Civil and Environmental Engineering Commons^™

Use Of Uhpc Stay-In-Place Shells In Bridge Column Construction For Accelerated Bridge Construction, Nerma Caluk

FIU Electronic Theses and Dissertations

This research utilizes Ultra-High Performance Concrete (UHPC), durable material that can be used to construct unique structural elements, to construct prefabricated shells that act as stay-in-place forms for circular bridge columns. These innovative structural elements are intended to (1) eliminate conventional formworks, (2) reduce the on-site construction time, (3) reduce life cycle costs by providing maintenance-free columns, and (4) improve the structural performance of bridge columns. The UHPC shell is placed around the column reinforcement that has been assembled using conventional methods, after which a UHPC step portion is cast at the column-to-footing interface to connect the UHPC shell with …

Retrofitting And Rehabilitation Of Bridge Components Subjected To Predominantly Flexural Load Using Thin Uhpc Shell, Alireza Valikhani

FIU Electronic Theses and Dissertations

The number of bridges exceeding their design life is increasing every year and Federal Highway Administration estimates that structurally deficient and functionally obsolete bridges comprise almost 24% of total bridge inventory in the U.S. Besides aging, the existing bridges can sustain damages due to various factors including exposure to severe environment, deleterious chemicals, and overloading. To avert any catastrophic loss of property and life, it is imperative that the existing bridge inventory is rehabilitated and repaired at a minimal cost and at an expedited schedule using advanced construction methodologies and materials.

One such advancement consists of the use of Ultra-High …

Risk-Based Decision Making Support For Construction Corporate Resource Management, Reza Sheykhi

FIU Electronic Theses and Dissertations

Competitive bidding typically challenges contractors to stay in business by reducing contingency and limiting profit margin, which imposes more prudent resource utilization and allocation decisions during both planning and construction phases of projects. Many of these decisions must be made considering uncertainties that affect resource production and construction performance through several factors such as weather, managerial practices, job-type, and market conditions, etc. Construction decision makers will therefore have varied approaches to deal with these uncertainties based on their risk utility or perception. This research presents the development of a model for investigating the impact of risk-based approaches on construction network …

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 …