Seismic Retrofit of the McIlraith Bridge

The McIlraith Bridge is a 202 m long six-span variable depth steel plate girder structure located in Ottawa, Ontario, with in-span joints in each girder at the second span from each end separating the structure into three segments. The seismic evaluation and retrofit design was completed to the newly adopted CSA S6-14 and based on the Seismic Performance Category of the structure, Performance Based Design was required. To decrease the demand on the substructure elements and increase the durability of the structure, seismic isolation bearings and flexible link slabs were selected as the preferred seismic retrofit scheme. Time History Analysis was performed to verify the results of the Elastic Dynamic Analysis.