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Recent damaging earthquakes in the United States and abroad have demonstrated |N XFla
the earthquake vulnerability of highway bridges that were designed to existing seismic y^ 3,X_ 0
codes. To address this inadequate performance, extensive research programs have been (KZUvsS k
carried out. These programs have advanced the state of the art to the point where a new )|Jr|8
specification for seismic design is necessary to take advantage of new insight into X=\x&Wt
ground motion and geotechnical effects, improved performance criteria, and more >
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advanced analytical and design methodologies. =w t-YM
The objective of this research was to enhance safety and economy through the !SN6
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development of new load and resistance factor design (LRFD) specifications and commentary ddl 3 fl#f
for the seismic design of bridges. The research considered design philosophy WGluZhRuT3
and performance criteria, seismic loads and site effects, analysis and modeling, and Kgps_tY%
design requirements. The specifications are nationally applicable with provisions for []!tT-Gzy
all seismic zones and are intended to be integrated into the AASHTO LRFD Bridge i;gw= Be
Design Specifications. H9/XW6W,"w
The research was performed by a joint venture of the Applied Technology Council *%;6P5n%
and the Multidisciplinary Center for Earthquake Engineering Research. The report r*xq(\v
fully documents the methodology used to develop the recommended specifications. j^: b-:F
The recommended specifications provided the technical basis for a stand-alone set of +38Lojb}
provisions prepared by the ATC/MCEER Joint Venture titled “Recommended LRFD e$gaE</
Guidelines for the Seismic Design of Highway Bridges.” AASHTO will consider these +W!'B
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provisions for adoption as a Guide Specification in 2002.
