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- Title
- STOCHASTIC BRIDGE CONDITION DETERIORATION MODELS FOR CONCRETE AND TIMBER BRIDGES.
- Creator
- Srikanth, Ishwarya, Arockiasamy, Madasamy, Florida Atlantic University, Department of Civil, Environmental and Geomatics Engineering, College of Engineering and Computer Science
- Abstract/Description
-
This dissertation presents methodologies to develop bridge condition deterioration models which accounts for non-stationarity in the deterioration process with applications to Florida concrete and timber bridges. A critical and comprehensive review of bridge deterioration modeling approaches is presented with illustrative examples based on regression, stochastic Markov-chain, mechanistic and Artificial Neural Network (ANN) models. This study also develops a framework for relating the...
Show moreThis dissertation presents methodologies to develop bridge condition deterioration models which accounts for non-stationarity in the deterioration process with applications to Florida concrete and timber bridges. A critical and comprehensive review of bridge deterioration modeling approaches is presented with illustrative examples based on regression, stochastic Markov-chain, mechanistic and Artificial Neural Network (ANN) models. This study also develops a framework for relating the qualitative National Bridge Inventory (NBI) condition ratings with normalized resistance of the concrete bridge component with application to concrete bridge T-beams to reduce the subjectivity of the NBI condition rating. A systematic approach for the prioritization of bridges for inspection is developed using the multivariate regression modeling technique, and forecasting models are developed based on multiple relevant variables for both concrete bridge superstructure and substructure components. This dissertation also develops an approach for risk and reliability assessments of concrete and timber bridges based on non-parametric deterioration modeling techniques such as average time-in condition rating (ATICR) and Kaplan-Meier (K-M) survival (reliability) models, for probabilistic prediction of bridge safety while accounting for the partial information from the incomplete bridge condition observations. This study develops relative deterioration rates based on the ATICR and illustrates the time-dependent probability of deterioration of the concrete and timber bridge components based on K-M estimates. Further, the relationship of explanatory variables to the survival time is discussed and estimates are made for the median survival years for reinforced concrete solid slab decks. This dissertation presents the code developed in R for multivariate regression analysis and data-driven reliability analysis. Future research studies in bridge deterioration modeling are also presented.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013764
- Subject Headings
- Bridges--Deterioration--Mathematical models, Concrete bridges, Wooden bridges, Bridges--Management--Data processing
- Format
- Document (PDF)
- Title
- Risk of injection using reclaimed water for aquifer recharge using rotavirus as surrogate contaminant.
- Creator
- Phonpornwithoon, Pollop, Bloetscher, Frederick, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Groundwater aquifers are precious resources that has been serving human consumption for many centuries. This resource is pristine in comparison with surface waters such as lakes and canals, however, as population grows exponentially so does the demand for groundwater and the need to study the potential of groundwater replenishment programs. The injection of treated water or wastewater into an aquifer is a method to protect this resource for current and future generations. Health concerns...
Show moreGroundwater aquifers are precious resources that has been serving human consumption for many centuries. This resource is pristine in comparison with surface waters such as lakes and canals, however, as population grows exponentially so does the demand for groundwater and the need to study the potential of groundwater replenishment programs. The injection of treated water or wastewater into an aquifer is a method to protect this resource for current and future generations. Health concerns would be expected since migration of water of “impaired quality” can affect the drinking water by contamination. Regulatory barriers resulting from the perceived risks of adverse health effects from pathogens such as viruses have limited the concept of this impaired water resources from being used for groundwater replenishment programs. The objective of this study is to examine the risk assessment using computational modeling with MODFLOW and MT3D groundwater transport simulation. The results from the simulation showed that after two years, the risk of contamination based on concentration contours from the injection well to the production wellfields for the City of Hollywood stabilized below 10- 6. The risk assessment provided important aspect to demonstrate the concept of using injection of treated water as an option for groundwater replenishment.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004317, http://purl.flvc.org/fau/fd/FA00004317
- Subject Headings
- Aquifer storage recovery, Artificial grounddwater recharge, Drinking water -- Contamination, Environmental health -- Mathematical models, Groundwater -- Pollution -- Mathematical models, Health risk assessment, Viral pollution of water
- Format
- Document (PDF)
- Title
- SEAWALL DETECTION IN FLORIDA COASTAL AREA FROM HIGH RESOLUTION IMAGERY USING MACHINE LEARNING AND OBIA.
