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ATC MCEER Joint Venture

Recommended LRFD Guidelines for the Seismic Design of Highway Bridges

Part I: Specifications and Part II: Commentary and Appendices


The ATC/MCEER Joint Venture, a partnership of the Applied Technology Council (ATC) and MCEER, is pleased to announce the availability of a new publication, Recommended LRFD Guidelines for the Seismic Design of Highway Bridges (MCEER/ATC 49). The Guidelines are based on significant enhancements in the state of knowledge and state of practice resulting from research investigations and lessons learned from earthquakes over the last 15 years. The Recommended Guidelines consist of specifications, commentary, and appendices developed to be compatible with the existing load-and-resistance-factor design (LRFD) provisions for highway bridges published by the American Association of State Highway and Transportation Officials (AASHTO). The new, updated, provisions are nationally applicable and cover all seismic zones, as well as all bridge construction types and materials. They reflect the latest design philosophies and approaches that will result in highway bridges with a high level of seismic performance.

The Recommended Guidelines contain numerous innovative and updated requirements and procedures, including:

  • State-of-knowledge seismic hazard maps developed by the U.S. Geological Survey (USGS);
  • Recommended design earthquakes and performance objectives;
  • Guidance on assessment of liquefaction and design solutions;
  • New soil factors and new spectral shapes;
  • Seismic design requirements for steel bridges;
  • “No analysis” design concept;
  • Use of some seismic resisting systems and elements not permitted in the current AASHTO provisions;
  • Capacity spectrum design procedures;
  • Displacement capacity verification (“Pushover”) analysis; and
  • Cost comparisons and implications.

Development of the consensus-based Guidelines was funded by the National Cooperative Highway Research Program (NCHRP) Project 12-49, and in part by the Federal Highway Administration as part of MCEER’s Highway Project. The project included a distinguished advisory committee of experts in earthquake and bridge engineering, and received significant input and guidance from the NCHRP Project Panel as well as from the AASHTO Highway Subcommittee on Bridges and Structures seismic design technical committee (T-3). As a result, the Recommended Guidelines reflect a broad consensus opinion of leaders in the field of seismically designed bridges and highway structures and can be considered the most advanced bridge seismic design tool available today. The price is $75.00 plus shipping and handling.



Liquefaction Study Report


The Liquefaction Study Report (MCEER/ATC 49-1) presents the results of a study of the effects of liquefaction and associated hazards, lateral spreading and flow. It is part of a series of reports that comprise these recommended guidelines. The study investigated liquefaction hazard implications for the design of bridges from the perspective of real sites and real structures. The study scope was limited to two sites in relatively high seismic locations, one in Washington State and the other in Missouri. Actual site profile data and bridge configurations were used. The study included:

  • Simplified, conventional liquefaction analyses
  • Development of both 475-year and 2,475-year acceleration time histories
  • Nonlinear assessment of the site response to these accelerations, including the time history of pore water increases
  • Assessment of stability of abutment end slopes
  • Estimates of lateral spreading and/or flow conditions
  • Design of structural systems to withstand predicted response and flow conditions
  • Evaluation of geotechnical mitigation of liquefaction-related ground displacement
  • Evaluation of cost impacts of the structural and geotechnical mitigation strategies

The results for the 475-year and 2,475-year events were compared to assess the implications of using the larger event for design. Additionally, the conduct of the study helped synthesize an overall approach for handling liquefaction-induced movements in the recommended design provisions. The report includes a CD-ROM containing detailed information for each study site. The price is $50.00 plus shipping and handling.



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Design Examples


The Design Examples (MCEER/ATC 49-2) illustrate use of the recommended LRFD guidelines. The two examples are the eighth and ninth in a series originally developed for FHWA to illustrate the use of the AASHTO Division 1-A Standard Specifications for Highway Bridges. The eighth design example was performed on a five-span continuous cast-in-place concrete box girder bridge and the ninth design example was performed on a three-span continuous steel girder bridge. Each example emphasizes different features that must be considered in the seismic analysis and design process.






The Recommended LRFD Guidelines for the Seismic Design of Highway Bridges reports are available from both ATC and MCEER. To order from MCEER, use the form above, or contact us via phone or email. To order from the Applied Technology Council, contact ATC Publication Sales at (650) 595-1542, , or use ATC’s Online store.

For further information, contact:

University at Buffalo, State University of New York
107 Red Jacket Quadrangle
Buffalo, New York, USA 14261
phone: 716-645-3395
fax: 716-645-3399


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