Lions Gate Bridge Seismic Retrofit

CEBC Award of Merit

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.

Challenges

  • Retrofit scheme had to be designed during a short bid period

Solutions

  • 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

Successes