- Creator
- Paudel, Sanjaya, Su, Hongbo, Florida Atlantic University, Department of Civil, Environmental and Geomatics Engineering, College of Engineering and Computer Science
- Abstract/Description
-
In this thesis, a methodology and framework were created to detect the seawalls accurately and efficiently in low coastal areas and was evaluated in the study area of Hallandale Beach City, Broward County, Florida. Aerial images collected from the Florida Department of Transportation (FDOT) were processed using eCognition Developer software for Multi-Resolution Segmentation and Classification of objects. Two classification approaches, pixel-based image analysis, and the object-based image...
Show moreIn this thesis, a methodology and framework were created to detect the seawalls accurately and efficiently in low coastal areas and was evaluated in the study area of Hallandale Beach City, Broward County, Florida. Aerial images collected from the Florida Department of Transportation (FDOT) were processed using eCognition Developer software for Multi-Resolution Segmentation and Classification of objects. Two classification approaches, pixel-based image analysis, and the object-based image analysis (OBIA) method were applied for image classification. However, Pixel based classification was discarded for having less accuracy in output. Three techniques within object-based classification-machine learning technique, knowledge-based technique and machine learning followed by knowledge-based technique were used to compare the most efficient method of classification. While performing the machine learning technique, three algorithms: Random Forest, support vector machine and decision tree were applied to test the best algorithm. Of all the approaches used, the combination of machine learning and a knowledge-based method was able to map the sea wall effectively.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013802
- Subject Headings
- Image analysis, Coasts--Florida, Machine learning
- Format
- Document (PDF)
- Title
- SELF-ASSEMBLING OF NEUTRAL AND CHARGED NANOPARTICLES INTO CORE-SHELL NANOHYBRIDS THROUGH HETEROAGGREGATION WITH SIZE CONTROL.
- Creator
- Hussain, Kazi Albab, Yi, Peng, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Core-shell nanohybrids have wide applications in pollutant degradation. In this study, core-shell nanohybrid was formed through heteroaggregation between neutral nanoparticles (i.e., hematite nanoparticles or HemNPs) and charged nanoparticles (i.e., carboxylated polystyrene nanoparticles or PSNPs). In the dispersant solution of 1 mM NaCl at pH 6.3, HemNPs were neutral and underwent favorable homoaggregation, whereas PSNPs were negatively charged and underwent no homoaggregation. When the two...
Show moreCore-shell nanohybrids have wide applications in pollutant degradation. In this study, core-shell nanohybrid was formed through heteroaggregation between neutral nanoparticles (i.e., hematite nanoparticles or HemNPs) and charged nanoparticles (i.e., carboxylated polystyrene nanoparticles or PSNPs). In the dispersant solution of 1 mM NaCl at pH 6.3, HemNPs were neutral and underwent favorable homoaggregation, whereas PSNPs were negatively charged and underwent no homoaggregation. When the two types of particles were mixed, homoaggregation of HemNPs and heteroaggregation between HemNPs and PSNPs took place simultaneously, forming HemNPs-PSNPs heteroaggregates. The transmission electron microscopy images of heteroaggregates show that HemNPs and PSNPs formed core-shell structure in which HemNPs were the cores and PSNPs were the shells. The size of the core-shell nanohybrids can be controlled by varying the concentration ratio of HemNPs to PSNPs. The increase of the size of charged nanoparticles resulted in larger nanohybrids. This new method has lower energy footprint than existing ones.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013317
- Subject Headings
- Nanoparticles, Core-shell structures, Nanohybrids, Aggregation (Chemistry)
- Format
- Document (PDF)
- Title
- Online Parameter Learning for Structural Condition Monitoring System.
- Creator
- Alqazzaz, Jaffar, Jang, Jinwoo, Florida Atlantic University, Department of Civil, Environmental and Geomatics Engineering, College of Engineering and Computer Science
- Abstract/Description
-
The purpose of online parameter learning and modeling is to validate and restore the properties of a structure based on legitimate observations. Online parameter learning assists in determining the unidentified characteristics of a structure by offering enhanced predictions of the vibration responses of the system. From the utilization of modeling, the predicted outcomes can be produced with a minimal amount of given measurements, which can be compared to the true response of the system. In...
Show moreThe purpose of online parameter learning and modeling is to validate and restore the properties of a structure based on legitimate observations. Online parameter learning assists in determining the unidentified characteristics of a structure by offering enhanced predictions of the vibration responses of the system. From the utilization of modeling, the predicted outcomes can be produced with a minimal amount of given measurements, which can be compared to the true response of the system. In this simulation study, the Kalman filter technique is used to produce sets of predictions and to infer the stiffness parameter based on noisy measurement. From this, the performance of online parameter identification can be tested with respect to different noise levels. This research is based on simulation work showcasing how effective the Kalman filtering techniques are in dealing with analytical uncertainties of data.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013540
- Subject Headings
- Kalman filtering, Kalman filtering--Data processing, Simulations, Parameter estimation
- Format
- Document (PDF)
- Title
- MACHINE LEARNING APPROACH FOR VEGETATION CLASSIFICATION USING UAS MULTISPECTRAL IMAGERY.
