Civil and Environmental Engineering Commons^™

Experimental And Analytical Methodologies For Predicting Peak Loads On Building Envelopes And Roofing Systems, Maryam Asghari Mooneghi

FIU Electronic Theses and Dissertations

The performance of building envelopes and roofing systems significantly depends on accurate knowledge of wind loads and the response of envelope components under realistic wind conditions. Wind tunnel testing is a well-established practice to determine wind loads on structures. For small structures much larger model scales are needed than for large structures, to maintain modeling accuracy and minimize Reynolds number effects. In these circumstances the ability to obtain a large enough turbulence integral scale is usually compromised by the limited dimensions of the wind tunnel meaning that it is not possible to simulate the low frequency end of the turbulence …

Understanding Immigrants' Travel Behavior In Florida: Neighborhood Effects And Behavioral Assimilation, Nishat Zaman

FIU Electronic Theses and Dissertations

The goal of this study was to develop Multinomial Logit models for the mode choice behavior of immigrants, with key focuses on neighborhood effects and behavioral assimilation. The first aspect shows the relationship between social network ties and immigrants’ chosen mode of transportation, while the second aspect explores the gradual changes toward alternative mode usage with regard to immigrants’ migrating period in the United States (US). Mode choice models were developed for work, shopping, social, recreational, and other trip purposes to evaluate the impacts of various land use patterns, neighborhood typology, socioeconomic-demographic and immigrant related attributes on individuals’ travel behavior. …

Improved Criteria For Estimating Calibration Factors For Highway Safety Manual (Hsm) Applications, Dibakar Saha

FIU Electronic Theses and Dissertations

The Highway Safety Manual (HSM) estimates roadway safety performance based on predictive models that were calibrated using national data. Calibration factors are then used to adjust these predictive models to local conditions for local applications. The HSM recommends that local calibration factors be estimated using 30 to 50 randomly selected sites that experienced at least a total of 100 crashes per year. It also recommends that the factors be updated every two to three years, preferably on an annual basis. However, these recommendations are primarily based on expert opinions rather than data-driven research findings. Furthermore, most agencies do not have …

Aerodynamic Testing Of Variable Message Signs, Debbie Meyer

FIU Electronic Theses and Dissertations

The increasing nationwide interest in intelligent transportation systems (ITS) and the need for more efficient transportation have led to the expanding use of variable message sign (VMS) technology. VMS panels are substantially heavier than flat panel aluminum signs and have a larger depth (dimension parallel to the direction of traffic). The additional weight and depth can have a significant effect on the aerodynamic forces and inertial loads transmitted to the support structure. The wind induced drag forces and the response of VMS structures is not well understood. Minimum design requirements for VMS structures are contained in the American Association of …

Variable Speed Limit Strategies To Reduce The Impacts Of Traffic Flow Breakdown At Recurrent Freeway Bottlenecks, Ali Darroudi

FIU Electronic Theses and Dissertations

Variable Speed Limit (VSL) strategies identify and disseminate dynamic speed limits that are determined to be appropriate based on prevailing traffic conditions, road surface conditions, and weather conditions. This dissertation develops and evaluates a shockwave-based VSL system that uses a heuristic switching logic-based controller with specified thresholds of prevailing traffic flow conditions. The system aims to improve operations and mobility at critical bottlenecks. Before traffic breakdown occurrence, the proposed VSL’s goal is to prevent or postpone breakdown by decreasing the inflow and achieving uniform distribution in speed and flow. After breakdown occurrence, the VSL system aims to dampen traffic congestion …

Numerical Modeling Of The Effects Of Hydrologic Conditions And Sediment Transport On Geomorphic Patterns In Wetlands, Mehrnoosh Mahmoudi

FIU Electronic Theses and Dissertations

This dissertation focused on developing a numerical model of spatial and temporal changes in bed morphology of ridge and slough features in wetlands with respect to hydrology and sediment transport when a sudden change in hydrologic condition occurs. The specific objectives of this research were: (1) developing a two-dimensional hydrology model to simulate the spatial distribution of flow depth and velocity over time when a pulsed flow condition is applied, (2) developing a process-based numerical model of sediment transport coupled with flow depth and velocity in wetland ecosystems, and (3) use the developed model to explore how sediment transport may …

Development Of A Methodology That Couples Satellite Remote Sensing Measurements To Spatial-Temporal Distribution Of Soil Moisture In The Vadose Zone Of The Everglades National Park, Luis G. Perez

FIU Electronic Theses and Dissertations

Spatial-temporal distribution of soil moisture in the vadose zone is an important aspect of the hydrological cycle that plays a fundamental role in water resources management, including modeling of water flow and mass transport. The vadose zone is a critical transfer and storage compartment, which controls the partitioning of energy and mass linked to surface runoff, evapotranspiration and infiltration. This dissertation focuses on integrating hydraulic characterization methods with remote sensing technologies to estimate the soil moisture distribution by modeling the spatial coverage of soil moisture in the horizontal and vertical dimensions with high temporal resolution.

