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Title: 3D Numerical Modeling of Hydrodynamics and Sediment Transport in Estuaries.
Creator: Liu, Xiaohai, Huang, Wenrui, Song, Kaisheng, Hilton, Amy Chan, Chen, Gang, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: As a USEPA recommended hydrodynamic and transport model, EFDC model has been widely used in modeling estuarine and coastal hydrodynamics and transport. EFDC employs sigma coordinate transformation to deal with irregular water depth. However, it is well known that this coordinate transformation introduces additional terms and produces computation errors in calculation of horizontal pressure gradient terms when a steep bottom slope exists in water domains. Errors in pressure gradient...
Show moreAs a USEPA recommended hydrodynamic and transport model, EFDC model has been widely used in modeling estuarine and coastal hydrodynamics and transport. EFDC employs sigma coordinate transformation to deal with irregular water depth. However, it is well known that this coordinate transformation introduces additional terms and produces computation errors in calculation of horizontal pressure gradient terms when a steep bottom slope exists in water domains. Errors in pressure gradient calculation can cause errors in velocity field and ultimately results in errors in spurious transports. In this study, a new algorithm is presented to reduce the numerical errors induced by the horizontal pressure gradient term near steep topography. The basic concept of this algorithm is to re-organize the pressure terms in sigma coordinate system to avoid the subtractions of two large horizontal pressure terms. To accomplish this objective, the 4th order Lagrangian interpolation method was firstly used in sigma space to obtain concentration in the corresponding z-level of the water column. Secondly, the horizontal concentration difference was determined. Finally, the horizontal pressure gradient in the water column was directly calculated from the horizontal concentration gradient. A stepwise bottom boundary condition was adopted for steep slopping bottom boundary. The algorithm has been used to enhance the EFDC model. The model code has been tested in three test cases: 1) flat bottom basin, 2) steep sloping channel, and a coastal shelf. Results indicate that conventional approach in current EFDC dealing with horizontal pressure gradient terms causes spurious surface elevation and velocity field. In comparison, the employment of the algorithm presented in this study this study significantly reduced numerical errors in predicting surface elevation and currents in navigation channels and coastal shelves. Equations for estimating horizontal diffusion coefficient in 3D numerical modeling of estuarine transport have been evaluated in this study in a shallow tidal river. In the application of a 3D hydrodynamic model to Little Manatee River located in Florida of USA, the popular Smagoringsky diffusion scheme was shown to result in the underestimate salinity in comparison with field observations. Another horizontal diffusion equation by Overton et al was also unable to provide satisfactory results of salinity variations in the shallow and narrow river. In an analytic test case of a non-tidal uniform flow channel, Smargorinsky equation results in unreasonable zero horizontal diffusion and no salinity intrusion in the nontidal one dimensional tidal river. An enhanced horizontal diffusion equation was presented in this study. Decoupled from the horizontal eddy viscosity, the enhanced horizontal diffusion equation is composed of the Smargorinsky equation with addition of a non-tidal background horizontal diffusion to account for the effects of shallow and narrow effects of streams. The enhanced equation has been calibrated with field observations of hourly surface and bottom salinity at two field stations during 2/15/2005-2/28/2005. It was also satisfactorily verified with field observations for the period of 3/1/2005-6/30/2005. Model predictions of salinity and currents fields from model predictions were presented to support water research. The enhanced horizontal diffusion equation will be helpful for more accurate modeling of other water quality constituents in tidal rivers. A 3D sediment transport model is applied to Apalachicola Bay to predict temporal and spatial distributions of sediment concentrations in water columns. The model is coupled with the 3D hydrodynamic model in the EFDC model code that provides information on estuarine circulations and salinity transport. The hydrodynamic model has been calibrated with field observations of water levels and salinity. The sediment transport model solves the transport equation with source and sinks terms to represent sediment deposition and re-suspension. The model is capable of predicting dye transport and fecol coliform. Basing on the collection of field observation and data analysis, the main driving force for sediment resuspension in the bay is found to be surface wind drive current. The calibrated hydrodynamic model then was used to simulate the total suspended sediments (TSS) transportation and get a satisfying result. The calibrated model can serve as an effective tool for environmental scientists and resources managers to examine effects of management scenarios on estuarine sediments transport and the aquatic ecosystem.
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Date Issued: 2007
Identifier: FSU_migr_etd-1164
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: 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: Aging Driver Focused Traffic Crash Frequency and Severity Analyses.
Creator: Omidvar, Aschkan, Vanli, Omer Arda, Ozguven, Eren Erman, Shrivastava, Abhishek Kumar, Park, Chiwoo, Florida State University, FAMU-FSU College of Engineering, Department of...
Show moreOmidvar, Aschkan, Vanli, Omer Arda, Ozguven, Eren Erman, Shrivastava, Abhishek Kumar, Park, Chiwoo, Florida State University, FAMU-FSU College of Engineering, Department of Industrial and Manufacturing Engineering
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Abstract/Description: The aim of this thesis is to investigate the effect of environmental and traffic-related factors on the frequency and severity of highway crashes with a focus on different age groups including the aging populations. Existing studies in the traffic safety have not specifically focused on aging driver-involved crashes. Aging drivers are more vulnerable to the roadway crashes than other adult age groups due to their cognitive, physical and health limitations. This problem becomes more...
Show moreThe aim of this thesis is to investigate the effect of environmental and traffic-related factors on the frequency and severity of highway crashes with a focus on different age groups including the aging populations. Existing studies in the traffic safety have not specifically focused on aging driver-involved crashes. Aging drivers are more vulnerable to the roadway crashes than other adult age groups due to their cognitive, physical and health limitations. This problem becomes more challenging due to the drastic variation in the traffic patterns that especially happen on the major highways. In this thesis, several data sets from different sources, such as the National Oceanic and Atmospheric Administration (NOAA) and Florida Automated Weather Network (FAWN), the Florida Department of Transportation (FDOT) and the United States Naval Observatory (USNO), are collected, refined and combined. With the aid of statistical correlation analysis and logistic regression, a top down analysis is performed in order to analyze the occurrence of crashes via a case study application on the I-95 highway corridor in the State of Florida. Using logit curves, a sensitivity analysis is carried out to quantify the effect of traffic volume on the crash frequency. In addition to the crash frequency analysis, factors influencing the crash severity are also analyzed in an integrated manner for two metropolitan areas in the City of Jacksonville and Miami, Florida. Both frequency- and severity-focused analyses have led to several important conclusions. Results suggest that the variation in the hourly traffic volume significantly affects the crash occurrences for both aging and non-aging drivers depending on the geographical location; however, the crash occurrence for aging drivers is less sensitive to the flow than other age groups in congested locations. Results indicate that crash severity for all other age groups decrease on roadways with narrower shoulders and at night unlike those of aging drivers. Furthermore, driving at night on I-95 in Jacksonville seems to be problematic for both age classes whereas that risk is less for Miami locations. Higher roadway surface width also appears to increase the chance of having a severe crash for aging drivers. The DUI-influenced crashes have also been detected considerably high on the I-95 highway corridor in the City of Miami, Florida. This problem seems critical both in terms of crash frequency and severity. The proposed methodology can help transportation officials to understand the nature of the aging driver-involved crashes, and formulate better safety-oriented decisions.
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Date Issued: 2016
Identifier: FSU_2016SU_Omidvar_fsu_0071N_13464
Format: Thesis

