were also calculated in this study. The leachate treated in the experiments was categorized as having high ammonia, high TOC concentration, low biodegradability and low UV transmittance. The impact of ammonia, carbonates and other oxidant scavengers on the overall efficiency of the oxidants was also investigated in this study.
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Date Issued: 2011
Identifier: FSU_migr_etd-3265
Format: Thesis

Title: Dynamic Response of Highway Bridges Subjected to Heavy Vehicles.
Creator: Li, Hongyi, Wekezer, Jerry, Chandra, Namas, Abdullah, Makola, Spainhour, Lisa, Tawfiq, Kamal, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Evaluation of existing structures is critical for an efficient management of transportation facilities, especially bridges. Knowledge of actual load effects and structure resistance can be very helpful for the determination of the load carrying capacity and condition of structures. It can help to make management decisions, such as establishing permissible weight limits, and can have important economical and safety implications. In particular, the dynamic nature of live loads and bridge...
Show moreEvaluation of existing structures is critical for an efficient management of transportation facilities, especially bridges. Knowledge of actual load effects and structure resistance can be very helpful for the determination of the load carrying capacity and condition of structures. It can help to make management decisions, such as establishing permissible weight limits, and can have important economical and safety implications. In particular, the dynamic nature of live loads and bridge-vehicle interaction is not sufficiently considered in current bridge codes. Impact factors suggested by the codes usually lead to inappropriate solutions for overweight vehicles which are the major concern of the Florida department of transportation which is involved every day in processing overload permit applications from trucking companies. This research consisted of analytical work validated by field tests. Static and dynamic field tests were performed on a selected two-lane highway bridge on US 90 over Mosquito Creek in northern Florida. The three-span bridge was a concrete structure with simply supported, precast girders and continuous, cast-in-place deck. One or two fully loaded truck(s) crossed over the bridge, which was instrumented with strain gauges, accelerometers and displacement transducers. Data collected from the tests were used for comprehensive assessment of the bridge under dynamic loading and validation of analytical procedures. The vehicle-bridge interaction was investigated using finite element models with different levels of representation. In the simple analytical model, the vehicle was modeled as a 3D mass-spring-damper system with eleven degrees of freedom. The bridge was discretized to a combination of plate and beam elements which represented slab and girders, respectively. The equations of motion for the vehicle were formulated with physical components while with modal components for the bridge. The coupled system was solved step by step using central difference method. More sophisticated bridge models with consistent stiffness and mass distribution and truck models with detailed representation of suspension systems and wheels were developed using LS-DYNA, a commercial explicit FE code. The advanced features of multi point constraint (MPC) and contact algorithm made it suitable in analysis of vehicle – bridge interaction. The advanced features of the truck model included the suspension system allowing wheel rotation, as well as application of internal pressure in tires. Good agreement was found between the field measurement and FE simulations in both frequency domain and time domain. Impact factors were calculated for some overweight vehicles using the validated finite element procedures. The effect of some parameters to bridge response was also investigated, including road roughness, bridge length, vehicle weight, vehicle speed and vehicle/bridge frequency ratio.
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Date Issued: 2005
Identifier: FSU_migr_etd-3067
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: Numerical Simulation of Dynamic Wave Force on Coastal Structures under Extrem Storm Surge Conditions.
Creator: Xiao, Hong, Huang, Wenrui, Hu, Bill, Hilton, Amy Chan, Abichou, Tarek, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Sea waves associated with storm surge is a key factor in the safety of coastal structures. Most of the damages on coastal structures during a storm event are caused by waves. Forces created by waves breaking against a vertical surface are often 10 or more times higher than the force created by high speed winds during a storm event. In hurricane season, a combination of storm surge and waves may cause overtopping of coastal protection structures such as breakwaters, dikes, seawalls, resulting...