- Creator
- Kesavan, Pandiyan, Sudhagar Nagarajan, Florida Atlantic University, Department of Civil, Environmental and Geomatics Engineering, College of Engineering and Computer Science
- Abstract/Description
-
Vegetation monitoring plays a significant role in improving the quality of life above the earth's surface. However, vegetation resources management is challenging due to climate change, global warming, and urban development. The research aims to identify and extract vegetation communities for Jupiter Inlet Lighthouse Outstanding Natural Area (JILONA) using developed Unmanned Aerial Systems (UAS) deployed with five bands of RedEdge Micasence Multispectral Sensor. UAS has a lot of potential for...
Show moreVegetation monitoring plays a significant role in improving the quality of life above the earth's surface. However, vegetation resources management is challenging due to climate change, global warming, and urban development. The research aims to identify and extract vegetation communities for Jupiter Inlet Lighthouse Outstanding Natural Area (JILONA) using developed Unmanned Aerial Systems (UAS) deployed with five bands of RedEdge Micasence Multispectral Sensor. UAS has a lot of potential for various applications as it provides high-resolution imagery at lower altitudes. In this study, spectral reflectance values for each vegetation species were collected using a spectroradiometer instrument. Those values were correlated with five band UAS Image values to understand the sensor's performance, also added with reflectance’s similarities and divergence for vegetation species. Pixel and Object-based classification methods were performed using 0.15 ft Multispectral Imagery to identify the vegetation classes. Supervised Machine Learning Support Vector Machine (SVM) and Random Forest (RF) algorithms with topographical information were used to produce thematic vegetation maps. The Pixel-based procedure using the SVM algorithm generated an overall accuracy and kappa coefficient of above 90 percent. Both classification approaches have provided aesthetic vegetation thematic maps. According to statistical cross-validation findings and visual interpretation of vegetation communities, the pixel classification method outperformed object-based classification.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013768
- Subject Headings
- Vegetation classification, Machine learning, Multispectral imaging, Unmanned aerial vehicles
- Format
- Document (PDF)
- Title
- MODIFYING SIGNAL RETIMING PROCEDURES AND POLICIES: A CASE OF HIGH-FIDELITY MODELING WITH MEDIUM-RESOLUTION DATA.
- Creator
- Dobrota, Nemanja, Stevanovic, Aleksandar, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Signal retiming, or signal optimization process, has not changed much over the last few decades. Traditional procedures rely on low-resolution data and a low-fidelity modeling approach. Such developed signal timing plans always require a fine-tuning process for deployed signal plans in field, thus questioning the very benefits of signal optimization. New trends suggest the use of high-resolution data, which are not easily available. At the same time, many improvements could be made if the...
Show moreSignal retiming, or signal optimization process, has not changed much over the last few decades. Traditional procedures rely on low-resolution data and a low-fidelity modeling approach. Such developed signal timing plans always require a fine-tuning process for deployed signal plans in field, thus questioning the very benefits of signal optimization. New trends suggest the use of high-resolution data, which are not easily available. At the same time, many improvements could be made if the traditional signal retiming process was modified to include the use of medium-resolution data and high-fidelity modeling. This study covers such an approach, where a traditional retiming procedure is modified to utilize large medium-resolution data sets, high-fidelity simulation models, and powerful stochastic optimization to develop robust signal timing plans. The study covers a 28-intersection urban corridor in Southeastern Florida. Medium-resolution data are used to identify peak-hour, Day-Of-Year (DOY) representative volumes for major seasons. Both low-fidelity and high-fidelity models are developed and calibrated with high precision to match the field signal operations. Then, by using traditional and stochastic optimization tools, signal timing plans are developed and tested in microsimulation. The findings reveal shortcomings of the traditional approach. Signal timing plans developed from medium-resolution data and high-fidelity modeling approach reduce average delay by 5%-26%. Travel times on the corridor are usually reduced by up to 10.5%, and the final solution does not transfer delay on the other neighboring streets (illustrated through latent delay), which is also decreased by 10%-49% when compared with the traditional results. In general, the novel approach has shown a great potential. The next step should be field testing and validation.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013298
- Subject Headings
- Traffic signal timing, Traffic signs and signals--Automatic control, Traffic signs and signals--Research, Stochastic optimization
- Format
- Document (PDF)
- Title
- IDENTIFICATION AND EVALUATION OF CRITICAL FREIGHT CORRIDORS.
