The seismic provisions of the AASHTO LRFD Bridge Design Specifications 4th edition (force-based approach), as well as the seismic design provisions of the WSDOT Bridge Design Manual (BDM) chapters 4 and 7 will no longer be applicable. The WSDOT Bridge Design Manual will be soon updated to reflect the AASHTO Guide Specifications for LRFD Seismic Bridge Design.
The following items summarize WSDOT’s additional requirements and deviations from the AASHTO Guide Specifications for LRFD Seismic Bridge Design:
Click on this link to view a .PDF document showing permissible Earthquake Resisting Systems (ERS)
WSDOT requires the implementation of the AASHTO Guide Specifications for LRFD Seismic Bridge Design beginning January 2008. This design memorandum describes WSDOT’s position in implementation of this document. Some areas with obvious discrepancy with WSDOT design and construction requirements are identified and itemized in this memorandum. More requirements may be follows with the experience gained from the upcoming designs. The WSDOT Bridge Design Manual LRFD will then be upgraded to incorporate all these changes.
cc: Mohammad Sheikhizadeh, Bridge Construction - 47354