Show moreSea waves associated with storm surge is a key factor in the safety of coastal structures. Most of the damages on coastal structures during a storm event are caused by waves. Forces created by waves breaking against a vertical surface are often 10 or more times higher than the force created by high speed winds during a storm event. In hurricane season, a combination of storm surge and waves may cause overtopping of coastal protection structures such as breakwaters, dikes, seawalls, resulting in flooding and damaging of the areas behind these structures. When a wave crest is overtopping a coastal structure, complex vortices patterns are generated behind the structure. The vortices induced by wave result in the swash of the seabed, the stagnation of contamination, the settlement of mud and sand around the coastal structures, and the resonance of the structures. As matter of fact, wave force on structures is a very important issue in design, construction and management of offshore and coastal structures. In this dissertation, a wave model based on Reynolds-Averaged-Navier-Stokes (RANS) equations is developed for estimating dynamic wave forces on coastal structures. Turbulent models are used for the closure of RANS equations. A generating-absorbing numerical wave paddle is used to generate waves, and an absorbing sponge layer for absorbing wave is adopted in front of the open boundary to absorb wave energy. In order to track the movement of the free surface, the Youngs' version of Volume of Fluid (VOF) method is used to reconstruct the profile of the free surface at every time step. The wave force model is validated against available experimental data and analytical results of wave force on coast structures. After validation, the model is applied to address several engineering problems in coastal engineering field: 1) Numerical modeling of wave run-up and forces on an idealized beachfront house The wave model is applied to estimate the impact of a solitary wave on an idealized beachfront house located at different elevations on a plane beach. The model is satisfactorily tested against the experimental data of wave run-up, and the analytical solution of wave forces on vertical walls. The time histories of wave profiles, forces, and overturning moments on the idealized house are demonstrated and analyzed. The variations of wave forces and overturning moments with the elevation of the idealized beachfront house are also investigated. 2) Numerical modeling of dynamic wave force acting on Escambia bay bridge deck during Hurricane Ivan Bridge decks in Escambia Bay were damaged during the storm surge of Hurricane Ivan in 2004. The wave model is used to investigate dynamic wave forces exerted on the bridge deck. The model was satisfactorily tested against experimental data of uplift wave forces on horizontal plates. The validated model was applied to investigate wave forces acting on the bridge deck in Escambia Bay in the case of Hurricane Ivan. The time history of wave profiles, turbulent velocity fields, and dynamic uplift and horizontal forces acting on the full-scale bridge deck were simulated and analyzed. Results indicate that, during the storm surge event of Hurricane Ivan, the maximum uplifting wave forces were larger than the weight of the simply supported bridge deck, causing direct damage to the bridge deck. Wave forces on three different deck elevations are discussed. 3) Effects of submersion depth on wave uplift force acting on bridge decks during Hurricane Katrina A large portion of the Biloxi Bay Bridge was submerged and destroyed by surface waves and storm surge associated with Hurricane Katrina in 2005. The time history of wave forces exerted on the Biloxi Bay Bridge during Hurricane Katrina was investigated by the wave model. In order to evaluate the maximum uplift wave force, five different bridge deck elevations submerged at different water depths were investigated. The wave profiles, velocity field in the vicinity of the bridge, and dynamic wave forces on the decks were analyzed. Results indicate that the uplift force on the submerged bridge deck span exceeded its own weight under the extreme wave and storm surge conditions during Hurricane Katrina. Moreover, the numerical simulations suggest that the maximum uplift wave force occurred when the storm surge water level reached the top of the bridge deck. 4) Numerical modeling of levee overtopping during Hurricane Katrina The wave model applied to estimate the impact of overtopping on levee during storm surge. The model was satisfactorily tested against empirical equation of overflow discharge at a vertical seawall, and experimental data of overtopping discharge at a sloping seawall. The validated model was used to simulate wave overtopping of the levee system during storm surge of Hurricane Katrina. The time history of wave profiles and velocity magnitude field in the vicinity of the levee are demonstrated and analyzed. It is concluded that the failure of parts of the levee system was caused by erosion during wave overtopping. 5) Numerical modeling of interactions of solitary wave and current in the vicinity of a horizontal cylinder The numerical model is applied to study the interaction of solitary wave and uniform current and their impacts on a horizontal cylinder near the free surface. The model is satisfactorily tested against both the experimental data of forces on a circular cylinder, and the analytical solution of solitary waves. The validated model was applied to simulate solitary wave, uniform current, and their interaction with coastal structures. The hydrodynamic features of velocity field and vortex contours are demonstrated and analyzed.
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Date Issued: 2009
Identifier: FSU_migr_etd-0412
Format: Thesis

Title: Feasibility Study, Primary Designs and Development of Alternative Evapotranspiration Covers for Landfills and Waste Dump Sites in Tropical Locations.
Creator: Escobar, Francisco Jose, Abichou, Tarek, Cheng, Gang, Clark, Clayton, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: People generate a large and ever-increasing volume of waste, which originates in rural and urban areas, industrial operations and other activities. In spite of waste recycling, which is the solution to the huge amount of solid waste, a large part of it is deposited into landfills, dumps, etc.Landfills are, at present, the most widely used waste disposal facilities. Final cover systems are used at landfills and other types of waste disposal sites to control moisture and percolation, promote...
Show morePeople generate a large and ever-increasing volume of waste, which originates in rural and urban areas, industrial operations and other activities. In spite of waste recycling, which is the solution to the huge amount of solid waste, a large part of it is deposited into landfills, dumps, etc.Landfills are, at present, the most widely used waste disposal facilities. Final cover systems are used at landfills and other types of waste disposal sites to control moisture and percolation, promote surface water runoff, and minimize erosion. In addition, covers prevent direct exposure to the waste, control gas emissions and odors, prevent occurrence of disease vectors and other nuisances, and meet aesthetic and other end-use purposes. The Resource Conservation and Recovery Act (RCRA) Subtitle D, requires the use of landfill covers to meet these needs.Prescribed covers, permitted by current regulations, are based on a barrier concept that requires them to employ resistive principles, i.e., a layer having low saturated hydraulic conductivity. The most important focus of this study, is the EvapoTranspiration cover (ET) concept, which utilizes one or more vegetated soil layers to retain water until it is either transpired through vegetation, or evaporated from the soil surface. These cover systems rely on the water storage capacity of the soil layer, rather than low hydraulic conductivity materials, to minimize percolation. ET cover designs are based on using the hydrological processes and water balance components at a specific site, which includes the water storage capacity of the soil, precipitation, surface runoff, evapotranspiration and infiltration. The objective of this study is to determine the feasibility of developing and using ET Covers in tropical locations with medium to high precipitation. Puerto Rico can be assimilated as a part and sample of the typical average "Tropical Zones," so the study was concentrated there. The obtained conclusions can be applied later, along with the same principles, to Tropical Zones in general, which will have similar characteristics of rainfall, vegetation, soil texture and classification, and temperature. The study consisted of collecting climate, soil, and vegetation data and characteristics from six regions or "Ecozones" determined on the Island of Puerto Rico, as a representative of the "Tropical Sub-climate." The collected data was then used as input of a software called PR-ET to calculate the PET or ETo of the location and then the basis data of a flow model (HYDRUS 1-D) to simulate infiltration into the waste during peak weather events. PET and ETo are similar terms and are defined as the "Potential Evapotranspiration." Simulations were performed to evaluate the effect of the weather period, the effect of soil thickness, the effect of vegetation, the LAI (Leaf Area Index) and finally to determine what regions in Puerto Rico show potential for implementing ET covers.Results from this study showed some sub-regions (or locations) belonging to the six Ecozones (or regions) of Puerto Rico were able to meet the preliminary requirements for hydrological performance as required by the RCRA. However, field evaluation of these designs should be performed before full implementation of ET covers in these regions. Of the 21 locations studied in the preliminary design, 15 were adequate for study by modeling them to confirm the feasibility of using the Evapotranspiration covers in them. After this modeling or simulation was conducted, the results were as follows: eight locations can effectively use ET covers using as covering vegetation pastures. Five locations can use ET covers, but the vegetation needs to be changed using then shrubs and grass. The other locations are being rejected for this study. The selected locations are supposed to have thickness less than 2.0 m.