- Creator
- Machado, Aline Anacleto, Kaisar, Evangelos I., Florida Atlantic University, Department of Civil, Environmental and Geomatics Engineering, College of Engineering and Computer Science
- Abstract/Description
-
Efficient freight mobility plays a major role in the economy, and its performance is closely related to the quality of the transportation system. Requirements for funding transportation infrastructure projects often do not specify the analytical tools planners should use to request funding. Critical Urban and Rural Freight Corridors are sections of the National Highway Freight Network providing critical connectivity of goods and must have improved system performance. This research study...
Show moreEfficient freight mobility plays a major role in the economy, and its performance is closely related to the quality of the transportation system. Requirements for funding transportation infrastructure projects often do not specify the analytical tools planners should use to request funding. Critical Urban and Rural Freight Corridors are sections of the National Highway Freight Network providing critical connectivity of goods and must have improved system performance. This research study offers a method for identifying these corridors considering temporal and spatial inputs. For this end, a multi-criteria spatial decision support system (MC-SDSS) was developed. This framework attributes a score to highway corridors (links) based on policy eligibility and prioritization. We apply the Analytic Hierarchy Process (AHP) to structure the problem and consider different stakeholder preferences and available data. The product of this study is a tool for decisionmakers to optimize the selection of critical freight corridors and analyze alternatives. It also offers flexibility to manipulate the framework to meet various agency goals, using the State of Florida as a case study.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013793
- Subject Headings
- Highway corridors, Freight and freightage, Transportation--Planning
- Format
- Document (PDF)
- Title
- INFLUENCES OF CLIMATE CHANGE AND VARIABILITY ON BASEFLOWS.
- Creator
- Chen, Hao, Teegavarapu, Ramesh S. V., Florida Atlantic University, Department of Civil, Environmental and Geomatics Engineering, College of Engineering and Computer Science
- Abstract/Description
-
Baseflow is the portion of the streamflow that is sustained between precipitation events, fed to streams by delayed pathways. Baseflow estimation and evaluation are two critical and essential tasks for water quality and quantity, drought management, water supply, and groundwater protection. In this research study, the influences of climate change and variability on baseflow derived from hundreds of watersheds in the continental United States are evaluated. Baseflows are estimated using...
Show moreBaseflow is the portion of the streamflow that is sustained between precipitation events, fed to streams by delayed pathways. Baseflow estimation and evaluation are two critical and essential tasks for water quality and quantity, drought management, water supply, and groundwater protection. In this research study, the influences of climate change and variability on baseflow derived from hundreds of watersheds in the continental United States are evaluated. Baseflows are estimated using streamflow data from these watersheds that are least affected by anthropogenic influences. In the initial phase of the study, an exhaustive evaluation of four different baseflow separation methods is carried out using streamflow data at several sites from the South Atlantic-Gulf region which includes a geographical region comprising of nine states in the southeastern U.S. Baseflows are estimated at different temporal scales and are used to assess the performances of different methods over a 44-year period starting from the year 1970 and the best method among these methods is selected for further analysis. Assessments of climate change influence on baseflows are then carried out using two nonparametric statistical trend tests (viz., Spearman’s Rho (SR) and Mann-Kendall (MK)). Trends in baseflows are evaluated at 574 sites located within the watersheds in the U.S. that are known to be least impacted by human influences. Trends were determined for annual maximum, mean, and median baseflows for the period 1970-2013. Spatially non-uniform trends and changes in characteristics of baseflows and strong influences of past precipitation events on the baseflow extremes were noted across the continental U.S. Some regions have shown decreasing baseflow trends and these are cause for concern and have severe implications for drought mitigation plans and low-flow management strategies in several watersheds in the U.S. In the final phase of the study influences of climate variability on baseflow manifested through different phases of individual and coupled oceanic and atmospheric oscillations are evaluated. Baseflows at 574 sites separated by temporal windows that coincide with two or more phases of different decadal, quasi-decadal and multi-year oscillations (viz., Pacific decadal oscillation (PDO), North Atlantic oscillation (NAO), Atlantic multidecadal oscillation (AMO), and El Niño-southern oscillation (ENSO)) are evaluated for statistically significant changes using nonparametric statistical hypothesis tests. Results from the study indicate that unlike climate change influences, climate variability effects are noted only in few specific physiographic regions of the U.S. This study documents an exhaustive and comprehensive assessment of changes in baseflows due to changing climate and results from this work can aid in short- and long-term management of low flows at a regional level that supports sustainable aquatic environment and handle droughts effectively.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013366
- Subject Headings
- Climatic changes, Streamflow, Base flow (Hydrology)
- Format
- Document (PDF)
- Title
- Monitoring of Traffic Signal System’s Performance and Reliability Based on the Data from ATMS.now Signal System Central Software.