Title: Analysis and Predictions of Extreme Coastal Water Levels.
Creator: Xu, Sudong, Huang, Wenrui, Niu, Xufeng, Nnaji, Soronnadi, Abichou, Tarek, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Understanding the characteristics of probability distribution of extreme water levels is important for coastal flood mitigation and engineering design. In this study, frequency analysis has been conducted to investigate probability distributions along the coast of the U.S. by using three-parameter General Extreme Value (GEV) method. The GEV model combines three types of probability distributions (Type I for Gumbel distribution, Type II for Fretchet, or Type III for Weibull) into one...
Show moreUnderstanding the characteristics of probability distribution of extreme water levels is important for coastal flood mitigation and engineering design. In this study, frequency analysis has been conducted to investigate probability distributions along the coast of the U.S. by using three-parameter General Extreme Value (GEV) method. The GEV model combines three types of probability distributions (Type I for Gumbel distribution, Type II for Fretchet, or Type III for Weibull) into one expression. Types of distributions can be clarified by one of the three parameters of the GEV model for the corresponding studied stations. In this study, the whole U.S. coast was divided into four study areas: Pacific Coast, Northeast Atlantic Coast, Southeast Atlantic Coast and Gulf of Mexico Coast. Nine National Oceanic and Atmospheric Administration (NOAA) stations with a long history of data (more than 70 years) in the four study areas were chosen in this study. Parameters of the GEV model were estimated by using the annual maximum water level of studied stations based on the Maximum Likelihood Estimation (MLE) method. T-test was applied in this study to tell if the parameter, , was greater than, less than or equal to 0, which was used to tell the type of the GEV model. Results show that different coastal areas have different probability distribution characteristics. The characteristics of probability distribution in Pacific Coast and Northeast Atlantic Coast are similar with extreme value I and III model. The Southeast Atlantic Coast and Gulf of Mexico Coast were found to have similar probability distribution characteristics. The probability distributions were found to be extreme value I and II model, which are different from those of the Pacific Coast and Northeast Atlantic Coast. The performance of the GEV model was also studied in the four coastal areas. GEV model works well in the five studied stations of both the Pacific Coast and the Northeast Atlantic Coast but does not work well in the Southeast Atlantic Coast and the Gulf of Mexico Coast. Adequate predictions of extreme annual maximum coastal water levels (such as 100-year flood elevation) are also very important for flood hazard mitigation in coastal areas of Florida, USA. In this study, a frequency analysis method has been developed to provide more accurate predictions of 1% annual maximum water levels for the Florida coast waters. Using 82 and 94 years of water level data at Pensacola and Fernandina, performances of traditional frequency analysis methods, including advanced method of Generalized Extreme Value distribution method, have been evaluated. Comparison with observations of annual maximum water levels with 83 and 95 return years indicate that traditional methods are unable to provide satisfactory predictions of 1% annual maximum water levels to account for hurricane-induced extreme water levels. Based on the characteristics of annual maximum water level distribution Pensacola and Fernandina stations, a new probability distribution method has been developed in this study. Comparison with observations indicates that the method presented in this study significantly improves the accuracy of predictions of 1% annual maximum water levels. For Fernandina station, predictions of extreme water level match well with the general trend of observations. With a correlation coefficient of 0.98, the error for the maximum observed extreme water level of 3.11 m (NGVD datum) with 95 return years is 0.92 %. For Pensacola station, the prediction error for the maximum observed extreme water level with a return period of 83 years is 5.5 %, with a correlation value of 0.98. In frequency analysis of 100 year coastal flood (FEMA 2005), annual extreme high water levels are often used. However, in many coastal areas, long history data of water levels are unavailable. In addition, some water level records may be missed due to the damage of measurement instruments during hurricanes. In this study, a method has been developed to employ artificial neural network and harmonic analysis for predicting extreme coastal water levels during hurricanes. The combined water levels were de-composed into tidal signals and storm surge. Tidal signal can be derived by harmonic analysis, while storm surge can be predicted by neural network modeling based on the observed wind speeds and atmospheric pressure. The neural network model employs three-layer feed-forward backgropagation structure with advanced scaled conjugate training algorithm. The method presented in this study has been successfully tested in Panama City Beach and Apalachicola located in Florida coast for Hurricane Dennis and Hurricane Ivan. In both stations, model predicted peak elevations match well with observations in both hurricane events. The decomposed storm surge hydrograph also make it possible for analysis potential extreme water levels if storm surge occurs during spring high tide.
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Date Issued: 2007
Identifier: FSU_migr_etd-0416
Format: Thesis

Title: Analysis of Cost Change in Air Force Construction Projects from Planning to Completion.
Creator: Barnes, Robert J., Sobanjo, John O., Abdelrazig, Yassir, Spainhour, Lisa, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Construction is a major industry in the United States. In 2010, over $506 billion was spent in construction and construction-related activity, amounting to over 3.4% of Gross Domestic Product (GDP). $21.2 billion, or 0.6% of federal outlays for 2010 was spent on military construction. This accounts for nearly 4% of total construction annually. This study examined three variables in the life of an Air Force military construction (MILCON) project: the programmed amount (PA), the contract award ...
Show moreConstruction is a major industry in the United States. In 2010, over $506 billion was spent in construction and construction-related activity, amounting to over 3.4% of Gross Domestic Product (GDP). $21.2 billion, or 0.6% of federal outlays for 2010 was spent on military construction. This accounts for nearly 4% of total construction annually. This study examined three variables in the life of an Air Force military construction (MILCON) project: the programmed amount (PA), the contract award (CA), and the final current working estimate (CWE). These variables, respectively, reflect the initial planning budget (PA), the actual contractor's estimate and bid (CA), and the final, actual cost of the project to the Air Force (CWE). Statistical hypothesis tests showed there is an appreciable difference between each variable. Generally speaking, the PA is higher than the CA, but the CWE approaches the PA at end of the project. The study suggests several reasons for this, including contractor estimate errors or "bad faith", non-inclusion of inflation, and initial estimate inaccuracy. The results of this study can be used to better analyze contractors' bids as well as initial budgetary estimates to get a more accurate picture of the cost of a particular MILCON project.
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Date Issued: 2012
Identifier: FSU_migr_etd-5317
Format: Thesis

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

Title: Analysis of Run-off-the-Road Crashes Involving Overcorrection a Study of Fatal Traffic Crashes in Florida in 2000.
Creator: Mishra, Abhishek, Spainhour, Lisa K., Sobanjo, John, Ping, W. Vigil, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Overcorrection crashes have long been a concern in crash analysis because the outcomes vary from the vehicle coming to rest after a rollover, to the vehicle passing through the opposite lanes either hitting or without hitting an oncoming vehicle, to rear end and sideswipe impacts. These crashes occur when a vehicle begins drifting off the road one way and the driver oversteers in the opposite direction resulting in a vehicle- vehicle, fixed object, or overturning crash. While analyzing fatal...
Show moreOvercorrection crashes have long been a concern in crash analysis because the outcomes vary from the vehicle coming to rest after a rollover, to the vehicle passing through the opposite lanes either hitting or without hitting an oncoming vehicle, to rear end and sideswipe impacts. These crashes occur when a vehicle begins drifting off the road one way and the driver oversteers in the opposite direction resulting in a vehicle- vehicle, fixed object, or overturning crash. While analyzing fatal crash data from the year 2000 in the state of Florida, it was found that these crashes represented around 25 % of the total number of run-off-the-road (ROR) crashes. With that intention, this research developed models to identify the factors that influence ROR crashes involving overcorrection. Since the outcome of these models is discrete in nature, logistic regression was identified as the most suitable approach. A set of binary logistic regression models were applied to fatal crash data, which were collected from different sources, primarily traffic homicide reports, for crashes occurring on state roads in Florida. Various results were derived from this study and the conclusions were made accordingly. It was found that female drivers are nearly 1.5 times more likely to overcorrect than males. A straight moving vehicle is less likely to be involved in an overcorrection crash than a vehicle that is moving in any other pattern. It was also found that the presence of rumble strips has a negative impact on overcorrection crashes. The odds ratio and p-value for this variable are 1.731 and 0.053 respectively. The odds ratio indicates that the presence of rumble strip increases the chances of overcorrection. All of these factors were significant at minimum at the 85 percent level. For the overcorrection crashes, an additional statistical model was developed to analyze the factors that led the vehicle to leave the paved shoulder prior to overcorrection. These factors are found to be driver sex, age, vehicle movement, vehicle type, speeding, annual daily traffic and presence of rumble strips. Based of the results of this study, recommendations were made suggesting various countermeasures, both behavioral and roadway related, to minimize the occurrence of overcorrection crashes.
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Date Issued: 2006
Identifier: FSU_migr_etd-2391
Format: Thesis