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Date Issued: 2011
Identifier: FSU_migr_etd-0523
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: 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: Connectionist Approach to Developing Highway Vehicles Classification for Use in Florida.
Creator: Kwigizile, Valerian, Mussa, Renatus, Sobanjo, John O., AbdelRazig, Yassir AbdAlla, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Federal, State, and local agencies use vehicle classification data for planning, design, and conducting safety and operational evaluation of highway facilities. The Federal Highway Administration (FHWA) Office of Highway Planning requires states to furnish vehicle classification data as part of the Highway Performance Monitoring System (HPMS). In conformity with the federal reporting requirements, most states use the "F" scheme to classify vehicles. Also, the mechanistic-empirical pavement...
Show moreFederal, State, and local agencies use vehicle classification data for planning, design, and conducting safety and operational evaluation of highway facilities. The Federal Highway Administration (FHWA) Office of Highway Planning requires states to furnish vehicle classification data as part of the Highway Performance Monitoring System (HPMS). In conformity with the federal reporting requirements, most states use the "F" scheme to classify vehicles. Also, the mechanistic-empirical pavement design methodology being developed under the National Cooperative Highway Research Program Project 1-37A will require accurate classification of vehicles in order to develop axle load spectra information needed as the design input. "Scheme F", used by most states to classify vehicles, can also be used to develop the required load spectra. Unfortunately, the scheme is difficult to automate and is prone to errors resulting from imprecise demarcation of class thresholds. In this work, the classification problem was viewed as a pattern recognition problem in which pattern recognition techniques such as probabilistic neural networks (PNN) was used to assign vehicles to their correct classes and hence to establish optimum axle spacing thresholds. The PNN was developed, trained and applied to field data composed of individual vehicle's axle spacing, number of axles per vehicle and overall vehicle weight. The PNN reduced the error rate from 9.7 percent to 6.1 percent compared to an existing classification algorithm used by the State of Florida Department of Transportation (FDOT). The inclusion of overall vehicle weight as a classification variable further reduced the error rate from 6.1 percent to only 2.9 percent. The promising results from the neural networks were used to set up new thresholds that reduce classification error rate. The proposed vehicle classification table thresholds were validated using additional data collected from the field. The validation results indicated a significant improvement in the accuracy of vehicle classification table compared to the existing FDOT table. The developed table will enable the FDOT to consistently collect more accurate vehicle classification data by using any vendor's equipment. This will enable the state to conduct more accurate environmental impact analysis during highway design and schedule for timely highway maintenance basing on projected remaining pavement life.
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Date Issued: 2004
Identifier: FSU_migr_etd-3029
Format: Thesis

Title: The Development of Florida Length Based Vehicle Classification Scheme Using Support Vector Machines.
Creator: Mauga, Timur, Mussa, Renatus, Ping, Wei-Chou Virgil, Sobanjo, John O., Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The Florida Department of Transportation (FDOT) collects vehicle classification data for transportation policy and system planning, traffic operational analysis, safety and accident analysis, and roadway maintenance. FDOT utilizes Scheme F method of classification, which classifies vehicles into 13 vehicle classes according to the number of axles the vehicle has and the lengths between the axles. The vehicle data are collected by inductive loops and piezoelectric sensors installed at more...
