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Recent damaging earthquakes in the United States and abroad have demonstrated ls [Ls
the earthquake vulnerability of highway bridges that were designed to existing seismic "Q3PC!7X:5
codes. To address this inadequate performance, extensive research programs have been 30A`\+^f
carried out. These programs have advanced the state of the art to the point where a new !S~,> ,yd
specification for seismic design is necessary to take advantage of new insight into <P+G7!KZ&
ground motion and geotechnical effects, improved performance criteria, and more @*CAn(@#N
advanced analytical and design methodologies. 'q{PtYr
The objective of this research was to enhance safety and economy through the C$$"{FfgU"
development of new load and resistance factor design (LRFD) specifications and commentary
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for the seismic design of bridges. The research considered design philosophy f %bc64N(
and performance criteria, seismic loads and site effects, analysis and modeling, and 8|w5QvCU?3
design requirements. The specifications are nationally applicable with provisions for Bv2z4D4f+
all seismic zones and are intended to be integrated into the AASHTO LRFD Bridge zWF
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Design Specifications. @`w'
The research was performed by a joint venture of the Applied Technology Council [>b
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and the Multidisciplinary Center for Earthquake Engineering Research. The report }s`jl` `PM
fully documents the methodology used to develop the recommended specifications. fQ=&@ >e
The recommended specifications provided the technical basis for a stand-alone set of ML=hKwCA
provisions prepared by the ATC/MCEER Joint Venture titled “Recommended LRFD ExN j|*
Guidelines for the Seismic Design of Highway Bridges.” AASHTO will consider these RnMB Gxa
provisions for adoption as a Guide Specification in 2002.
