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Recent damaging earthquakes in the United States and abroad have demonstrated ~0worI?
the earthquake vulnerability of highway bridges that were designed to existing seismic gbKms ; :
codes. To address this inadequate performance, extensive research programs have been ^*R r x
carried out. These programs have advanced the state of the art to the point where a new Fdvex$r&
specification for seismic design is necessary to take advantage of new insight into vw+
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ground motion and geotechnical effects, improved performance criteria, and more nc l-VN
advanced analytical and design methodologies. n DaQ1
The objective of this research was to enhance safety and economy through the <E p P;
development of new load and resistance factor design (LRFD) specifications and commentary (u$Q
for the seismic design of bridges. The research considered design philosophy zFv>'1$
and performance criteria, seismic loads and site effects, analysis and modeling, and x ~Pv
design requirements. The specifications are nationally applicable with provisions for \ _BaV0<
all seismic zones and are intended to be integrated into the AASHTO LRFD Bridge rF
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Design Specifications. )! M:=}."
The research was performed by a joint venture of the Applied Technology Council Pm;"Y!S<
and the Multidisciplinary Center for Earthquake Engineering Research. The report #PtV=Ee1
fully documents the methodology used to develop the recommended specifications. = u73AM}
The recommended specifications provided the technical basis for a stand-alone set of Pk*EnA)
provisions prepared by the ATC/MCEER Joint Venture titled “Recommended LRFD 5z#>>|1>#
Guidelines for the Seismic Design of Highway Bridges.” AASHTO will consider these zf2]|] *xz
provisions for adoption as a Guide Specification in 2002.