Show moreThe Florida Department of Transportation (FDOT) collects vehicle classification data for transportation policy and system planning, traffic operational analysis, safety and accident analysis, and roadway maintenance. FDOT utilizes Scheme F method of classification, which classifies vehicles into 13 vehicle classes according to the number of axles the vehicle has and the lengths between the axles. The vehicle data are collected by inductive loops and piezoelectric sensors installed at more than 300 sites on the state highway system. The Federal Highway Administration (FHWA) requires states' departments of transportation to report vehicle classification data using Scheme F regardless of the method used in data collection. Moreover, the current FHWA's Traffic Monitoring Guide allows the states to collect vehicle classification data in urban areas based on the overall vehicle length. The guide states that three or four general vehicle length categories are sufficient for many practical analyses. The guide also provides flexibility for states to select data collection equipments that meet their local and federal traffic data needs and priorities without hindrance from budgets, geographic and organizational constraints. The objective of this research was to develop a length based vehicle classification scheme for Florida. The scheme will be used by non-intrusive traffic detection systems to collect vehicle class data. The task of developing the scheme comprised of collection of vehicle length data throughout the state highway system. The identification of length patterns from the vehicle length data was done using support vector machines. The analysis of the vehicle lengths collected from the Florida state highway system showed three patterns of vehicles: passenger vehicles, single unit trucks and multi-unit trucks. These groups corresponds to classes 1-3, classes 4-7 and classes 8-13 of Scheme F, respectively. The three vehicle categories were defined using length thresholds of 0-21.4 ft, 21.5-42.4 ft, and 42.5 ft and above with an accuracy of 91.1% on the sample data and at least 90.8% on the validation data. The study showed that a large part of misclassification errors was caused by the presence of vehicles towing light trailers. The study recommends the use of an additional variable such as the vehicle profile in order to reduce misclassifications.
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Date Issued: 2006
Identifier: FSU_migr_etd-2659
Format: Thesis

Title: College of Engineering Characterization of Microbial Activity in Soils Nearby Landfills in Northwest Florida.
Creator: Williams, Mitchell Duren, Chen, Gang, Hilton, Amy Chan, Abichou, Tarek, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Elevated iron concentrations have been observed in the groundwater downgradient of the landfills in Northwest Florida. It is suspected microbial mediated iron reduction should be responsible for the iron release. The purpose of this research is to characterize the microbial community in the soils nearby landfills in Northwest Florida to determine the dominant bacterial species. The iron rich soil in Northwest Florida and leachate from landfills are considered the primary contributors to the...
Show moreElevated iron concentrations have been observed in the groundwater downgradient of the landfills in Northwest Florida. It is suspected microbial mediated iron reduction should be responsible for the iron release. The purpose of this research is to characterize the microbial community in the soils nearby landfills in Northwest Florida to determine the dominant bacterial species. The iron rich soil in Northwest Florida and leachate from landfills are considered the primary contributors to the elevated iron concentrations observed in groundwater. Iron reducing bacteria are capable of releasing soluble Fe (II) by reducing Fe (III) bound to the soil minerals. The leachate has potential for providing carbon sources for the reaction, allowing the bacteria to more rapidly reduce the iron in the soil. In this research, the soils from sixteen landfills (fifteen Northwest Florida counties) were characterized through sieve analysis and the bacteria were quantified and identified. Traditional plate count method was used for bacterial quantification and morphology by means of microscopy and Polymerase Chain Reaction (PCR) were utilized for bacterial identification. The plate counts resulted in 0.03 million to 2.0 million colony-forming units (CFU) per gram of soil. The identification through morphology found typical rod and cocci bacteria to be the dominating species. Although potentially iron reducing bacteria were identified through morphology, they were not confirmed through DNA analysis. They need further enriched culturing in order to observe obvious iron reducing. The PCR analysis identified typical soil bacteria, Bacillus subtilis, Bacillus cereus, Bacillus thuringiensis, and Pseudomonas aeruginosa. These bacteria are common soil bacteria that are well characterized. The sieve analysis of the soils showed a correlation of increased bacterial population in well-graded soils. The soils also showed an increase in water content when there was a higher percentage of finer particles. However, increased water content and finer particles resulted in lower bacterial populations. Further studies are currently underway to quantify the iron release from the soils and the effects the leachate have on the bacterial processes.
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Date Issued: 2007
Identifier: FSU_migr_etd-0975
Format: Thesis

Title: An Environmental Systems Analysis of Cathode Ray Tube Waste Management.
Creator: Lundy, Chancee, Chan-Hilton, Amy B., Abichou, Tarek, Nnaji, Soronnadi, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: As new technology becomes available, consumers are likely to dispose of old equipment in favor the most upgraded electronics. It becomes increasingly difficult to manage electronic solid and hazardous waste when the lifespan of such devices is decreasing. In the computer industry, new technology demands that we upgrade software and eventually hardware on a consistent basis to avoid malfunction. Of particular concern are computer monitors, which contain 4-8 pounds of lead in the cathode ray...
Show moreAs new technology becomes available, consumers are likely to dispose of old equipment in favor the most upgraded electronics. It becomes increasingly difficult to manage electronic solid and hazardous waste when the lifespan of such devices is decreasing. In the computer industry, new technology demands that we upgrade software and eventually hardware on a consistent basis to avoid malfunction. Of particular concern are computer monitors, which contain 4-8 pounds of lead in the cathode ray tube. According to a study completed by Townsend et al, cathode ray tubes from televisions and computer monitors exceed the 5 mg/L leaching limit as set forth in the Environmental Protection Agency's Toxicity Characteristic Leaching Procedure. The cathode ray tubes from these devices leached over 18 mg/L of lead. (1999) In the state of Florida most counties recycle computer monitors such that these toxic machines will not end up in the landfill where there is a potential for groundwater leaching. The cost for processing computer monitors is a burden to the landfill; therefore, this research minimized cost to the landfill through a linear programming approach using Microsoft Excel Solver. Using this program, an advanced disposal fee was imposed to residents within the state of Florida to alleviate the cost burden from the local governments. After using various scenarios to impose these fees, it was determined that the advanced disposal fee could be a partial solution to the funding issues for the counties. It does indeed assist counties in keeping these hazardous computer monitors out of the landfill and lower costs for processing these items with various recycling facilities.