- Creator
- Radivojevic, Danilo, Stevanovic, Aleksandar, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
The monitoring of traffic signal systems can be of great importance for identifying problems, self-assessment, budgeting, creating the strategy for future steps, etc. Monitoring procedure was developed through a set of dashboards with relevant signal performance and reliability measures. The dashboards were created to reflect performance and reliability of a specific signal system on a weekly or monthly level. The author used data from ATMS.now signal system central software to illustrate how...
Show moreThe monitoring of traffic signal systems can be of great importance for identifying problems, self-assessment, budgeting, creating the strategy for future steps, etc. Monitoring procedure was developed through a set of dashboards with relevant signal performance and reliability measures. The dashboards were created to reflect performance and reliability of a specific signal system on a weekly or monthly level. The author used data from ATMS.now signal system central software to illustrate how similar dashboards could be developed from any central software to enable operators to promptly and efficiently monitor various parameters of traffic signals. The main outcome of the study is a pair of Excel dashboards accompanied with appropriate user manual. The dashboards represent the tool for monitoring which can be helpful in the process of evaluation for traffic signal systems.
Show less - Date Issued
- 2017
- PURL
- http://purl.flvc.org/fau/fd/FA00004864, http://purl.flvc.org/fau/fd/FA00004864
- Subject Headings
- Traffic signs and signals--Control systems., Traffic signs and signals--Evaluation., Multiuser detection (Telecommunication)
- Format
- Document (PDF)
- Title
- An Experimental Evaluation of High Volume Fly Ash Structural Concrete made from Recycled Aggregate.
- Creator
- Theodorou, Anthony Lloyd, Sobhan, Khaled, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Three vital factors, namely environmental protection, savings in costs, and strength/durability benefits, make it advantageous to incorporate fly ash of controlled quality and composition in all concrete made from construction demolition (C&D) recycled aggregate. The specific objective of this research was to compare the performance characteristics of High-Volume-Fly-Ash (HVFA) structural concrete containing C&D aggregate with that of normal recycled aggregate concrete containing no fly ash....
Show moreThree vital factors, namely environmental protection, savings in costs, and strength/durability benefits, make it advantageous to incorporate fly ash of controlled quality and composition in all concrete made from construction demolition (C&D) recycled aggregate. The specific objective of this research was to compare the performance characteristics of High-Volume-Fly-Ash (HVFA) structural concrete containing C&D aggregate with that of normal recycled aggregate concrete containing no fly ash. A coordinated experimental program was undertaken which comprised of ( 1) Compressive and Split Tensile strength tests; (2) ASTM durability tests by measuring resistance to chloride-ion penetration; and (3) Flexural strength tests on reinforced concrete beam specimens. Three mix designs were used, all of which had the same water/cement ratio of 0.45 and the same amount of recycled aggregate/yd^3. Mix 1 contained cement and no fly ash, Mix 2 contained 16% replacement of cement by weight, and Mix 3 contained 40% replacement of cement, called a HVF A mix. Results indicate that fly ash increases compressive strength, improves both moment carrying capacity and tension resistance, and increases resistance to chloride-ion attack.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/fau/fd/FA00012563
- Subject Headings
- Aggregates (Building materials)--Recycling, Fly ash--Recycling, Concrete--Additives--Evaluation, Concrete--Permeability, Industrial minerals--Evaluation
- Format
- Document (PDF)
- Title
- Analytical evaluation of marine concrete pile repairs.
- Creator
- Saleh, Zaher A. Abou., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
The purpose of the thesis is to determine and compare the performance characteristics of marine piles corroded by chloride diffusion and repaired by several different methods for both uncracked and cracked concrete and to determine their structural integrity. The long-term objective is the comparison of the analytical values with those from an on-going experimental evaluation. The time for chloride concentration reach the threshold value that initiates corrosion in the reinforcement has been...
