Civil Engineering Commons^™

Innovative Modular High Performance Lightweight Decks For Accelerated Bridge Construction, Sahar Ghasemi

FIU Electronic Theses and Dissertations

At an average age of 42 years, 10% of the nation’s over 607,000 bridges are posted for load restrictions, with an additional 15% considered structurally deficient or functionally obsolete. While there are major concerns with decks in 75% of structurally deficient bridges, often weight and geometry of the deck further limit the load rating and functionality of the bridge. Traditional deck systems and construction methods usually lead to prolonged periods of traffic delays, limiting options for transportation agencies to replace or widen a bridge, especially in urban areas.

The purpose of this study was to develop a new generation of …

Effect Of Pavement-Vehicle Interaction On Highway Fuel Consumption And Emission, Xin Jiao

FIU Electronic Theses and Dissertations

Vehicle fuel consumption and emission are two important effectiveness measurements of sustainable transportation development. Pavement plays an essential role in goals of fuel economy improvement and greenhouse gas (GHG) emission reduction. The main objective of this dissertation study is to experimentally investigate the effect of pavement-vehicle interaction (PVI) on vehicle fuel consumption under highway driving conditions. The goal is to provide a better understanding on the role of pavement in the green transportation initiates.

Four study phases are carried out. The first phase involves a preliminary field investigation to detect the fuel consumption differences between paired flexible-rigid pavement sections with …

Use Of Fiber Reinforced Polymer Composite Cable For Post-Tensioning Application, Xiong Yang

FIU Electronic Theses and Dissertations

Corrosion of steel tendons is a major problem for post-tensioned concrete, especially because corrosion of the steel strands is often hard to detect inside grouted ducts. Non-metallic tendons can serve as an alternative material to steel for post-tensioning applications. Carbon fiber reinforced polymer (CFRP), given its higher strength and elastic modulus, as well as excellent durability and fatigue strength, is the most practical option for post-tensioning applications.

The primary objective of this research project was to assess the feasibility of the use of innovative carbon fiber reinforced polymer (CFRP) tendons and to develop guidelines for CFRP in post-tensioned bridge applications, …

Robust Modeling And Predictions Of Greenhouse Gas Fluxes From Forest And Wetland Ecosystems, Khandker S. Ishtiaq

FIU Electronic Theses and Dissertations

The land-atmospheric exchanges of carbon dioxide (CO₂) and methane (CH₄) are major drivers of global warming and climatic changes. The greenhouse gas (GHG) fluxes indicate the dynamics and potential storage of carbon in terrestrial and wetland ecosystems. Appropriate modeling and prediction tools can provide a quantitative understanding and valuable insights into the ecosystem carbon dynamics, while aiding the development of engineering and management strategies to limit emissions of GHGs and enhance carbon sequestration. This dissertation focuses on the development of data-analytics tools and engineering models by employing a range of empirical and semi-mechanistic approaches to robustly …

Impacts Of Climate, Land Cover And Hydrologic Changes On Stormwater Runoff In Central Florida, Mohammad S. Islam

FIU Electronic Theses and Dissertations

Changes in climate and land use/cover can cause great impacts on the hydrologic processes, especially on stormwater runoff generation. Considering the Shingle Creek Basin in Central Florida as an example of complex inland urban-natural basins, we quantified reference sensitivities of stormwater runoff to plausible scenarios of climatic, land use/cover and hydrologic changes by developing a dynamic rainfall-runoff model with the EPA Storm Water Management Model (SWMM 5.1). Potential storm runoff in the coupled urban-natural basin exhibited high and notably different seasonal sensitivities to rainfall. The total basin runoff was highly sensitive to the basin imperviousness, while showing moderate to low …

The Performance And Service Life Prediction Of High Performance Concrete In Sulfate And Acidic Environments, Shuo Zhang

FIU Electronic Theses and Dissertations

Concrete substructures are often subjected to environmental deterioration, such as sulfate and acid attack, which leads to severe damage and causes structure degradation or even failure. In order to improve the durability of concrete, the High Performance Concrete (HPC) has become widely used by partially replacing cement with pozzolanic materials. However, HPC degradation mechanisms in sulfate and acidic environments are not completely understood. It is therefore important to evaluate the performance of the HPC in such conditions and predict concrete service life by establishing degradation models.

This study began with a review of available environmental data in the State of …

Long-Term Trends In Magnitude And Frequency Of Extreme Rainfall Events In Florida, Tasnuva Mahjabin

FIU Electronic Theses and Dissertations

This study computed trends in extreme precipitation events of Florida for 1950-2010. Hourly aggregated rainfall data from 24 stations of the National Climatic Data Centre were analyzed to derive time-series of extreme rainfalls for 12 durations, ranging from 1 hour to 7 day. Non-parametric Mann-Kendall test and Theil-Sen Approach were applied to detect the significance of trends in annual maximum rainfalls, number of above threshold events and average magnitude of above threshold events for four common analysis periods. Trend Free Pre-Whitening (TFPW) approach was applied to remove the serial correlations and bootstrap resampling approach was used to detect the field …

Automatic Extraction Of Number Of Lanes From Aerial Images For Transportation Applications, Li Tang

FIU Electronic Theses and Dissertations

Number of lanes is a basic roadway attribute that is widely used in many transportation applications. Traditionally, number of lanes is collected and updated through field surveys, which is expensive especially for large coverage areas with a high volume of road segments. One alternative is through manual data extraction from high-resolution aerial images. However, this is feasible only for smaller areas. For large areas that may involve tens of thousands of aerial images and millions of road segments, an automatic extraction is a more feasible approach. This dissertation aims to improve the existing process of extracting number of lanes from …

Dynamic Behavior And Fatigue Life Of Highway Bridges Due To Doubling Heavy Vehicles, Arash Tarighi

FIU Electronic Theses and Dissertations

An increase in the demand for the freight shipping in the United States has been predicted for the near future and Longer Combination Vehicles (LCVs), which can carry more loads in each trip, seem like a good solution for the problem. Currently, utilizing LCVs is not permitted in most states of the US and little research has been conducted on the effects of these heavy vehicles on the roads and bridges. In this research, efforts are made to study these effects by comparing the dynamic and fatigue effects of LCVs with more common trucks.

Ten Steel and prestressed concrete bridges …

Large-Scale Testing To Study The Effects Of Critical Parameters On The Aerodynamic Behavior Of Long Span Bridges, Ramtin Kargarmoakhar

FIU Electronic Theses and Dissertations

Long-span bridges are flexible and therefore are sensitive to wind induced effects. One way to improve the stability of long span bridges against flutter is to use cross-sections that involve twin side-by-side decks. However, this can amplify responses due to vortex induced oscillations.

Wind tunnel testing is a well-established practice to evaluate the stability of bridges against wind loads. In order to study the response of the prototype in laboratory, dynamic similarity requirements should be satisfied. One of the parameters that is normally violated in wind tunnel testing is Reynolds number. In this dissertation, the effects of Reynolds number on …

Time, Cost, And Environmental Impact Analysis For Sustainable Design At Multiple Building Levels, Peeraya Inyim

FIU Electronic Theses and Dissertations

Construction projects are complex endeavors that require the involvement of different professional disciplines in order to meet various project objectives that are often conflicting. The level of complexity and the multi-objective nature of construction projects lend themselves to collaborative design and construction such as integrated project delivery (IPD), in which relevant disciplines work together during project conception, design and construction. Traditionally, the main objectives of construction projects have been to build in the least amount of time with the lowest cost possible, thus the inherent and well-established relationship between cost and time has been the focus of many studies. The …