The Lions Gate Bridge is a 472m main span suspension bridge in Vancouver that opened to traffic in 1938. The bridge deck had reached the end of its service life in the late 1990s, therefore a scheme was developed to replace the entire suspended structure and hangers. However, because the nearest alternative crossing entailed a 3-hour detour, the owner required the contractor to keep the bridge open during peak traffic flows throughout the project, and only limited night-time and weekend closures were allowed for deck replacement operations.
The deck was therefore replaced sequentially during night-time closures and the bridge was re-opened for traffic during daytime. The erection sequence was supported by sophisticated erection analysis models which took into account the geometry of the existing bridge, positioning of the erection equipment on the deck, and necessary hanger and lifting equipment adjustments. Wind tunnel testing and analysis was also performed to ensure the bridge would remain aerodynamic stable during erection and in its final condition.
Mark Bulmer, Complex Bridge Director, AECOM
Mark is AECOM’s UK Complex Bridge Director, but he was Project Engineer for the contractor American Bridge Company on this project before he joined AECOM.
Mark designed complex temporary works to facilitate deck replacement and connect the old and new deck together and was the ‘Engineer in Charge’ of deck replacement operations.