Rapid Short and Medium Span Bridge Construction Using Innovative Precast Structural Systems

[摘要] The direct costs of bridge construction, such as materials, labor, and equipment are all wellknown. Recently however the indirect costs such as the cost of traffic disruptions, and constructionsafety are beginning to be factored into design decisions. These new considerations have led theFederal Highway Administration (FHWA) to explore Accelerated Bridge Construction (ABC), which is alsoknown as a ?get in, get out, stay out? approach to bridge construction and replacement.Accelerated Bridge Construction is defined as replacement, or new bridge construction that usesdesign and construction methods to minimize impacts to the traveling public, river traffic, railroads, andthe environment ? all while maintaining high levels of quality and safety. In other words, make bridgeconstruction faster, and safer, while also making bridges last longer by using modern technology. Thisproject focuses on one approach to ABC construction, using more precast elements, in an attempt tomove towards an all precast bridge.Precast elements are fabricated offsite, in a controlled environment, and shipped to the project,where a crane is used to place them. Systems being examined in this project include precast stay?inplaceforms for short to medium span bridges, and precast pile bent caps. Both of these systems can beused to dramatically reduce the amount of cast?in?place concrete on a typical bridge project.For the precast stay?in?place formwork system, this report first examines current practices ofusing precast concrete and bridges, and then identifies possible precast sections for further study in theproposed system. Double?T beam sections are identified for further study, next a series of analyses arerun to identify a group of characteristics that would make a newly designed section more efficient.Using these characteristics, a new Channel section is designed, and analyzed against the Double?Tsection, the new section is found to offer a broader span range, and is designed to reduce several key12maintenance issues prevalent in adjacent member bridges. A list of recommendations for further studyand discussion on this topic is included.Also included in this report is a construction study done on a bridge near Reynolds Wisconsinwhich used precast pile bent caps. The report follows the project from the precasting of the pile caps atCounty Materials in Roberts Wisconsin, to the placement and connection of caps to the piles, inReynolds Wisconsin. Several problems were experienced with the construction process, and from thesea list of recommendations for improvement was generated, and is included with the report.

[发布机构] University of Wisconsin