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Recent damaging earthquakes in the United States and abroad have demonstrated 4g}eqW
the earthquake vulnerability of highway bridges that were designed to existing seismic D ^ mfWJS
codes. To address this inadequate performance, extensive research programs have been {Z>OAR#
carried out. These programs have advanced the state of the art to the point where a new +V"t't7
specification for seismic design is necessary to take advantage of new insight into r!qr 'Ht<
ground motion and geotechnical effects, improved performance criteria, and more ZH9sf ~7
advanced analytical and design methodologies. F_m[EB
The objective of this research was to enhance safety and economy through the g~5$X{
development of new load and resistance factor design (LRFD) specifications and commentary hOI| #(-
for the seismic design of bridges. The research considered design philosophy VEolyPcsg&
and performance criteria, seismic loads and site effects, analysis and modeling, and JEF2fro:Z
design requirements. The specifications are nationally applicable with provisions for &N{XLg>
all seismic zones and are intended to be integrated into the AASHTO LRFD Bridge "=7y6bM
Design Specifications. 80X #V
The research was performed by a joint venture of the Applied Technology Council a$ f$CjQ
and the Multidisciplinary Center for Earthquake Engineering Research. The report Ppw0vaJ^
fully documents the methodology used to develop the recommended specifications. '\I.P
The recommended specifications provided the technical basis for a stand-alone set of ,a N8`M
provisions prepared by the ATC/MCEER Joint Venture titled “Recommended LRFD gNon*\a,-B
Guidelines for the Seismic Design of Highway Bridges.” AASHTO will consider these _z:7Dj#
provisions for adoption as a Guide Specification in 2002.
