Civil Engineering Commons^™

Real-Time Atmospheric Compensation And Surface Temperature Estimates From Satellite Using Neural Networks, Gary Bouton

Dissertations and Theses

Military satellites are being used to determine potential security threats using accurate high sensitivity measurements from defense satellites. These systems focus much more on sensitivity and Signal/Noise Ratio (SNR) than on multispectral capability. Therefore, these systems are highly vulnerable to thermal absorption and reemission that can affect the thermal signature prior to launch. In particular, there is a need to use additional assets to estimate the atmospheric temperature and water vapor profile so that an estimate of the atmospheric processes can be obtained and a correction developed to improve the thermal detection. In particular, the use of existing meteorological geostationary …

Reliability Analysis Of The Hec-18 Scour Equation And Aashto Deep Foundation Design Codes, Jun Yan

Dissertations and Theses

This research project studied the reliability of driven pile foundations subjected to scour, gravity loads including dead loads and live loads, and their combinations. The design of the foundation followed the procedures of the AASHTO LRFD Bridge Design Specification. The design methods were the HEC-18 pier scour equation used to determine the scour depth, and the α-Method and Nordlund-Thurman Method used to design the driven pile. The limit state considered was the axial bearing resistance of the piles in the soil. The reliability indexes for bridges subjected to maximum expected scour depth and gravity loads were found through Monte Carlo …

Investigation Of The Mechanical Behavior Of I-Shaped Steel Beams Strengthened By Mechanically-Fastened Frp Laminates, Hothifa Nayef Rojob

Theses

Retrofitting and strengthening of steel structures have gained significant importance due to the highly increasing number of deteriorated steel structures in many places around the globe. The conventional method of retrofitting or strengthening of steel structures by replacing steel members or attaching additional external steel plates are usually time-consuming, corrodible, and a cumbersome task. Many of the drawbacks of the conventional retrofitting systems can be overcome through the use of Fiber Reinforced Polymers (FRP) due to their high strength-to-weight ratio. Furthermore, FRP materials are corrosion resistant, which makes them more durable especially when environmental deterioration is a concern. In recent …

Investigation Into The Relationship Between Hurricane Storm Parameters And Damage, Jeremy S. Young

UNF Graduate Theses and Dissertations

“Economic damage, such as damage to property and infra-structure, from hurricane surges depends on two factors 1) the depth of coastal inundation and 2) the area covered by the surge” (Irish et. al 2007). Typically, damage estimates are developed after hurricanes have dissipated. To have the ability to predict hurricane damage in advance based upon various physical parameters would be a technical advance that could aid vulnerable coastal communities with hurricane planning. This thesis advances this goal forward by relating “Total Normalized Damage” to “Surge Scale” along with other key parameters. In this thesis Total Normalized Damages are compared to …

A Methodology To Consolidate Transit Stops For Enhancing Transit Users Travel Times, Mohammad Nurul Hassan

Theses

This study develops a methodology to consolidate transit stops. It develops a mathematical model and a program which takes stop consolidation decision(s) according to users travel time savings and desired accessibility. The model iterates until the users travels time savings are maximized. The study tests this mathematical model in different hypothetical scenarios. Six factors (distance between stops, passengers’ activity, average cruising speed, and maximum walkable distance, frequency of service and percentage of decreased passengers) with multiple levels were set to build the scenarios. Three responses (percentage of consolidated stops, percentage of travel time savings and percentage of operating …

Estimation Of Performance Indices For The Planning Of Sustainable Transportation Systems, Alexander Paz, Pankaj Maheshwari, Pushkin Kachroo, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

In the context of sustainable transportation systems, previous studies have either focused only on the transportation system or have not used a methodology that enables the treatment of incomplete, vague, and qualitative information associated with the available data. This study proposes a system of systems (SOS) and a fuzzy logic modeling approach. The SOS includes the Transportation, Activity, and Environment systems. The fuzzy logic modeling approach enables the treatment of the vagueness associated with some of the relevant data. Performance Indices (PIs) are computed for each system using a number of performance measures. The PIs illustrate the aggregated performance of …

Shear And Fracture Behavior Of High Performance Concretes, Mahdi Arezoumandi

Doctoral Dissertations

"Concrete is the most widely used man-made material in the world. Like other materials, it has been improved over time. Nowadays, with continued development of science and technology, a new generation of concretes is produced and is termed high performance concretes. A review of previously published work indicates that very few studies (in some cases none) have addressed the structural behavior of full-scale, high performance concrete elements. This study investigated the shear and fracture behavior of two types of high performance concrete - high-volume fly ash concrete (HVFAC) and self-consolidating concrete (SCC). The HVFAC incorporates up to 70% cement replacement …

