Abutment Sesimic Design for Single Span Bridges
Abutment Sesimic Design for Single Span Bridges
(OP)
AASHTO LRFD and Standard Specifications call out to neglect sesimic design for single span bridges regardless of any sesimic zone. Does this depict that No Sesimic Analysis and Forces are to be considered for the desing of the abutments and wingwalls for a single span bridge. Please share your experience. This info is required for a single span bridge design one in NY and one in NJ. Any help is greatly appreciated.






RE: Abutment Sesimic Design for Single Span Bridges
RE: Abutment Sesimic Design for Single Span Bridges
RE: Abutment Sesimic Design for Single Span Bridges
RE: Abutment Sesimic Design for Single Span Bridges
RE: Abutment Sesimic Design for Single Span Bridges
I believe that in California LRFD is superseded by the Caltrans Seismic Design Criteria, and that also abutments are still designed using WSD and conventional analysis techniques.
It's certainly a good idea to design correctly in spite of the LRFD code.
RE: Abutment Sesimic Design for Single Span Bridges
RE: Abutment Sesimic Design for Single Span Bridges
If you apply a seismic force to the backfill it's still a convential abutment desgn.
RE: Abutment Sesimic Design for Single Span Bridges
The only earth pressures I remember that were specifically seismic related were the mobilized passive earth pressures. Generally the abutment was engineered to allow the superstructure to yield and/or not constrain superstructure.
I agree with bridgebuster from what you said there is probably not any analysis that goes into an abutment in NY or NJ. Whatever is necessary is likely already addressed in the standard bridge details.
If anyone has a reference, link, or knowledge of an abutment failure due to active seismic pressures it would be news to me and I would be much appreciative for the new information.
RE: Abutment Sesimic Design for Single Span Bridges
We perform an analysis for a sesimic load case using the Mononobe-Okabe method to determine the active pressure. No modelling; no sprngs, nothing out of the ordinary; just plain old-fashioned stability analysis and concrete design.