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

Title: 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: Ant Colony Optimization and Bayesian Analysis for Long-Term Groundwater Monitoring.
Creator: Li, Yuanhai, Hilton, Amy Chan, Hu, Bill X., Navon, I. Michael, Huang, Wenrui, Leszczynska, Danuta, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: This dissertation presents the work of groundwater long-term monitoring optimization based on an ant colony optimization algorithm and Bayesian analysis. Groundwater longterm monitoring (LTM) is required to assess human health and environmental risk of residual contaminants after active groundwater remediation activities are completed. However, LTM can be costly because of the large number of sampling locations and frequencies that exist at a site from previous site characterization and...
Show moreThis dissertation presents the work of groundwater long-term monitoring optimization based on an ant colony optimization algorithm and Bayesian analysis. Groundwater longterm monitoring (LTM) is required to assess human health and environmental risk of residual contaminants after active groundwater remediation activities are completed. However, LTM can be costly because of the large number of sampling locations and frequencies that exist at a site from previous site characterization and remediation activities. Two LTM spatial sampling optimization methods based on ant colony optimization (ACO) algorithm were developed to identify optimal sampling networks that minimize the cost of LTM by reducing the number of monitoring locations with minimum overall data loss. The first method is called the primal ACO-LTM algorithm, which minimizes the number of remaining wells given the constraint on data loss quality, and it was implemented by binary decision variables. The second method is inspired by primal algorithm, and named as the dual ACO-LTM algorithm, here the role of the number of remaining wells is reversed from objective function to constraint, and this algorithm was to minimize the data loss given a fixed number of remaining wells. This dual ACO-LTM algorithm has a close analogy to the ACO paradigm for solving the traveling salesman problem (TSP). However, unlike the xii TSP problem, in the LTM problem, the ants will not necessarily visit all the wells. The ant terminates traveling when it has visited a given number of wells equal to the described number of redundant monitoring wells. Comparisons among the primal and dual ACO-LTM, the GA, and complete enumeration show that The dual ACO-LTM algorithm showed the best performance and identified global optimal solutions. A statistical guideline for LTM temporal redundancy problem was proposed. Instead of relying on pollutant transport simulation models, this method is a data driven analysis approach. This study uses a Bayesian statistics-based methodology to optimize the scheduling of groundwater long-term monitoring. The technique combines information from different sets of observations over multiple sampling periods with spatial sampling optimization by ant colony optimization algorithm to provide probability distribution for future sampling schedule. Thus, the output of this method is not binary results (0/1), but fuzzy probabilistic scale (0 1) for future monitoring schedule of each individual monitoring well. The results from medium size site were compared with those from other LTM design methods, including MAROS, CES, and 3-tiered approach. Similar but outperforming results with other methods verified that this method is a promising approach for LTM temporal problem.
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Date Issued: 2006
Identifier: FSU_migr_etd-1438
Format: Thesis

Title: The Applicability of Using Soil Concentrations to Predict Groundwater Concentrations during Assessments at Petroleum Contaminated Sites in Florida.
Creator: Monteiro, Natalie Marie, Hilton, Amy B. Chan, Chen, Gang, Huang, Wenrui, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Various empirical equations have been offered to facilitate the prediction of the concentration of pollutants in different phases in the environment. Using one such equation, Brown and Flagg (1981), the predicted separation between the saturated soil and the groundwater of benzene, toluene, ethylbenzene and xylenes were compared to the actual laboratory samples from 18 petroleum contaminated sites across Florida. In this study, 50 underground soil and groundwater samples were used to see if...
Show moreVarious empirical equations have been offered to facilitate the prediction of the concentration of pollutants in different phases in the environment. Using one such equation, Brown and Flagg (1981), the predicted separation between the saturated soil and the groundwater of benzene, toluene, ethylbenzene and xylenes were compared to the actual laboratory samples from 18 petroleum contaminated sites across Florida. In this study, 50 underground soil and groundwater samples were used to see if the actual soil data could reliably predict the associated groundwater concentration; if the equation is appropriate to use to predict the groundwater concentration of the sum of the four volatile organic aromatics (benzene, toluene, ethylbenzene and xylenes or BTEX); how five variable involved in the sample collection affected the results: sample type; lithology; horizontal distance between the soil and groundwater sample; vertical distance between the soil and groundwater sample; and magnitude of the soil concentration; and how the calculated foc compared to the default foc used in the development of FDEP's CTLs. The soil concentration had a positive correlation with the groundwater concentration and a positive correlation with the Equation. While at first it appeared that the samples collected via direct push technology had a better correlation than those collected via monitoring wells, after further analysis, the groundwater samples collected via monitoring wells and with a vertical distance between the soil sample and the top of the water table of between 1-2 feet, had the best overall correlation. The poorly graded sands, with little to no fines, (SP) had good correlations for ethyl benzene and xylenes concentrations, but not for benzene and toluene concentrations. Meanwhile, the silty sands (SM) and the clayey sand/sandy clays (SC) were the reverse with good correlations with benzene and toluene, but not for the ethyl benzene and xylenes concentrations. As could be reasonably expected, the horizontal distance of less than or equal to five feet between the soil and groundwater sample had a good correlation (with the same location being the best), and greater than 5 feet away was a poor correlation. The vertical distance of one to two feet had the best correlation with the same location not as good, and greater than two feet worse. The soil concentration magnitude range results were not great for any individual constituents but the correlation for BTEX was pretty good from 0.1 to 100 mg/kg. What was interesting was how the individual constituent's concentrations varied over the soil concentration magnitude ranges. Of the 50 data points, the majority of the benzene and toluene concentrations were in the lower ranges ( The average fractional organic carbon, foc, as calculated from the soil and groundwater concentrations, was the highest in the clayey sands/sandy clays, then silty sands, and finally poorly graded sands. More than 80% of the soil samples had a calculated average foc of greater than 0.006 (0.002 and 0.006 are the default foc used to develop FDEP's Cleanup Target Levels). For soils other than poorly graded sands, the fractional organic carbon should be measured during the site assessments to calculate site-specific CTLs to reduce unnecessary remedial efforts. Trying to use the Brown and Flagg (1981) empirical equation to predict the groundwater concentration from the soil concentration at petroleum contaminated sites in Florida, may lead to erroneous data without analyzing the soil for fractional organic carbon. Better data correlation may be obtained if the corresponding organic content of the soil is analyzed along with the soil contaminant concentration. Further research into this subject could be refined by the following methods: 1) ensure the soil and groundwater data are collected from the same location but at various depths (within 0 to 3 ft); 2) analyze the soil for carbon content instead of assuming a carbon content; 3) obtain a better distribution of lithological and soil concentration magnitude samples; 4) collect groundwater samples at the same location via dpt and MWs; and 5) test aging, lithology and surface covering through a controlled field experiment with multiple cells.
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Date Issued: 2009
Identifier: FSU_migr_etd-2334
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: An Assessement of on-Site Renewable Energy Source Consideration with Original Building Construction Procurement Efforts.
Creator: Sneed, Troy Lenard, Clark, Clayton J., AbdelRazig, Yassir, Sobanjo, John, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: As energy resources are needed in abundance to sustain the ever evolving global economy, the world's energy dependency for good reason, is beginning to shift. Various studies have shown that although fossil fuels are still the primary source of energy for the world, the utilization of more sustainable energy resources is on the rise. However due to current competitive bidding strategies and underlying practices that typically consider sustainable features such as renewable energy sources as...
Show moreAs energy resources are needed in abundance to sustain the ever evolving global economy, the world's energy dependency for good reason, is beginning to shift. Various studies have shown that although fossil fuels are still the primary source of energy for the world, the utilization of more sustainable energy resources is on the rise. However due to current competitive bidding strategies and underlying practices that typically consider sustainable features such as renewable energy sources as costly additions rather than effective options to program requirements, building construction procurement strategies have been slow to embrace this change. In this thesis, a methodology is derived for assessing the overall benefits of utilizing a renewable energy source as a program option from the original building construction procurement effort. This methodology was developed by utilizing project procurement methods and techniques, in addition to certain life cycle costing concepts. Data from the original procurement of The Basic School in Quantico, Virginia was used to apply this methodology. The results of this application and supplemental research show that the incorporation of a renewable energy source into the original building construction procurement effort as opposed to additions that are incorporated later in the project procurement effort produced cost and schedule benefits. Furthermore, a contractor could apply this methodology to similar projects that incorporate sustainable features into its original design and cost estimates, and utilize the findings of the application in the technical components of future projects.
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Date Issued: 2012
Identifier: FSU_migr_etd-5437
Format: Thesis