Show moreThe purpose of the thesis is to determine and compare the performance characteristics of marine piles corroded by chloride diffusion and repaired by several different methods for both uncracked and cracked concrete and to determine their structural integrity. The long-term objective is the comparison of the analytical values with those from an on-going experimental evaluation. The time for chloride concentration reach the threshold value that initiates corrosion in the reinforcement has been determined by Fick's law, extended to 2-D and 3-D chloride diffusion, for (a) uncracked concrete, and (b) for cracked concrete with the Simplified Smeared Approach (SSA). The structural integrity of the concrete circular pile is compared before and alter repair, by (a) finite element modeling using ANSYS software with the maximum deflection, and (b) beam strength analysis to find the moment capacity for cracked and ultimate conditions. The overall findings indicate the adequacy of the repair procedures.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13062
- Subject Headings
- Concrete piling, Reinforced concrete--Corrosion, Seawater corrosion
- Format
- Document (PDF)
- Title
- Effect of elevated temperature and fire on structural elements retrofitted by carbon fiber reinforced polymer composites.
- Creator
- Young, Jody David, Jr., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
This thesis presents an experimental investigation for evaluating effects of fire exposure on properties of structural elements retrofitted by carbon fiber reinforced polymers. Mechanical properties of CFRP-strengthened reinforced concrete members, protected with secondary insulation, were investigated, before and after (residual) direct fire exposure. Direct fire contact resulted in a reduction in capacity of 9-20% for CFRP-strengthened RC beams, and 15-34% for CFRP-strengthened RC columns....
Show moreThis thesis presents an experimental investigation for evaluating effects of fire exposure on properties of structural elements retrofitted by carbon fiber reinforced polymers. Mechanical properties of CFRP-strengthened reinforced concrete members, protected with secondary insulation, were investigated, before and after (residual) direct fire exposure. Direct fire contact resulted in a reduction in capacity of 9-20% for CFRP-strengthened RC beams, and 15-34% for CFRP-strengthened RC columns. Furthermore, a dimensional analysis was developed for a heat transfer relationship between full and small-scale specimens, allowing a ¼ exposure time reduction for the latter. Results from experimental investigations demonstrate benefits of employing secondary fire protection to CFRP-strengthened structures, in spite of the glass transition temperature being exceeded in the early stages of the elevated-temperature exposure. Therefore, it is suggested, that fire protection is necessary for a CFRP-strengthened structural member to retain integrity throughout the duration of the fire exposure, and upon return to ambient temperature.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13322
- Subject Headings
- Buildings--Repair and reconstruction, Reinforced concrete, Fiber reinforced plastics, Fire resistant materials, Thermodynamics, Heat engineering, Concrete--Effect of temperature on
- Format
- Document (PDF)
- Title
- Developing a Relationship between NEXRAD Generated Rainfall Values and Rain Gauge Measurements in South Florida.
- Creator
- Skinner, Courtney L., Bloetscher, Frederick, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
The South Florida Water Management District (SFWMD) is an agency which relies on a network of nearly 300 rain gauges in order to provide rainfall data for use in operations, modeling, water supply planning, and environmental projects. However, the prevalence of convective and tropical rain events in South Florida during the wet season presents a challenge in that the current rain gauge network may not fully capture rainfall demonstrating high spatial variability. NEXRAD (Next Generation Radar...
Show moreThe South Florida Water Management District (SFWMD) is an agency which relies on a network of nearly 300 rain gauges in order to provide rainfall data for use in operations, modeling, water supply planning, and environmental projects. However, the prevalence of convective and tropical rain events in South Florida during the wet season presents a challenge in that the current rain gauge network may not fully capture rainfall demonstrating high spatial variability. NEXRAD (Next Generation Radar) technology offers water management officials the advantage of providing a spatial account of rainfall, although the relative quality of radar rainfall measurements remains largely unknown. The intent of this study is to examine the relationship between gauge-adjusted NEXRAD data and corresponding rain gauge measurements in order to assess the relative performance of radar and rain gauge technologies for a variety of different conditions.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fau/fd/FA00012554
- Subject Headings
- Storms--United States--Florida, Radar meteorology, Precipitation (Meteorology)--Measurement, Rain and rainfall--Measurement
- Format
- Document (PDF)
- Title
- Modeling of gasoline emissions from stationary and mobile sources at Port Everglades.
- Creator
- Kimmlingen, Martina M., Florida Atlantic University, Scarlatos, Panagiotis (Pete) D., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Available air quality data has been analyzed using the Industrial Source Complex Dispersion Model (ISC3). The FORTRAN program Mobile 5a was utilized to obtain the emission factors. Concerning the toxic volatile organic compounds, the simulations indicate that benzene exceeded the previous permissible air quality standard. Toluene, ethylbenzene and xylene values remained within allowable concentration levels. Long-term annual benzene emissions from stationary sources exceeded the former...
