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Recent damaging earthquakes in the United States and abroad have demonstrated [3x*47o "z
the earthquake vulnerability of highway bridges that were designed to existing seismic R#rfnP >
codes. To address this inadequate performance, extensive research programs have been zP|^@Homk
carried out. These programs have advanced the state of the art to the point where a new 5E}]U,$
specification for seismic design is necessary to take advantage of new insight into r*FAUb`bG
ground motion and geotechnical effects, improved performance criteria, and more bY~V?yNgKM
advanced analytical and design methodologies. \(zUI
The objective of this research was to enhance safety and economy through the I y5)SZ'
development of new load and resistance factor design (LRFD) specifications and commentary {T0Au{88H
for the seismic design of bridges. The research considered design philosophy "wxyY^"
and performance criteria, seismic loads and site effects, analysis and modeling, and e YiqT Wn:
design requirements. The specifications are nationally applicable with provisions for e Dpt1
all seismic zones and are intended to be integrated into the AASHTO LRFD Bridge w(*},
Design Specifications. o,$K=#Iv
The research was performed by a joint venture of the Applied Technology Council `84, R!
and the Multidisciplinary Center for Earthquake Engineering Research. The report N7)K\)DS!z
fully documents the methodology used to develop the recommended specifications. V%`\x\Xat
The recommended specifications provided the technical basis for a stand-alone set of x}{O9LiR
provisions prepared by the ATC/MCEER Joint Venture titled “Recommended LRFD $j4/ohwTDY
Guidelines for the Seismic Design of Highway Bridges.” AASHTO will consider these Lg-!,Y
provisions for adoption as a Guide Specification in 2002.