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Date Issued: 2006
Identifier: FSU_migr_etd-0999
Format: Thesis

Title: Numerical Investigations of Scale Effects on Local Scour Around a Bridge Pier.
Creator: Yang, Qiping, Huang, Wenrui, Abdullah, Makola, Yazdani, Nur, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Local scour around a bridge pier (a cylinder) is a problem of much concern to hydraulic engineers. This is a complex phenomenon resulting from the interaction of the three-dimensional turbulent flow field around the cylinder and the mobile channel bed. Under-prediction of scour depth can lead to costly bridge failures, while over-prediction can result in millions of dollars in unnecessary construction costs. Therefore, the knowledge of the anticipated maximum scour depth is essential for a...
Show moreLocal scour around a bridge pier (a cylinder) is a problem of much concern to hydraulic engineers. This is a complex phenomenon resulting from the interaction of the three-dimensional turbulent flow field around the cylinder and the mobile channel bed. Under-prediction of scour depth can lead to costly bridge failures, while over-prediction can result in millions of dollars in unnecessary construction costs. Therefore, the knowledge of the anticipated maximum scour depth is essential for a proper design of the foundation of the bridge piers. Local scours around bridge piers have resulted in more bridge failures than all other causes in recent history. Local pier scour has been a popular topic of study by many laboratory researchers. The scour prediction methods developed in the laboratories and the scour equations based on laboratory data did not always produce reasonable results for field conditions. Recent research indicates that laboratory investigations often oversimplify or ignore many of the complexities of the flow fields around the bridge piers. The physical scales, the fluid properties and the boundary conditions in the small-scale models (the laboratory conditions) should be derived from the large-scale prototype (the field conditions) according to the Hydraulic Similitude Laws. Geometric similarity is usually required for all models, Reynolds number similarity for models involving flow around bodies and Froude number similarity for models involving free-surface flows. In fact, it is not practical for a physical model of local scour around a bridge pier to satisfy all these similarities. However, unlike a physical model, which suffers from scale effects, the CFD model employs the actual dimensions and operating conditions to calculate turbulent velocity and sediment scour. This thesis 1) verified the capabilities of the 3-D computational fluid dynamics (CFD) software package, FLUENT, to simulate local scour around a bridge pier by applying the numerical model to the experimental conditions and comparing the computed results with their laboratory data; 2) conducted the numerical simulations to compare turbulent flow characteristics between small-scale and large-scale local scour around a bridge pier according to Froude similitude by using the computational fluid dynamics software package, FLUENT; 3) compared and analyzed the differences of the simulation results between the small-scale and large-scale models; and 4) concluded that Reynolds number would provide useful information for adequately adopted equations which were derived from small scale laboratory experiments and applied to large bridge piers in field applications.
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Date Issued: 2005
Identifier: FSU_migr_etd-1094
Format: Thesis

Title: Transverse Analysis and Field Measurements of Segmental Box Girder Bridges.
Creator: Kuhn, Dan, Rambo-Roddenberry, Michelle, Tawfiq, Kamal, Mtenga, Primus, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Parapets placed on bridge deck surfaces, commonly known as barriers, are purposely omitted from the structural analysis model for design or load rating. Barriers should not be considered primary structural members because they are designed to withstand the impact of a vehicular collision. After a forceful collision, a barrier would sustain some structural damage and would no longer support or strengthen the bridge deck. However, when completely intact, these secondary structural members do,...
Show moreParapets placed on bridge deck surfaces, commonly known as barriers, are purposely omitted from the structural analysis model for design or load rating. Barriers should not be considered primary structural members because they are designed to withstand the impact of a vehicular collision. After a forceful collision, a barrier would sustain some structural damage and would no longer support or strengthen the bridge deck. However, when completely intact, these secondary structural members do, significantly, absorb and distribute any applied load, thus acting as fully functional structural members. The amount that appurtenances, specifically parapets, contribute to deck strength is of interest to permitting agencies, such as the Florida Department of Transportation (FDOT). For a concrete segmental box girder bridge, load ratings for oversized load permits are currently determined with a calculation that involves the transverse analysis of the bridge without factoring in the extra strength of fully intact appurtenances. Moreover, within the transverse analysis, the maximum moment generated from the live load is typically calculated from Homberg charts. These generalized influence surfaces were designed based on plate surface models and are conservative. When added to the standard "error on the side of caution" design methods, this moment estimation and the lack of consideration for the appurtenances create an overly conservative transverse load rating for the bridge. With 3D finite element bridge models, created using LUSAS, it is shown, qualitatively and quantitatively, how much of an effect the barrier has on the live load distribution for three concrete segmental box girder bridges located in the Florida Keys. Data obtained from these models is directly compared to measurements obtained from FDOT load tests on the actual bridges and also to predictions made from Homberg influence surfaces. Modifying the current method of load rating, for structurally sound bridges, with fully functional appurtenances should interest permitting agencies and would prove beneficial to those transporting oversized loads.