Show moreAvailable air quality data has been analyzed using the Industrial Source Complex Dispersion Model (ISC3). The FORTRAN program Mobile 5a was utilized to obtain the emission factors. Concerning the toxic volatile organic compounds, the simulations indicate that benzene exceeded the previous permissible air quality standard. Toluene, ethylbenzene and xylene values remained within allowable concentration levels. Long-term annual benzene emissions from stationary sources exceeded the former reference concentration of 0.12 mug/m 3 about five times per year, whereas the data for 8 and 24 hours were relatively low. Simulation results for the mobile sources demonstrated that the emission factor is a highly sensitive parameter. Possible realistic scenarios at Port Everglades were obtained through varying benzene concentrations. The results are plotted as concentration contours, in order to visualize areas of suspected health risk associated to air pollution. Compared to the Reference Concentration for Chronic Inhalation Exposure, EPA, the modeled results appear significantly less.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13123
- Subject Headings
- Automobiles--Motors--Exhaust gas--Mathematical models, Harbors--Environmental aspects--Florida, Air--Pollution--Mathematical models, Port Everglades (Fort Lauderdale, Fla)
- Format
- Document (PDF)
- Title
- Evaluation of flexible pipes under shallow burial depths.
- Creator
- Wang, Ning., Florida Atlantic University, Arockiasamy, Madasamy, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Flexible plastic and metal pipes are increasingly being used for drainage and storm sewers. When flexible pipes are buried at shallow depths, the pipe behavior will not depend on the dead load pressure above the crown, but rather on the live load pressure (vehicle load). Field tests were designed to evaluate the performance of large diameter flexible pipes of 36 in. (915 mm.) and 48 in. (1050 mm.) under shallow burial depths subjected to the actual vehicle loading. The test pipes included...
Show moreFlexible plastic and metal pipes are increasingly being used for drainage and storm sewers. When flexible pipes are buried at shallow depths, the pipe behavior will not depend on the dead load pressure above the crown, but rather on the live load pressure (vehicle load). Field tests were designed to evaluate the performance of large diameter flexible pipes of 36 in. (915 mm.) and 48 in. (1050 mm.) under shallow burial depths subjected to the actual vehicle loading. The test pipes included high-density polyethylene (HDPE) pipes, polyvinyl chloride (PVC) pipes, steel pipes and aluminum pipes. AASHTO standard pipe installation procedures were followed and pipes subjected to vehicle loads simulating the effect of HS 20-44 trucks. Measurements of interior pipe-wall strains, soil pressures at different depths and pipe deformations were taken to determine the influence of surface vehicle loads. Results of field tests are compared with those based on theoretical analyses.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12929
- Subject Headings
- Underground pipelines--Design and construction, Soil-structure interaction, Structural analysis (Engineering), Earth pressure
- Format
- Document (PDF)
- Title
- Primary and secondary compression behavior of Florida organic soils.
- Creator
- Riedy, Kristopher W., Florida Atlantic University, Sobhan, Khaled, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
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A comprehensive laboratory investigation was conducted to evaluate the primary and secondary compression behavior of undisturbed organic silts and peats obtained from 11 locations along SR 15/US 98 in Palm Beach County, Florida. A total of 43 consolidation tests were performed. The primary objectives were as follows: (i) to conduct a series of standard consolidation tests to determine the Compression Index, Cc, and the Coefficient of Consolidation, cnu; (ii) to determine the Secondary...
Show moreA comprehensive laboratory investigation was conducted to evaluate the primary and secondary compression behavior of undisturbed organic silts and peats obtained from 11 locations along SR 15/US 98 in Palm Beach County, Florida. A total of 43 consolidation tests were performed. The primary objectives were as follows: (i) to conduct a series of standard consolidation tests to determine the Compression Index, Cc, and the Coefficient of Consolidation, cnu; (ii) to determine the Secondary Compression Index, Calpha, at stress levels (sigmanu'/sigmap') ranging from 0.30 to 1.15; and (iii) to employ the well-known Time-Stress-Compressibility concept to establish a unique relationship between C alpha and Cc. It was found that for all practical purposes, the Calpha/C c ratio at any stress level is 0.03, which is consistent with the values reported in the literature for similar soils. A constant Calpha/Cc ratio provides an approximation of Calpha once C c is determined from a standard consolidation test, and without the need of ongoing laboratory testing to predict long-term settlement.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13386
- Subject Headings
- Soil consolidation--Measurement--Florida, Soil mechanics--Florida--Palm Beach County, Soils--Testing
- Format
- Document (PDF)
- Title
- Sediment exchange in tidal inlets.