Title: Assessing the Financial Feasibility of Implementing Wireless Technologies for Construction Management.
Creator: Singletary, Matthew Ryan, AbdelRazig, Yassir, Ping, Wei-Chou V., Sobanjo, John, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The construction industry has been one of the slowest to assimilate new technologies into its business processes. There are several barriers to technology adoption within the construction industry that have created a general low tolerance for risk and conservative attitude towards change. Wireless technologies, web-based collaboration, and mobile computing devices have agreeably high potential benefits for the construction industry; however, there is a lack of research and well-documented...
Show moreThe construction industry has been one of the slowest to assimilate new technologies into its business processes. There are several barriers to technology adoption within the construction industry that have created a general low tolerance for risk and conservative attitude towards change. Wireless technologies, web-based collaboration, and mobile computing devices have agreeably high potential benefits for the construction industry; however, there is a lack of research and well-documented projects that stand as proof of their value. An extensive review of wireless technology applications for the construction industry is presented in this thesis, along with a review of Earned Value Management (EVM) and Life Cycle Cost (LCC) analysis. A methodology is developed for applying and assessing wireless technologies for construction project control with EVM incorporated as a project control technique. Data from the Jefferson County High School construction project located in Monticello, Florida, is used to apply the methodology that was developed. The results of this application indicate that the implementation of a wireless IT investment could have reduced the total project cost.
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Date Issued: 2006
Identifier: FSU_migr_etd-0337
Format: Thesis

Title: Barrier, Joint, and Diaphragm Effects on Force Distribution in Prestressed Concrete Girder Bridges.
Creator: Chipperfield, Jonathan Darren, Rambo-Roddenberry, Michelle, Jung, Sungmoon, Tawfiq, Kamal, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The American Association of State Highway and Transportation Officials (AASHTO) determine the load effects to interior and exterior girders by the Bridge Design Specifications. The equations in both the AASHTO Standard and AASHTO Load and Resistance Factor Design (LRFD) specifications do not take into account secondary elements, such as barriers, curbs, or diaphragms. Research has shown that the AASHTO equations are conservative,and that girders could be overdesigned. With the addition of...
Show moreThe American Association of State Highway and Transportation Officials (AASHTO) determine the load effects to interior and exterior girders by the Bridge Design Specifications. The equations in both the AASHTO Standard and AASHTO Load and Resistance Factor Design (LRFD) specifications do not take into account secondary elements, such as barriers, curbs, or diaphragms. Research has shown that the AASHTO equations are conservative,and that girders could be overdesigned. With the addition of secondary elements in the equations it would be possible to reduce the distribution factors after the secondary elements have been placed. The Florida Department of Transportation (FDOT) Structures Research Lab made field strain measurements on two bridges, one a Florida Bulb-T bridge and the other an AASHTO Type IV Girder bridge. The Florida Bulb-T bridge strain measurements were taken before and after barriers were placed, and the AASHTO bridge strain measurements were only for a post-barrier condition. The purpose of this research was to create two finite element models (FEM) using ANSYS 11.0 and calibrate them to the measured test results. After the calibrated models were validated a parametric study was performed comparing the effects of secondary elements on live load distribution. Included in this parametric study are the effects of the barrier, the barrier joint, and the diaphragms, on the girders, both interior and exterior. The results of this project show the effects of secondary elements and whether they are localized or global on the longitudinal span of the bridge, as well as tell how the live load is being distributed. Also, for load testing, recommendations on placement of strain gages will be discussed.
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Date Issued: 2010
Identifier: FSU_migr_etd-3806
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: Bio-Reactive Landfill Covers: An Inexpensive Approach to Mitigate Methane Emissions.
Creator: Escoriaza, Sharon Czarina, Abichou, Tarek, Chanton, Jeff, Chan-Hilton, Amy, Powelson, Dave, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Methane is one of two primary gases produced from the decomposition of landfill waste. Studies have been directed to collection and mitigation of methane gas. In small landfills, collection is not an economically feasible solution. Bio-cover placement is an inexpensive approach to mitigating methane emissions. The enhancing of oxidation processes by placement of bio-covers will reduce emissions even while gas extraction is employed and improve aesthetic quality of solid waste facilities. The...
Show moreMethane is one of two primary gases produced from the decomposition of landfill waste. Studies have been directed to collection and mitigation of methane gas. In small landfills, collection is not an economically feasible solution. Bio-cover placement is an inexpensive approach to mitigating methane emissions. The enhancing of oxidation processes by placement of bio-covers will reduce emissions even while gas extraction is employed and improve aesthetic quality of solid waste facilities. The overall objective of the research is to mitigate methane emissions from landfills. To reach this objective, a test site was selected to evaluate the effects of compost placement over a closed landfill. The static chamber technique was used to estimate methane emissions and the stable isotope tracing method was used to determine oxidation rates. Hot spots were identified in the grid area and emissions at these spots were analyzed more in detail. Results obtained during the first year of the study are presented in this thesis. In these investigative efforts, it was noted that moisture content plays a significant role in controlling emissions and oxidation. At high water contents, low flux emissions were measured observed and at low water contents, emissions were higher. Oxidation rates varied in much the same way. High water contents corresponded with low oxidation rates and vise versa. Further study on the effects of moisture content and other variables on flux emission and oxidation is warranted.
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Date Issued: 2005
Identifier: FSU_migr_etd-0520
Format: Thesis

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

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

Title: Bulb-T Girder Bridge Barrier Effect on Live Load Distribution.
Creator: Stricker, Tal, Rambo-Roddenberry, Michelle, Spainhour, Lisa, Tawfiq, Kamal, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Bulb-T girder bridges are composed of precast, prestressed concrete beams with a reinforced concrete slab. Typically, the slab extends transversely beyond the exterior beam, and there is a traffic barrier on the edge. The bridges are designed for dead and live loads and prestressing effects. For the live loads, the transverse distribution of moment and shear load effects to interior and exterior girders is determined by using equations in the American Association of State Highway and...
Show moreBulb-T girder bridges are composed of precast, prestressed concrete beams with a reinforced concrete slab. Typically, the slab extends transversely beyond the exterior beam, and there is a traffic barrier on the edge. The bridges are designed for dead and live loads and prestressing effects. For the live loads, the transverse distribution of moment and shear load effects to interior and exterior girders is determined by using equations in the American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications. These equations give the designer a factor, which is then multiplied by the moment or shear load effect determined by a line analysis. The equations assume that barriers are not present. The Florida Department of Transportation (FDOT) Structures Research Lab has made field measurements on a Bulb-T bridge, both before and after the barriers were placed, due to a truck loaded with blocks. For this project, this data was analyzed to determine the barrier's effect on the live load distribution. The results of this project may be used to determine if load ratings can be improved by consideration of the barrier effect, which can be done as a Posting Avoidance (Exception) technique.
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Date Issued: 2008
Identifier: FSU_migr_etd-1542
Format: Thesis