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Date Issued: 2008
Identifier: FSU_migr_etd-2937
Format: Thesis

Title: Modeling Leakage in Water Distribution Systems.
Creator: Brown, Kristin, Hilton, Amy Chan, Nnaji, Soronnadi, Huang, Wenrui, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Due to the continuous need to improve water supply sources, water operators are looking towards ways to conserve water and protect water quality through leakage protection. Currently computer generated models have been used to try to identify leakage areas and develop a relationship between leakage and pressure variations in water systems. The method of the leakage prediction has used both transient analysis and inverse transient analysis to determine the relationship between leakage and...
Show moreDue to the continuous need to improve water supply sources, water operators are looking towards ways to conserve water and protect water quality through leakage protection. Currently computer generated models have been used to try to identify leakage areas and develop a relationship between leakage and pressure variations in water systems. The method of the leakage prediction has used both transient analysis and inverse transient analysis to determine the relationship between leakage and pressure variations. Currently there has been limited success in both these methods. The experiment expressed in this research will explore the accuracy of the WaterCAD software to develop a relationship between pressure variations and leakage quantities and leakage locations. Engineers and owners of water systems use the WaterCAD software to develop models of both proposed and existing water distribution systems. If these same models could be calibrated using post-condition pressure values and using system parameters (roughness coefficients, etc.) pressure differences in the system which do not match the calibrated computer generated model could be identified thereby indicating a leakage and possibly suggest a location for the leakage. Using a previous transient experiment for both reference and calibration, the effects of leakage on pressure variations within a distribution system were explored. The results found within this experiment suggest that there is a relationship between pressure variations and leakage quantities. The location of leakage areas also affects the pressures within the distribution system. By examining the results of this experiment, both engineers and water operators can learn how leakage affects pressure within a water system and become more aware of these symptoms for leakage prevention.
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Date Issued: 2007
Identifier: FSU_migr_etd-2936
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: Parametric Optimization of Steel Floor System Cost Using Evolver.
Creator: Platt, Bethany Susan, Mtenga, Primus V., Sobanjo, John O., Tawfiq, Kamal S., Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: This paper examines the application of Evolver, a genetic algorithm (GA) solving program, in a three-parameter optimization of a steel truss floor system with a concrete slab floor deck. The floor system is comprised of truss girders supporting beams running in a direction perpendicular to the truss girders with a composite floor deck along the top. Using Evolver, three parameters are optimized for two truss girder topologies in order to find the least cost floor system. The weight of the...
Show moreThis paper examines the application of Evolver, a genetic algorithm (GA) solving program, in a three-parameter optimization of a steel truss floor system with a concrete slab floor deck. The floor system is comprised of truss girders supporting beams running in a direction perpendicular to the truss girders with a composite floor deck along the top. Using Evolver, three parameters are optimized for two truss girder topologies in order to find the least cost floor system. The weight of the structural members is correlated to the expenses of material, labor, equipment, and overhead and profit required for the construction of the floor through information given by Means Building Construction Cost Data and interviews with steel fabricators. This procedure may be modified to optimize the cost of any floor area size that may use different truss girder topologies, beam sections, and connections. Parametric optimization is defined in this paper as the combination of configuration, size, and topology optimization of a truss girder, the size optimization of beams, and the optimization of the spacings of both beams and truss girders in the system. A discrete set of values has been selected for each variable that makes up the search space from which all solutions to the problem exist. A GA is a search algorithm, incorporated to quickly explore a wide range of answers and focus on better areas of the search space to find improved solutions.
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Date Issued: 2006
Identifier: FSU_migr_etd-0645
Format: Thesis

Title: Fuzzy Control of Magnetorheological Dampers for Vibration Reduction of Seismically Excited Structures.
Creator: Wilson, Claudia Mara Dias, Abdullah, Makola M., Collins, Emmanuel G., Spainhour, Lisa K., Yazdani, Nur, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Since civil structures have little damping capability, extensive damage and even failure often occur when they are subjected to seismic excitations. Control devices have therefore been developed and implemented to dissipate energy from earthquakes and reduce structural vibrations. Magnetorheological (MR) dampers are examples of such devices and consist of a hydraulic cylinder containing a solution that, in the presence of a magnetic field, can reversibly change from viscous fluid to semi...
