Ausenco Sandwell developed the seismic safety retrofit designs for three bridges on the TransCanada Highway in North Vancouver. The three bridges have an interesting variety of both substructures and superstructures:

• Mountain Highway Underpass has prestressed concrete girders supported on discretely supported cell type abutments
• Lynn Creek is a steel bow-string arch type bridge with buried abutments
• #2 Overpass is a three span curved bridge with a reinforced c-i-p concrete box girder superstructure with single column piers

The bridges, which were all built in the early 1960’s, were found to have a number of seismic deficiencies, particularly with the seatings and bearings. Ausenco Sandwell conducted the seismic safety retrofit assessments and prepared conceptual retrofit designs. For the Lynn Creek Bridge, a moment frame was found to be lacking at the ends of the arches and cross beams were installed beneath the roadway. This seismic retrofit minimised disruption to traffic on the busy highway.

View the full factsheet here.