Lions Gate Bridge Seismic Retrofit
KCB was retained by American Bridge/Surespan JV to provide design-build engineering for the seismic retrofit of the North Approach Viaduct of the Lions Gate Bridge. This was the first major structure to receive a seismic retrofit using the design-build contract format. (in Canada?)
KCB also provided engineering assistance to the contractor for the suspension span deck replacement.
- Retrofit scheme had to be designed during a short bid period
- KCB determined most economical and robust retrofit strategy was to dissipate energy by allowing braced steel support bents to rock by uplifting at baseplate level
- Retrofit included strengthening steel superstructure, additional bracing, concrete tie beams between existing footings, and piles in locations where large liquefaction-induced displacements were anticipated