Show moreSince civil structures have little damping capability, extensive damage and even failure often occur when they are subjected to seismic excitations. Control devices have therefore been developed and implemented to dissipate energy from earthquakes and reduce structural vibrations. Magnetorheological (MR) dampers are examples of such devices and consist of a hydraulic cylinder containing a solution that, in the presence of a magnetic field, can reversibly change from viscous fluid to semi-solid. The objective of this research is to develop fuzzy controllers to regulate the damping properties of MR dampers and reduce structural responses of single degree-of-freedom seismically excited structures. Three fuzzy controllers were therefore designed and their effectiveness evaluated through series of numerical simulations. Since fuzzy control uses expert knowledge instead of differential equations, it allows for the development of simple and robust algorithms that do not require information on plant's structural and vibration characteristics. They are therefore an attractive alternative for controlling systems that are complex, nonlinear, or that contain ambiguity or vagueness. The first algorithm proposed is a fuzzy control system with two inputs: structural displacement and velocity. The second is referred to as gain-scheduled fuzzy control and varies the velocity input scaling factor according to incoming ground acceleration. The last one, self-tuning fuzzy control, uses a fuzzy inference mechanism based on ground acceleration intensity and building displacement to adjust the velocity input scaling factor. Robustness of these controllers to changes in seismic motions and structural characteristics were evaluated by subjecting two different buildings controlled by each of these strategies to a wide range of earthquake records. Results show that the algorithms proposed effectively reduced responses of both structures to a wide range of seismic motions. They were also found to be robust to changes in ground excitations and structural characteristics. In addition, adjusting the velocity input scaling factor according to ground acceleration intensity considerably improved the controller's ability to reduce structural vibrations, since both the gain-scheduled and the self-tuning fuzzy algorithms reduced structural responses more effectively than the fuzzy controller with constant scaling factors. Finally, the self-tuning controller outperformed all other strategies for most earthquakes considered.
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Date Issued: 2005
Identifier: FSU_migr_etd-0891
Format: Thesis

Title: Development of a Measure of Effectiveness for the Florida Elder Road User Program.
Creator: Pierre, Velouse, Spainhour, Lisa, Mussa, Renatus, Sobanjo, John, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Older drivers may have more difficulty than the general driving public in attending to the driving task, and they may be slower at processing information, especially when required to make complex decisions. Traffic crashes caused by elderly drivers have been attributed to neglect of, or inattention to, relevant information from road signs, as well as to other cars and pedestrians on the road. This is especially true at intersections. To combat these safety issues, implementation of the...
Show moreOlder drivers may have more difficulty than the general driving public in attending to the driving task, and they may be slower at processing information, especially when required to make complex decisions. Traffic crashes caused by elderly drivers have been attributed to neglect of, or inattention to, relevant information from road signs, as well as to other cars and pedestrians on the road. This is especially true at intersections. To combat these safety issues, implementation of the Florida Elder Road User Program began on state-maintained roads. This program sought to improve roadways by increasing visibility and adding advanced signage and reflective pavement markings. This study sought to evaluate the effectiveness of the Florida Elder Road User Program by building a crash prediction model that examines older driver crash frequency using variables obtained from quantitative variables such as maximum posted speed limit and qualitative variables such as sign visibility. Crash data was collected for 601 intersections in the state of Florida for the years 2000-2002. Detailed analysis of geometric and traffic data collected from various resources, such as crash reports, Roadway Characteristics Inventory data, and video log archives, was performed to determine the correlation between these independent factors and crash frequency. The crash distribution was found to be negative binomial; the model needed to be inflated due to the presence of many zero-crash intersections. Therefore, a Zero-Inflated Negative Binomial (ZINB) crash prediction model was developed. The response variable in the model was crash frequency, and independent variables included roadway geometrics, traffic characteristics, and intersection characteristics. Crash frequency was found to have a very strong relationship with most of the independent variables as indicated by their p-values. Traffic volumes, signalization, and sign visibility had positive coefficients, indicating that, higher traffic volumes, signalized intersections, and sign visibility were associated with increased crash frequency. Many of the improvements, including sign visibility and reflective pavement markers listed in the Florida Elder Road User Program were found to be significant but did not reduce elderly driver crashes, proving that the program is not effective.
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Date Issued: 2006
Identifier: FSU_migr_etd-0792
Format: Thesis

Title: Methane Emission and Oxidation Through Landfill Covers.
Creator: Yuan, Lei, Abichou, Tarek, Chanton, Jeffrey, Tawfiq, Kamal, Ping, Wei-Chou V., Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: This dissertation presents the work of investigating methane emission and oxidation through landfill covers. Methane as a major source of greenhouse and is being emitted from solid waste landfill at a tremendous rates. These emissions could be mitigated by methanotrophic bacteria in enriched and non-enriched soil covers. Compost biofilters were constructed to study the methane oxidation capacity of compost. The aged chipped yard waste compost was obtained from Leon County landfill (Florida,...
Show moreThis dissertation presents the work of investigating methane emission and oxidation through landfill covers. Methane as a major source of greenhouse and is being emitted from solid waste landfill at a tremendous rates. These emissions could be mitigated by methanotrophic bacteria in enriched and non-enriched soil covers. Compost biofilters were constructed to study the methane oxidation capacity of compost. The aged chipped yard waste compost was obtained from Leon County landfill (Florida, USA). A one-dimensional dynamical numerical model was developed to simulate the methane transport and oxidation through the biofilter. This model was designed to incorporate dynamic parameters and use flux bottom boundary, which is measured by a flow meter. General agreements of methane outflux and oxidations were obtained between model simulation and experimental data. Field scale control cells and biocells were evaluated in the same landfill for methane emission and oxidation. Methane oxidation in biocells was significantly higher than in control cells. When outliers were removed, methane emission from biocells was significant less than from control cells. A numerical model was developed to separate blockage of the thicker biocells cover and the biological oxidation. Results showed that the low emission from biocells is caused by blockage of soil cover underneath the compost cover as well the high oxidation capacity of this compost cover. An additional modeling investigation was conducted to evaluate how landfill final earthen cover's construction and climate conditions affect methane emission and oxidation under different boundary condition and different soil oxidation capacities. This numerical model combined a water and heat flow model (HYDRUS1D) and a gas transport and oxidation model. Simulations showed that soil covers in subhumid areas can prevent high methane emission with blockage and decent oxidation capacity. In semi-arid sites, higher emission was obtained due to the higher air filled void space of the soil. Oxidation capacities in semi-arid sites are higher than those in subhumid sites since influxes of methane are higher in semiarid sites. High pressure underneath the cover caused higher emission in all sites. Even with active gas collection system (vacuum pressure), emissions were significant in semiarid climates.
