NOTE

the project is combined with NCHRP 12-106 Proposed Guidelines for Performance-Based Seismic Bridge Design

The current AASHTO site coefficients are based on the 2003 (and 2009) NEHRP Recommended Seismic Provisions for Building and Other Structures. In 2015, the Building Seismic Safety Council (BSSC) Provisions Update Committee (PUC) updated those site coefficients, based on research from the PEER NGA-West2 Project. The updated site coefficients have also been adopted for the 2016 edition American Society of Civil Engineers (ASCE) 7 Standard. For the next edition of the NEHRP Recommended Seismic Provisions, the BSSC PUC is considering site coefficients that are directly based on hazard maps for different site classes.

The objective of the project is to update the seismic hazard maps presented in the AASHTO LRFD Bridge Design Specifications and AASHTO Guide Specifications for LRFD Seismic Bridge Design.