Title: Calibration and Evaluation of Link Congestion Functions: Applying Intrinsic Sensitivity of Link Speed as a Practical Consideration to Heterogeneous Facility Types within Urban Network.
Creator: Mtoi, Enock T., Moses, Ren
Abstract/Description: This paper explores the use of archived data to calibrate volume delay functions (VDFs) and updates their input parameters (capacity and free-flow speed) for planning applications. The sensitivity analysis of speed to change in congestion level is performed to capture functional characteristics of VDFs in modeling specific facility types. Different sensitivity characteristics shown by the VDFs indicate that each function is suitable to a particular facility type. The results of sensitivity...
Show moreThis paper explores the use of archived data to calibrate volume delay functions (VDFs) and updates their input parameters (capacity and free-flow speed) for planning applications. The sensitivity analysis of speed to change in congestion level is performed to capture functional characteristics of VDFs in modeling specific facility types. Different sensitivity characteristics shown by the VDFs indicate that each function is suitable to a particular facility type. The results of sensitivity analysis are confirmed by the root mean square percent error (RMSPE) values calculated using the Orlando Urban Area Transportation Study (OUATS) model results and observed data. The modified Davidson's function exhibits remarkable performance in nearly all facility types. The strength of the modified Davidson's function across a broad range of facilities can be attributed to the flexibility of its tuning parameter, μ. Fitted Bureau of Public Road (BPR) and conical delay functions show lower RMSPE for uninterrupted flow facilities (freeways/expressways, managed lanes) and higher values for toll roads (which might have partial interruptions due to toll booths) and signalized arterials. Akcelik function underperforms on freeways/expressways and managed lanes but shows some improvements for toll roads and superior results for the signalized arterials. This was a desired strength of Akcelik function when modeling link travel speed on facilities where stopped delays were encountered.
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Date Issued: 2014
Identifier: FSU_migr_cee_faculty_publications-0001, 10.4236/jtts.2014.42014
Format: Citation

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: Colloid and Surfactant Transport Modeling Through Agricultural Soil.
Creator: Patil, Sandip R. (Sandip Raman), Chen, Gang, Ordóñez, Juan Carlos, Clark, Clayton, Watts, Michael, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: National Water-Quality Assessment Program (NAWQA) was designed just after the U.S. Geological was established. The primary objective of the NAWQA was to understand the key processes controlling contaminant fate and transport into the Nation's water resources. In particular, wide use of pesticides and fertilizers in agricultural field can impact on the quality of surface and ground waters. Contaminants can be carried to the water bodies by several ways. In colloid-facilitated transport process...
Show moreNational Water-Quality Assessment Program (NAWQA) was designed just after the U.S. Geological was established. The primary objective of the NAWQA was to understand the key processes controlling contaminant fate and transport into the Nation's water resources. In particular, wide use of pesticides and fertilizers in agricultural field can impact on the quality of surface and ground waters. Contaminants can be carried to the water bodies by several ways. In colloid-facilitated transport process colloidal particles serves as a transport media for the contaminants. Colloid release from the agricultural soil under unsaturated conditions is controlled by the hydrodynamic force, capillary force and electrostatic force that is determined by the solution chemistry in terms of solution ionic strength and pH. In this research, colloid release from the agricultural soil was investigated using an intact soil column collected from an agricultural site in Gadsden County of Florida. Colloid release was monitored and the colloid release curve was simulated using an implicit, finite-difference scheme to obtain the colloid release coefficient. It was found that the hydrodynamic force and electrostatic force overcame the capillary force under the experimental conditions of this research and consequently, colloids were released. For the colloid release, solution chemistry played a key role by controlling the colloid repulsive electrostatic force within the pore system. Colloid release exponentially decreased with the increase of solution ionic strength and increased with the increase of solution pH. Colloid release was finally found to be correlated to the colloid repulsive electrostatic force within the pore system, i.e., the greater the repulsive electrostatic force, more colloids were released. In situ colloid mobilization and transport has been studied under both saturated and unsaturated conditions. In saturated conditions, the controlling parameters are solution ionic strength and pH. Colloid mobilization and transport have been modeled by the advection-dispersion equation with a first-order colloid release. The inverse version of these models can provide a platform to estimate transport parameters based on transport observations. In this research, we taken the advantages of existing contaminants transport models by fully utilizing them to investigate colloid interactions with the surrounding environment and provide parameter constraints for colloid transport modeling applications under saturated conditions. In natural systems, colloids present a potential health risk due to their propensity to associate with contaminants or in the case of certain biological colloids, inherent pathogenic nature. Although colloidal interactions have been studied for many years and much has been learned about the physical and chemical processes that control colloid retention, there still remains significant uncertainty about the processes that govern colloid release. The aim of this study was to investigate the release of in situ colloids as a function of soil depth. Colloid release from intact agricultural soil columns with variable length was investigated. Colloid release curves were simulated using an implicit, finite-difference scheme and colloid release rate coefficient was found to be an exponential function of the soil depth. The simulated results demonstrated that transport parameters were not consistent along the depth of the soil profile. Wetting agents wet hydrophobic soil by lowering the cohesive and/or adhesive surface tension, which allows the water to spread out more evenly and allows for better penetration into the hydrophobic soils. While enhancing water penetration, wetting agent applications may bring adverse impact on the soil and groundwater at the same time. The residual organic phase in the soil pores poses a long-term source of groundwater contamination. After use, residual wetting agents and their degradation products are discharged to groundwater or directly to surface waters, then dispersed into different environmental compartments. In order to assess their environmental risks, we need to understand the distribution, behavior, fate and biological effects of these surfactants in the environment. This research was designed to investigate the application of nonionic wetting agents in agricultural soils. Performance of nonionic surfactants in intact soil columns collected from agricultural soils was explored and related to the soil and wetting agent properties. In addition, the impact of the organic concentration of wetting agent fate and transport was investigated. The transport of wetting agents in the agricultural soil columns was simulated using the proposed transport models and subsequently, the effect of organic compounds on wetting agent transport was quantified.
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Date Issued: 2012
Identifier: FSU_migr_etd-5098
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: 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: Correlation Between Falling Head and Double Ring Testing for a Full-Scale Infiltration Study.
Creator: Hayden, Audra H., Tawfiq, Kamal, Rambo-Roddenberry, Michelle, Ping, Wei-Chou V., Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Stormwater management facility design is a branch of engineering that demands a full understanding of soil and permeability and how water infiltrates into the ground. With new residential and commercial developments, holding facilities for rainwater are required. Due to the cost associated with purchasing land for holding water, the idea is to make the pond dimensions as small as possible. With this idea, the engineer will need a precise way to determine the rate at which water will...
Show moreStormwater management facility design is a branch of engineering that demands a full understanding of soil and permeability and how water infiltrates into the ground. With new residential and commercial developments, holding facilities for rainwater are required. Due to the cost associated with purchasing land for holding water, the idea is to make the pond dimensions as small as possible. With this idea, the engineer will need a precise way to determine the rate at which water will infiltrate into the soil. This research centers on determining how permeability most accurately predicts a stormwater pond's actual infiltration rate. Several estimations for permeability have been evaluated: grain-size correlations, falling head permeameters, double ring infiltrometer tests and single ring infiltrometer tests. For this research, an existing stormwater facility was chosen. At this location, the field tests were conducted and subsurface samples were taken for laboratory analysis. In addition, to measure the actual field infiltration rate, a staff gage was installed and monitored after a precipitation event. The program MODRET was utilized to determine which of the various estimations of permeability yield an infiltration that most closely resembles that of monitored existing conditions.
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Date Issued: 2010
Identifier: FSU_migr_etd-4193
Format: Thesis