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Date Issued: 2006
Identifier: FSU_migr_etd-0919
Format: Thesis

Title: Reducing Hydrogen Sulfide (H2S) Concentrations at Wastewater Collection Systems and Treatment Facilities Using Chemical Oxidation.
Creator: Thomas, Dornelle S., Hilton, Amy Chan, Chen, Gang, Abichou, Tarek, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Wastewater collection systems and treatment facilities are known for emitting offensive odors that cause neighboring residents to complain. One of the main odor compound contributors is hydrogen sulfide (H2S). Presently, H2S removal from wastewater facilities is mainly being accomplished by biological means relying heavily on the use of microorganisms. However, the use of microorganisms requires a more consistent and stable environment. In the absence of the previously stated conditions, the...
Show moreWastewater collection systems and treatment facilities are known for emitting offensive odors that cause neighboring residents to complain. One of the main odor compound contributors is hydrogen sulfide (H2S). Presently, H2S removal from wastewater facilities is mainly being accomplished by biological means relying heavily on the use of microorganisms. However, the use of microorganisms requires a more consistent and stable environment. In the absence of the previously stated conditions, the removal of H2S has to be carried out by other means. Therefore, an alternative for wastewaters with unstable characteristics requiring minimal maintenance/human involvement is preferred to deal with H2S emissions. This study investigated the effectiveness of chemical oxidation by employing three oxidants, 50% hydrogen peroxide (H2O2), 12% sodium hypochlorite (NaOCl), and 5% potassium permanganate (KMnO4) at mitigating H2S aqueous and gas concentrations at wastewater collection systems and treatment facilities. The chemicals were supplied to the systems throughout four distinct testing phases using peristaltic pumps. H2S(g) levels were obtained using a Jerome Meter (860 model) while the dissolved sulfide concentrations were measured using a LaMotte Sulfide Test Kit. This study found that of the three chemicals chosen, H2O2 is most effective and efficient at removing H2S from wastewater collection and treatment facilities. However, throughout this study, H2S(g) removal efficiencies were affected by the physical conditions at the testing facilities. Therefore, after taking the corrective action needed to improve facility conditions, further investigation is required to appropriately evaluate the use of H2O2 at odor mitigation.
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Date Issued: 2007
Identifier: FSU_migr_etd-1580
Format: Thesis

Title: Simulation Analysis of Truck Restricted and HOV Lanes.
Creator: Siuhi, Saidi, Mussa, Renatus N., Sobanjo, John O., Ping, Wei-Chou V., Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Numerous studies have reported the efficacy of high occupancy vehicles (HOV) lane restriction and truck lane restriction implemented independently but the simultaneous use of both restrictions on an urban freeway corridor raises interesting questions related to the operational and safety implications of various confluence factors. This research study analyzed the operational and safety experience of an 83-mile corridor of Interstate 95 in South Florida that has both HOV and truck lane...
Show moreNumerous studies have reported the efficacy of high occupancy vehicles (HOV) lane restriction and truck lane restriction implemented independently but the simultaneous use of both restrictions on an urban freeway corridor raises interesting questions related to the operational and safety implications of various confluence factors. This research study analyzed the operational and safety experience of an 83-mile corridor of Interstate 95 in South Florida that has both HOV and truck lane restrictions implemented individually and in combination. The results of a field-validated VISSIM simulation model emulating the current policy of restricting trucks from using the leftmost lane(s) in this corridor showed that high occupancy vehicles and automobiles gained significantly more travel time savings and speeds on the restricted lanes than on the general lanes. Also, vehicle queue lengths around critical merging and diverging areas increased significantly as the percentage of trucks increased imposing severe disruption on freeway traffic flow and vehicle backups spilling into the major intersecting arterial streets. The results indicated that during peak traffic conditions right lanes had high lane occupancy than left lanes whereas during off peak traffic conditions center lanes carried more vehicles per lane than the outermost lanes suggesting that congestion forces automobiles to use the left lanes. Furthermore, the results showed that the majority of lane changes occurred during peak traffic flow conditions—about twice that of off-peak—and appreciable speed differences existed between restricted and non-restricted lanes. The simulation results for off-peak traffic conditions did not show appreciable changes in traffic operating characteristics resulting from lane restriction strategies. Furthermore, simulation results showed that restricting trucks from using either center lane or the rightmost lane in lieu of the current policy of restricting trucks from using the leftmost lane(s) aggravate operational efficiency and safety. Based on these results, it can fairly be concluded that significant operational and safety benefits of combined implementation of HOV and truck lane restrictions on urban freeways accrue during congested traffic conditions rather than uncongested conditions when trucks are restricted from the leftmost lane(s).
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Date Issued: 2006
Identifier: FSU_migr_etd-1693
Format: Thesis

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