Numerical Analyses Of Long Carbon Fiber Reinforced Concrete Panels Exposed To Dynamic Loading, Zahra Sadat Tabatabaei

Doctoral Dissertations

"The purpose of this research was to evaluate impact and blast performance of long carbon fiber reinforced concrete experimentally and numerically. Experimental tests were conducted on plain concrete (PC), reinforced concrete, and four different types of long carbon fiber reinforced concrete (LCFRC). The results from each test were then compared to one another. This comparison indicates that adding long carbon fibers to concrete both increases the post-cracking behavior of concrete and decreases the spalls in either an impact or blast test. Among all of the fibers tested, Fiber Type B3 outperformed the other fibers, absorbing more energy during impact. Numerical …

Effects Of Openings On The Analysis And Design Of Precast Prestressed Hollow Core Slabs, Eoghan Lodge

Theses

Precast prestressed hollow core floors are a widely used structural element which offers increased speed of construction, reduced self-weight and many other advantages. Due to the relatively low span-to-depth ratio and the speed of construction hollow core slabs are utilised in a large number of commercial buildings. In order to carry the services to the upper floors an opening must be made within the prestressed slab. Cutting an opening in a prestressed slab has significant effects on the structural behaviour of the slab and can considerably reduce the ultimate capacity of the slab.

This paper outlines the limited available guidance …

Reinforced Concrete Deterioration Of A 100 Year Old Structure In A Marine Environment, Ross O'Donovan

Theses

The current study investigates the deterioration of a 100 year old bridge located in a harsh marine environment. Constructed in 1908 - 1909 the Mizen Head Footbridge was one of the oldest reinforced concrete bridges in Ireland. The demolition of the bridge in 2009 provided a unique opportunity to examine its service life and to extract samples for analysis and investigation. A review of the construction of the bridge, and its maintenance history are presented, with a view to analysing their influence on the behaviour of the concrete.

Reinforcement corrosion due to chloride attack was identified. A focused study indicates …

Investigation Of Wastewater Treatment Plant Sustainability Potential In Terms Of Resource Recovery Essentials, Aoife Moloney

Theses

This thesis aims to explore the sustainability potential which exists in Wastewater Treatment Plants (WWTP's); particularly focusing on nutrient, energy, and water recovery and reuse. The core of the research will focus on the establishment of a sustainable Resource Recovery Treatment Plant (RRTP) plan for Limerick Main Drainage (LMD) WWTP, and potentially utilising this as a case study plant which could act as a foundation example within the sector.

There is a genuine need to investigate more sustainable options in wastewater treatment (WWT); increasing energy and sludge management costs are a real issue for non-sustainable WWTP's given that thousands of …

Risk Assessment Of Driving Safety In Long Scaled Bridge Under Severe Weather Conditions, Shengdi Chen

USF Tampa Graduate Theses and Dissertations

Weather conditions have certain impacts on roadway traffic operations, especially traffic safety. Bridges differ from most surface streets and highways in terms of their physical properties and operational characteristics. This research assess the driving risk under different weather conditions through focus group firstly, then it develops a multi-ordered discrete choice model that is used to analyze and evaluate driving risks under both single and dual weather conditions. The data is derived from an extensive questionnaire survey in Shanghai. And the questionnaire includes those factors related to roadway, drivers, vehicles, and traffic that may have significant impacts on traffic safety under …

A Study On Lane-Change Recognition Using Support Vector Machine, Weiping Deng

USF Tampa Graduate Theses and Dissertations

This research focuses primary on recognition of lane-change behaviors using support vector machines (SVMs). Previous research and statistical results show that the vast majority of motor vehicle accidents are caused by driver behavior and errors. Therefore, the interpretation and evaluation of driver behavior is important for road safety analysis and improvement. The main limit to understanding driver behavior is the data availability. In particular, a full-scale lane-change data set is difficult to collect in a real traffic environment because of the safety and cost issues. Considering the data demands of the recognition model development and the obstacles of field data …