Title: Correlation of Water Quality Indicators for Coastal Marshes.
Creator: Hendrix, Matthew, Chen, Gang, Watts, Michael, Clark, Clayton, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Florida provides some of the most diverse and beautiful environments in the United States, with northwest Florida being a nearly undisturbed bounty of lush lands, springs, and other geological and ecological features. Increases in population have recently started to jeopardize some of Florida's prized areas, including the Ochlocknee-St Marks Basins. Development and agriculture has started to affect watersheds and waterbodies. This study has evaluated the water quality of coastal marshes at...
Show moreFlorida provides some of the most diverse and beautiful environments in the United States, with northwest Florida being a nearly undisturbed bounty of lush lands, springs, and other geological and ecological features. Increases in population have recently started to jeopardize some of Florida's prized areas, including the Ochlocknee-St Marks Basins. Development and agriculture has started to affect watersheds and waterbodies. This study has evaluated the water quality of coastal marshes at the St. Marks national Wildlife Refuge in terms of coliform and chlorophyll a. With these constituents, dissolved oxygen (DO), temperature, pH, conductivity, and total suspended solids were evaluated. The study took place with data from January 2009 to June 2009. The study site of this research, St. Marks National Wildlife Refuge, is located 25 miles south of Tallahassee along the Gulf Coast of Florida. To analyze for coliform, 100ml samples were filtered on cellulose nitrate membranes and subsequently incubated. After 24hrs the fecal coli forms were counted and recorded. Measuring the chlorophyll a was done taking a volume of water from a particular depth and filtering it through a fine glass fiber filter to collect all of the particulate material great than 1 micron. To extract the chlorophyll, acetone/alcohol was used as a solvent and then measured using an optical kit and Luminometer utilizing a chlorophyll a standard. Effective diffusion was then measured in the lab using a diffusion coefficient in distilled water. This process was also observed using a Hamamatsu high sensitivity monochrome digital camera in a dark room, with the sample being placed in a petri dish with native soil. Chlorophyll a adsorption was measured by introducing the sample to a column filled with goethite-coated silica sand. Transport parameters were obtained by fitting the experimentally obtained Chlorophyll a breakthrough data using an implicit, finite-difference scheme. All the parameters were optimized by minimizing the sum of squared differences between observed and fitted concentrations using the nonlinear least-square method. Some key observations over the sample period include the dropping of DO as the summer months began indicating increased microbial activity with temperature. TKN and Chlorophyll were observed to increase as temperature increased. When observing Chlorophyll as a function of TKN, the Pearson Correlation and the plot indicate that with increased TKN more microbiological activity occurs - such as with plants, algae, etc. Interestingly when Chlorophyll was plotted as a function of DO, the low DO encourages microbial growth, however only to an extent. The point can be made that less polluted water has less microbial activity. The correlation between coliform and turbidity showed an increase of coliform with NTU. Chlorophyll as a function of turbidity showed no correlation. However as a first order function, d[Chlorophyll a]/d[Turbidity] displayed a linear relationship with turbidity, indicating the correlation of chlorophyll a variation with respect to turbidity. When conductivity was plotted against pH, the variability of conductivity and pH was not significantly different. Chlorophyll a also had a correlation with pH. With the increase of pH, chlorophyll a exponentially decreased. This research shows the increased ability to forecast and assess risk presented by development and agriculture of coastal environment based on physical and chemical variations in coastal wetland ecosystems.
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Date Issued: 2012
Identifier: FSU_migr_etd-5361
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: Decision Support System to Rank and Evaluate Crash Attenuators.
Creator: Roth, Jason, Spainhour, Lisa, Mtenga, Primus V., Sobanjo, John, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Understanding the behavior and performance of roadside safety devices, such as guardrails, concrete barriers, end terminals, and crash attenuators, is of great importance to improving the safety of roadways and intersections. Crash attenuators have saved numerous lives by reducing the severity of vehicle crashes. However, while a great deal of crash test data exists on barriers and end terminals, information on their performance under field conditions is limited. Because of a variety of...
Show moreUnderstanding the behavior and performance of roadside safety devices, such as guardrails, concrete barriers, end terminals, and crash attenuators, is of great importance to improving the safety of roadways and intersections. Crash attenuators have saved numerous lives by reducing the severity of vehicle crashes. However, while a great deal of crash test data exists on barriers and end terminals, information on their performance under field conditions is limited. Because of a variety of reasons described in more detail below, the field performance of barriers and attenuators can vary drastically from their behavior during crash tests. Four research objectives were established for this project. They are as follows: 1) Develop a database system. 2) Design and implement a framework for a Decision Support System (D.S.S.). 3) Input the appropriate data from FDOT into the database. 4) Use the D.S.S. and data to rank and evaluate attenuators. The DSS is a computer program, based on a decision tree, which recommends an action that best meets a set of prioritized goals. The designer specifies goals, measures (criteria by which the goals can be quantified), and alternates (different ways in which the goal can be met). Weights are used to prioritize or indicate the relative importance of each goal and measure. They are also used to indicate the degree to which each alternate meets the objectives. A series of graphs were developed to explain and compute the relationship between each DSS site criteria and the relevant site characteristics; these graphs are known as the importance functions. The importance functions range from zero (meaning that the site characteristic is not relevant at all for the given value of the DSS criteria) to one (meaning that the site characteristic is very important for the given value of the DSS criteria). In some cases, the graphs were developed based on numeric evidence found through researching accident reports, roadway design and attenuator selection standards, and other relevant literature. For relationships where numeric values could not be found, common sense was used to develop the graph. Based on the test cases included in Chapter 5 and other test cases that were run, the Decision Support System does work and recommends different attenuators to meet different site characteristics and/or situations. It was determined that the Decision Support System results are more sensitive to changes in the objective weights and test standards and not so sensitive to changes in the site characteristics. The only time there were significant changes in the recommendations based on site characteristics is when the type of site was drastically changed. In the case of a mild site, based on the current setup, the recommendation could be that an attenuator may not be needed. Therefore, the importance functions should be fine-tuned to help in different recommendations. Another recommendation is that more data needs to be added to the database. This could help give better or more accurate recommendations, since the recommendations are based on historical performance data. More historical data is required on attenuators that meet the NCHRP-350 standards. As with any program that gives results based on its database, the more data that is available the more accurate the results will be.
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Date Issued: 2004
Identifier: FSU_migr_etd-1781
Format: Thesis

Title: Deficiency Analysis of Coastal Buildings for Storm Damage Reduction.
Creator: Dowgul, Ronald Walter, Yazdani, Nur, Tawfiq, Kamal, Leszczynska, Dauta, Martinko, Mark, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Since 1984 the author has provided engineering services to property owners, insurance companies, attorneys, and others. The scope of those services typically included identifying the cause and origin of damage to residential and commercial structures as well as an estimation of the magnitude of damage sustained by those structures. The majority of those damaged structures were located in proximity to a coastal region and have experienced recent exposure to a storm or other weather event. The...
Show moreSince 1984 the author has provided engineering services to property owners, insurance companies, attorneys, and others. The scope of those services typically included identifying the cause and origin of damage to residential and commercial structures as well as an estimation of the magnitude of damage sustained by those structures. The majority of those damaged structures were located in proximity to a coastal region and have experienced recent exposure to a storm or other weather event. The long-term performance of any building (structure) is directly related to, among other things, the design or physical features of the building, construction practices, routine maintenance, and exposure to severe weather events. During periods of increased external loading and water exposure, such as those resulting from severe weather events, deficiencies in design, construction, or maintenance often result in what would otherwise be avoidable building damage. As a result of more than one thousand case studies involving site inspections, it has become apparent that building related deficiencies are often found to exist as a common feature in similar structures. Some of those recurring deficiencies could be eliminated with alternate building design, better construction practices, or proper routine maintenance procedures. Compilation of those case studies has allowed identification and ranking of the occurrence of chronic building problems. Where applicable, proposed remedial solutions are presented for specific building deficiencies or problems identified. It appears that a significant lack of feedback to engineers, architects, and builders exists regarding long term building performance. An increased awareness of existing chronic deficiencies in the design and construction of buildings and a subsequent effort to eliminate those deficiencies is essential to the future performance of new construction, in general, and specifically to the storm survivability of many structures in coastal regions. Much of what has been learned as a result of this analysis can be of considerable value to professionals or future professionals involved in the building design and construction communities.
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Date Issued: 2005
Identifier: FSU_migr_etd-0681
Format: Thesis

