Norman Bridge Seismic Evaluation, King County Road Services Division
CivilTech provided structural engineering services to identify seismic retrofit alternatives to bring Norman Bridge into compliance with King County’s Level II serviceability requirements. We performed seismic analysis on the bridge to determine capacity-to-demand (C/D) ratios for all structural elements. Elements with failing C/D ratios included the backwall and girder stops, which were determined to be non-critical elements. Therefore, immediate retrofit measures were not required. However, recommendations were made for repairing the backwall and girder stops after a seismic event to ensure access to the public.