Geometric Optimization Of Retroreflective Raised Pavement Markers, Lukai Guo

USF Tampa Graduate Theses and Dissertations

As the field service life of retroreflective raised pavement marker (RRPM) is much shorter than expected, it is necessary to identify the causes and thus improve the RRPM structural design to mitigate the main failure modes, such as poor retention from pavements, structural damage, and loss of retroreflectivity. One strategy for extending RRPM service life is to enhance RRPM geometric characteristics to decrease critical stresses in markers. The main purpose of this thesis is to analyze the relationship between stresses, failure modes, and RRPM profiles. Based on this research, some measures are suggested in order to avoid corresponding failure modes …

Flexible Urban Water Distribution Systems, Seneshaw Amare Tsegaye

USF Tampa Graduate Theses and Dissertations

With increasing global change pressures such as urbanization and climate change, cities of the future will experience difficulties in efficiently managing scarcer and less reliable water resources. However, projections of future global change pressures are plagued with uncertainties. This increases the difficulty in developing urban water systems that are adaptable to future uncertainty.

A major component of an urban water system is the distribution system, which constitutes approximately 80-85% of the total cost of the water supply system (Swamee and Sharma, 2008). Traditionally, water distribution systems (WDS) are designed using deterministic assumptions of main model input variables such as water …

Environmental Implications Of Pavements: A Life Cycle View, Bin Yu

USF Tampa Graduate Theses and Dissertations

Environmental aspect of pavement, unlike its economic counterpart, is seldom considered in the theoretical study and field practices. As a highly energy and material intensive infrastructure, pavement has great potential to contribute to the environment protection, which, in root, depends on the in-depth understanding of the environmental impacts, holistically and specifically. A life cycle assessment (LCA) model is used to fulfill the goal.

This research firstly carried out extensive literature review of LCA studies on pavement to identify the major research gaps, including: incompleteness of the methodology, controversy of the functional unit, and unawareness of feedstock energy of asphalt, etc. …

Prediction Of The Performance Of A Flexible Footing On A Stone-Column Modified Subgrade, Justin Callahan

USF Tampa Graduate Theses and Dissertations

When foundations are designed on weak clay layers, it is a common practice to modify the subgrade by installing stone columns. Currently used methods for determining the level of ground modification, represented by the percentage of soil replaced (replacement ratio), assume a rigid foundation. These analytical methods provide the designer with the potential settlement reduction based on the compressibility parameters of the subgrade and the replacement ratio. The deficiencies of these methods are the assumption of rigidity of the foundation and the consideration of the settlement reduction as the only design criterion. Furthermore, they do not consider the effects that …

Effect Of Cement Chemistry And Properties On Activation Energy, Andre J. Bien-Aime

USF Tampa Graduate Theses and Dissertations

The objective of this work is to examine the effect of cement chemistry and physical properties on activation energy. Research efforts indicated that time dependent concrete properties such as strength, heat evolution, and thermal cracking are predictable through the concept of activation energy. Equivalent age concept, which uses the activation energy is key to such predictions. Furthermore, research has shown that Portland cement concrete properties are affected by particles size distribution, Blaine fineness, mineralogy and chemical composition. In this study, four Portland cements were used to evaluate different methods of activation energy determination based on strength and heat of hydration …

Spatial Transferability Of Activity-Based Travel Forecasting Models, Sujan Sikder

USF Tampa Graduate Theses and Dissertations

Spatial transferability of travel forecasting models, or the ability to transfer models from one geographical region to another, can potentially help in significant cost and time savings for regions that cannot invest in extensive data-collection and model-development procedures. This issue is particularly important in the context of tour-based/activity-based models whose development typically involves significant data inputs, skilled staff, and long production times. However, most literature on model transferability has been in the context of traditionally used trip-based models, particularly for linear regression-based trip generation and logit-based mode choice models, with little evidence on the transferability of activity-based models and that …

Time Scale Of Groundwater Recharge: A Generalized Modeling Technique, Makhan Virdi

USF Tampa Graduate Theses and Dissertations

Estimating the quantity of water that reaches the water table following an infiltration event is vital for modeling and management of water resources. Estimating the time scale of groundwater recharge after a rainfall event is difficult because of the dependence on nonlinear soil characteristics and variability in antecedent conditions. Modeling the flow of water through the variably saturated zone is computationally intensive since it requires simulation of Richards' equation, a nonlinear partial differential equation without a closed-form analytical solution, with parametric relationships that are difficult to approximate. Hence, regional scale coupled (surface water - groundwater) hydrological models make simplistic assumptions …