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Recent damaging earthquakes in the United States and abroad have demonstrated b?y1cxTT
the earthquake vulnerability of highway bridges that were designed to existing seismic pxY5S}@
codes. To address this inadequate performance, extensive research programs have been 9td(MZ%i~N
carried out. These programs have advanced the state of the art to the point where a new #o^E1cI
specification for seismic design is necessary to take advantage of new insight into <B``/EX^
ground motion and geotechnical effects, improved performance criteria, and more m=}kGzIY4
advanced analytical and design methodologies. j5 /H#_ .
The objective of this research was to enhance safety and economy through the J J3 vC
development of new load and resistance factor design (LRFD) specifications and commentary Jhut>8
for the seismic design of bridges. The research considered design philosophy +b{h*WW dj
and performance criteria, seismic loads and site effects, analysis and modeling, and z+\>e~U6J}
design requirements. The specifications are nationally applicable with provisions for `zsKc 6%
all seismic zones and are intended to be integrated into the AASHTO LRFD Bridge sY#K=5R
Design Specifications. yNN2}\[.
The research was performed by a joint venture of the Applied Technology Council U 9 k}y
and the Multidisciplinary Center for Earthquake Engineering Research. The report Y*AHwc<w`
fully documents the methodology used to develop the recommended specifications. q&W#nWBV
The recommended specifications provided the technical basis for a stand-alone set of \+> b W (
provisions prepared by the ATC/MCEER Joint Venture titled “Recommended LRFD YInW)My.h
Guidelines for the Seismic Design of Highway Bridges.” AASHTO will consider these /aPq9B@
provisions for adoption as a Guide Specification in 2002.
