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Recent damaging earthquakes in the United States and abroad have demonstrated y jFe'
the earthquake vulnerability of highway bridges that were designed to existing seismic 8""mp]o9
codes. To address this inadequate performance, extensive research programs have been JN|VPvjE
carried out. These programs have advanced the state of the art to the point where a new g Jk[Ja
specification for seismic design is necessary to take advantage of new insight into VXwPdMy*L
ground motion and geotechnical effects, improved performance criteria, and more C 38%H
advanced analytical and design methodologies. @C=M
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The objective of this research was to enhance safety and economy through the 3p&jLFphL
development of new load and resistance factor design (LRFD) specifications and commentary IkU|W3Vo
for the seismic design of bridges. The research considered design philosophy Dp`HeSKU^
and performance criteria, seismic loads and site effects, analysis and modeling, and > 0T
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design requirements. The specifications are nationally applicable with provisions for dhtb?n{
all seismic zones and are intended to be integrated into the AASHTO LRFD Bridge 1a8$f5
Design Specifications. 8(Fu
The research was performed by a joint venture of the Applied Technology Council CKd3w8;
and the Multidisciplinary Center for Earthquake Engineering Research. The report Jn#K0( FQ
fully documents the methodology used to develop the recommended specifications. Dft%ip2
The recommended specifications provided the technical basis for a stand-alone set of |!}wF}iLc)
provisions prepared by the ATC/MCEER Joint Venture titled “Recommended LRFD !M^\f
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Guidelines for the Seismic Design of Highway Bridges.” AASHTO will consider these !.-.#<<_a
provisions for adoption as a Guide Specification in 2002.