Title: Design of Cost Effective Lysimeter for Field Evaluation of Alternative Landfill Cover Projects Using HYDRYS 2D Simulation.
Creator: Liu, Xiaoli, Abichou, Tarek, Hilton, Amy Chan, Tawfiq, Kamal, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Landfills are the most widely used facilities for solid waste disposal. Landfill covers are used to reduce the quantity of water that infiltrates into solid waste landfills, isolate solid waste from the environment and control gas migration. Resource Conservation and Recovery Act (RCRA) regulations prescribe that the covers employ layers which have low saturated hydraulic conductivity as hydraulic barriers. Those barriers can limit flow into underlying solid wastes, and consequently, reduce...
Show moreLandfills are the most widely used facilities for solid waste disposal. Landfill covers are used to reduce the quantity of water that infiltrates into solid waste landfills, isolate solid waste from the environment and control gas migration. Resource Conservation and Recovery Act (RCRA) regulations prescribe that the covers employ layers which have low saturated hydraulic conductivity as hydraulic barriers. Those barriers can limit flow into underlying solid wastes, and consequently, reduce the rate of leachate generation and risk of additional groundwater contamination. Experience has shown that the prescribed clay barrier layers are susceptible to failure caused by desiccation and cracking damage by freeze â thaw actions, and are expensive to build. An effective alternative cover design is Evapor-Transpiration (ET) cover. ET covers possess many advantages over prescribed covers such as working with nature, long life time, easy maintenance and lower cost. Once the feasibility of an ET cover is verified in a region, an evaluation of hydraulic equivalency is required for alternative cover to be approved by regulatory authorities. The hydraulic equivalency requires that percolation from the base of the alternative cover is less than or equal to percolation rate from the prescriptive cover. Lysimeters was suggested to be used in facilities measuring the percolation rate. There are some concerns about the precision with which percolation rate can be measured with lysimeters. A series of numerical simulations were performed in this study to investigate the performance of lysimeters of various geometries and develop the optimal lysimeters dimensions for percolation rate measurement. The simulations consist of inputting data for lysimeter geometry, soil hydraulic property, weather condition, boundary condition, vegetation distribution and density. The output cumulative flux data was used to evaluate the performance of lysimeters. The study shows at the specific weather condition, the lysimeters without sidewalls underestimate percolation rate by at least 25%. Installation of full sidewalls remarkably improved the lysimeter performance. The lysimeter with full scale sidewalls still underestimate by at least 10%. Lateral diversion and no-flow boundary at the bottom of lysimeter and the drainage layer right above the bottom pan caused the decrement of lysimeter performance. To measure percolation rate accurately, soil - specific and site - specific coefficients have to be determined. The coefficients can to be used to correct lysimeter performance.
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Date Issued: 2004
Identifier: FSU_migr_etd-1198
Format: Thesis

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

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

Title: 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: 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: 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: 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: Development of User Cost Model for Movable Bridge Openings in Florida.
Creator: Buxton-Tetteh, Bernard, Sobanjo, John O., Mussa, Renatus N., Spainhour, Lisa, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: The Florida Department of Transportation (FDOT) is currently implementing the AASHTO Pontis® Bridge Management System (BMS) to support network-level and project-level decision making at the state and district levels. User cost models in the Pontis BMS quantify in economic terms, the potential safety and mobility benefits of maintenance, repair and replacement of bridge structures. Movable bridge openings force vehicles traveling over the bridges to be held in queues and this results in extra...
Show moreThe Florida Department of Transportation (FDOT) is currently implementing the AASHTO Pontis® Bridge Management System (BMS) to support network-level and project-level decision making at the state and district levels. User cost models in the Pontis BMS quantify in economic terms, the potential safety and mobility benefits of maintenance, repair and replacement of bridge structures. Movable bridge openings force vehicles traveling over the bridges to be held in queues and this results in extra travel time for motorists. The extra travel times are quantifiable as traffic delays costs, which are indirectly borne by commerce and the motoring public, and can be used in an economic analysis to justify the replacement of movable bridges. This thesis presents a study that involved the collection of Florida specific data on vehicular and vessel traffic, including vehicle queue counts, average daily traffic, hourly distribution of vehicular traffic, movable bridge openings, vessel counts and vessel heights at six (6) selected, geographically unbiased, movable bridge sites within the Florida. The data were analyzed and used in development of a user cost model for movable bridge openings for implementation in the Florida Pontis BMS. The movable bridge openings were modeled as bottleneck incidents on the roadways carried by the movable bridges and a deterministic queue model was used in analyzing the resulting delays to vehicular traffic. The developed model was used in a network analysis of Florida's inventory of 147 movable bridges to estimate the economic benefits of bridge replacement projects with the objective of correcting load carrying capacity deficiencies and elimination of traffic delays that were caused by the movable bridge openings. Results obtained showed that the savings in delays to vehicular traffic caused by movable bridge openings would contribute about eight (8) times more than the economic benefits that may be obtained from strengthening movable bridges in Florida.
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Date Issued: 2004
Identifier: FSU_migr_etd-2395
Format: Thesis

