Serviceability-related Issues for Bridge Live Load Deflection and Construction Closure Pours
Author: Chung C. Fu
Publisher:
Published: 2015
Total Pages: 66
ISBN-13:
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Author: Chung C. Fu
Publisher:
Published: 2015
Total Pages: 66
ISBN-13:
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Publisher:
Published: 2002
Total Pages:
ISBN-13:
DOWNLOAD EBOOKThis research examined the American Association of State Highway and Transportation Officials (AASHTO) live-load deflection limit for steel bridges. The AASHTO Standard Specification limits live-load deflections to L/800 for ordinary bridges and L/1000 for bridges in urban areas that are subject to pedestrian use. This limit is also incorporated in the AASHTO Load and Resistance Factor Design (LRFD) Specifications in the form of optional serviceability criteria. This limit has not been a controlling factor in most past bridge designs, but it will play a greater role in the design of bridges built with new high performance 70W steel. This study documented the role of the AASHTO live-load deflection limit of steel bridge design, determined whether the limit has beneficial effects on serviceability and performance, and established whether the deflection limit was needed. Limited time and funding was provided for this study, but an ultimate goal was to establish recommendations for new design provisions that would assure serviceability, good structural performance and economy in design and construction.
Author: Hung-Jung Hung
Publisher:
Published: 2012
Total Pages:
ISBN-13: 9781267657008
DOWNLOAD EBOOKCurrent practice in California requires up to 60 days waiting period for closure pour after the release of falsework for both staged construction and widening of existing bridges. The relatively long waiting time is intended to reduce the stress build-up and mitigate the damage in the bridge deck due to the potential differential displacement between the newly constructed deck and previously constructed deck. The current waiting period does not take into account the displacement capacity of the closure slab, which varies depending on the dimensions and reinforcement details, and the time-dependent differential displacement that will be imposed on the closure slab. In this research, closure pour waiting time is evaluated in three steps. In step 1, a predictive model based on an age-adjusted effective modulus with traditional elastic analysis is used to predict the time-dependent displacement of the bridge. The predictive model is shown to correlate well with field-measured deflections for two concrete box-girder bridges. In step 2, four full-size closure slabs were tested to determine the displacement capacity of typical California closure slabs. Closure slabs with current California details exhibit rather brittle shear failure with limited displacement capacity. In step 3, a procedure based on the predictive model of differential displacements and laboratory-determined displacement capacity is proposed to determine the closure pour waiting time. Preliminary numerical examples in this research indicate that the current waiting time is conservative, especially in staged construction or bridges with small instantaneous deflections, and shortening of closure pour waiting time is warranted.
Author: Federal Highway Federal Highway Administration
Publisher:
Published: 2020-07-19
Total Pages: 669
ISBN-13:
DOWNLOAD EBOOKThis manual is intended to serve as a reference. It will provide technical information which will enable Manual users to perform the following activities:Describe typical erection practices for girder bridge superstructures and recognize critical construction stagesDiscuss typical practices for evaluating structural stability of girder bridge superstructures during early stages of erection and throughout bridge constructionExplain the basic concepts of stability and why it is important in bridge erection* Explain common techniques for performing advanced stability analysis along with their advantages and limitationsDescribe how differing construction sequences effect superstructure stabilityBe able to select appropriate loads, load combinations, and load factors for use in analyzing superstructure components during constructionBe able to analyze bridge members at various stages of erection* Develop erection plans that are safe and economical, and know what information is required and should be a part of those plansDescribe the differences between local, member and global (system) stability
Author: Khaled M Mahmoud
Publisher: CRC Press
Published: 2017-08-10
Total Pages: 355
ISBN-13: 1351338013
DOWNLOAD EBOOKMaintaining bridges in good condition has extended service life and proven to be more cost effective than allowing degradation to advance, necessitating costlier bridge rehabilitation or replacement projects. Preventive maintenance is therefore an important tool to retard deterioration and sustain the safe operation of bridges. This includes a continuous effort of periodic inspections, condition evaluations and prioritizing repairs accordingly. The above measures define the framework for asset management of bridges. On August 21-22, 2017, bridge engineering experts from around the world convened at the 9th New York City Bridge Conference to discuss issues of construction, design, inspection, monitoring, preservation and rehabilitation of bridge structures. This volume documents their contributions to the safe operation of bridge assets.
Author: American Association of State Highway and Transportation Officials
Publisher: AASHTO
Published: 2009
Total Pages: 38
ISBN-13: 1560514698
DOWNLOAD EBOOKAuthor: Mohiuddin Ali Khan
Publisher: Elsevier
Published: 2014-08-12
Total Pages: 651
ISBN-13: 0124072259
DOWNLOAD EBOOKThe traveling public has no patience for prolonged, high cost construction projects. This puts highway construction contractors under intense pressure to minimize traffic disruptions and construction cost. Actively promoted by the Federal Highway Administration, there are hundreds of accelerated bridge construction (ABC) construction programs in the United States, Europe and Japan. Accelerated Bridge Construction: Best Practices and Techniques provides a wide range of construction techniques, processes and technologies designed to maximize bridge construction or reconstruction operations while minimizing project delays and community disruption. Describes design methods for accelerated bridge substructure construction; reducing foundation construction time and methods by using pile bents Explains applications to steel bridges, temporary bridges in place of detours using quick erection and demolition Covers design-build systems' boon to ABC; development of software; use of fiber reinforced polymer (FRP) Includes applications to glulam and sawn lumber bridges, precast concrete bridges, precast joints details; use of lightweight aggregate concrete, aluminum and high-performance steel
Author:
Publisher:
Published: 1999
Total Pages: 192
ISBN-13:
DOWNLOAD EBOOKAuthor: John F. Stanton
Publisher: Transportation Research Board
Published: 1999
Total Pages: 416
ISBN-13: 9780309066143
DOWNLOAD EBOOKAuthor: Michael A. Ritter
Publisher: Datamotion Publishing LLC
Published: 1990
Total Pages: 916
ISBN-13: 9781937299095
DOWNLOAD EBOOKThis report presents a comprehensive analysis of the design, construction, inspection, and maintenance of timber bridges.