- Creator
- Merz, Clifford Ronald., Florida Atlantic University, Scarlatos, Panagiotis (Pete) D., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
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Sediment exchange characteristics of tidal inlets subjected to tidal excitations are investigated and the results compared to field data measured at Jupiter Inlet, Florida. A specially written computer program combines inlet/nearshore hydrodynamic expressions with bed-load and suspended load sediment transport relationships to examine the building mechanisms of the near-shore tidal ebb shoal. The ebb tidal flow is modeled as a turbulent, plane jet which includes lateral mixing and entrainment...
Show moreSediment exchange characteristics of tidal inlets subjected to tidal excitations are investigated and the results compared to field data measured at Jupiter Inlet, Florida. A specially written computer program combines inlet/nearshore hydrodynamic expressions with bed-load and suspended load sediment transport relationships to examine the building mechanisms of the near-shore tidal ebb shoal. The ebb tidal flow is modeled as a turbulent, plane jet which includes lateral mixing and entrainment, bottom friction, and offshore bathymetric changes. Flood tidal flow is modeled as a potential flow sink with the water being drawn into the inlet from one or more dominant offshore areas depending on the offshore bottom slope. Sediment transport expressions are evaluated at various locations within the offshore flow field and the sediment deposition depth is calculated at that location over one tidal cycle. Model results are plotted and compared to field data for analysis.
Show less - Date Issued
- 1995
- PURL
- http://purl.flvc.org/fcla/dt/15206
- Subject Headings
- Tides, Marine sediments, Sediment transport--Florida--Jupiter Inlet, Inlets
- Format
- Document (PDF)
- Title
- Reliability and accuracy of a GPS unit for tracking vehicles in Palm Beach and Broward counties.
- Creator
- Le Strat, Maud Gael., Florida Atlantic University, Scarlatos, Panagiotis (Pete) D., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
The purpose of this thesis was to study the reliability and the accuracy of GPS positioning in Palm Beach and Broward counties. By studying the predictions of DOP values using Pathfinder Office and performing some statistical analysis on theoretical GPS data using the software SAS 8.0, the conclusion was made that PDOP values not only depend on the number of available satellites, but also on their relative positions. By field testing, and comparing the recorded data with the theoretical GPS...
Show moreThe purpose of this thesis was to study the reliability and the accuracy of GPS positioning in Palm Beach and Broward counties. By studying the predictions of DOP values using Pathfinder Office and performing some statistical analysis on theoretical GPS data using the software SAS 8.0, the conclusion was made that PDOP values not only depend on the number of available satellites, but also on their relative positions. By field testing, and comparing the recorded data with the theoretical GPS data, it was seen that non-DGPS could be rather accurate. Furthermore, it can be justified for a GPS unit to eliminate the Z coordinate measurement since vertical position errors are larger than horizontal errors, which may lead to improved accuracy. On the other hand, some 'visibility problems' were encountered while testing the GPS units under driving conditions. Different ways to compensate for this disadvantage were studied. In the end, the different features of the GPS unit were discussed and a way to improve the system was also proposed.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12862
- Subject Headings
- Global Positioning System
- Format
- Document (PDF)
- Title
- The effect of pollution prevention in wood furniture, marina and auto repair industries.
- Creator
- Shalan, Samira Ghazi., Florida Atlantic University, Scarlatos, Panagiotis (Pete) D., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
- Abstract/Description
-
Since the industrial revolution, industrial operations have been accompanied with a problem: production of industrial waste, which may be toxic, ignitable, corrosive or reactive. If improperly managed this waste can pose dangerous health and environmental consequences. This study defines the meaning of pollution prevention and outlines its major categories. Three different industries: wood furniture, marina and auto repair industries where chosen to emphasize pollution prevention practices...
Show moreSince the industrial revolution, industrial operations have been accompanied with a problem: production of industrial waste, which may be toxic, ignitable, corrosive or reactive. If improperly managed this waste can pose dangerous health and environmental consequences. This study defines the meaning of pollution prevention and outlines its major categories. Three different industries: wood furniture, marina and auto repair industries where chosen to emphasize pollution prevention practices throughout their operations.
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12994
- Subject Headings
- Pollution prevention, Furniture industry and trade--Environmental aspects, Marinas--Environmental aspects, Automobile repair shops--Environmental aspects
- Format
- Document (PDF)
