Seismic Retrofitting Guidelines for Complex Steel Truss Highway Bridges
Author: Tom Ho, Roupen Donikian, Tim Ingham, Chuck Seim and Austin Pan | Size: 12.1 MB | Format: PDF | Publisher: FHWA | Year: 2006 | pages: 190
This manual, entitled Seismic Retrofitting Guidelines for Complex Steel Truss Highway Bridges (referred to as Guidelines in this document), collects and summarizes the state-of-the-practice, up to 2005, for retrofitting steel truss bridges on the highway system within the United States. These Guidelines are based on and are supplementary to the Seismic Retrofitting Manual for Highway Structures Part 1: Bridges (referred to in these Guidelines as the Bridge Retrofitting Manual), developed by the Multidisciplinary Center for Earthquake Engineering Research (MCEER), to be published by the Federal Highway Administration (FHWA) in 2006. The Bridge Retrofitting Manual divides ordinary highway bridges into two classifications, “essential” and “standard,” by their expected performance after a seismic event. Essential bridges are all bridges that are expected to function after a seismic event by continuing to carry traffic. Standard bridges are all other ordinary highway bridges, which may sustain minor to serious damage after a seismic event (but preserve life safety) and may need extensive repair or replacement. These Guidelines also define two classifications of highway steel trusses by their truss configurations: “seismically standard” trusses, which are “ordinary highway bridge” trusses; “seismically complex” trusses, which are the “unusual” types of highway steel trusses; and “long-span” highway steel trusses. All highway truss bridges that meet the classification of “essential bridges” in the Bridge Retrofitting Manual are automatically classified as “seismically complex” trusses in these Guidelines. As in the Bridge Retrofitting Manual, a performance-based seismic retrofit philosophy is used in these Guidelines with performance criteria specified for two earthquake ground motions: a lower level earthquake with a mean return period of 100 years, and an upper level earthquake with a mean return period of 1,000 years. For the “seismically standard truss” classification, a higher performance requirement is specified for the lower level earthquake than for the upper level earthquake. For the “seismically complex truss” classification, a higher performance requirement is specified for both lower level and upper level earthquakes, because seismically complex trusses have special structural configurations that behave under seismic excitation in a complex manner; thus they require a higher standard of seismic retrofit. These Guidelines are written primarily for practicing bridge design engineers who have some familiarity with the seismic retrofitting design of ordinary steel and concrete girder bridges. Experience in the applications of more advanced design techniques such as nonlinear analysis, soil-foundation-structure interaction, and experience with bridge construction methods are helpful in applying these Guidelines. U.S. customary units are used rather than SI units because they were used in the construction of most of the truss bridges that will require seismic retrofitting. Theses Guidelines comprise seven chapters on the technical application of the seismic retrofitting of steel truss highway bridges:
1 Introduction
2 Retrofitting Philosophy and Process
3 Screening and Prioritization
4 Structural Analysis
5 Design Parameters
6 Evaluation of Members, Connections and Subsystems
7 Retrofit Measures, Approach and Strategy
Three additional chapers provide supporting information:
8 Case Studies
9 Glossary
10 References and Bibliography
1 Introduction
2 Retrofitting Philosophy and Process
3 Screening and Prioritization
4 Structural Analysis
5 Design Parameters
6 Evaluation of Members, Connections and Subsystems
7 Retrofit Measures, Approach and Strategy
Three additional chapers provide supporting information:
8 Case Studies
9 Glossary
10 References and Bibliography
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