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Status Needs review
Created by Guest
Created on Nov 4, 2026

Implementation of Response Spectrum Analysis (RSA) as per latest AASHTO Requirement

Product/Version: RCP v24.0.0.183, included within OBD v24.0.0.179
Area: Seismic Analysis / Response Spectrum Analysis (RSA)

Current Behavior:
When AASHTO LRFD 9th Edition is selected as the design code, the RSA seismic parameters still reference the 2014 edition of AASHTO. The user is designing a simple-span bridge in California and would like to use more current seismic design parameters, particularly S1 and SD1.

Requested Enhancement:
Update the RSA seismic parameters and associated seismic design provisions to correspond with AASHTO LRFD 9th Edition whenever LRFD-9 is selected as the design code.

Expected Behavior:
When LRFD-9 is selected, the seismic design/RSA workflow should use the seismic provisions and parameters applicable to that edition rather than continuing to present the 2014 AASHTO seismic criteria.

Business/User Need:
This enhancement would allow engineers working under newer AASHTO requirements, including projects in seismic regions such as California, to perform seismic analysis using parameters consistent with the selected design-code edition.

Civil Product Used OpenBridge Designer