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Recent damaging earthquakes in the United States and abroad have demonstrated _|M8xI
the earthquake vulnerability of highway bridges that were designed to existing seismic ?. `
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codes. To address this inadequate performance, extensive research programs have been %9>w|%+;U+
carried out. These programs have advanced the state of the art to the point where a new o^2MfFS
specification for seismic design is necessary to take advantage of new insight into Yt#;
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ground motion and geotechnical effects, improved performance criteria, and more 95'+8*YCY
advanced analytical and design methodologies. 0V<kpC,4
The objective of this research was to enhance safety and economy through the 5T#v &
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 o C|oh
and performance criteria, seismic loads and site effects, analysis and modeling, and g J |#xZ
design requirements. The specifications are nationally applicable with provisions for j ^j"w( a
all seismic zones and are intended to be integrated into the AASHTO LRFD Bridge XF(D %ygeC
Design Specifications. ys=}
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The research was performed by a joint venture of the Applied Technology Council 4O-LLH
and the Multidisciplinary Center for Earthquake Engineering Research. The report *MmH{!=
fully documents the methodology used to develop the recommended specifications. =O O4C
The recommended specifications provided the technical basis for a stand-alone set of 2JK
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provisions prepared by the ATC/MCEER Joint Venture titled “Recommended LRFD K c\8GkdB
Guidelines for the Seismic Design of Highway Bridges.” AASHTO will consider these o+.L@3RT4
provisions for adoption as a Guide Specification in 2002.