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

Title: Dynamic Interaction Between Heavy Vehicles and Highway Bridges.
Creator: Ford, Eduardo E. Taft, Wekezer, Jerry, Jung, Sungmoon, Rambo-Roddenberry, Michelle, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: Modern prestressed reinforced concrete bridges are designed per LRFD standards, and are lighter with smaller safety factors. At the same time bridges are loaded with heavier vehicles with substantial masses when compared to the mass of the bridge. It requires fairly detailed FE models of the vehicles (in addition to the FE models of the bridges) for a meaningful analysis of the vehicle-bridge dynamic system. Imperfections in road surfaces can trigger significant dynamic loads on the bridge...
Show moreModern prestressed reinforced concrete bridges are designed per LRFD standards, and are lighter with smaller safety factors. At the same time bridges are loaded with heavier vehicles with substantial masses when compared to the mass of the bridge. It requires fairly detailed FE models of the vehicles (in addition to the FE models of the bridges) for a meaningful analysis of the vehicle-bridge dynamic system. Imperfections in road surfaces can trigger significant dynamic loads on the bridge with adverse effects, which are not well understood. FDOT issues over 90,000 permits for heavy vehicles every year, therefore finding newer, easier, and more economical ways to study and understand the actual impact of dynamic loads on bridges is critical for design and maintenance of highway bridges. The main goal of this research was to develop numerical models of heavy vehicles and bridges and to use them for transient analysis of dynamic interaction between the vehicle and the bridge. An assessment of three finite element (FE) vehicle models and one bridge FE model was carried out and the necessary improvements were implemented. Additional bridges in North Florida were surveyed, and two substructures were selected for modeling. The two selected bridges had different geometric characteristics and their FE models were developed according to AASHTO specifications. Three FE models of heavy vehicles were used with three different bridges for computational dynamics analysis using the LS-DYNA computer code. The influence of several factors such as vehicle mass and speed, road surface condition, and loosely secured cargo were assessed. Dynamic load allowance (DLA) was determined for each vehicle-bridge combination. Practical conclusions regarding methods to mitigate DLAs were presented.
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Date Issued: 2010
Identifier: FSU_migr_etd-1753
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: 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: Effect of Friction on Vehicle Crashworthiness during Rollover.
Creator: Gleba, Michal, Jung, Sungmoon, Rambo-Roddenberry, Michelle Deanna, Spainhour, Lisa, Wekezer, Jerry W., Florida State University, College of Engineering, Department of Civil and...
Show moreGleba, Michal, Jung, Sungmoon, Rambo-Roddenberry, Michelle Deanna, Spainhour, Lisa, Wekezer, Jerry W., Florida State University, College of Engineering, Department of Civil and Environmental Engineering
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Abstract/Description: The State of Florida acquires over 300 cutaway buses every year. The increasing popularity of such buses raised concerns about passenger safety and overall crashworthiness of this transportation mode. Dimensions of the cutaway buses and their two-stage manufacturing process made them exempted from safety standards which were developed for smaller passenger cars as well as for large coaches. To fill this gap, cutaway bus manufacturers try to demonstrate the strength of their bus roof...
Show moreThe State of Florida acquires over 300 cutaway buses every year. The increasing popularity of such buses raised concerns about passenger safety and overall crashworthiness of this transportation mode. Dimensions of the cutaway buses and their two-stage manufacturing process made them exempted from safety standards which were developed for smaller passenger cars as well as for large coaches. To fill this gap, cutaway bus manufacturers try to demonstrate the strength of their bus roof structures by using FMVSS 220 standard, which follows conservative quasi-static load tests for school buses in the US. However, more advanced, dynamic based safety standard - Regulation 66, was developed in Europe. It is based on a dynamic rollover test which more closely resembles an actual rollover accident. A cutaway bus is placed on a tilt table 800 mm above a concrete slab. The bus is tilted until it falls and impacts the concrete deck and the deformation of the sidewalls is measured in order to check if there is any intrusion into a so called 'survival space'. This standard was endorsed by 44 countries through the United Nation resolution. However, the Regulation 66 standard does not specify all the parameters regarding the rollover test. From multiple tests it can be observed that the friction between the vehicle and the concrete slab which is being impacted by the bus has an influence on the outcomes of the experiment and has great contribution to either a positive or negative assessment of the crashworthiness of a tested vehicle. This Master thesis focuses on the friction parameters between the impacting cutaway bus and a concrete slab used in the Regulation 66 standard. Due to dynamic nature of the experiment, the impact of the bus exerts a high normal force on the concrete slab. Together with an uneven and non-standard geometry of the elements in contact with the concrete deck the standard coefficient of friction found in the literature or obtained using standard tests may not hold. The proper assessment of this coefficient is important since many rollover tests are carried out numerically using Finite Element Methods. The use of numerical analysis reduces the cost of an expensive full scale rollover test. However, it requires verified and validated parameters in order to consider the results trustworthy. The experimental part of this thesis consists of designing and carrying out experiments to evaluate the coefficient of friction for an impacting cutaway bus and a concrete slab. The results from the experiments are incorporated into an explicit computer code LS-DYNA, which is used for numerical analysis of the cutaway buses. The final outcome of this thesis will be validating the coefficient of friction used in the Finite Element Analysis which will lead to improvement of the Finite Element models and will be used to check the influence of the coefficient of friction on vehicle structure deformation (Deformation Index) during rollover accidents.
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Date Issued: 2015
Identifier: FSU_2015fall_Gleba_fsu_0071N_12953
Format: Thesis

Title: The Effect of High Groundwater Level on Pavement Subgrade Performance.
Creator: Zhang, Chaohan, Ping, W. Virgil, Niu, Xufeng, Hilton, Amy Chan, Abichou, Tarek, Abdullah, Makola, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: High groundwater table exerts detrimental effects on the roadway base and the whole pavement. Base clearance guidelines have been developed to prevent water from entering the pavement system in order to reduce its detrimental effects. This dissertation presents an experimental study to evaluate the effects of high groundwater and the moisture on determining pavement base clearance for granular subgrades. Full-scale in-lab and test-pit tests were conducted to simulate pavement profile and...
Show moreHigh groundwater table exerts detrimental effects on the roadway base and the whole pavement. Base clearance guidelines have been developed to prevent water from entering the pavement system in order to reduce its detrimental effects. This dissertation presents an experimental study to evaluate the effects of high groundwater and the moisture on determining pavement base clearance for granular subgrades. Full-scale in-lab and test-pit tests were conducted to simulate pavement profile and vehicle dynamic impact on the pavement. Eight types of granular subgrades were tested for this study. From the test, using layer theory, the results of the resilient modulus for each layer (layer resilient modulus) can be compared with the resilient modulus results from laboratory test. Multiple regression model will be established to predict soil resilient modulus without doing resilient modulus test. The dominant factor or factors of the effect of moisture to resilient modulus will be discussed. The results showed that a 24-inch base clearance was considered adequate for the base protection of most A-3 and A-2 subgrades against high groundwater tables. The lab resilient modulus and layer resilient modulus have the same trend for each soil according to the moisture content change. The SR-70 A-2-4 (14% fines) soil was the most susceptible to the change of groundwater table than the other soils. The percent of fines or the percent of clays of subgrade soil is not good indicator to measure the influence of moisture effect on the resilient modulus. The coefficient of uniformity and coefficient of curvature of the subgrade gradations, which better represent the whole shape of the gradation curve, are better indicators of the effect of moisture to modulus.
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Date Issued: 2004
Identifier: FSU_migr_etd-0545
Format: Thesis

Title: Effects of Secondary Elements and Joints on Strain Distribution in Composite Steel Girder Bridges.
Creator: Lewis, Michael, Tawfiq, Kamal, Rambo-Roddenberry, Michelle, Jung, Sungmoon, Department of Civil and Environmental Engineering, Florida State University
Abstract/Description: When considering the design of bridge girders, the American Association of State Highway and Transportation Officials (AASHTO) determine how the loads will be transferred to each girder. The equations used in AASHTO Load and Resistance Factor Design (LRFD) neglect the inertia added from secondary elements such as barriers and curbs. By neglecting these added effects, many bridges that are already built could have more strength than initially designed for. If the effects of these secondary...
Show moreWhen considering the design of bridge girders, the American Association of State Highway and Transportation Officials (AASHTO) determine how the loads will be transferred to each girder. The equations used in AASHTO Load and Resistance Factor Design (LRFD) neglect the inertia added from secondary elements such as barriers and curbs. By neglecting these added effects, many bridges that are already built could have more strength than initially designed for. If the effects of these secondary elements were considered, it would be possible to reduce the distribution factors that are given for interior and exterior girders. The bridge of concern for this project has four spans and was built in the early 1950s. Some repair work and modifications were conducted on the bridge and a load test was performed a week afterwards. The tests were done to find out if the repairs were adequate based on full composite action between the girders and the slab. During this initial test, some problems were discovered in one of the interior spans. This interior span is unique because it contains an expansion joint and a physical barrier and curb joint at the mid-span of the bridge. After problems were discovered, the physical joints were recommended to be grouted and a second load test was conducted afterwards. The second load test yielded much lower strains in the exterior girders due to the decrease in localized stress at the physical joint. In order to prove that filling the joint could improve the bridges strength, a finite element model was constructed to simulate this activity. Two models were made, one prior to filling the physical barrier and curb joints and one after. The test data was compared to the data from the finite element model to ensure accuracy. After the model was calibrated, the secondary members of the bridge were modified to study their effects. The primary goal of this research is to prove that a physical joint in a continuous exterior secondary element will cause the same amount of strain at its location as if they weren't there to begin with. By analyzing the finite element model data, it was found that when the joint is filled the behavior of the bridge changes and the exterior girder has up to 50% reduction in strain. The effect of concrete cracking and stress distribution that is associated with it is a secondary topic that was discussed because it was a driving factor in the model calibration.
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Date Issued: 2012
Identifier: FSU_migr_etd-4986
Format: Thesis

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

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