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Recent damaging earthquakes in the United States and abroad have demonstrated AtN=G"c>_
the earthquake vulnerability of highway bridges that were designed to existing seismic ^L(}c O
codes. To address this inadequate performance, extensive research programs have been H}QOoXWkg
carried out. These programs have advanced the state of the art to the point where a new #eT{?_wM
specification for seismic design is necessary to take advantage of new insight into 'o2x7~C@
ground motion and geotechnical effects, improved performance criteria, and more ~',<7eW
advanced analytical and design methodologies. =M'y& iz-
The objective of this research was to enhance safety and economy through the 47xJ(yO
development of new load and resistance factor design (LRFD) specifications and commentary q*oUd/F8
for the seismic design of bridges. The research considered design philosophy AopCxaJ`
and performance criteria, seismic loads and site effects, analysis and modeling, and t/K<fy
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design requirements. The specifications are nationally applicable with provisions for &41=YnC6
all seismic zones and are intended to be integrated into the AASHTO LRFD Bridge !' No5
Design Specifications. eGS1% [
The research was performed by a joint venture of the Applied Technology Council n;0bVVMV
and the Multidisciplinary Center for Earthquake Engineering Research. The report :mU,g|~55
fully documents the methodology used to develop the recommended specifications. hmOhXE[a&
The recommended specifications provided the technical basis for a stand-alone set of 88
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provisions prepared by the ATC/MCEER Joint Venture titled “Recommended LRFD \5$N>
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Guidelines for the Seismic Design of Highway Bridges.” AASHTO will consider these '~ 3a(1@8
provisions for adoption as a Guide Specification in 2002.