The methodology consists of using …

Integrated Construction Project Delivery System In The U.S. Public Sector: An Information Modeling Framework, Nida Azhar

FIU Electronic Theses and Dissertations

Integrated project delivery (IPD) method has recently emerged as an alternative to traditional delivery methods. It has the potential to overcome inefficiencies of traditional delivery methods by enhancing collaboration among project participants. Information and communication technology (ICT) facilitates IPD by effective management, processing and communication of information within and among organizations. While the benefits of IPD, and the role of ICT in realizing them, have been generally acknowledged, the US public construction sector is very slow in adopting IPD. The reasons are - lack of experience and inadequate understanding of IPD in public owner as confirmed by the results of …

Development Of A Precast Concrete Supertile Roofing System For The Mitigation Of Extreme Wind Events, Brandon L. Mintz

FIU Electronic Theses and Dissertations

Residential roofs have traditionally formed the weakest part of the structure. The connections of roofs to the walls has lacked a clear load path with the result that the structure is weak at this point, leading to the compromise of the structure. Indeed roofs have multiple points of failure that lead to the weakness of the residential structure as a whole. Even if structural failure does not occur, compromise the roofing membrane can lead to high repair costs and property loss. The failure lies in the complex forming of the roof components as the roof aesthetics are placed to protect …

Advanced Methodologies In Dynamic Traffic Assignment Modeling Of Managed Lanes, Shaghayegh Shabanian

FIU Electronic Theses and Dissertations

Managed lane strategies are innovative road operation schemes for addressing congestion problems. These strategies operate a lane (lanes) adjacent to a freeway that provides congestion-free trips to eligible users, such as transit or toll-payers. To ensure the successful implementation of managed lanes, the demand on these lanes need to be accurately estimated. Among different approaches for predicting this demand, the four-step demand forecasting process is most common. Managed lane demand is usually estimated at the assignment step. Therefore, the key to reliably estimating the demand is the utilization of effective assignment modeling processes.

Managed lanes are particularly effective when the …

Development Of Test-Based Wind-Driven Rain Intrusion Model For Hurricane-Induced Building Interior And Contents Damage, Thomas Baheru

FIU Electronic Theses and Dissertations

Major portion of hurricane-induced economic loss originates from damages to building structures. The damages on building structures are typically grouped into three main categories: exterior, interior, and contents damage. Although the latter two types of damages, in most cases, cause more than 50% of the total loss, little has been done to investigate the physical damage process and unveil the interdependence of interior damage parameters. Building interior and contents damages are mainly due to wind-driven rain (WDR) intrusion through building envelope defects, breaches, and other functional openings. The limitation of research works and subsequent knowledge gaps, are in most part …

U.S. Construction Worker Fall Accidents: Their Causes And Influential Factors, Sohaib Siddiqui

FIU Electronic Theses and Dissertations

The purpose of this study is to investigate the main causes of fall accidents and, to pinpoint the factors that influence the risk of falls in the U.S. construction industry. This study employed the Integrated Management Information System (IMIS) data from the Occupational Safety and Health Administration (OSHA) to examine 9,141 fall accidents, recorded for the period of last 20 years. The results show that specialty trade contractors working on low-budget, residential housing and commercial building projects are more susceptible to fall accidents. In terms of fall height, 85% of the fall accidents occurred on heights less than 30 ft., …

Comprehending Performance Of Cross-Frames In Skewed Straight Steel I-Girder Bridges, Jawad H. Gull

FIU Electronic Theses and Dissertations

The effects of support in steel bridges can present significant challenges during the construction. The tendency of girders to twist or layovers during the construction can present a particularly challenging problem regarding detailing cross-frames that provide bracing to steel girders. Methods of detailing cross-frames have been investigated in the past to identify some of the issues related to the behavior of straight and skewed steel bridges. However, the absence of a complete and simplified design approach has led to disputes between stakeholders, costly repairs and delays in the construction.

The main objective of this research is to develop a complete …